Patent Application
20200262031
The following is directed to abrasive articles, and particularly, methods of forming abrasive articles.
Abrasive particles and abrasive articles made incorporating abrasive particles are useful for various material removal operations including grinding, finishing, and polishing. Depending upon the type of abrasive material, such abrasive particles can be useful in shaping or grinding a wide variety of materials and surfaces in the manufacturing of goods. Certain types of abrasive particles have been formulated to date that have particular geometries, such as triangular shaped abrasive particles and abrasive articles incorporating such objects. See, for example, U.S. Pat. Nos. 5,201,916; 5,366,523; and 5,984,988.
Some basic technologies that have been employed to produce abrasive particles having a specified shape are (1) fusion, (2) sintering, and (3) chemical ceramic. In the fusion process, abrasive particles can be shaped by a chill roll, the face of which may or may not be engraved, a mold into which molten material is poured, or a heat sink material immersed in an aluminum oxide melt. See, for example, U.S. Pat. No. 3,377,660, disclosing a process comprising the steps of flowing molten abrasive material from a furnace onto a cool rotating casting cylinder, rapidly solidifying the material to form a thin semisolid curved sheet, densifying the semisolid material with a pressure roll, and then partially fracturing the strip of semisolid material by reversing its curvature by pulling it away from the cylinder with a rapidly driven cooled conveyor.
In the sintering process, abrasive particles can be formed from refractory powders having a particle size of 45 micrometers or less in diameter. Binders can be added to the powders along with a lubricant and a suitable solvent, e.g., water. The resulting mixtures or slurries can be shaped into platelets or rods of various lengths and diameters. See, for example, U.S. Pat. No. 3,079,242, which discloses a method of making abrasive particles from calcined bauxite material comprising the steps of (1) reducing the material to a fine powder, (2) compacting under affirmative pressure and forming the fine particles of said powder into grain sized agglomerations, and (3) sintering the agglomerations of particles at a temperature below the fusion temperature of the bauxite to induce limited recrystallization of the particles, whereby abrasive grains are produced directly to size.
Chemical ceramic technology involves: converting a colloidal dispersion or hydrosol (sometimes called a sol), optionally in a mixture, with solutions of other metal oxide precursors, to a gel; drying; and firing to obtain a ceramic material. See, for example, U.S. Pat. Nos. 4,744,802 and 4,848,041.
Still, there remains a need in the industry for improving performance, life, and efficacy of abrasive particles, and the abrasive articles that employ abrasive particles.
The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
The following is directed to: methods of forming and using shaped abrasive particles, features of shaped abrasive particles; methods of forming and using abrasive articles that include shaped abrasive particles; and features of abrasive articles. The shaped abrasive particles may be used in various abrasive articles, including for example bonded abrasive articles, coated abrasive articles, and the like. In particular instances, the abrasive articles of embodiments herein can be coated abrasive articles defined by a single layer of abrasive grains, and more particularly a discontinuous, single layer of shaped abrasive particles, which may be bonded or coupled to a backing and used to remove material from workpieces. Notably, the shaped abrasive particles can be placed in a controlled manner such that the shaped abrasive particles define a predetermined distribution relative to each other.
Methods of Forming Shaped Abrasive Particles
Various methods may be employed to form shaped abrasive particles. For example, the shaped abrasive particles may be formed using techniques such as extrusion, molding, screen printing, rolling, melting, pressing, casting, segmenting, sectioning, and a combination thereof. In certain instances, the shaped abrasive particles may be formed from a mixture, which may include a ceramic material and a liquid. In particular instances, the mixture may be a gel formed of a ceramic powder material and a liquid, wherein the gel can be characterized as a shape-stable material having the ability to substantially hold a given shape even in the green (i.e., unfired) state. In accordance with an embodiment, the gel can be formed of the ceramic powder material as an integrated network of discrete particles.
The mixture may contain a certain content of solid material, liquid material, and additives such that it has suitable rheological characteristics for forming the shaped abrasive particles. That is, in certain instances, the mixture can have a certain viscosity, and more particularly, suitable rheological characteristics that facilitate formation a dimensionally stable phase of material. A dimensionally stable phase of material is a material that can be formed to have a particular shape and substantially maintain the shape such that the shape is present in the finally-formed object.
According to a particular embodiment, the mixture can be formed to have a particular content of solid material, such as the ceramic powder material. For example, in one embodiment, the mixture can have a solids content of at least about 25 wt %, such as at least about 35 wt %, or even at least about 38 wt % for the total weight of the mixture. Still, in at least one non-limiting embodiment, the solid content of the mixture can be not greater than about 75 wt % such as not greater than about 70 wt %, not greater than about 65 wt %, not greater than about 55 wt %, not greater than about 45 wt %, or not greater than about 42 wt %. It will be appreciated that the content of the solids materials in the mixture can be within a range between any of the minimum and maximum percentages noted above.
According to one embodiment, the ceramic powder material can include an oxide, a nitride, a carbide, a boride, an oxycarbide, an oxynitride, and a combination thereof. In particular instances, the ceramic material can include alumina. More specifically, the ceramic material may include a boehmite material, which may be a precursor of alpha alumina. The term “boehmite” is generally used herein to denote alumina hydrates including mineral boehmite, typically being Al2O3.H2O and having a water content on the order of 15%, as well as pseudoboehmite, having a water content higher than 15%, such as 20-38% by weight. It is noted that boehmite (including pseudoboehmite) has a particular and identifiable crystal structure, and accordingly unique X-ray diffraction pattern, and as such, is distinguished from other aluminous materials including other hydrated aluminas such as ATH (aluminum trihydroxide) a common precursor material used herein for the fabrication of boehmite particulate materials.
Furthermore, the mixture can be formed to have a particular content of liquid material. Some suitable liquids may include water. In accordance with one embodiment, the mixture can be formed to have a liquid content less than the solids content of the mixture. In more particular instances, the mixture can have a liquid content of at least about 25 wt %, such as at least about 35 wt %, at least about 45 wt %, at least about 50 wt %, or even at least about 58 wt % for the total weight of the mixture. Still, in at least one non-limiting embodiment, the liquid content of the mixture can be not greater than about 75 wt %, such as not greater than about 70 wt %, not greater than about 65 wt %, not greater than about 62 wt %, or even not greater than about 60 wt %. It will be appreciated that the content of the liquid in the mixture can be within a range between any of the minimum and maximum percentages noted above.
Furthermore, for certain processes, the mixture may have a particular storage modulus. For example, the mixture can have a storage modulus of at least about 1×104 Pa, such as at least about 4×104 Pa, or even at least about 5×104 Pa. However, in at least one non-limiting embodiment, the mixture may have a storage modulus of not greater than about 1×107 Pa, such as not greater than about 2×106 Pa. It will be appreciated that the storage modulus of the mixture 101 can be within a range between any of the minimum and maximum values noted above.
The storage modulus can be measured via a parallel plate system using ARES or AR-G2 rotational rheometers, with Peltier plate temperature control systems. For testing, the mixture can be extruded within a gap between two plates that are set to be approximately 8 mm apart from each other. After extruding the gel into the gap, the distance between the two plates defining the gap is reduced to 2 mm until the mixture completely fills the gap between the plates. After wiping away excess mixture, the gap is decreased by 0.1 mm and the test is initiated. The test is an oscillation strain sweep test conducted with instrument settings of a strain range between 01% to 100%, at 6.28 rad/s (1 Hz), using 25-mm parallel plate and recording 10 points per decade. Within 1 hour after the test completes, lower the gap again by 0.1 mm and repeat the test. The test can be repeated at least 6 times. The first test may differ from the second and third tests. Only the results from the second and third tests for each specimen should be reported.
Furthermore, to facilitate processing and forming shaped abrasive particles according to embodiments herein, the mixture can have a particular viscosity. For example, the mixture can have a viscosity of at least about 4×103 Pa s, at least about 5×103 Pa s, at least about 6×103 Pa s, at least about 8×103 Pa s, at least about 10×103 Pa s, at least about 20×103 Pa s, at least about 30×103 Pa s, at least about 40×103 Pa s, at least about 50×103 Pa s, at least about 60×103 Pa s, at least about 65×103 Pa s. In at least one non-limiting embodiment, the mixture may have a viscosity of not greater than about 100×103 Pa s, not greater than about 95×103 Pa s, not greater than about 90×103 Pa s, or even not greater than about 85×103 Pa s. It will be appreciated that the viscosity of the mixture can be within a range between any of the minimum and maximum values noted above. The viscosity can be measured in the same manner as the storage modulus as described above.
Moreover, the mixture can be formed to have a particular content of organic materials, including for example, organic additives that can be distinct from the liquid, to facilitate processing and formation of shaped abrasive particles according to the embodiments herein. Some suitable organic additives can include stabilizers, binders, such as fructose, sucrose, lactose, glucose, UV curable resins, and the like.
Notably, the embodiments herein may utilize a mixture that can be distinct from slurries used in conventional forming operations. For example, the content of organic materials, within the mixture, particularly, any of the organic additives noted above, may be a minor amount as compared to other components within the mixture. In at least one embodiment, the mixture can be formed to have not greater than about 30 wt % organic material for the total weight of the mixture. In other instances, the amount of organic materials may be less, such as not greater than about 15 wt %, not greater than about 10 wt %, or even not greater than about 5 wt %. Still, in at least one non-limiting embodiment, the amount of organic materials within the mixture can be at least about 0.01 wt %, such as at least about 0.5 wt % for the total weight of the mixture. It will be appreciated that the amount of organic materials in the mixture can be within a range between any of the minimum and maximum values noted above.
Moreover, the mixture can be formed to have a particular content of acid or base distinct from the liquid, to facilitate processing and formation of shaped abrasive particles according to the embodiments herein. Some suitable acids or bases can include nitric acid, sulfuric acid, citric acid, chloric acid, tartaric acid, phosphoric acid, ammonium nitrate, ammonium citrate. According to one particular embodiment, the mixture can have a pH of less than about 5, and more particularly, within a range between about 2 and about 4, using a nitric acid additive.
According to one particular method of forming, the mixture can be used to form shaped abrasive particles via a screen printing process. Generally, a screen printing process may include extrusion of the mixture from a die into openings of a screen in an application zone. A substrate combination including a screen having openings and a belt underlying the screen can be translated under the die and the mixture can be delivered into the openings of the screen. The mixture contained in the openings can be later extracted from the openings of the screen and contained on the belt. The resulting shaped portions of mixture can be precursor shaped abrasive particles.
In accordance with an embodiment, the screen can have one or more openings having a predetermined two-dimensional shape, which may facilitate formation of shaped abrasive particles having substantially the same two-dimensional shape. It will be appreciated that there may be features of the shaped abrasive particles that may not be replicated from the shape of the opening. According to one embodiment, the opening can have various shapes, for example, a polygon, an ellipsoid, a numeral, a Greek alphabet letter, a Latin alphabet letter, a Russian alphabet character, a Kanji character, a complex shape including a combination of polygonal shapes, and a combination thereof. In particular instances, the openings may have two-dimensional polygonal shape such as, a triangle, a rectangle, a quadrilateral, a pentagon, a hexagon, a heptagon, an octagon, a nonagon, a decagon, and a combination thereof.
Notably, the mixture can be forced through the screen in rapid fashion, such that the average residence time of the mixture within the openings can be less than about 2 minutes, less than about 1 minute, less than about 40 seconds, or even less than about 20 seconds. In particular non-limiting embodiments, the mixture may be substantially unaltered during printing as it travels through the screen openings, thus experiencing no change in the amount of components from the original mixture, and may experience no appreciable drying in the openings of the screen.
The belt and/or the screen may be translated at a particular rate to facilitate processing. For example, the belt and/or the screen may be translated at a rate of at least about 3 cm/s. In other embodiments, the rate of translation of the belt and/or the screen may be greater, such as at least about 4 cm/s, at least about 6 cm/s, at least about 8 cm/s, or even at least about 10 cm/s. For certain processes according to embodiments herein, the rate of translation of the belt as compared to the rate of extrusion of the mixture may be controlled to facilitate proper processing.
Certain processing parameters may be controlled to facilitate features of the precursor shaped abrasive particles (i.e., the particles resulting from the shaping process) and the finally-formed shaped abrasive particles described herein. Some exemplary process parameters can include a release distance defining a point of separation between the screen and the belt relative to a point within the application zone, a viscosity of the mixture, a storage modulus of the mixture, mechanical properties of components within the application zone, thickness of the screen, rigidity of the screen, a solid content of the mixture, a carrier content of the mixture, a release angle between the belt and screen, a translation speed, a temperature, a content of release agent on the belt or on the surfaces of the openings of the screen, a pressure exerted on the mixture to facilitate extrusion, a speed of the belt, and a combination thereof.
After completing the shaping process, the resultant precursor shaped abrasive particles may be translated through a series of zones, wherein additional treatments can occur. Some suitable exemplary additional treatments can include drying, heating, curing, reacting, radiating, mixing, stirring, agitating, planarizing, calcining, sintering, comminuting, sieving, doping, and a combination thereof. According to one embodiment, the precursory shaped abrasive particles may be translated through an optional shaping zone, wherein at least one exterior surface of the particles may be further shaped. Additionally or alternatively, the precursor shaped abrasive particles may be translated through an application zone wherein a dopant material can be applied to at least one exterior surface of the precursor shaped abrasive particles. A dopant material may be applied utilizing various methods including for example, spraying, dipping, depositing, impregnating, transferring, punching, cutting, pressing, crushing, and any combination thereof. In particular instances, the application zone may utilize a spray nozzle, or a combination of spray nozzles to spray dopant material onto the precursor shaped abrasive particles.
In accordance with an embodiment, applying a dopant material can include the application of a particular material, such as a precursor. Some exemplary precursor materials can include a dopant material to be incorporated into the finally-formed shaped abrasive particles. For example, the metal salt can include an element or compound that is the precursor to the dopant material (e.g., a metal element). It will be appreciated that the salt may be in liquid form, such as in a mixture or solution comprising the salt and liquid carrier. The salt may include nitrogen, and more particularly, can include a nitrate. In other embodiments, the salt can be a chloride, sulfate, phosphate, and a combination thereof. In one embodiment, the salt can include a metal nitrate, and more particularly, consist essentially of a metal nitrate.
In one embodiment, the dopant material can include an element or compound such as an alkali element, alkaline earth element, rare earth element, hafnium, zirconium, niobium, tantalum, molybdenum, vanadium, or a combination thereof. In one particular embodiment, the dopant material includes an element or compound including an element such as lithium, sodium, potassium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, cesium, praseodymium, niobium, hafnium, zirconium, tantalum, molybdenum, vanadium, chromium, cobalt, iron, germanium, manganese, nickel, titanium, zinc, and a combination thereof.
In particular instances, the process of applying a dopant material can include select placement of the dopant material on an exterior surface of a precursor shaped abrasive particle. For example, the process of applying a dopant material can include the application of a dopant material to an upper surface or a bottom surface of the precursor shaped abrasive particles. In still another embodiment, one or more side surfaces of the precursor shaped abrasive particles can be treated such that a dopant material is applied thereto. It will be appreciated that various methods may be used to apply the dopant material to various exterior surfaces of the precursor shaped abrasive particles. For example, a spraying process may be used to apply a dopant material to an upper surface or side surface of the precursor shaped abrasive particles. Still, in an alternative embodiment, a dopant material may be applied to the bottom surface of the precursor shaped abrasive particles through a process such as dipping, depositing, impregnating, or a combination thereof. It will be appreciated that a surface of the belt may be treated with dopant material to facilitate a transfer of the dopant material to a bottom surface of precursor shaped abrasive particles.
And further, the precursor shaped abrasive particles may be translated on the belt through a post-forming zone, wherein a variety of processes, including for example, drying, may be conducted on the precursor shaped abrasive particles as described in embodiments herein. Various processes may be conducted in the post-forming zone, including treating of the precursor shaped abrasive particles. In one embodiment, the post-forming zone can include a heating process, wherein the precursor shaped abrasive particles may be dried. Drying may include removal of a particular content of material, including volatiles, such as water. In accordance with an embodiment, the drying process can be conducted at a drying temperature of not greater than about 300° C., such as not greater than about 280° C., or even not greater than about 250° C. Still, in one non-limiting embodiment, the drying process may be conducted at a drying temperature of at least about 50° C. It will be appreciated that the drying temperature may be within a range between any of the minimum and maximum temperatures noted above. Furthermore, the precursor shaped abrasive particles may be translated through the post-forming zone at a particular rate, such as at least about 0.2 feet/min (0.06 m/min) and not greater than about 8 feet/min (2.4 m/min).
In accordance with an embodiment, the process of forming shaped abrasive particles may further comprise a sintering process. For certain processes of embodiments herein, sintering can be conducted after collecting the precursor shaped abrasive particles from the belt. Alternatively, the sintering may be a process that is conducted while the precursor shaped abrasive particles are on the belt. Sintering of the precursor shaped abrasive particles may be utilized to densify the particles, which are generally in a green state. In a particular instance, the sintering process can facilitate the formation of a high-temperature phase of the ceramic material. For example, in one embodiment, the precursor shaped abrasive particles may be sintered such that a high-temperature phase of alumina, such as alpha alumina is formed. In one instance, a shaped abrasive particle can comprise at least about 90 wt % alpha alumina for the total weight of the particle. In other instances, the content of alpha alumina may be greater, such that the shaped abrasive particle may consist essentially of alpha alumina.
Shaped Abrasive Particles
The shaped abrasive particles can be formed to have various shapes. In general, the shaped abrasive particles may be formed to have a shape approximating shaping components used in the forming process. For example, a shaped abrasive particle may have a predetermined two-dimensional shape as viewed in any two dimensions of the three dimension shape, and particularly in a dimension defined by the length and width of the particle. Some exemplary two-dimensional shapes can include a polygon, an ellipsoid, a numeral, a Greek alphabet letter, a Latin alphabet letter, a Russian alphabet character, a Kanji character, a complex shape including a combination of polygonal shapes, and a combination thereof. In particular instances, the shaped abrasive particle may have two-dimensional polygonal shape such as, a triangle, a rectangle, a quadrilateral, a pentagon, a hexagon, a heptagon, an octagon, a nonagon, a decagon, and a combination thereof.
In one particular aspect, the shaped abrasive particles may be formed to have a shape as illustrated in
The body 801 can further include a width (w) that is the longest dimension of the body and extending along a side. The shaped abrasive particle can further include a height (h), which may be a dimension of the shaped abrasive particle extending in a direction perpendicular to the length and width in a direction defined by a side surface of the body 801. Notably, as will be described in more detail herein, the body 801 can be defined by various heights depending upon the location on the body. In specific instances, the width can be greater than or equal to the length, the length can be greater than or equal to the height, and the width can be greater than or equal to the height.
Moreover, reference herein to any dimensional characteristic (e.g., h1, h2, hi, w, Lmiddle, Lp, and the like) can be reference to a dimension of a single particle of a batch. Alternatively, any reference to any of the dimensional characteristics can refer to a median value or an average value derived from analysis of a suitable sampling of particles from a batch. Unless stated explicitly, reference herein to a dimensional characteristic can be considered reference to a median value that is a based on a statistically significant value derived from a sample size of suitable number of particles of a batch. Notably, for certain embodiments herein, the sample size can include at least 40 randomly selected particles from a batch of particles. A batch of particles may be a group of particles that are collected from a single process run, and more particularly, may include an amount of shaped abrasive particles suitable for forming a commercial grade abrasive product, such as at least about 20 lbs. of particles.
In accordance with an embodiment, the body 801 of the shaped abrasive particle can have a first corner height (hc) at a first region of the body defined by a corner 813. Notably, the corner 813 may represent the point of greatest height on the body 801; however, the height at the corner 813 does not necessarily represent the point of greatest height on the body 801. The corner 813 can be defined as a point or region on the body 301 defined by the joining of the upper surface 803 and two side surfaces 805 and 807. The body 801 may further include other corners, spaced apart from each other, including for example, corner 811 and corner 812. As further illustrated, the body 801 can include edges 814, 815, and 816 that can separated from each other by the corners 811, 812, and 813. The edge 814 can be defined by an intersection of the upper surface 803 with the side surface 806. The edge 815 can be defined by an intersection of the upper surface 803 and side surface 805 between corners 811 and 813. The edge 816 can be defined by an intersection of the upper surface 803 and side surface 807 between corners 812 and 813.
As further illustrated, the body 801 can include a second midpoint height (hm) at a second end of the body 801, which can be defined by a region at the midpoint of the edge 814, which can be opposite the first end defined by the corner 813. The axis 850 can extend between the two ends of the body 801.
In accordance with an embodiment, the shaped abrasive particles of the embodiments herein, including for example, the particle of
As illustrated in
Moreover, it will be appreciated that the average difference in height can be based upon an average value of hc. For example, the average height of the body at the corners (Ahc) can be calculated by measuring the height of the body at all corners and averaging the values, and may be distinct from a single value of height at one corner (hc). Accordingly, the average difference in height may be given by the absolute value of the equation [Ahc-hi], wherein hi is the interior height which can be the smallest dimension of height of the body as measured along a dimension between any corner and opposite midpoint edge on the body. Furthermore, it will be appreciated that the average difference in height can be calculated using a median interior height (Mhi) calculated from a suitable sample size of a batch of shaped abrasive particles and an average height at the corners for all particles in the sample size. Accordingly, the average difference in height may be given by the absolute value of the equation [Ahc-Mhi].
In particular instances, the body 801 can be formed to have a primary aspect ratio, which is a ratio expressed as width:length, wherein the length may be Lmidddle, having a value of at least 1:1. In other instances, the body can be formed such that the primary aspect ratio (w:1) is at least about 1.5:1, such as at least about 2:1, at least about 4:1, or even at least about 5:1. Still, in other instances, the abrasive particle can be formed such that the body has a primary aspect ratio that is not greater than about 10:1, such as not greater than 9:1, not greater than about 8:1, or even not greater than about 5:1. It will be appreciated that the body 801 can have a primary aspect ratio within a range between any of the ratios noted above. Furthermore, it will be appreciated that reference herein to a height is the maximum height measurable of the abrasive particle. It will be described later that the abrasive particle may have different heights at different positions within the body 801.
In addition to the primary aspect ratio, the abrasive particle can be formed such that the body 801 comprises a secondary aspect ratio, which can be defined as a ratio of length:height, wherein the length may be Lmiddle and the height is an interior height (hi). In certain instances, the secondary aspect ratio can be within a range between about 5:1 and about 1:3, such as between about 4:1 and about 1:2, or even between about 3:1 and about 1:2. It will be appreciated that the same ratio may be measured using median values (e.g., median length and interior median height) for a batch of particles.
In accordance with another embodiment, the abrasive particle can be formed such that the body 801 comprises a tertiary aspect ratio, defined by the ratio width:height, wherein the height is an interior height (hi). The tertiary aspect ratio of the body 801 can be within a range between about 10:1 and about 1.5:1, such as between 8:1 and about 1.5:1, such as between about 6:1 and about 1.5:1, or even between about 4:1 and about 1.5:1. It will be appreciated that the same ratio may be measured using median values (e.g., median length, median middle length, and/or interior median height) for a batch of particles.
According to one embodiment, the body 801 of the shaped abrasive particle can have particular dimensions, which may facilitate improved performance. For example, in one instance, the body can have an interior height (hi), which can be the smallest dimension of height of the body as measured along a dimension between any corner and opposite midpoint edge on the body. In particular instances, wherein the body is a generally triangular two-dimensional shape, the interior height (hi) may be the smallest dimension of height (i.e., measure between the bottom surface 804 and the upper surface 805) of the body for three measurements taken between each of the three corners and the opposite midpoint edges. The interior height (hi) of the body of a shaped abrasive particle is illustrated in
A batch of shaped abrasive particles can be fabricated, wherein the median interior height value (Mhi) can be controlled, which may facilitate improved performance. In particular, the median internal height (hi) of a batch can be related to a median width of the shaped abrasive particles of the batch in the same manner as described above. Notably, the median interior height (Mhi) can be at least about 28%, such as at least about 29%, at least about 30%, or even at least about 33% of the median width of the shaped abrasive particles of the batch. For one non-limiting embodiment, the median interior height (Mhi) of the body can be not greater than about 80%, such as not greater than about 76%, not greater than about 73%, not greater than about 70%, not greater than about 68% of the width, not greater than about 56% of the width, not greater than about 48% of the width, or even not greater than about 40% of the median width. It will be appreciated that the median interior height (Mhi) of the body can be within a range between any of the above noted minimum and maximum percentages.
Furthermore, the batch of shaped abrasive particles may exhibit improved dimensional uniformity as measured by the standard deviation of a dimensional characteristic from a suitable sample size. According to one embodiment, the shaped abrasive particles can have an interior height variation (Vhi), which can be calculated as the standard deviation of interior height (hi) for a suitable sample size of particles from a batch. According to one embodiment, the interior height variation can be not greater than about 60 microns, such as not greater than about 58 microns, not greater than about 56 microns, or even not greater than about 54 microns. In one non-limiting embodiment, the interior height variation (Vhi) can be at least about 2 microns. It will be appreciated that the interior height variation of the body can be within a range between any of the above noted minimum and maximum values.
For another embodiment, the body of the shaped abrasive particle can have an interior height (hi) of at least about 400 microns. More particularly, the height may be at least about 450 microns, such as at least about 475 microns, or even at least about 500 microns. In still one more non-limiting embodiment, the height of the body can be not greater than about 3 mm, such as not greater than about 2 mm, not greater than about 1.5 mm, not greater than about 1 mm, not greater than about 800 microns. It will be appreciated that the height of the body can be within a range between any of the above noted minimum and maximum values. Moreover, it will be appreciated that the above range of values can be representative of a median interior height (Mhi) value for a batch of shaped abrasive particles.
For certain embodiments herein, the body of the shaped abrasive particle can have particular dimensions, including for example, a width≥length, a length≥height, and a width≥height. More particularly, the body 801 of the shaped abrasive particle can have a width (w) of at least about 600 microns, such as at least about 700 microns, at least about 800 microns, or even at least about 900 microns. In one non-limiting instance, the body can have a width of not greater than about 4 mm, such as not greater than about 3 mm, not greater than about 2.5 mm, or even not greater than about 2 mm. It will be appreciated that the width of the body can be within a range between any of the above noted minimum and maximum values. Moreover, it will be appreciated that the above range of values can be representative of a median width (Mw) for a batch of shaped abrasive particles.
The body 801 of the shaped abrasive particle can have particular dimensions, including for example, a length (L middle or Lp) of at least about 0.4 mm, such as at least about 0.6 mm, at least about 0.8 mm, or even at least about 0.9 mm. Still, for at least one non-limiting embodiment, the body 801 can have a length of not greater than about 4 mm, such as not greater than about 3 mm, not greater than about 2.5 mm, or even not greater than about 2 mm. It will be appreciated that the length of the body 801 can be within a range between any of the above noted minimum and maximum values. Moreover, it will be appreciated that the above range of values can be representative of a median length (Ml), which may be more particularly, a median middle length (MLmiddle) or median profile length (MLp) for a batch of shaped abrasive particles.
The shaped abrasive particle can have a body 801 having a particular amount of dishing, wherein the dishing value (d) can be defined as a ratio between an average height of the body 801 at the corners (Ahc) as compared to smallest dimension of height of the body at the interior (hi). The average height of the body 801 at the corners (Ahc) can be calculated by measuring the height of the body at all corners and averaging the values, and may be distinct from a single value of height at one corner (hc). The average height of the body 801 at the corners or at the interior can be measured using a STIL (Sciences et Techniques Industrielles de la Lumiere—France) Micro Measure 3D Surface Profilometer (white light (LED) chromatic aberration technique). Alternatively, the dishing may be based upon a median height of the particles at the corner (Mhc) calculated from a suitable sampling of particles from a batch. Likewise, the interior height (hi) can be a median interior height (Mhi) derived from a suitable sampling of shaped abrasive particles from a batch. According to one embodiment, the dishing value (d) can be not greater than about 2, such as not greater than about 1.9, not greater than about 1.8, not greater than about 1.7, not greater than about 1.6, or even not greater than about 1.5. Still, in at least one non-limiting embodiment, the dishing value (d) can be at least about 0.9, such as at least about 1.0. It will be appreciated that the dishing ratio can be within a range between any of the minimum and maximum values noted above. Moreover, it will be appreciated that the above dishing values can be representative of a median dishing value (Md) for a batch of shaped abrasive particles.
The shaped abrasive particles of the embodiments herein, including for example, the body 801 of the particle of
Furthermore the shaped abrasive particles of the embodiments herein, including for example, the particle of
In another instance, the body 801 can have a profile ratio of at least about 0.04, wherein the profile ratio is defined as a ratio of the average difference in height [hc-hm] to the length (Lmiddle) of the shaped abrasive particle, defined as the absolute value of [(hc-hm)/(Lmiddle)]. It will be appreciated that the length (Lmiddle) of the body can be the distance across the body 801 as illustrated in
According to another embodiment, the body 801 can have a particular rake angle, which may be defined as an angle between the bottom surface 804 and a side surface 805, 806 or 807 of the body. For example, the rake angle may be within a range between about 1° and about 80°. For other particles herein, the rake angle can be within a range between about 5° and 55°, such as between about 10° and about 50°, between about 15° and 50°, or even between about 20° and 50°. Formation of an abrasive particle having such a rake angle can improve the abrading capabilities of the abrasive particle. Notably, the rake angle can be within a range between any two rake angles noted above.
According to another embodiment, the shaped abrasive particles herein, including for example the particles of
The shaped abrasive particle can be formed such that the body includes a crystalline material, and more particularly, a polycrystalline material. Notably, the polycrystalline material can include abrasive grains. In one embodiment, the body can be essentially free of an organic material, including for example, a binder. More particularly, the body can consist essentially of a polycrystalline material.
In one aspect, the body of the shaped abrasive particle can be an agglomerate including a plurality of abrasive particles, grit, and/or grains bonded to each other to form the body 801 of the abrasive particle 800. Suitable abrasive grains can include nitrides, oxides, carbides, borides, oxynitrides, oxyborides, diamond, superabrasives (e.g., cBN) and a combination thereof. In particular instances, the abrasive grains can include an oxide compound or complex, such as aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, chromium oxide, strontium oxide, silicon oxide, and a combination thereof. In one particular instance, the abrasive particle 800 is formed such that the abrasive grains forming the body 800 include alumina, and more particularly, may consist essentially of alumina. In an alternative embodiment, the shaped abrasive particles can include geosets, including for example, polycrystalline compacts of abrasive or superabrasive materials including a binder phase, which may include a metal, metal alloy, super alloy, cermet, and a combination thereof. Some exemplary binder materials can include cobalt, tungsten, and a combination thereof.
The abrasive grains (i.e., crystallites) contained within the body may have an average grain size that is generally not greater than about 100 microns. In other embodiments, the average grain size can be less, such as not greater than about 80 microns, not greater than about 50 microns, not greater than about 30 microns, not greater than about 20 microns, not greater than about 10 microns, or even not greater than about 1 micron. Still, the average grain size of the abrasive grains contained within the body can be at least about 0.01 microns, such as at least about 0.05 microns, such as at least about 0.08 microns, at least about 0.1 microns, or even at least about 1 micron. It will be appreciated that the abrasive grains can have an average grain size within a range between any of the minimum and maximum values noted above.
In accordance with certain embodiments, the abrasive particle can be a composite article including at least two different types of abrasive grains within the body. It will be appreciated that different types of abrasive grains are abrasive grains having different compositions with regard to each other. For example, the body can be formed such that is includes at least two different types of abrasive grains, wherein the two different types of abrasive grains can be nitrides, oxides, carbides, borides, oxynitrides, oxyborides, diamond, and a combination thereof.
In accordance with an embodiment, the abrasive particle 800 can have an average particle size, as measured by the largest dimension measurable on the body 801, of at least about 100 microns. In fact, the abrasive particle 800 can have an average particle size of at least about 150 microns, such as at least about 200 microns, at least about 300 microns, at least about 400 microns, at least about 500 microns, at least about 600 microns, at least about 700 microns, at least about 800 microns, or even at least about 900 microns. Still, the abrasive particle 800 can have an average particle size that is not greater than about 5 mm, such as not greater than about 3 mm, not greater than about 2 mm, or even not greater than about 1.5 mm. It will be appreciated that the abrasive particle 100 can have an average particle size within a range between any of the minimum and maximum values noted above.
The shaped abrasive particles of the embodiments herein can have a percent flashing that may facilitate improved performance. Notably, the flashing defines an area of the particle as viewed along one side, such as illustrated in
The percent flashing can be measured by mounting the shaped abrasive particle on its side and viewing the body at the side to generate a black and white image, such as illustrated in
A batch of shaped abrasive particles according to embodiments herein may exhibit improved dimensional uniformity as measured by the standard deviation of a dimensional characteristic from a suitable sample size. According to one embodiment, the shaped abrasive particles can have a flashing variation (Vf), which can be calculated as the standard deviation of flashing percentage (f) for a suitable sample size of particles from a batch. According to one embodiment, the flashing variation can be not greater than about 5.5%, such as not greater than about 5.3%, not greater than about 5%, or not greater than about 4.8%, not greater than about 4.6%, or even not greater than about 4.4%. In one non-limiting embodiment, the flashing variation (Vf) can be at least about 0.1%. It will be appreciated that the flashing variation can be within a range between any of the minimum and maximum percentages noted above.
The shaped abrasive particles of the embodiments herein can have a height (hi) and flashing multiplier value (hiF) of at least 4000, wherein hiF=(hi)(f), an “hi” represents a minimum interior height of the body as described above and “f” represents the percent flashing. In one particular instance, the height and flashing multiplier value (hiF) of the body can be greater, such as at least about 4500 micron %, at least about 5000 micron %, at least about 6000 micron %, at least about 7000 micron %, or even at least about 8000 micron %. Still, in one non-limiting embodiment, the height and flashing multiplier value can be not greater than about 45000 micron %, such as not greater than about 30000 micron %, not greater than about 25000 micron %, not greater than about 20000 micron %, or even not greater than about 18000 micron %. It will be appreciated that the height and flashing multiplier value of the body can be within a range between any of the above minimum and maximum values. Moreover, it will be appreciated that the above multiplier value can be representative of a median multiplier value (MhiF) for a batch of shaped abrasive particles.
The shaped abrasive particles of the embodiments herein can have a dishing (d) and flashing (F) multiplier value (dF) as calculated by the equation dF=(d)(F), wherein dF is not greater than about 90%, “d” represents the dishing value, and “f” represents the percentage flashing of the body. In one particular instance, the dishing (d) and flashing (F) multiplier value (dF) of the body can be not greater than about 70%, such as not greater than about 60%, not greater than about 55%, not greater than about 48%, not greater than about 46%. Still, in one non-limiting embodiment, the dishing (d) and flashing (F) multiplier value (dF) can be at least about 10%, such as at least about 15%, at least about 20%, at least about 22%, at least about 24%, or even at least about 26%. It will be appreciated that the dishing (d) and flashing (F) multiplier value (dF) of the body can be within a range between any of the above minimum and maximum values. Moreover, it will be appreciated that the above multiplier value can be representative of a median multiplier value (MdF) for a batch of shaped abrasive particles.
The shaped abrasive particles of the embodiments herein can have a height and dishing ratio (hi/d) as calculated by the equation hi/d=(hi)/(d), wherein hi/d is not greater than about 1000, “hi” represents a minimum interior height as described above, and “d” represents the dishing of the body. In one particular instance, the ratio (hi/d) of the body can be not greater than about 900 microns, not greater than about 800 microns, not greater than about 700 microns, or even not greater than about 650 microns. Still, in one non-limiting embodiment, the ratio (hi/d), can be at least about 10 microns, such as at least about 50 microns, at least about 100 microns, at least about 150 microns, at least about 200 microns, at least about 250 microns, or even at least about 275 microns. It will be appreciated that the ratio (hi/d) of the body can be within a range between any of the above minimum and maximum values. Moreover, it will be appreciated that the above height and dishing ratio can be representative of a median height and dishing ratio (Mhi/d) for a batch of shaped abrasive particles.
Abrasive Articles
As further illustrated, the abrasive article 100 can include a shaped abrasive particle 102 overlying the backing 101, and more particularly, coupled to the backing 101. Notably, the shaped abrasive particle 102 can be placed at a first, predetermined position 112 on the backing 101. As further illustrated, the abrasive article 100 can further include a shaped abrasive particle 103 that may be overlying the backing 101, and more particularly, coupled to the backing 101 in a second, predetermined position 113. The abrasive article 100 can further include a shaped abrasive particle 104 overlying the backing 101, and more particularly, coupled to the backing 101 in a third, predetermined position 114. As further illustrated in
In accordance with an embodiment, the shaped abrasive particle 102 can have a first composition. For example, the first composition can comprise a crystalline material. In one particular embodiment, the first composition can comprise a ceramic material, such as an oxide, carbide, nitride, boride, oxynitride, oxycarbide, and a combination thereof. More particularly, the first composition may consist essentially of a ceramic, such that it may consist essentially of an oxide, carbide, nitride, boride, oxynitride, oxycarbide, and a combination thereof. Still, in an alternative embodiment, the first composition can comprise a superabrasive material. Still in other embodiments, the first composition can comprise a single phase material, and more particularly may consist essentially of a single phase material. Notably, the first composition may be a single phase polycrystalline material. In specific instances, the first composition may have limited binder content, such that the first composition may have not greater than about 1% binder material. Some suitable exemplary binder materials can include organic materials, and more particularly, polymer containing compounds. More notably, the first composition may be essentially free of binder material and may be essentially free of an organic material. In accordance with one embodiment, the first composition can comprise alumina, and more particularly, may consist essentially of alumina, such as alpha alumina.
Still, in yet another aspect, the shaped abrasive particle 102 can have a first composition that can be a composite including at least two different types of abrasive grains within the body. It will be appreciated that different types of abrasive grains are abrasive grains having different compositions with regard to each other. For example, the body can be formed such that is comprises at least two different types of abrasive grains, wherein the two different types of abrasive grains can be nitrides, oxides, carbides, borides, oxynitrides, oxyborides, diamond, and a combination thereof.
In one embodiment, the first composition may include a dopant material, wherein the dopant material is present in a minor amount. Some suitable exemplary dopant materials can comprise an element or compound such as an alkali element, alkaline earth element, rare earth element, hafnium, zirconium, niobium, tantalum, molybdenum, vanadium, or a combination thereof. In one particular embodiment, the dopant material comprises an element or compound including an element such as lithium, sodium, potassium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, cesium, praseodymium, niobium, hafnium, zirconium, tantalum, molybdenum, vanadium, chromium, cobalt, iron, germanium, manganese, nickel, titanium, zinc, and a combination thereof.
The second shaped abrasive particle 103 may have a second composition. In certain instances, the second composition of the second shaped abrasive particle 103 may be substantially the same as the first composition of the first shaped abrasive particle 102. More particularly, the second composition may be essentially the same as the first composition. Still, in an alternative embodiment, the second composition of the second shaped abrasive particle 103 may be significantly different that the first composition of the first shaped abrasive particle 102. It will be appreciated that the second composition can comprise any of the materials, elements, and compounds described in accordance with the first composition.
In accordance with an embodiment, and as further illustrated in
A predetermined distribution can be defined by a combination of predetermined positions on a backing that are purposefully selected. A predetermined distribution can comprise a pattern, design, sequence, array, or arrangement. In a particular embodiment predetermined positions can define an array, such as a two-dimensional array, or a multidimensional array. An array can have short range order defined by a unit, or group, of shaped abrasive particles. An array can also be a pattern, having long range order including regular and repetitive units linked together, such that the arrangement may be symmetrical and/or predictable; however, it should be noted that a predictable arrangement is not necessarily a repeating arrangement (i.e., an array or pattern or arrangement can be both predictable and non-repeating). An array may have an order that can be predicted by a mathematical formula. It will be appreciated that two-dimensional arrays can be formed in the shape of polygons, ellipsis, ornamental indicia, product indicia, or other designs. A predetermined distribution can also include a non-shadowing arrangement. A non-shadowing arrangement can comprise a controlled, non-uniform distribution; a controlled uniform distribution; or a combination thereof. In particular instances, a non-shadowing arrangement can comprise a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, a self-avoiding random distribution, or a combination thereof. Non-shadowing arrangements can include a particular arrangement of abrasive particles (i.e., a particular arrangement of shaped abrasive particles, standard abrasive particles, or a combination thereof) and/or diluent particles, relative to each other, wherein the abrasive particles, diluent particles, or both, can have a degree of overlap. The degree of overlap of the abrasive particles during an initial phase of a material removal operation is not greater than about 25%, such as not greater than about 20%, not greater than about 15%, not greater than about 10%, or even not greater than about 5%. In particular instances, a non-shadowing arrangement can comprise a distribution of abrasive particles wherein upon engagement with a workpiece during an initial stage of a material removal operation, essentially none of the abrasive particles engage the region of the surface of the workpiece.
The predetermined distribution can be partially, substantially, or fully asymmetric. The predetermined distribution can overlie the entire abrasive article, can cover substantially the entire abrasive article (i.e. greater than 50% but less than 100%), overlie multiple portions of the abrasive article, or overlie a fraction of the abrasive article (i.e., less than 50% of the surface area of the article).
As used herein, “a phyllotactic pattern” means a pattern related to phyllotaxis. Phyllotaxis is the arrangement of lateral organs such as leaves, flowers, scales, florets, and seeds in many kinds of plants. Many phyllotactic patterns are marked by the naturally occurring phenomenon of conspicuous patterns having arcs, spirals, and whorls. The pattern of seeds in the head of a sunflower is an example of this phenomenon. An additional example of a phyllotactic pattern is the arrangement of scales about the axis of a pinecone or pineapple. In a specific embodiment, the predetermined distribution conforms to a phyllotactic pattern that describes the arrangement of the scales of a pineapple and which conforms to the below mathematical model for describing the packing of circles on the surface of a cylinder. According to the below model, all components lie on a single generative helix generally characterized by the formula (1.1)
φ=n*α,r=const,H=h*n, (1.1)
where:
The pattern described by formula (1.1) is shown in
Furthermore, according to one embodiment, a non-shadowing arrangement can include a microunit, which may be defined as a smallest arrangement of shaped abrasive particles relative to each other. The microunit may repeat a plurality of times across at least a portion of the surface of the abrasive article. A non-shadowing arrangement may further include a macrounit, which can include a plurality of microunits. In particular instances, the macrounit may have a plurality of microunits arranged in a predetermined distribution relative to each other and repeating a plurality of times with the non-shadowing arrangement. Abrasive articles of the embodiments herein can include one or more microunits. Furthermore, it will be appreciated that the abrasive articles of the embodiments herein can include one or more macrounits. In certain embodiments, the macrounits may be arranged in a uniform distribution having a predictable order. Still, in other instances, the macrounits may be arranged in a non-uniform distribution, which may include a random distribution, having no predictable long range or short range order.
Referring briefly to
A predetermined distribution between shaped abrasive particles can also be defined by at least one of a predetermined orientation characteristic of each of the shaped abrasive particles. Exemplary predetermined orientation characteristics can include a predetermined rotational orientation, a predetermined lateral orientation, a predetermined longitudinal orientation, a predetermined vertical orientation, a predetermined tip height, and a combination thereof. The backing 101 can be defined by a longitudinal axis 180 that extends along and defines a length of the backing 101 and a lateral axis 181 that extends along and defines a width of a backing 101.
In accordance with an embodiment, the shaped abrasive particle 102 can be located in a first, predetermined position 112 defined by a particular first lateral position relative to the lateral axis of 181 of the backing 101. Furthermore, the shaped abrasive particle 103 may have a second, predetermined position defined by a second lateral position relative to the lateral axis 181 of the backing 101. Notably, the shaped abrasive particles 102 and 103 may be spaced apart from each other by a lateral space 121, defined as a smallest distance between the two adjacent shaped abrasive particles 102 and 103 as measured along a lateral plane 184 parallel to the lateral axis 181 of the backing 101. In accordance with an embodiment, the lateral space 121 can be greater than 0, such that some distance exists between the shaped abrasive particles 102 and 103. However, while not illustrated, it will be appreciated that the lateral space 121 can be 0, allowing for contact and even overlap between portions of adjacent shaped abrasive particle.
In other embodiments, the lateral space 121 can be at least about 0.1 (w), wherein w represents the width of the shaped abrasive particle 102. According to an embodiment, the width of the shaped abrasive particle is the longest dimension of the body extending along a side. In another embodiment, the lateral space 121 can be at least about 0.2 (w), such as at least about 0.5 (w), at least about 1 (w), at least about 2 (w), or even greater. Still, in at least one non-limiting embodiment, the lateral space 121 can be not greater than about 100 (w), not greater than about 50 (w), or even not greater than about 20 (w). It will be appreciated that the lateral space 121 can be within a range between any of the minimum and maximum values noted above. Control of the lateral space between adjacent shaped abrasive particles may facilitate improved grinding performance of the abrasive article.
In accordance with an embodiment, the shaped abrasive particle 102 can be in a first, predetermined position 112 defined by a first longitudinal position relative to a longitudinal axis 180 of the backing 101. Furthermore, the shaped abrasive particle 104 may be located at a third, predetermined position 114 defined by a second longitudinal position relative to the longitudinal axis 180 of the backing 101. Further, as illustrated, a longitudinal space 123 may exist between the shaped abrasive particles 102 and 104, which can be defined as a smallest distance between the two adjacent shaped abrasive particles 102 and 104 as measured in a direction parallel to the longitudinal axis 180. In accordance with an embodiment, the longitudinal space 123 can be greater than 0. Still, while not illustrated, it will be appreciated that the longitudinal space 123 can be 0, such that the adjacent shaped abrasive particles are touching, or even overlapping each other.
In other instances, the longitudinal space 123 can be at least about 0.1 (w), wherein w is the width of the shaped abrasive particle as described herein. In other more particular instances, the longitudinal space can be at least about 0.2 (w), at least about 0.5 (w), at least about 1 (w), or even at least about 2 (w). Still, the longitudinal space 123 may be not greater than about 100 (w), such as not greater than about 50 (w), or even not greater than about 20 (w). It will be appreciated that the longitudinal space 123 can be within a range between any of the above minimum and maximum values. Control of the longitudinal space between adjacent shaped abrasive particles may facilitate improved grinding performance of the abrasive article.
In accordance with an embodiment, the shaped abrasive particles may be placed in a predetermined distribution, wherein a particular relationship exists between the lateral space 121 and longitudinal space 123. For example, in one embodiment the lateral space 121 can be greater than the longitudinal space 123. Still, in another non-limiting embodiment, the longitudinal space 123 may be greater than the lateral space 121. Still, in yet another embodiment, the shaped abrasive particles may be placed on the backing such that the lateral space 121 and longitudinal space 123 are essentially the same relative to each other. Control of the relative relationship between the longitudinal space and lateral space may facilitate improved grinding performance.
As further illustrated, a longitudinal space 124 may exist between the shaped abrasive particles 104 and 105. Moreover, the predetermined distribution may be formed such that a particular relationship can exist between the longitudinal space 123 and longitudinal space 124. For example, the longitudinal space 123 can be different than the longitudinal space 124. Alternatively, the longitudinal space 123 can be essentially the same at the longitudinal space 124. Control of the relative difference between longitudinal spaces of different abrasive particles may facilitate improved grinding performance of the abrasive article.
Furthermore, the predetermined distribution of shaped abrasive particles on the abrasive article 100 can be such that the lateral space 121 can have a particular relationship relative to the lateral space 122. For example, in one embodiment the lateral space 121 can be essentially the same as the lateral space 122. Alternatively, the predetermined distribution of shaped abrasive particles on the abrasive article 100 can be controlled such that the lateral space 121 is different than the lateral space 122. Control of the relative difference between lateral spaces of different abrasive particles may facilitate improved grinding performance of the abrasive article.
In accordance with an embodiment, the abrasive article 100 can include an adhesive layer 151 overlying the backing. In accordance with one embodiment, the adhesive layer 151 can include a make coat. The make coat can be overlying the surface of the backing 101 and surrounding at least a portion of the shaped abrasive particles 102 and 104. Abrasive articles of the embodiments herein can further include an adhesive layer 152 overlying the adhesive layer 151 and the backing 101 and surrounding at least a portion of the shaped abrasive particles 102 and 104. The adhesive layer 152 may be a size coat in particular instances.
A polymer formulation may be used to form any of a variety of the adhesive layers 151 or 152 of the abrasive article, which can include but not limited to, a frontfill, a pre-size coat, a make coat, a size coat, and/or a supersize coat. When used to form the frontfill, the polymer formulation generally includes a polymer resin, fibrillated fibers (preferably in the form of pulp), filler material, and other optional additives. Suitable formulations for some frontfill embodiments can include material such as a phenolic resin, wollastonite filler, defoamer, surfactant, a fibrillated fiber, and a balance of water. Suitable polymeric resin materials include curable resins selected from thermally curable resins including phenolic resins, urea/formaldehyde resins, phenolic/latex resins, as well as combinations of such resins. Other suitable polymeric resin materials may also include radiation curable resins, such as those resins curable using electron beam, UV radiation, or visible light, such as epoxy resins, acrylated oligomers of acrylated epoxy resins, polyester resins, acrylated urethanes and polyester acrylates and acrylated monomers including monoacrylated, multiacrylated monomers. The formulation can also comprise a nonreactive thermoplastic resin binder which can enhance the self-sharpening characteristics of the deposited abrasive composites by enhancing the erodability. Examples of such thermoplastic resin include polypropylene glycol, polyethylene glycol, and polyoxypropylene-polyoxyethene block copolymer, etc. Use of a frontfill on the backing can improve the uniformity of the surface, for suitable application of the make coat and improved application and orientation of shaped abrasive particles in a predetermined orientation.
Either of the adhesive layers 151 and 152 can be applied to the surface of the backing 101 in a single process, or alternatively, the shaped abrasive particles 102 and 104 can be combined with a material of one of the adhesive layers 151 or 152 and applied as a mixture to the surface of the backing 101. Suitable materials of the adhesive layer 151 for use as a make coat can include organic materials, particularly polymeric materials, including for example, polyesters, epoxy resins, polyurethanes, polyamides, polyacrylates, polymethacrylates, poly vinyl chlorides, polyethylene, polysiloxane, silicones, cellulose acetates, nitrocellulose, natural rubber, starch, shellac, and mixtures thereof. In one embodiment, the adhesive layer 151 can include a polyester resin. The coated backing 101 can then be heated in order to cure the resin and the abrasive particulate material to the substrate. In general, the coated backing 101 can be heated to a temperature of between about 100° C. to less than about 250° C. during this curing process.
The adhesive layer 152 may be formed on the abrasive article, which may be in the form of a size coat. In accordance with a particular embodiment, the adhesive layer 152 can be a size coat formed to overlie and bond the shaped abrasive particles 102 and 104 in place relative to the backing 101. The adhesive layer 152 can include an organic material, may be made essentially of a polymeric material, and notably, can use polyesters, epoxy resins, polyurethanes, polyamides, polyacrylates, polymethacrylates, poly vinyl chlorides, polyethylene, polysiloxane, silicones, cellulose acetates, nitrocellulose, natural rubber, starch, shellac, and mixtures thereof.
It will be appreciated, that while not illustrated, the abrasive article can include diluent abrasive particles different than the shaped abrasive particles 104 and 105. For example, the diluent particles can differ from the shaped abrasive particles 102 and 104 in composition, two-dimensional shape, three-dimensional shape, size, and a combination thereof. For example, the abrasive particles 507 can represent conventional, crushed abrasive grit having random shapes. The abrasive particles 507 may have a median particle size less than the median particle size of the shaped abrasive particles 505.
As further illustrated, the shaped abrasive particle 102 can be oriented in a side orientation relative to the backing 101, wherein a side surface 171 of the shaped abrasive particle 102 can be in direct contact with the backing 101 or at least a surface of the shaped abrasive particle 102 closest to the upper surface of the backing 101. In accordance with an embodiment, the shaped abrasive particle 102 can have a vertical orientation defined by a tilt angle (AT1) 136 between a major surface 172 of the shaped abrasive particle 102 and a major surface 161 of the backing 101. The tilt angle 136 can be defined as the smallest angle or acute angle between the surface 172 of the shaped abrasive particle 102 and the upper surface 161 of the backing 101. In accordance with an embodiment, the shaped abrasive particle 102 can be placed in a position having a predetermined vertical orientation. In accordance with an embodiment, the tilt angle 136 can be at least about 2°, such as at least about 5°, at least about 10°, at least about 15°, at least about 20°, at least about 25°, at least about 30°, at least about 35°, at least about 40°, at least about 45°, at least about 50°, at least about 55°, at least about 60°, at least about 70°, at least about 80°, or even at least about 85°. Still, the tilt angle 136 may be not greater than about 90°, such as not greater than about 85°, not greater than about 80°, not greater than about 75°, not greater than about 70°, not greater than about 65°, not greater than about 60°, such as not greater than about 55°, not greater than about 50°, not greater than about 45°, not greater than about 40°, not greater than about 35°, not greater than about 30°, not greater than about 25°, not greater than about 20°, such as not greater than about 15°, not greater than about 10°, or even not greater than about 5°. It will be appreciated that the tilt angle 136 can be within a range between any of the above minimum and maximum degrees.
As further illustrated, the abrasive article 100 can include a shaped abrasive particle 104 in a side orientation, wherein a side surface 171 of the shaped abrasive particle 104 is in direct contact with or closest to an upper surface 161 of the backing 101. In accordance with an embodiment, the shaped abrasive particle 104 can be in a position having a predetermined vertical orientation defined by a second tilt angle (AT2) 137 defining an angle between a major surface 172 of the shaped abrasive particle 104 and the upper surface 161 of the backing 101. The tilt angle 137 may be defined as the smallest angle between a major surface 172 of the shaped abrasive particle 104 and an upper surface 161 of the backing 101. Moreover, the tilt angle 137 can have a value of at least about 2°, such as at least about 5°, at least about 10°, at least about 15°, at least about 20°, at least about 25°, at least about 30°, at least about 35°, at least about 40°, at least about 45°, at least about 50°, at least about 55°, at least about 60°, at least about 70°, at least about 80°, or even at least about 85°. Still, the tilt angle 136 may be not greater than about 90°, such as not greater than about 85°, not greater than about 80°, not greater than about 75°, not greater than about 70°, not greater than about 65°, not greater than about 60°, such as not greater than about 55°, not greater than about 50°, not greater than about 45°, not greater than about 40°, not greater than about 35°, not greater than about 30°, not greater than about 25°, not greater than about 20°, such as not greater than about 15°, not greater than about 10°, or even not greater than about 5°. It will be appreciated that the tilt angle 136 can be within a range between any of the above minimum and maximum degrees.
In accordance with an embodiment, the shaped abrasive particle 102 can have a predetermined vertical orientation that is the same as the predetermined vertical orientation of the shaped abrasive particle 104. Alternatively, the abrasive article 100 may be formed such that the predetermined vertical orientation of the shaped abrasive particle 102 can be different than the predetermined vertical orientation of the shaped abrasive particle 104.
In accordance with an embodiment, the shaped abrasive particles 102 and 104 may be placed on the backing such that they have different predetermined vertical orientations defined by a vertical orientation difference. The vertical orientation difference can be the absolute value of the difference between the tilt angle 136 and the tilt angle 137. In accordance with an embodiment, the vertical orientation difference can be at least about 2°, such as at least about 5°, at least about 10°, at least about 15°, at least about 20°, at least about 25°, at least about 30°, at least about 35°, at least about 40°, at least about 45°, at least about 50°, at least about 55°, at least about 60°, at least about 70°, at least about 80°, or even at least about 85°. Still, the vertical orientation difference may be not greater than about 90°, such as not greater than about 85°, not greater than about 80°, not greater than about 75°, not greater than about 70°, not greater than about 65°, not greater than about 60°, such as not greater than about 55°, not greater than about 50°, not greater than about 45°, not greater than about 40°, not greater than about 35°, not greater than about 30°, not greater than about 25°, not greater than about 20°, such as not greater than about 15°, not greater than about 10°, or even not greater than about 5°. It will be appreciated that the vertical orientation difference can be within a range between any of the above minimum and maximum degrees. Control of the vertical orientation difference between shaped abrasive particles of the abrasive article 100 may facilitate improved grinding performance.
As further illustrated, the shaped abrasive particles can be placed on the backing to have a predetermined tip height. For example, the predetermined tip height (hT1) 138 of the shaped abrasive particle 102 can be the greatest distance between an upper surface of the backing 161 and an uppermost surface 143 of the shaped abrasive particle 102. In particular, the predetermined tip height 138 of the shaped abrasive particle 102 can define the greatest distance above the upper surface of the backing 161 that the shaped abrasive particle 102 extends. As further illustrated, the shaped abrasive particle 104 can have a predetermined tip height (hT2) 139 defined as the distance between the upper surface 161 of the backing 101 and an uppermost surface 144 of the shaped abrasive particle 104. Measurements may be evaluated via X-ray, confocal microscopy CT, micromeasure, white-light interferometry, and a combination thereof.
In accordance with an embodiment, the shaped abrasive particle 102 can be placed on the backing 101 to have a predetermined tip height 138 that can be different that than predetermined tip height 139 of the shaped abrasive particle 104. Notably, the difference in the predetermined tip height (ΔhT) can be defined as the difference between the average tip height 138 and average tip height 139. In accordance with an embodiment, the difference in the predetermined tip height can be at least about 0.01 (w), wherein (w) is the width of the shaped abrasive particle as described herein. In other instances, the tip height difference can be at least about 0.05 (w), at least about 0.1 (w), at least about 0.2 (w), at least about 0.4 (w), at least about 0.5 (w), at least about 0.6 (w), at least about 0.7 (w), or even at least about 0.8 (w). Still, in one non-limiting embodiment, the tip height difference can be not greater than about 2 (w). It will be appreciated that the difference in tip height can be in a range between any of the minimum and maximum values noted above. Control of the average tip height and more particularly the difference in average tip height, between shaped abrasive particles of the abrasive article 100 can facilitate improved grinding performance.
While reference herein is made to shaped abrasive particles having a difference in average tip height, it will be appreciated that the shaped abrasive particles of the abrasive articles may have a same average tip height such that there is essentially no difference between the average tip height between the shaped abrasive particles. For example, as described herein, shaped abrasive particles of a group may be positioned on the abrasive article such that the vertical tip height of each of the shaped abrasive particles of the group is substantially the same.
As further illustrated in
In accordance with an embodiment, the shaped abrasive particle 102 can have a predetermined rotational orientation as defined by the rotational angle 201 that is different that the predetermined rotational orientation of the shaped abrasive particle 103 as defined by the rotational angle 208. In particular, the difference between the rotational angle 201 and rotational angle 208 between the shaped abrasive particles 102 and 103 can define a predetermined rotational orientation difference. In particular instances, the predetermined rotational orientation difference can be 0°. In other instances, the predetermined rotation orientation difference between any two shaped abrasive particles can be greater, such as at least about 1°, at least about 3°, at least about 5°, at least about 10°, at least about 15°, at least about 20°, at least about 25°, at least about 30°, at least about 35°, at least about 40°, at least about 45°, at least about 50°, at least about 55°, at least about 60°, at least about 70°, at least about 80°, or even at least about 85°. Still, the predetermined rotational orientation difference between any two shaped abrasive particles may be not greater than about 90°, such as not greater than about 85°, not greater than about 80°, not greater than about 75°, not greater than about 70°, not greater than about 65°, not greater than about 60°, such as not greater than about 55°, not greater than about 50°, not greater than about 45°, not greater than about 40°, not greater than about 35°, not greater than about 30°, not greater than about 25°, not greater than about 20°, such as not greater than about 15°, not greater than about 10°, or even not greater than about 5°. It will be appreciated that the predetermined rotational orientation difference can be within a range between any of the above minimum and maximum values.
For simplicity of explanation, the embodiments herein reference certain features relative to a plane defined by X, Y, and Z directions. However, it is appreciated and contemplated that abrasive articles can have other shapes (e.g., coated abrasive belts defining an ellipsoidal or looped geometry or even coated abrasive sanding disks having an annular-shaped backing). The description of the features herein is not limited to planar configurations of abrasive articles and the features described herein are applicable to abrasive articles of any geometry. In such instances wherein the backing has a circular geometry, the longitudinal axis and lateral axis can be two diameters extending through the center point of the backing and having an orthogonal relationship relative to each other.
As further illustrated, the abrasive article can include a group 305. The group 305 can include a plurality of shaped abrasive particles, including shaped abrasive particles 331, 332, and 333 (331-333) having at least one common predetermined orientation characteristic. As illustrated in the embodiment of
As further illustrated, the abrasive article 300 can include groups 301, 303, and 305, which may be separated by channel regions 307 and 308 extending between the groups 301, 303, 305. In particular instances, the channel regions can be regions on the abrasive article that can be substantially free of shaped abrasive particles. Moreover, the channel regions 307 and 308 may be configured to move liquid between the groups 301, 303, and 305, which may improve swarf removal and grinding performance of the abrasive article. The channel regions 307 and 308 can be predetermined regions on the surface of the shaped abrasive article. The channel regions 307 and 308 may define dedicated regions between groups 301, 303, and 305 that are different, and more particularly, greater in width and/or length, than the longitudinal space or lateral space between adjacent shaped abrasive particles in the groups 301, 303, and 305.
The channel regions 307 and 308 can extend along a direction that is parallel or perpendicular to the longitudinal axis 180 or parallel or perpendicular to the lateral axis 181 of the backing 101. In particular instances, the channel regions 307 and 308 can have axes, 351 and 352 respectively, extending along a center of the channel regions 307 and 308 and along a longitudinal dimension of the channel regions 307 and 308 can have a predetermined angle relative to the longitudinal axis 380 of the backing 101. Moreover, the axes 351 and 352 of the channel regions 307 and 308 may form a predetermined angle relative to the lateral axis 181 of the backing 101. Controlled orientation of the channel regions may facilitate improved performance of the abrasive article.
Furthermore, the channel regions 307 and 308 may be formed such that they have a predetermined orientation relative to the direction of grinding 350. For example, the channel regions 307 and 308 can extend along a direction that is parallel or perpendicular to the direction of grinding 350. In particular instances, the channel regions 307 and 308 can have axes, 351 and 352 respectively, extending along a center of the channel regions 307 and 308 and along a longitudinal dimension of the channel regions 307 and 308 can have a predetermined angle relative to the direction of grinding 350. Controlled orientation of the channel regions may facilitate improved performance of the abrasive article.
For at least one embodiment, as illustrated the group 301 can include a plurality of shaped abrasive particles, wherein at least a portion of the plurality of shaped abrasive particles in the group 301 can define a pattern 315. As illustrated, the plurality of shaped abrasive particles 311-314 can be arranged with respect to each other in a predetermined distribution that further defines a two-dimensional array, such as in the form of a quadrilateral, as viewed top-down. An array is a pattern having short range order defined by a unit arrangement of shaped abrasive particles and further having long range order including regular and repetitive units linked together. It will be appreciated that other two-dimensional arrays can be formed, including other polygonal shapes, ellipsis, ornamental indicia, product indicia, or other designs. As further illustrated, the group 303 can include the plurality of shaped abrasive particles 321-324 that can also be arranged in a pattern 325 defining a quadrilateral two-dimensional array. Furthermore, the group 305 can include a plurality of shaped abrasive particles 331-334 which can be arranged with respect to each other to define a predetermined distribution in the form of a triangular pattern 335.
In accordance with an embodiment, the plurality of shaped abrasive particles of a group 301 may define a pattern that is different than the shaped abrasive particles of another group (e.g., group 303 or 305). For example, the shaped abrasive particles of the group 301 may define a pattern 315 that is different than the pattern 335 of the group 305 with respect to the orientation on the backing 101. Moreover, the shaped abrasive particles of the group 301 may define a pattern 315 that has a first orientation relative to the direction of grinding 350 as compared to the orientation of the pattern of a second group (e.g., 303 or 305) relative to the direction of grinding 350.
Notably, any one of the groups (301, 303, or 305) of the shaped abrasive particles can have a pattern defining one or more vectors (e.g., 361 or 362 of group 305) that can have a particular orientation relative to the direction of grinding. In particular, the shaped abrasive particles of a group can have a predetermined orientation characteristic that define a pattern of the group, which may further define one or more vectors of the pattern. In an exemplary embodiment, the vectors 361 and 362 of the pattern 335 can be controlled to form a predetermined angle relative to the grinding direction 350. The vectors 361 and 362 may have various orientations including for example, a parallel orientation, perpendicular orientation, or even a non-orthogonal or non-parallel orientation (i.e., angled to define an acute angle or obtuse angle) relative to the grinding direction 350.
In accordance with an embodiment, the plurality of shaped abrasive particles of the first group 301 can have at least one predetermined orientation characteristic that is different than the plurality of shaped abrasive particles in another group (e.g. 303 or 305). For example, at least a portion of the shaped abrasive particles of the group 301 can have a predetermined rotational orientation that is different than the predetermined rotational orientation of at least a portion of the shaped abrasive particles of the group 303. Still, in one particular aspect, all of the shaped abrasive particles of the group 301 can have a predetermined rotational orientation that is different than the predetermined rotational orientation of all of the shaped abrasive particles of the group 303.
In accordance with another embodiment, at least a portion of the shaped abrasive particles of the group 301 can have a predetermined lateral orientation that is different than the predetermined lateral orientation of at least a portion of the shaped abrasive particles of the group 303. For yet another embodiment, all of the shaped abrasive particles of the group 301 can have a predetermined lateral orientation that is different than the predetermined lateral orientation of all of the shaped abrasive particles of the group 303.
Moreover, in another embodiment, at least a portion of the shaped abrasive particles of the group 301 can have a predetermined longitudinal orientation that may be different than the predetermined longitudinal orientation of at least a portion of the shaped abrasive particles of the group 303. For another embodiment, all of the shaped abrasive particles of the group 301 can have a predetermined longitudinal orientation that may be different than the predetermined longitudinal orientation of all of the shaped abrasive particles of the group 303.
Furthermore, at least a portion of the shaped abrasive particles of the group 301 can have a predetermined vertical orientation that is different than the predetermined vertical orientation of at least a portion of the shaped abrasive particles of the group 303. Still, for one aspect, all of the shaped abrasive particles of the group 301 can have a predetermined vertical orientation that is different than the predetermined vertical orientation of all of the shaped abrasive particles of the group 303
Moreover, in one embodiment, at least a portion of the shaped abrasive particles of the group 301 may have a predetermined tip height that is different than the predetermined tip height of at least a portion of the shaped abrasive particles of the group 303. In yet another particular embodiment, all of the shaped abrasive particles of the group 301 may have a predetermined tip height that is different than the predetermined tip height of all of the shaped abrasive particles of the group 303.
It will be appreciated that any number of groups may be included in the abrasive article creating various regions on the abrasive article having predetermined orientation characteristics. Moreover, each of the groups can be different from each other as described in the foregoing for the groups 301 and 303.
As described in one or more embodiments herein, the shaped abrasive particles can be arranged in a predetermined distribution defined by predetermined positions on the backing. More notably, the predetermined distribution can define a non-shadowing arrangement between two or more shaped abrasive particles. For example, in one particular embodiment, the abrasive article can include a first shaped abrasive particle in a first predetermined position and a second shaped abrasive particle in a second predetermined position, such that the first and second shaped abrasive particle define a non-shadowing arrangement relative to each other. A non-shadowing arrangement can be defined by an arrangement of the shaped abrasive particles such that they are configured to make initial contact with the workpiece at separate locations on the workpiece and limiting or avoiding an initial overlap in the location of initial material removal on the workpiece. A non-shadowing arrangement can facilitate improved grinding performance. In one particular embodiment, the first shaped abrasive particle can be part of a group defined by a plurality of shaped abrasive particles, and the second shaped abrasive particle can be part of a second group defined by a plurality of shaped abrasive particles. The first group can define a first row on the backing and the second group can define a second row on the backing, and each of the shaped abrasive particles of the second group can be staggered relative to each of the shaped abrasive particles of the first group, thus defining a particular non-shadowing arrangement.
The shaped abrasive particle 103 can have different predetermined orientation characteristics relative to the shaped abrasive particle 102 and the grinding direction 385. As illustrated, the shaped abrasive particle 103 can include major surfaces 391 and 392, which can be joined by side surfaces 371 and 372. Moreover, as illustrated, the shaped abrasive particle 103 can have a bisecting axis 373 forming a particular angle relative to the vector of the grinding direction 385. As illustrated, the bisecting axis 373 of the shaped abrasive particle 103 can have a substantially parallel orientation with the grinding direction 385 such that the angle between the bisecting axis 373 and the grinding direction 385 is essentially 0 degrees. Accordingly, the predetermined orientation characteristics of the shaped abrasive particle facilitate initial contact of the side surface 372 with a workpiece before any of the other surfaces of the shaped abrasive particle. Such an orientation of the shaped abrasive particle 103 may be considered a sideways orientation relative to the grinding direction 385.
It will be appreciated that the abrasive article can include one or more groups of shaped abrasive particles that can be arranged in a predetermined distribution relative to each other, and more particularly can have distinct predetermined orientation characteristics that define groups of shaped abrasive particles. The groups of shaped abrasive particles, as described herein, can have a predetermined orientation relative to a grinding direction. Moreover, the abrasive articles herein can have one or more groups of shaped abrasive particles, each of the groups having a different predetermined orientation relative to a grinding direction. Utilization of groups of shaped abrasive particles having different predetermined orientations relative to a grinding direction can facilitate improved performance of the abrasive article.
As further illustrated, the abrasive article 400 can include a group 404 including a plurality of shaped abrasive particles which can be arranged on the surface of the backing 101 to define a predetermined distribution. Notably, the predetermined distribution can include an arrangement of the plurality of the shaped abrasive particles that define a pattern, and more particularly, a generally quadrilateral pattern 424. As illustrated, the group 404 can define a macro-shape 434 on the surface of the abrasive article 400. In one embodiment, the macro-shape 434 of the group 404 can have a two-dimensional shape as viewed top down, including for example a polygonal shape, and more particularly, a generally quadrilateral (diamond) shape as viewed top down on the surface of the abrasive article 400. In the illustrated embodiment of
As further illustrated, the abrasive article can include groups 401, 402, 403, and 404 which can be separated by channel regions 422 and 421 extending between the groups 401-404. In particular instances, the channel region can be substantially free of shaped abrasive particles. Moreover, the channel regions 421 and 422 may be configured to move liquid between the groups 401-404 and further improve swarf removal and grinding performance of the abrasive article. Furthermore, in a certain embodiment, the abrasive article 400 can include channel regions 421 and 422 extending between groups 401-404, wherein the channel regions 421 and 422 can be patterned on the surface of the abrasive article 400. In particular instances, the channel regions 421 and 422 can represent a regular and repeating array of features extending along a surface of the abrasive article.
As further illustrated in
In accordance with another embodiment, the abrasive article 500 can include shaped abrasive particles 503 arranged relative to each other and defining a row 531. The row 531 can have any of the characteristics as described in accordance with other embodiments, particularly with respect to row 511 or row 521. Furthermore, as illustrated, each of the shaped abrasive particles 503 within the row 531 can have at least one predetermined orientation characteristic that is the same with respect to each other. Moreover, each of the shaped abrasive particles 503 within the row 531 can have at least one predetermined orientation characteristic that is different than a predetermined orientation characteristic relative to any one of the shaped abrasive particles 501 of row 511 or the shaped abrasive particles 502 of row 521. Notably, as illustrated, each of the shaped abrasive particles 503 of row 531 can have a same predetermined rotational orientation that is different with respect to the predetermined rotational orientation of the shaped abrasive particles 501 and row 511 and the predetermined rotational orientation of the shaped abrasive particles 502 and row 521.
As further illustrated, the abrasive article 500 can include shaped abrasive particles 504 arranged relative to each other and defining a row 541 on the surface of the abrasive article 500. As illustrated, each of the shaped abrasive particles 504 and the row 541 can have at least one of the same predetermined orientation characteristic. Furthermore, in accordance with an embodiment, each of the shaped abrasive particles 504 can have at least one of the same predetermined orientation characteristic, such as a predetermined rotational orientation that is different than the predetermined rotational orientation of any of the shaped abrasive particles 501 of row 511, the shaped abrasive particles 502 of the row 521, and the shaped abrasive particles 503 of the row 531.
As further illustrated, the abrasive article 500 can include a column 561 of shaped abrasive particles including at least one shaped abrasive particle from each of the rows 511, 521, 531, and 541. Notably, each of the shaped abrasive particles within the column 561 can share at least one predetermined orientation characteristic, and more particularly at least a predetermined longitudinal orientation with respect to each other. As such, each of the shaped abrasive particles within the column 561 can have a predetermined longitudinal orientation with respect to each other and a longitudinal plane 562. In certain instances, the arrangement of shaped abrasive particles in groups, which can include the arrangement of shaped abrasive particles in rows, columns, vertical companies, rotational companies, and tip height companies can facilitate improved performance of the abrasive article.
As further illustrated, the abrasive article 600 can include shaped abrasive particles 602 arranged relative to each other on the backing 101 and defining a column 622 with respect to each other along a longitudinal plane 652. It will be appreciated that the shaped abrasive particles 602 of the column 622 can share at least one other predetermined orientation characteristic, including for example a same predetermined rotational orientation with respect to each other. Still, each of the shaped abrasive particles 602 of the column 622 can define a group having at least one predetermined orientation characteristic different than at least one predetermined orientation characteristic of at least one of the shaped abrasive particles 621 of the column 621. More particularly, each of the shaped abrasive particles 602 of the column 622 can define a group having a combination of predetermined orientation characteristics different than a combination of predetermined orientation characteristics of the shaped abrasive particles 601 of the column 621.
Furthermore, as illustrated, the abrasive article 600 can include shaped abrasive particles 603 having a same predetermined longitudinal orientation with respect to each other along the a longitudinal plane 653 on the backing 101 and defining a column 623. Still, each of the shaped abrasive particles 603 of the column 623 can define a group having at least one predetermined orientation characteristic different than at least one predetermined orientation characteristic of at least one of the shaped abrasive particles 621 of the column 621 and the shaped abrasive particles 602 of the column 622. More particularly, each of the shaped abrasive particles 603 of the column 623 can define a group having a combination of predetermined orientation characteristics different than a combination of predetermined orientation characteristics of the shaped abrasive particles 601 of the column 621 and the shaped abrasive particles 602 of the column 622.
As illustrated in
According to one embodiment, the orientation regions 721-723 can be associated with an alignment structure, and more particularly, part of an alignment structure (e.g., discrete contact regions) as described in more detail herein. The orientation regions 721-723 can be integrated within any of the components of the abrasive article, including for example, the backing 101 or adhesive layers, and thus may be considered contact regions as described in more detail herein. Alternatively, the orientation regions 721-723 can be associated with an alignment structure use in forming the abrasive article, which may be a separate component from the backing and integrated within the abrasive article, and which may not necessarily form a contact region associated with the abrasive article.
As further illustrated, the abrasive article 700 can further include shaped abrasive particles 704, 705, 706 (704-706), wherein each of the shaped abrasive particles 704-706 can be associated with an orientation region 724, 725, 726, respectively. The orientation regions 724-726 can be configured to control at least one predetermined orientation characteristic of the shaped abrasive particles 704-706. Moreover, the orientation regions 724-726 can be configured to define a group 792 of shaped abrasive particle 704-706. In accordance with an embodiment, the orientation regions 724-726 can be spaced apart from the orientation regions 721-723. More particularly the orientation regions 724-726 can be configured to define a group 792 having at least one predetermined orientation characteristic that is different than a predetermined orientation characteristic of the shaped abrasive particles 701-703 of the group 791.
The abrasive article of
According to one embodiment, the alignment structure 761 can be configured to deliver and in particular instances, temporarily or permanently hold the shaped abrasive particle 701 at a first position 771. In particular instances, such as illustrated in
In particular instances, the contact regions 721 and 722 can be formed to have controlled two-dimensional shapes that may facilitate a predetermined rotational orientation of the corresponding shaped abrasive particles 701 and 702. For example, the contact region 721 can have a controlled and predetermined two-dimensional shape configured to determine a predetermined rotational orientation of the shaped abrasive particle 701. Moreover, the contact region 722 can have a controlled and predetermined two-dimensional shape configured to determine a predetermined rotational orientation of the shaped abrasive particle 702.
As illustrated, the alignment structure can include a plurality of discrete contact regions 721 and 722, wherein each of the contact regions 721 and 722 can be configured to deliver, and temporarily or permanently hold, one or more shaped abrasive particles. In some instances, the alignment structure can include a web, a fibrous material, a mesh, a solid structure having openings, a belt, a roller, a patterned material, a discontinuous layer of material, a patterned adhesive material, and a combination thereof.
The plurality of contact regions 721 and 722 can define at least one of the predetermined rotational orientation of a shaped abrasive particle, a predetermined rotational orientation difference between at least two shaped abrasive particles, the predetermined longitudinal orientation of a shaped abrasive particle, a longitudinal space between two shaped abrasive particles, the predetermined lateral orientation, a lateral space between two shaped abrasive particles, a predetermined vertical orientation, a predetermined vertical orientation difference between two shaped abrasive particles, a predetermined tip height, a predetermined tip height difference between two shaped abrasive particles. In particular instances, as illustrated in
In one particular embodiment, the contact regions 721 and 722 can have a two-dimensional shape selected from the group consisting of polygons, ellipsoids, numerals, crosses, multi-armed polygons, Greek alphabet characters, Latin alphabet characters, Russian alphabet characters, Arabic alphabet characters, rectangle, quadrilateral, pentagon, hexagon, heptagon, octagon, nonagon, decagon, and a combination thereof. Moreover, while the contact regions 721 and 722 are illustrated as having substantially the same two-dimensional shape, it will be appreciated, that in alternative embodiments, the contact regions 721 and 722 can have different two-dimensional shapes. Two-dimensional shapes are the shapes of the contact regions 721 and 722 as viewed in the plane of the length and width of the contact regions, which may be the same plane defined by the upper surface of the backing.
Moreover, it will be appreciated that the alignment structure 761 may be a temporary part of the abrasive article. For example, the alignment structure 761 can represent a template or other object that temporarily fixes the shaped abrasive particles at the contact regions, facilitating placement of the shaped abrasive particles in a desired position having one or more predetermined orientation characteristics. After placement of the shaped abrasive particles, the alignment structure may be removed leaving the shaped abrasive particle on the backing in the predetermined positions.
According to one particular embodiment, the alignment structure 761 can be a discontinuous layer of material including the plurality of contact regions 721 and 722 that may be made of an adhesive material. In more particular instances, the contact region 721 can be configured to adhere at least one shaped abrasive particle. In other embodiments, the contact region 721 can be formed to adhere more than one shaped abrasive particle. It will be appreciated that according to at least one embodiment, the adhesive material can include an organic material, and more particularly, at least one resin material.
Furthermore, the plurality of contact regions 721 and 722 can be arranged on the surface of the backing 101 to define a predetermined distribution of contact regions. The predetermined distribution of contact regions can have any characteristic of predetermined distributions described herein. In particular, the predetermined distribution of contact regions can define a controlled, non-shadow arrangement. The predetermined distribution of contact regions can define and substantially correspond to a same predetermined distribution of shaped abrasive particles on the backing, wherein each contact region can define a position of a shaped abrasive particle.
As illustrated, in certain instances, the contact regions 721 and 722 can be spaced apart from each other. In at least one embodiment, the contact regions 721 and 722 can be spaced apart from each other by a distance 731. The distance 731 between contact regions 721 and 722 is generally the smallest distance between adjacent contact regions 721 and 722 in a direction parallel to the lateral axis 181 or longitudinal axis 180.
In an alternative embodiment, the plurality of discrete contact regions 721 and 722 can be openings in a structure, such as a substrate. For example, each of the contact regions 721 and 722 can be openings in a template that is used to temporarily place the shaped abrasive particles in particular positions on the backing 101. The plurality of openings can extend partially or entirely through the thickness of the alignment structure. Alternatively, the contact regions 7821 and 722 can be openings in a structure, such as a substrate or layer that is permanently part of the backing and final abrasive article. The openings can have particular cross-sectional shapes that may be complementary to a cross-sectional shape of the shaped abrasive particles to facilitate placement of the shaped abrasive particles in predetermined positions and with one or more predetermined orientation characteristics.
Moreover, according to an embodiment, the alignment structure can include a plurality of discrete contact regions separated by non-contact regions, wherein the non-contact regions are regions distinct from the discrete contact regions and may be substantially free of the shaped abrasive particles. In one embodiment, the non-contact regions can define regions configured to be essentially free of adhesive material and separating contract regions 721 and 722. In one particular embodiment, the non-contact region can define regions configured to be essentially free of shaped abrasive particles.
Various methods may be utilized for form an alignment structure and the discrete contact regions, including but not limited to process such as coating, spraying, depositing, printing, etching, masking, removing, molding, casting, stamping, heating, curing, tacking, pinning, fixing, pressing, rolling, stitching, adhering, irradiating, and a combination thereof. In particular instances, wherein the alignment structure is in the form of a discontinuous layer of adhesive material, which can include a plurality of discrete contact regions including an adhesive material spaced apart from each other by non-contact regions, the forming process can include a selective deposition of the adhesive material.*
As illustrated and noted above,
According to one embodiment, the alignment structure 762 can be configured to deliver and in particular instances, temporarily or permanently hold the shaped abrasive particle 704 at a first position 773. In particular instances, such as illustrated in
According to at least one embodiment, the contact region 724 can be formed to have a shape (e.g., a two-dimensional shape), which may facilitate controlled orientation of the shaped abrasive particle 704. More particularly, the contact region 724 can have a two-dimensional shape configured to control one or more (e.g., at least two of) a particular predetermined orientation characteristic, including for example, a predetermined rotational orientation, a predetermined lateral orientation, and a predetermined longitudinal orientation. In at least one embodiment, the contact region 724 can be formed to have a two-dimensional shape, wherein the dimensions of the contact region 724 (e.g., length and/or width) substantially correspond to and are substantially the same as dimensions of the shaped abrasive particle 704, thereby facilitating positioning of the shaped abrasive particle at the position 772 and facilitating one or a combination of predetermined orientation characteristics of the shaped abrasive particle 704. Furthermore, according to an embodiment, the alignment structure 762 can include a plurality of contact regions having controlled two-dimensional shapes configured to facilitate and control one or more predetermined orientation characteristics of associated shaped abrasive particles.
As further illustrated, and according to an embodiment, the alignment structure 762 can be configured to deliver and in particular instances, temporarily or permanently hold the shaped abrasive particle 705 at a second position 774. In particular instances, such as illustrated in
As illustrated and noted above,
According to one embodiment, the alignment structure 763 can be configured to deliver and in particular instances, temporarily or permanently hold the shaped abrasive particle 744 at a first position 775. Likewise, as illustrated, the alignment structure 763 can be configured to deliver and in particular instances, temporarily or permanently hold the shaped abrasive particle 745 at a second position 776.
In particular instances, such as illustrated in
According to at least one embodiment, the contact region 754 can be formed to have a shape (e.g., a two-dimensional shape), which may facilitate controlled orientation of the shaped abrasive particle 744. More particularly, the contact region 754 can have a two-dimensional shape configured to control one or more (e.g., at least two of) a particular predetermined orientation characteristic, including for example, a predetermined rotational orientation, a predetermined lateral orientation, and a predetermined longitudinal orientation. In at least one alternative embodiment as illustrated, the contact region 754 can have a circular shape, which may facilitate some freedom of a predetermined rotational orientation. For example, in comparison of the shaped abrasive particles 744 and 745, each of which are associated with the contact regions 754 and 755, respectively, and further wherein each of the contact regions 754 and 755 have circular two-dimensional shapes, the shaped abrasive particles 744 and 745 have different predetermined rotational orientations with respect to each other. The circular two-dimensional shape of the contact regions 754 and 755 may facilitate a preferential side orientation of the shaped abrasive particles 744 and 745, while also allowing for a degree of freedom in at least one predetermined orientation characteristic (i.e., a predetermined rotational orientation) with respect to each other.
It will be appreciated, that in at least one embodiment, a dimensions of the contact region 754 (e.g., diameter) may substantially correspond to and may be substantially the same as a dimension of the shaped abrasive particle 744 (e.g., a length of a side surface), which may facilitate positioning of the shaped abrasive particle 744 at the position 775 and facilitating one or a combination of predetermined orientation characteristics of the shaped abrasive particle 744. Furthermore, according to an embodiment, the alignment structure 763 can include a plurality of contact regions having controlled two-dimensional shapes configured to facilitate and control one or more predetermined orientation characteristics of associated shaped abrasive particles. It will be appreciated, that while the foregoing alignment structure 763 includes contact regions 754 and 755 having substantially similar shapes, the alignment structure 763 can include a plurality of contact regions having a plurality of different two-dimensional shapes.
As illustrated and noted above,
According to one embodiment, the alignment structure 764 can be configured to deliver and in particular instances, temporarily or permanently hold the shaped abrasive particle 746 at a first position 777. Likewise, as illustrated, the alignment structure 764 can be configured to deliver and in particular instances, temporarily or permanently hold the shaped abrasive particle 747 at a second position 778.
In particular instances, such as illustrated in
According to at least one embodiment, the contact region 756 can be formed to have a shape (e.g., a two-dimensional shape), which may facilitate controlled orientation of the shaped abrasive particle 746. More particularly, the contact region 756 can have a two-dimensional shape configured to control one or more (e.g., at least two of) a particular predetermined orientation characteristic, including for example, a predetermined rotational orientation, a predetermined lateral orientation, and a predetermined longitudinal orientation. In at least one alternative embodiment as illustrated, the contact region 756 can have a cross-shaped two-dimensional shape, which may facilitate some freedom of a predetermined rotational orientation of the shaped abrasive particle 746.
For example, in comparison of the shaped abrasive particles 746 and 747, each of which are associated with the contact regions 756 and 757, respectively, and further wherein each of the contact regions 756 and 757 have cross-shaped two-dimensional shapes, the shaped abrasive particles 746 and 747 can have different predetermined rotational orientations with respect to each other. The cross-shaped two-dimensional shapes of the contact regions 756 and 757 may facilitate a preferential side orientation of the shaped abrasive particles 746 and 747, while also allowing for a degree of freedom in at least one predetermined orientation characteristic (i.e., a predetermined rotational orientation) with respect to each other. As illustrated, the shaped abrasive particles 746 and 747 are oriented substantially perpendicular to each other. The cross-shaped two-dimensional shape of the contact regions 756 and 757 facilitates generally two preferred predetermined rotational orientations of shaped abrasive particles, each of which are associated with the direction of the arms of the cross-shaped contact regions 756 and 757, and each of the two orientations are illustrated by the shaped abrasive particles 746 and 747.
It will be appreciated, that in at least one embodiment, a dimensions of the contact region 756 (e.g., length) may substantially correspond to and may be substantially the same as a dimension of the shaped abrasive particle 746 (e.g., a length of a side surface), which may facilitate positioning of the shaped abrasive particle 746 at the position 777 and facilitating one or a combination of predetermined orientation characteristics of the shaped abrasive particle 746. Furthermore, according to an embodiment, the alignment structure 764 can include a plurality of contact regions having controlled two-dimensional shapes configured to facilitate and control one or more predetermined orientation characteristics of associated shaped abrasive particles. It will be appreciated, that while the foregoing alignment structure 764 includes contact regions 756 and 757 having substantially similar shapes, the alignment structure 764 can include a plurality of contact regions having a plurality of different two-dimensional shapes.
An abrasive article can have a number of discrete contact regions. The number of contact regions can influence the amount of abrasive particles adhered to the abrasive article, which in turn can influence the abrasive performance of the abrasive article. In an embodiment the number of contact regions can be specific or variable. In an embodiment, the number of contact regions can be least 1, such as at least 5, at least 10, at least 100, at least 500, at least 1000, at least 2000, at least 5000, at least 7500, at least 10,000; at least 15,000; at least 17,000; at least 20,000; at least 30,000; at least 40,000; or at least 50,000. In an embodiment, the number of contact regions can be not greater than 100,000; such as not greater than 90,000; not greater than 80,000, not greater than 70,000; not greater than 60,000; not greater than 50,000; not greater than 40,000; not greater than 30,000, or not greater than 20,000. It will be appreciated that the number of contact regions can be in a range of any maximum or minimum value indicated above. In a specific embodiment the number of contact regions is in a range from 1000 to 50,000; such as 5,000 to 40,000, such as 10,000 to 17,000. In a specific embodiment, the number of contact regions is 10,000. In another specific embodiment, the number of contact regions is 17,000.
As stated elsewhere herein, the size of an individual contact region, and similarly an adhesive region size, can be specific or variable. In an embodiment, the size of a contact region can be defined by its average area or average diameter (polygon or circular).
In an embodiment, a contact region can have an average area of at least 0.01 mm2, such as at least 0.02 mm2, at least 0.05 mm2, at least 0.1 mm2, at least 0.2 mm2, at least 0.3 mm2, at least 0.4 mm2, at least 0.5 mm2, at least 0.60 mm2, at least 0.70 mm2, at least 0.80 mm2, at least 0.90 mm2, or at least 1 mm2. In an embodiment, a contact region can have an average area not greater than 800 cm2, such as not greater than 500 cm2, not greater than 200 cm2, not greater than 100 cm2, not greater than 10 cm2, not greater than 5 cm2, or not greater than 3.5 cm2. It will be appreciated that the number of adhesive regions can be in a range of any maximum or minimum value indicated above. In average area of a contact region is in a range from 0.1 mm2 to 100 cm2; such as 0.1 mm2 to 10 cm2. In a specific embodiment, the average area of a contact region is in a range from 0.1 mm2 to 20 mm2.
In an embodiment, a contact region can have an average diameter of at least 0.3 mm, such as at least 0.05 mm, at least 0.06 mm, at least 0.7 mm, at least 0.8 mm, at least 0.9 mm, or at least 1 mm. In an embodiment, a contact region can have an average diameter not greater than 40 cm, such as not greater than 30 cm, not greater than 20 cm, not greater than 15 cm, not greater than 10 cm, not greater than 5 cm, or not greater than 3.5 cm. It will be appreciated that the number of adhesive regions can be in a range of any maximum or minimum value indicated above. In average diameter of a contact region is in a range from 0.1 mm to 40 cm; such as 0.1 mm to 10 cm. In a specific embodiment, the average diameter of a contact region is in a range from 0.1 mm to 20 mm.
Methods and Systems for Forming Abrasive Articles
The foregoing has described abrasive articles of the embodiments having predetermined distributions of shaped abrasive particles. The following describes various methods used to form such abrasive articles of the embodiments herein. It will be appreciated that any of the methods and systems described herein can be used in combination to facilitate the formation of an abrasive article according to an embodiment.
According to one embodiment, a method of forming an abrasive article includes placing a shaped abrasive particle on the backing in a first position defined by one or more predetermined orientation characteristics. In particular, the method of placing the shaped abrasive particle can include a templating process. A templating process may make use of an alignment structure, which may be configured to hold (temporarily or permanently) one or more shaped abrasive particles in a predetermined orientation and deliver the one or more shaped abrasive particles onto the abrasive article in a predetermined position defined having one or more predetermined orientation characteristics.
According to one embodiment, the alignment structure can be various structures, including but not limited to, a web, a fibrous material, a mesh, a solid structure having openings, a belt, a roller, a patterned material, a discontinuous layer of material, a patterned adhesive material, and a combination thereof. In one particular embodiment, the alignment structure can include a discrete contact region configured to hold a shaped abrasive particle. In certain other instances, the alignment structure can include a plurality of discrete contact regions spaced apart from each other and configured to hold a plurality of shaped abrasive particles. For certain embodiments herein, a discrete contact region can be configured to temporarily hold a shaped abrasive particle and place the first shaped abrasive particle at a predetermined position on the abrasive article. Alternatively, in another embodiment, the discrete contact region can be configured to permanently hold a first shaped abrasive particle and place the first shaped abrasive particle at the first position. Notably, for embodiments utilizing a permanent hold between the discrete contact region and the shaped abrasive particle, the alignment structure may be integrated within the finished abrasive article.
Some exemplary alignments structures according to embodiments herein are illustrated in
As will be appreciated, the construction and arrangement of the fibers 901 and 902 can facilitate control of the discrete contact regions 904-906 and further can facilitate control of one or more predetermined orientation characteristics of the shaped abrasive particles on the abrasive article. For example, the discrete contact regions 904-906 can be configured to define at least one of a predetermined rotational orientation of a shaped abrasive particle, a predetermined rotational orientation difference between at least two shaped abrasive particles, a predetermined longitudinal orientation of a shaped abrasive particle, a longitudinal space between two shaped abrasive particles, a predetermined lateral orientation, a lateral space between two shaped abrasive particles, a predetermined vertical orientation of a shaped abrasive particle, a predetermined vertical orientation difference between two shaped abrasive particles, a predetermined tip height orientation of a shaped abrasive particle, a predetermined tip height difference between two shaped abrasive particles, and a combination thereof.
In yet another embodiment, the alignment structure can include discrete contact regions defined by openings, wherein the openings extend partially through the entire thickness of the alignment structure. For example,
Various processing steps may be utilized to facilitate the placement of the shaped abrasive particles on the alignment structure. Suitable processes can include, but are not limited to, vibration, adhesion, electromagnetic attraction, patterning, printing, pressure differential, roll coat, gravity drop, and a combination thereof. Moreover, particular devices may be used to facilitate orientation of the shaped abrasive particles on the alignment structure, including for example, cams, acoustics, and a combination thereof.
In yet another embodiment, the alignment structure can be in the form of a layer of adhesive material. Notably, the alignment structure can be in the form of a discontinuous layer of adhesive portions, wherein the adhesive portions define discrete contact regions configured to hold (temporarily or permanently) one or more shaped abrasive particles. According to one embodiment, the discrete contact regions can include an adhesive, and more particularly, the discrete contact regions are defined by a layer of adhesive, and still more particularly, each of the discrete contact regions are defined by a discrete adhesive region. In certain instances, the adhesive can include a resin, and more particularly, can include a material for use as a make coat as described in embodiments herein. Moreover, the discrete contact regions can define a predetermined distribution relative to each other, and can further define positions of the shaped abrasive particles on the abrasive article. Furthermore, the discrete contact regions comprising the adhesive can be arranged in a predetermined distribution, which is substantially the same as a predetermined distribution of shaped abrasive particles overlying the backing. In one particular instance, the discrete contact regions comprising the adhesive can be arranged in a predetermined distribution, can be configured to hold a shaped abrasive particle, and further can define at least one of a predetermined orientation characteristic for each shaped abrasive particle.
In an embodiment the number of adhesive regions can be specific or variable. In an embodiment, the number of adhesive regions can be least 1, such as at least 5, at least 10, at least 100, at least 500, at least 1000, at least 2000, at least 5000, at least 7500, at least 10,000; at least 15,000; at least 17,000; at least 20,000; at least 30,000; at least 40,000; or at least 50,000. In an embodiment, the number of adhesive regions can be not greater than 100,000; such as not greater than 90,000; not greater than 80,000, not greater than 70,000; not greater than 60,000; not greater than 50,000; not greater than 40,000; not greater than 30,000, or not greater than 20,000. It will be appreciated that the number of adhesive regions can be in a range of any maximum or minimum value indicated above. In a specific embodiment the number of adhesive regions is in a range from 1000 to 50,000; such as 5,000 to 40,000, such as 10,000 to 17,000. In a specific embodiment, the number of adhesive regions is 10,000. In another specific embodiment, the number of adhesive regions is 17,000.
In accordance with a particular embodiment, the first discrete contact region 1301 can be spaced apart from the second discrete contact region 1302 via a longitudinal gap 1305, which is a measure of the shortest distance between immediately adjacent discrete contact regions 1301 and 1302 in a direction parallel to the longitudinal axis 180 of the backing 101. In particular, control of the longitudinal gap 1305 may facilitate control of the predetermined distribution of the shaped abrasive particles on the surface of the abrasive article, which may facilitate improved performance. According to one embodiment, the longitudinal gap 1305 can be related to a dimension of one or a sampling of shaped abrasive particle. For example, the longitudinal gap 1305 can be at least equal to a width (w) of a shaped abrasive particle, wherein the width is a measure of the longest side of the particle as described herein. It will be appreciated that reference herein to a width (w) of the shaped abrasive particle can be reference to an average width or median width of a suitable sample size of a batch of shaped abrasive particles. In a particular instance, the longitudinal gap 1305 can be greater than the width, such as at least about 1.1 (w), at least about 1.2 (w), at least about 1.5 (w), at least about 2 (w), at least about 2.5 (w), at least about 3 (w) or even at least about 4 (w). Still, in one non-limiting embodiment, the longitudinal gap 1305 can be not greater than about 10 (w), not greater than about 9 (w), not greater than about 8 (w), or even not greater than about 5 (w). It will be appreciated that the longitudinal gap 1305 can be within a range between any of the minimum and maximum values noted above.
In accordance with a particular embodiment, the second discrete contact region 1302 can be spaced apart from the third discrete contact region 1303 via a lateral gap 1306, which is a measure of the shortest distance between immediately adjacent discrete contact regions 1302 and 1303 in a direction parallel to the lateral axis 181 of the backing 101. In particular, control of the lateral gap 1306 may facilitate control of the predetermined distribution of the shaped abrasive particles on the surface of the abrasive article, which may facilitate improved performance. According to one embodiment, the lateral gap 1306 can be related to a dimension of one or a sampling of shaped abrasive particle. For example, the lateral gap 1306 can be at least equal to a width (w) of a shaped abrasive particle, wherein the width is a measure of the longest side of the particle as described herein. It will be appreciated that reference herein to a width (w) of the shaped abrasive particle can be reference to an average width or median width of a suitable sample size of a batch of shaped abrasive particles. In a particular instance, the lateral gap 1306 can be less than the width of the shaped abrasive particle. Still, in other instances, the lateral gap 1306 can be greater than the width of the shaped abrasive particle. According to one aspect, the lateral gap 1306 can be zero. In yet another aspect, the lateral gap 1306 can be at least about 0.1 (w), at least about 0.5 (w), at least about 0.8 (w), at least about 1 (w), at least about 2 (w), at least about 3 (w) or even at least about 4 (w). Still, in one non-limiting embodiment, the lateral gap 1306 may be not greater than about 100 (w), not greater than about 50 (w), not greater than about 20 (w), or even not greater than about 10 (w). It will be appreciated that the lateral gap 1306 can be within a range between any of the minimum and maximum values noted above.
The first discrete contact region 1301 can be formed on an upper major surface of a backing using various methods, including for example, printing, patterning, gravure rolling, etching, removing, coating, depositing, and a combination thereof.
In at least one particular aspect, an abrasive article of an embodiment can including forming a patterned structure comprising an adhesive on at least a portion of the backing. Notably, in one instance, the patterned structure can be in the form of a patterned make coat. The patterned make coat can be a discontinuous layer including at least one adhesive region overlying the backing, a second adhesive region overlying the backing separate from the first adhesive region, and at least one exposed region between the first and second adhesive regions. The at least one exposed region can be essentially free of adhesive material and represent a gap in the make coat. In one embodiment, the patterned make coat can be in the form of an array of adhesive regions coordinated relative to each other in a predetermined distribution. The formation of the patterned make coat with a predetermined distribution of adhesive regions on the backing can facilitate placement of the shaped abrasive grains in a predetermined distribution, and particularly, the predetermined distribution of the adhesive regions of the patterned make coat can correspond to the positions of the shaped abrasive particles, wherein each of the shaped abrasive particles can be adhered to the backing at the adhesive regions, and thus correspond to the predetermined distribution of shaped abrasive particles on the backing. Moreover, in at least one embodiment, essentially no shaped abrasive particles of the plurality of shaped abrasive particles are overlying the exposed regions. Furthermore, it will be appreciated that a single adhesive region can be shaped and sized to accommodate a single shaped abrasive particle. However, in an alternative embodiment, an adhesive region can be shaped and sized to accommodate a plurality of shaped abrasive particles.
As already stated, a make coat can be selectively applied to a backing such that a portion of the backing surface is not covered with any make coat material. Any portion not covered by make coat, though, can be partially to fully covered by another coating layer such as a size coat or supersize coat. Alternatively, portions of the backing surface can be free of any overlying coatings (i.e., “bare” portions). A portion of the backing surface not covered with make coat material can be defined as a fraction of the total surface of the backing. Similarly, a portion of the backing surface not covered with any overlying coating can be defined as a fraction of the total surface of the backing. It will be appreciated that the total contact area for the abrasive article is based on the sum of the discrete contact areas (i.e., the sum of all the discrete contact areas and can be equal to the fraction of the total surface area of the backing that is covered with make coat.
In an embodiment, the portion of the backing covered by make coat material can range from 0.01 to 1.0 of the total backing surface. In a specific embodiment, the portion of the total area of the backing surface covered by make coat material can range from 0.05 to 0.9 of the total backing surface, such as 0.1 to 0.8 of the total backing surface. In a specific embodiment, the portion of the total backing surface covered by make coat material is in a range from 0.1 to 0.6 of the total backing surface, such as 0.15 to 0.55, such as 0.16 to 0.16 to 0.5 of the total backing surface.
In an embodiment, the portion of the backing surface not covered by any overlying coating material (i.e., “bare” surface) can range from 0.0 to 0.99 of the total backing surface. In a specific embodiment, the portion of the backing surface that is bare can range from 0.1 to 0.95 of the total backing surface, such as 0.2 to 0.9 of the total backing surface. In a specific embodiment, the bare portion of the backing surface is in a range from 0.4 to 0.85 of the total backing surface.
Various processes may be utilized in the formation of a patterned structure, including for example, a patterned make coat. In one embodiment, the process can include selectively depositing the make coat. In yet another embodiment, the process can include selectively removing at least a portion of the make coat. Some exemplary processes can include coating, spraying, rolling, printing, masking, irradiating, etching, and a combination thereof. According to a particular embodiment, forming the patterned make coat can include providing a patterned make coat on a first structure and transferring the patterned make coat to at least a portion of the backing. For example, a gravure roller may be provided with a patterned make coat layer, and the roller can be translated over at least a portion of the backing and transferring the patterned make coat from the roller surface to the surface of the backing.
Methods of Applying Adhesive Coating
In an embodiment, an adhesive layer can be applied by a screen printing process. The screen printing process can be a discrete adhesive layer application process, a semi-continuous adhesive layer application process, a continuous adhesive layer application process, or combinations thereof. In an embodiment, the application process includes the use of a rotary screen. In a particular embodiment, a rotary screen can be in the form of a hollow cylinder, or drum, having a plurality of apertures located on the wall of the cylinder or drum. An aperture, or combination of apertures, can correspond to the desired location of a discrete contact region, or a combination of discrete contact regions. A discrete contact region can include one, or more, discrete adhesive regions. In a particular embodiment, a contact region includes a plurality of discrete adhesive regions. The adhesive regions can be arranged in the form of a non-shadowing pattern.
Methods of Making
The selective application of a make resin and a size resin can be achieved using contact coating and printing methods, non-contact coating and printing methods, transfer contact coating and printing methods, or a combination thereof. Suitable methods include mounting a template, such as a stencil or screen, against the backing of the article to mask off areas of the backing that are not to be coated. A screen printing process can be a discrete adhesive application process, a semi-continuous adhesive application process, a continuous adhesive application process, or combinations thereof. In an embodiment, the application process can include the use of a rotary screen. In a particular embodiment, a rotary screen 2801 can be in the form of a hollow cylinder, or drum, having a plurality of apertures 2803 located on the wall of the cylinder or drum. In an embodiment, an aperture or combination of apertures can be located in the wall of the rotary screen. The apertures can correspond to one or more discrete contact regions, including one or more discrete adhesive regions 2805.
In an embodiment the number of apertures can be specific or variable. In an embodiment, the number of apertures can be least 1, such as at least 5, at least 10, at least 100, at least 500, at least 1000, at least 2000, at least 5000, at least 7500, at least 10,000; at least 15,000; at least 17,000; at least 20,000; at least 30,000; at least 40,000; or at least 50,000. In an embodiment, the number of apertures can be not greater than 100,000; such as not greater than 90,000; not greater than 80,000, not greater than 70,000; not greater than 60,000; not greater than 50,000; not greater than 40,000; not greater than 30,000, or not greater than 20,000. It will be appreciated that the number of apertures can be in a range of any maximum or minimum value indicated above. In a specific embodiment the number of apertures is in a range from 1000 to 50,000; such as 5,000 to 40,000, such as 10,000 to 17,000. In a specific embodiment, the number of apertures is 10,000. In another specific embodiment, the number of apertures is 17,000.
A rotary screen process can include an open squeegee system or a closed squeegee system. In a specific embodiment, the rotary screen process includes a closed squeegee system 2809. The rotary screen can be filled with the adhesive resin 2811 (i.e., polymeric resin for use in one or more specific coating layers, such as make resin, size resin) and the squeegee, or the like, can be used to guide the resin through the apertures. Closed rotary squeegee systems can have a number of advantages over other coating and printing systems. For instance, rotary screen printing systems allow the screen and the backing material to run at the same speed, thus reducing friction, at times marked by there being no friction, between the screen and the backing material. Additionally, tension on the backing material is reduced, allowing more delicate or sensitive backing materials, such as much thinner backing materials or open backing materials to be coated effectively. Also, rotary screen printing systems can reduce or eliminate the pressure required to push an adhesive material through the apertures of the rotary screen, which allows for enhanced control of the thickness of the adhesive material applied to the backing. In an embodiment, the thickness of the adhesive material is precisely controlled and applied at a thickness that promotes at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, or at least about 95% of the abrasive particles have tips that are upright. The thickness of the adhesive material can be the thickness of the make layer alone, or can be the thickness in combination with the size layer. The thickness of the adhesive layer can be adversely affected by penetration into the backing material. The penetration of the adhesive material into the backing material can be reduced, if desired, so as to control strike-through of the adhesive material and selectively control the flexibility of the backing material, also known as the “hand” of the backing material, when dealing with a fabric backing. Another benefit of a rotary screen printing system is that the shape of adhesive material deposited onto the backing will be less disturbed, thus discontinuous distributions of make coat resin, such as a discontinuous distributions of dots, stripes, or the like as described herein will have a more controlled shape, thus providing sharply defined coating areas, or images, on the substrate. Embodiments of suitable rotary screen processes that include a closed squeegee system can include Specific STORK printing machines makes and models. An illustration of a rotary screen process system is shown in
Phyllotactic
In an embodiment, the adhesive layer can have a substantially uniform thickness. The thickness can be less than the d50 height of the abrasive particle. The thickness can be less than 50% of the height of the abrasive particle, such as less than 45%, such as less than 40%, such as less than 35%, such as less than 30%, such as less than 25%, such as less than 20%, such as less than 15%, such as less than 10%, such as less than 5%, such as less than 4%, such as less than 3%, such as less than 2%, such as less than 1%, such as less than 0.5%.
In an embodiment, the width of the discrete adhesive contact regions can be the same or different. In an embodiment, the width of the discrete adhesive contact region is substantially equal to the d50 width of the at least one abrasive particle.
In an alternate embodiment, stencil printing can be used, such as by use of a frame to support a resin-blocking stencil. The stencil can be a woven or nonwoven material. The stencil can form open areas allowing the transfer of resin to produce a sharply-defined image onto a substrate. A roller or squeegee can be moved across the screen stencil, forcing or pumping the resin or slurry through the open areas in the stencil, such as open areas in the mesh of a woven stencil.
Screen printing can also include a stencil method of print making in which a design is imposed on a screen of silk or other fine mesh, wherein portions of the backing that are desired to be blank areas, or open areas, are coated with an impermeable substance, and the resin or slurry is forced through the mesh onto the printing surface (i.e., the desired backing or substrate). Printing of low profile and high fidelity features can be enabled by screen printing.
An alternate embodiment includes a contact method that includes a combination of screen printing and stencil printing, where a woven mesh is used to support a stencil. The stencil includes open areas of mesh through which resin (adhesive) can be deposited in a desired distribution, such as a pattern of discrete areas onto the backing material. The resin can be applied as a make coat, a size coat, a supersize coat, or other coating layer known in the art, or combinations thereof.
In an alternate embodiment, a method can include an inkjet-type printing and other technologies capable of selectively coating patterns onto the backing without need for a template.
Another suitable method, is a continuous kiss coating operation where the adhesive material (make coat or size coat) is coated over the backing material by passing the backing material between a delivery roll and a nip roll. Such a method can be well suited for coating a size coat over abrasive particles by passing the backing sheet between a delivery roll and a nip roll. Optionally, the adhesive resin can be metered directly onto the delivery roll. The final coated material can then be cured to provide the completed article.
A rotary screen for preparing a patterned coated abrasive article can include a generally cylindrical body and a plurality of perforations extending through the body. Alternatively a stencil for preparing a patterned coated abrasive article can include a generally planar body and a plurality of perforations extending through the body. Optionally, a frame can surround the stencil partially or completely.
A screen or stencil can be made from any material generally known in the art, such as a natural fiber, polymer, metal, ceramic, composite, or combinations thereof. The material can be of any desired dimension. In an embodiment, the screen is preferably thin. In an embodiment, combinations of metal and woven plastics are used. Metal stencils can be etched in one or more patterns, or a combination of patterns. Other suitable screen and stencil materials include polyester films, such as those having a thickness ranging from 1 to 20 mils (0.076 to 0.51 millimeters), more preferably ranging from 3 to 7 mils (0.13 to 0.25 millimeters).
As mentioned above, a rotary screen can be advantageously used to provide precisely defined coating patterns. In an embodiment, a layer of make resin is selectively applied to the backing by rotatively overlaying the rotary screen above the backing at a desired distance (to determine the thickness of the coat) and applying the make resin through the rotary screen. The make resin can be applied in a single pass or multiple passes using a squeegee, doctor blade, or other blade-like device.
The viscosity of the make resin can be manipulated to be in a range that is sufficiently high so that distortion of the overall distribution pattern, as well as the individual adhesive contact regions (e.g., dots, stripes, etc.) is minimized, and in some embodiments eliminated (i.e., not detectable).
Adhesive Spacing
The adhesive application methods described above can be used to impart one or more desirable orientation characteristics for the discrete adhesive regions or to establish one or more desirable predetermined distributions of the discrete adhesive regions. A predetermined distribution between discrete adhesive regions can also be defined by at least one of a predetermined orientation characteristic of each of the discrete adhesive regions. Exemplary predetermined orientation characteristics can include a predetermined rotational orientation, a predetermined lateral orientation, a predetermined longitudinal orientation, a predetermined vertical orientation, and combinations thereof.
As shown in
In other embodiments, the lateral space 2921 can be at least about 0.1 (w), wherein w represents the width of the discrete adhesive region 2902. According to an embodiment, the width of the discrete adhesive region is the longest dimension of the body extending along a side. In another embodiment, the lateral space 2921 can be at least about 0.2 (w), such as at least about 0.5 (w), at least about 1 (w), at least about 2 (w), or even greater. Still, in at least one non-limiting embodiment, the lateral space 2921 can be not greater than about 100 (w), not greater than about 50 (w), or even not greater than about 20 (w). It will be appreciated that the lateral space 2921 can be within a range between any of the minimum and maximum values noted above. Control of the lateral space between adjacent discrete adhesive regions can facilitate improved grinding performance of the abrasive article.
In accordance with an embodiment, the discrete adhesive region 2902 can be in a first, predetermined position 2912 defined by a first longitudinal position relative to a longitudinal axis 2980 of the backing 2901. Furthermore, the discrete adhesive region 2904 can be located at a third, predetermined position 2914 defined by a second longitudinal position relative to the longitudinal axis 2980 of the backing 2901. Further, as illustrated, a longitudinal space 2923 can exist between the discrete adhesive regions 2902 and 2904, which can be defined as a smallest distance between the two adjacent discrete adhesive regions 2902 and 2904 as measured in a direction parallel to the longitudinal axis 2980. In accordance with an embodiment, the longitudinal space 2923 can be greater than zero (0). Still, while not illustrated, it will be appreciated that the longitudinal space 2923 can be zero (0), such that the adjacent discrete adhesive regions are touching, or even overlapping each other.
In other instances, the longitudinal space 2923 can be at least about 0.1 (w), wherein w is the width of the discrete adhesive region as described herein. In other more particular instances, the longitudinal space can be at least about 0.2 (w), at least about 0.5 (w), at least about 1 (w), or even at least about 2 (w). Still, the longitudinal space 2923 may be not greater than about 100 (w), such as not greater than about 50 (w), or even not greater than about 20 (w). It will be appreciated that the longitudinal space 2923 can be within a range between any of the above minimum and maximum values. Control of the longitudinal space between adjacent discrete adhesive regions may facilitate improved grinding performance of the abrasive article.
In accordance with an embodiment, the discrete adhesive regions may be placed in a predetermined distribution, wherein a particular relationship exists between the lateral space 2921 and longitudinal space 2923. For example, in one embodiment the lateral space 2921 can be greater than the longitudinal space 2923. Still, in another non-limiting embodiment, the longitudinal space 2923 may be greater than the lateral space 2921. Still, in yet another embodiment, the discrete adhesive regions may be placed on the backing such that the lateral space 2921 and longitudinal space 2923 are essentially the same relative to each other. Control of the relative relationship between the longitudinal space and lateral space may facilitate improved grinding performance.
In accordance with an embodiment, the discrete adhesive region 2905 may be located at a fourth, predetermined position 2915 defined by a third longitudinal position relative to the longitudinal axis 2980 of the backing 2901. Further, as illustrated, a longitudinal space 2925 may exist between the discrete adhesive regions 2902 and 2905, which can be defined as a smallest distance between the two adjacent discrete adhesive regions 2902 and 2905 as measured in a direction parallel to the longitudinal axis 2980. In accordance with an embodiment, the longitudinal space 2925 can be greater than zero (0). Still, while not illustrated, it will be appreciated that the longitudinal space 2925 can be zero (0), such that the adjacent discrete adhesive regions are touching, or even overlapping each other.
In other instances, the longitudinal space 2925 can be at least about 0.1 (w), wherein w is the width of the discrete adhesive region as described herein. In other more particular instances, the longitudinal space can be at least about 0.2 (w), at least about 0.5 (w), at least about 1 (w), or even at least about 2 (w). Still, the longitudinal space 2925 may be not greater than about 100 (w), such as not greater than about 50 (w), or even not greater than about 20 (w). It will be appreciated that the longitudinal space 2925 can be within a range between any of the above minimum and maximum values. Control of the longitudinal space between adjacent discrete adhesive regions may facilitate improved grinding performance of the abrasive article.
As further illustrated, a longitudinal space 2924 may exist between the discrete adhesive regions 2904 and 2905. Moreover, the predetermined distribution may be formed such that a particular relationship can exist between the longitudinal space 2923 and longitudinal space 2924. For example, the longitudinal space 2923 can be different than the longitudinal space 2924. Alternatively, the longitudinal space 2923 can be essentially the same at the longitudinal space 2924. Control of the relative difference between longitudinal spaces of different abrasive particles may facilitate improved grinding performance of the abrasive article. As further illustrated, a longitudinal space 2927 may exist between the discrete adhesive regions 2903 and 2906. Moreover, the predetermined distribution may be formed such that a particular relationship can exist between the longitudinal space 2927 and longitudinal space 2926. For example, the longitudinal space 2927 can be different than the longitudinal space 2926. Alternatively, the longitudinal space 2927 can be essentially the same at the longitudinal space 2926. Still further, the longitudinal space 2927 can be different than, or essentially the same as, the longitudinal space 2923. Likewise, the longitudinal space 2928 can be different than, or essentially the same as, the longitudinal space 2924. Control of the relative difference between longitudinal spaces of different abrasive particles may facilitate improved grinding performance of the abrasive article.
Furthermore, the predetermined distribution of shaped abrasive particles on the abrasive article 2900 can be such that the lateral space 2921 can have a particular relationship relative to the lateral space 2922. For example, in one embodiment the lateral space 2921 can be essentially the same as the lateral space 2922. Alternatively, the predetermined distribution of shaped abrasive particles on the abrasive article 2900 can be controlled such that the lateral space 2921 is different than the lateral space 2922. Control of the relative difference between lateral spaces of different abrasive particles may facilitate improved grinding performance of the abrasive article.
As further illustrated, a longitudinal space 2926 may exist between the discrete adhesive regions 2903 and 2906. Moreover, the predetermined distribution may be formed such that a particular relationship can exist between the longitudinal space 2925 and longitudinal space 2926. For example, the longitudinal space 2925 can be different than the longitudinal space 2926. Alternatively, the longitudinal space 2925 can be essentially the same at the longitudinal space 2926. Control of the relative difference between longitudinal spaces of different abrasive particles may facilitate improved grinding performance of the abrasive article. In addition to the latitudinal spacing and longitudinal spacing already described herein, the spacing between discrete contact regions, discrete adhesive regions, or abrasive particles can also be described as having a particular or variable “adjacent spacing” wherein said adjacent spacing need not be strictly latitudinal or longitudinal (but can be the shortest distance that extends between adjacent discrete contact regions, discrete adhesive regions, or abrasive particles even if at an oblique angle. Adjacent spacing can be constant or variable.
In an embodiment adjacent spacing can be defined as a fraction of abrasive particle length, abrasive particle width, discrete contact area length, discrete contact area width, discrete adhesive region length, adhesive region width, or combinations thereof. In an embodiment, adjacent spacing is defined as a fraction of abrasive particle length (l). In an embodiment, adjacent spacing is at least 0.5 (l), such as at least 0.5 (l), at least 0.6 (l), at least 0.7 (l), at least 1.0 (l), or at least 1.1 (l). In an embodiment, the adjacent spacing is not greater than 10 (l), such is not greater than 9 (l), not greater than 8 (l), not greater than 7 (l), not greater than 6 (l), not greater than 5 (l), not greater than 4 (l), or not greater than 3 (l). It will be appreciated that the adjacent spacing can be in a range of any maximum or minimum value indicated above. In an embodiment, adjacent spacing is in a range from 0.5 (l) to 3 (l), such as 1 (l) to 2.5 (l), such as 1.25 (l) to 2.25 (l), such as 1.25 (l) to 1.75 (l), such as 1.5 (l) to 1.6 (l).
In an embodiment, the adjacent spacing is at least 0.2 mm, such as at least 0.3 mm, such as at least 0.4 mm, such as at least 0.5 mm, such as at least 0.6 mm, such as at least 0.7 mm, such as at least 1.0 mm. In an embodiment, adjacent spacing can be not greater than 4.0 mm, such as not greater than 3.5 mm, not greater than 2.8 mm, or not greater than 2.5 mm. It will be appreciated that the adjacent spacing can be in arrange of any maximum or minimum value indicated above. In a particular embodiment, the adjacent spacing is in a range from 1.4 mm to 2.8 mm.
In an embodiment, the adjacent spacing tween discrete contact areas can be at least about 0.1 (W), where in W is the wit of the discrete adhesive region as described herein.
It will be appreciated that abrasive particles, such as embodiments of shaped abrasive particles described herein, can be disposed on the discrete adhesive regions described above. The number of abrasive particles disposed on a discrete adhesive region can be from 1 to n, where n=1 to 3. The number of abrasive particles disposed per discrete abrasive region can be the same or different. Furthermore, a predetermined distribution of shaped abrasive particles can be defined by the predetermined distribution of discrete adhesive regions to which they are relatively adhered. A predetermined distribution of discrete adhesive regions can also be defined by the precision and accuracy of the actual placement of a discrete adhesive region (i.e., an adhesive strike location) with respect to its intended target location (i.e., adhesive target location), and more precisely defined by the precision and accuracy of the placement of the center (or centroid) of an adhesive strike area compared to the center (or centroid) of the intended adhesive target area. The difference in distance between the adhesive target location and the adhesive strike location is the differential distance. Control of the differential distance can facilitate improved grinding performance of the abrasive article. As explained in greater detail below, control of the differential distance can be defined by one or more of several well known measures of variability, such as Range, Interquartile Range, Variance, and Standard Deviation, among others.
In accordance with an embodiment,
In an embodiment, the first differential distance 3001 can be less than about 0.1 (d), wherein (d) represents the diameter of the first adhesive strike area 3004. the diameter of the adhesive strike area is the longest dimension of the strike area, including for non-circular shapes, extending through its center. In an embodiment, the differential distance 3001 can be less than about 5 (d), such as less than about 2 (d), less than about 1 (d) less than about 0.5 (d), less than about 0.2 (d), or even less than about 0.1 (d). It will be appreciated that the first differential distance 3001 can be within a range between any of the minimum and maximum values noted above. Control of the differential distance between the adhesive strike area and the adhesive target area can facilitate improved grinding performance of the abrasive article.
In an embodiment, a predetermined, or controlled, distribution 3000 can also include a second adhesive target area 3006 and a second adhesive strike area 3008. Similar to the first adhesive target area and first adhesive strike area, the relationship between the second adhesive target area 3006 and the second adhesive strike area 3008 can be defined by a second differential distance 3010 between the second adhesive target location 3007 and the adhesive strike location 3009. Preferably, the second differential distance will be equal to zero, but in actuality will likely be an acceptably small value. In an embodiment, the second differential distance 3010 can be zero (0), or an acceptable distance greater than zero, such that some distance can exist between locations 3007 and 3009. As illustrated, the second differential distance 3010 can be less than the length or width, or diameter of either the second adhesive strike area 3008 or the second adhesive target area 3006, allowing for contact and even overlap between portions of the second adhesive strike area 3006 and the second adhesive target area 3006. Moreover, while not illustrated, it will be appreciated that the second differential distance 3010 can be zero (0), indicating completely accurate placement of the second adhesive strike area 3008 on the second adhesive target area 3006.
Similarly, the predetermined distribution 3000 of adhesive areas can also include three or more adhesive target areas and three or more adhesive strike areas, such as a third adhesive target area 3011 and a third adhesive strike area 3013, or a plurality of other target areas and strike areas as illustrated in
Further with regard to the differential distance, such as the first differential distance 3001, second differential distance 3010, or any other of the plurality of differential distances can be defined as a vector, having a magnitude (i.e., distance or length) and a direction (or degree of rotation). As illustrated in
As mentioned previously, adhesive contact regions that are applied with a high level of control (i.e., high accuracy, high precision, low variability) can facilitate improved grinding performance of the abrasive article. In an embodiment, a substantial number (greater than 50%) of the adhesive contact regions are applied “on target”, i.e., such that the magnitude and direction (or degree of rotation) of the differential distance between an adhesive strike area and an adhesive target area is zero or an acceptably small value. In an embodiment the number of adhesive contact regions that are “on target” in a given sample area (such as 1 square meter) is at least about 55%, such as at least about 60%, at least about 65%, at least about 68%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about %, at least about 98%, at least about 99%, at least about 99.5%, or even about 100% (all measured values are within an acceptable limit). In another embodiment, the accuracy and precision of the application and placement of the adhesive contact areas (as defined by the differential distance between the adhesive target location and adhesive strike location) can be measured as a percentage of adhesive contact regions that are “on target” within a standard deviation. In an embodiment, the number of adhesive contact regions that are “on target” within a standard deviation is at least at least about 65%, at least about 68%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about 97%, at least about 98%, at least about 99%, at least about 99.5%, or even about 100% (all measured values are within an acceptable limit). In another embodiment, at least a specific number or percentage of adhesive contact regions have a differential distance that is within one standard deviation of the mean differential distance of the sample population. In a specific embodiment, at least about 68% of the population (or alternatively a sample of the population) of adhesive contact regions are within one (1) standard deviation of the mean differential distance of the population or sample population. In another embodiment, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about %, at least about 95%, at least about 97%, at least about 98%, at least about 99%, at least about 0.5%, or even about 100% (all measured values are within an acceptable limit) of adhesive contact regions are within one (1) standard deviation of the mean differential distance of the population or sample population.
Lateral Spacing
As mentioned previously, the adhesive contact regions can be spaced apart from each other by a lateral space, defined as a smallest distance between two adjacent adhesive contact regions as measured along a lateral plane parallel to the lateral axis of the backing upon which the adhesive contact regions are disposed. In an embodiment, *the lateral spacing between adhesive contact regions can exhibit a high level of control (i.e., high accuracy, high precision, low variability). In an embodiment, a substantial number (greater than 50%) of the adhesive contact regions are applied “on target” such that the difference between the lateral spacing of adjacent adhesive contact areas is zero or an acceptably small value. In an embodiment at least about 55% such as at least about 60%, at least about 65%, at least about 68%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about %, at least about 98%, at least about 99%, at least about 99.5%, or even about 100% (all measured values are within an acceptable limit) of the lateral spacing between the adjacent adhesive contact regions is within 2.5 standard deviations of the mean. In another embodiment, at least about 65% of a sample population of the lateral spacing between adjacent adhesive contact areas will be within 2.5 standard deviation of the mean, such as within 2.25 standard deviations, within 2.0 standard deviations, within 1.75, standard deviations, within 1.5 standard deviations, within 1.25 standard deviations, or within 1.0 standard deviations of the mean. It will be appreciated that alternative ranges can be constructed by using the above combinations of percentages and deviations from the mean.
Longitudinal Spacing
As mentioned previously, the adhesive contact regions can be spaced apart from each other by a longitudinal space, defined as a smallest distance between two adjacent adhesive contact regions as measured along a longitudinal plane parallel to the longitudinal axis of the backing upon which the adhesive contact regions are disposed. In an embodiment, *the longitudinal spacing between adhesive contact regions can exhibit a high level of control (i.e., high accuracy, high precision, low variability). In an embodiment, a substantial number (greater than 50%) of the adhesive contact regions are applied “on target” such that the difference between the longitudinal spacing of adjacent adhesive contact areas is zero or an acceptably small value. In an embodiment at least about 55% such as at least about 60%, at least about 65%, at least about 68%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about %, at least about 98%, at least about 99%, at least about 99.5%, or even about 100% (all measured values are within an acceptable limit) of the longitudinal spacing between the adjacent adhesive contact regions is within 2.5 standard deviations of the mean. In another embodiment, at least about 65% of a sample population of the longitudinal spacing between adjacent adhesive contact areas will be within 2.5 standard deviation of the mean, such as within 2.25 standard deviations, within 2.0 standard deviations, within 1.75, standard deviations, within 1.5 standard deviations, within 1.25 standard deviations, or within 1.0 standard deviations of the mean. It will be appreciated that alternative ranges can be constructed by using the above combinations of percentages and deviations from the mean.
As mentioned above, at least one abrasive particle can be disposed on an adhesive contact region. Similar to the lateral spacing and longitudinal spacing between adjacent adhesive contact areas, a lateral spacing and longitudinal spacing can exist between the at least one abrasive particles disposed on the adjacent contact regions.
In an embodiment, the lateral spacing between the at least one abrasive particles can exhibit a high level of control (i.e., high accuracy, high precision, low variability). In an embodiment, a substantial number (greater than 50%) of the at least one abrasive particles are applied “on target” such that the difference between the lateral spacing of the at least one abrasive particles is zero or an acceptably small value. In an embodiment at least about 55% such as at least about 60%, at least about 65%, at least about 68%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about %, at least about 98%, at least about 99%, at least about 99.5%, or even about 100% (all measured values are within an acceptable limit) of the lateral spacing between the adjacent at least one abrasive particles is within 2.5 standard deviations of the mean. In another embodiment, at least about 65% of a sample population of the lateral spacing between the at least one abrasive particles will be within 2.5 standard deviation of the mean, such as within 2.25 standard deviations, within 2.0 standard deviations, within 1.75, standard deviations, within 1.5 standard deviations, within 1.25 standard deviations, or within 1.0 standard deviations of the mean. It will be appreciated that alternative ranges can be constructed by using the above combinations of percentages and deviations from the mean.
As mentioned previously, the at least one abrasive particles can be spaced apart from each other by a longitudinal space, defined as a smallest distance between the at least one abrasive particles as measured along a longitudinal plane parallel to the longitudinal axis of the backing upon which the at least one abrasive particles are disposed. In an embodiment, the longitudinal spacing between the at least one abrasive particles can exhibit a high level of control (i.e., high accuracy, high precision, low variability). In an embodiment, a substantial number or percentage (greater than 50%) of the at least one abrasive particles are applied “on target” such that the difference between the longitudinal spacing of the at least one abrasive particles is zero or an acceptably small value. In an embodiment at least about 55% such as at least about 60%, at least about 65%, at least about 68%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least about 95%, at least about %, at least about 98%, at least about 99%, at least about 99.5%, or even about 100% (all measured values are within an acceptable limit) of the longitudinal spacing between the at least one abrasive particles is within 2.5 standard deviations of the mean. In another embodiment, at least about 65% of a sample population of the longitudinal spacing between adjacent adhesive contact areas will be within 2.5 standard deviation of the mean, such as within 2.25 standard deviations, within 2.0 standard deviations, within 1.75, standard deviations, within 1.5 standard deviations, within 1.25 standard deviations, or within 1.0 standard deviations of the mean. It will be appreciated that alternative ranges can be constructed by using the above combinations of percentages and deviations from the mean.
High accuracy, high precision, low variability placement of adhesive contact regions can directly contribute to improved abrasive performance of the abrasive article by directly improving accuracy, precision, an lower variability in the placement of abrasive particles, as well as, promoting efficient swarf removal. It will be appreciated that several different measures of variability related to the location of the predetermined distribution of the adhesive contact regions can be evaluated. Such measures can include well known statistical analytical measures including variability, standard deviation, interquartile range, range, mean difference, median absolute deviation, average absolute deviation, distance standard deviation, coefficient of variation, quartile coefficient of dispersion, relative mean difference, variance, variance-to-mean ratio, or combinations thereof. For instance, the ratio for the variance-to-mean can not greater than 35%, such as not greater than 30%, such as not greater than 20%. Whichever tool is utilized, the purpose for analysis is to measure the accuracy and precision of embodiments that can be defined by the location of a predetermined distribution of adhesive strike areas with respect to adhesive target areas. As used herein, “precision” and “precise” are terms meaning the degree to which repeated measurements under unchanged conditions reveal the same results. As used herein, “accuracy” and “accurate” are terms meaning the degree of closeness of a measurement to its actual, or target, value.
Abrasive particles can be disposed on an adhesive layer (e.g., make layer, size layer, or other layer of the abrasive article) using a suitable deposition method, such as electrostatic coating process, gravity drop coating, and all other abrasive particle deposition processes described herein. During electrostatic coating, the abrasive particles are applied in an electric field, allowing the particles to be advantageously aligned with their long axes normal to the major surface. In another embodiment, the abrasive particles are coated over the entire surface of the make coat that has been applied to the backing. In another embodiment, the abrasive particles are applied to only a portion of the make coat that has been applied to the backing. abrasive particles will preferentially bond to the areas coated with the make resin.
As mentioned previously, the shaped abrasive particles may be disposed on the adhesive contact region such that the footprint of the abrasive particle can substantially be the same as the discrete adhesive contact region. Thus the lateral and longitudinal spacing between the adjacent adhesive contact regions and associated abrasive particles can be controlled.
In accordance with one embodiment, the process of delivering shaped abrasive particles to the abrasive article can include expelling the first shaped abrasive particle from an opening within the alignment structure. Some suitable exemplary methods for expelling can include applying a force on the shaped abrasive particle and removing it from the alignment structure. For example, in certain instances, the shaped abrasive particle can be contained in the alignment structure and expelled from the alignment structure using gravity, electrostatic attraction, surface tension, pressure differential, mechanical force, magnetic force, agitation, vibration, and a combination thereof. In at least one embodiment, the shaped abrasive particles can be contained in the alignment structure until a surface of the shaped abrasive particles are contacted to a surface of the backing, which may include an adhesive material, and the shaped abrasive particles are removed from the alignment structure and delivered to a predetermined position on the backing.
According to another aspect, the shaped abrasive particles can be delivered to the surface of the abrasive article in a controlled manner by sliding the shaped abrasive particles along a pathway. For example, in one embodiment, the shaped abrasive particles can be delivered to a predetermined position on the backing by sliding the abrasive particles down a pathway and through an opening via gravity.
Moreover, the backing 1501 may further be translated over a vibrating table 1506 that can agitate or vibrate the backing 1501 and the shaped abrasive particles contained on the backing 1501 to facilitate improved orientation of the shaped abrasive particles.
In yet another embodiment, the shaped abrasive particles can be delivered to a predetermined position by expelling individual shaped abrasive particles on to the backing via a throwing process. In the throwing process, shaped abrasive particles may be accelerate and expelled from a container at a rate sufficient to hold the abrasive particles at a predetermined position on the backing. For example,
In particular instances, the shaped abrasive particles 1702 can be formed to have a coating. The coating can be overlying at least portion of the exterior surface of the shaped abrasive particles 1702. In one particular embodiment, the coating can include an organic material, and more particularly, a polymer, and still more particularly an adhesive material. The coating comprising an adhesive material may facilitate attachment of the shaped abrasive particles 1702 to the backing 1701.
According to another embodiment, the process of delivering the shaped abrasive particles in a predetermined position on the abrasive article and forming an abrasive article having a plurality of shaped abrasive particles in a predetermined distribution relative to each other can include the application of magnetic force.
As illustrated, the shaped abrasive particles 1802 can be translated along the belt 1803 to an alignment structure 1805 configured to contain each of the shaped abrasive particles at a discrete contact region. According to one embodiment, the shaped abrasive particles 1802 can be transferred from the belt 1803 to the alignment structure 1805 via a transfer roller 1804. In particular instances, the transfer roller 1804 may utilize a magnet to facilitate controlled removal of the shaped abrasive particles 1802 from the belt 1803 to the alignment structure 1805. The provision of a coating comprising a magnetic material may facilitate the use of the transfer roller 1804 with magnetic capabilities.
The shaped abrasive particles 1802 and can be delivered from the alignment structure 1805 to a predetermined position on the backing 1807. As illustrated, the backing 1807 may be translated on a separate belt and from the alignment structure 1805 and contact the alignment structure to facilitate the transfer of the shaped abrasive particles 1802 from the alignment structure 1805 to the backing 1807.
In still another embodiment, the process of delivering the shaped abrasive particles in a predetermined position on the abrasive article and forming an abrasive article having a plurality of shaped abrasive particles in a predetermined distribution relative to each other can include the use of an array of magnets.
Moreover, each of the magnets of the array of magnets 1905 can be moveable between a first position and a second position, which can facilitate control of the shape of the array of magnets 1905 and further facilitate control of the predetermined distribution of the magnets and the predetermined distribution of shaped abrasive particles 1902 on the backing. According to one embodiment, the array of magnets 1905 can be changed to facilitate control of one or more predetermined orientation characteristics of the shaped abrasive particles 1902 on the abrasive article.
Furthermore, each of the magnets of the array of magnets 1905 may be operable between a first state and a second state, wherein a first state can be associated with a first magnetic strength (e.g., an on state) and the second state can be associated with a second magnetic strength (e.g., an off state). Control of the state of each of the magnets can facilitate selective delivery of shaped abrasive particles to particular regions of the backing 1906 and further facilitate control of the predetermined distribution. According to one embodiment, the state of the magnets of the array of magnets 1905 can be changed to facilitate control of one or more predetermined orientation characteristics of the shaped abrasive particles 1902 on the abrasive article.
As illustrated, the shaped abrasive particles 2001 can define a group 2002. The group 2002 can have a predetermined distribution of shaped abrasive particles 2001, wherein each of the shaped abrasive particles has substantially the same predetermined rotational orientation. Moreover, each of the shaped abrasive particles 2001 has substantially the same predetermined vertical orientation and predetermined tip height orientation. Furthermore, the group 2002 includes multiple rows (e.g., 2005, 2006, and 2007) oriented in a plane parallel to a lateral axis 2081 of the tool 2051. Moreover, within the group 2002, smaller groups (e.g., 2012, 2013, and 2014) of the shaped abrasive particles 2001 may exist, wherein the shaped abrasive particles 2001 share a same difference in a combination of a predetermined lateral orientation and predetermined longitudinal orientation relative to each other. Notably, the shaped abrasive particle 2001 of the groups 2012, 2013, and 2014 can be oriented in raked columns, wherein the group extends at an angle to the longitudinal axis 2080 of the tool 2051, however, the shaped abrasive particles 2001 can have substantially a same difference in the predetermined longitudinal orientation and predetermined lateral orientation relative to each other. As also illustrated, the predetermined distribution of shaped abrasive particles 2001 can defines a pattern, which may be considered a triangular pattern 2011. Moreover, the group 2002 can be arranged such that the boundary of the group defines a two-dimensional macro-shape of a quadrilateral (see dotted line).
FIGs.
For certain abrasive articles herein, at least about 75% of the plurality of shaped abrasive particles on the abrasive article can have a predetermined orientation relative to the backing, including for example a side orientation as described in embodiments herein. Still, the percentage may be greater, such as at least about 77%, at least about 80%, at least about 81%, or even at least about 82%. And for one non-limiting embodiment, an abrasive article may be formed using the shaped abrasive particles herein, wherein not greater than about 99% of the total content of shaped abrasive particles have a predetermined side orientation. It will be appreciated that reference herein to percentages of shaped abrasive particles in a predetermined orientation is based upon a statistically relevant number of shaped abrasive particles and a random sampling of the total content of shaped abrasive particles.
To determine the percentage of particles in a predetermined orientation, a 2D microfocus x-ray image of the abrasive article is obtained using a CT scan machine run in the conditions of Table 1 below. The X-ray 2D imaging was conducted using Quality Assurance software. A specimen mounting fixture utilizes a plastic frame with a 4″×4″ window and an Ø0.5″ solid metallic rod, the top part of which is half flattened with two screws to fix the frame. Prior to imaging, a specimen was clipped over one side of the frame where the screw heads were faced with the incidence direction of the X-rays (
The image is then imported and analyzed using the ImageJ program, wherein different orientations are assigned values according to Table 2 below.
Three calculations are then performed as provided below in Table 3. After conducting the calculations the percentage of shaped abrasive particles in a side orientation per square centimeter can be derived. Notably, a particle having a side orientation is a particle having a vertical orientation, as defined by the angle between a major surface of the shaped abrasive particle and the surface of the backing, wherein the angle is 45 degrees or greater. Accordingly, a shaped abrasive particle having an angle of 45 degrees or greater is considered standing or having a side orientation, a shaped abrasive particle having an angle of 45 degrees is considered standing slanted, and a shaped abrasive particle having an angle of less than 45 degrees is considered having a down orientation.
Furthermore, the abrasive articles made with the shaped abrasive particles can utilize various contents of the shaped abrasive particles. For example, the abrasive articles can be coated abrasive articles including a single layer of the shaped abrasive particles in an open-coat configuration or a closed coat configuration. However, it has been discovered, quite unexpectedly, that the shaped abrasive particles demonstrate superior results in an open coat configuration. For example, the plurality of shaped abrasive particles can define an open coat abrasive product having a coating density of shaped abrasive particles of not greater than about 70 particles/cm2. In other instances, the density of shaped abrasive particle per square centimeter of the abrasive article may be not greater than about 65 particles/cm2, such as not greater than about 60 particles/cm2, not greater than about 55 particles/cm2, or even not greater than about 50 particles/cm2. Still, in one non-limiting embodiment, the density of the open coat coated abrasive using the shaped abrasive particle herein can be at least about 5 particles/cm2, or even at least about 10 particles/cm2. It will be appreciated that the density of shaped abrasive particles per square centimeter of abrasive article can be within a range between any of the above minimum and maximum values.
In certain instances, the abrasive article can have an open coat density of a coating not greater than about 50% of abrasive particle covering the exterior abrasive surface of the article. In other embodiments, the percentage coating of the abrasive particles relative to the total area of the abrasive surface can be not greater than about 40%, not greater than about 30%, not greater than about 25%, or even not greater than about 20%. Still, in one non-limiting embodiment, the percentage coating of the abrasive particles relative to the total area of the abrasive surface can be at least about 5%, such as at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, or even at least about 40%. It will be appreciated that the percent coverage of shaped abrasive particles for the total area of abrasive surface can be within a range between any of the above minimum and maximum values.
Some abrasive articles may have a particular content of abrasive particles for a length (e.g., ream) of the backing. For example, in one embodiment, the abrasive article may utilize a normalized weight of shaped abrasive particles of at least about 10 lbs/ream (148 grams/m2), at least about 15 lbs/ream, at least about 20 lbs/ream, such as at least about 25 lbs/ream, or even at least about 30 lbs/ream. Still, in one non-limiting embodiment, the abrasive articles can include a normalized weight of shaped abrasive particles of not greater than about 60 lbs/ream (890 grams/m2), such as not greater than about 50 lbs/ream, or even not greater than about 45 lbs/ream. It will be appreciated that the abrasive articles of the embodiments herein can utilize a normalized weight of shaped abrasive particle within a range between any of the above minimum and maximum values.
Applicants have observed that certain abrasive article embodiments according to the teachings herein exhibit a beneficial amount of make coat material (aka the “make weight”) compared to the amount of abrasive particles (aka the “grain weight”) disposed on the backing. In an embodiment, the ratio of the make weight to the grain weight can be constant or variable. In an embodiment, the ratio of make weight to grain weight can be in a range of 1:40 to 1:1, such as 1:40 to 1:1.3, such as 1:25 to 1:2, such as 1:20 to 1:5. In a particular embodiment the ratio of make weight to grain weight is in a range of 1:20 to 1:9.
In an embodiment, the make weight can be at least 0.1 pound per ream, such as at least 0.2 pounds per ream, at least 0.3 pounds per ream, at least 0.4 pounds per ream, at least 0.5 pounds per ream, at least 0.6 pounds per ream, at least 0.7 pounds per ream, at least 0.8 pounds per ream, at least 0.9 pounds per ream, or at least 1.0 pound per ream. In an embodiment the make weight can be not greater than 40 pounds per ream, such as not greater than 35 pounds per ream, not greater than 30 pounds per ream, not greater than 28 pounds per ream, not greater than 25 pounds per ream, not greater than 20 pounds per ream, or not greater than 15 pounds per ream. It will be appreciated that make weight can be in a range of any of the maximum and minimum values given above. In specific embodiment, the make weight can be in a range of 0.5 pounds per ream to 20 pounds per ream, such as 0.6 pounds per ream to 15 pounds per ream, such as 0.7 pounds per ream to 10 pounds per ream. In a particular embodiment, the make weight is in a range of 0.5 pounds per ream to 5 pounds per ream.
In certain instances, the abrasive articles can be used on particular workpieces. A suitable exemplary workpiece can include an inorganic material, an organic material, a natural material, and a combination thereof. According to a particular embodiment, the workpiece can include a metal or metal alloy, such as an iron-based material, a nickel-based material, and the like. In one embodiment, the workpiece can be steel, and more particularly, can consist essentially of stainless steel (e.g., 304 stainless steel).
A grinding test is conducted to evaluate the effect of orientation of a shaped abrasive grain relative to a grinding direction. In the test, a first set of shaped abrasive particles (Sample A) are oriented in frontal orientation relative to the grinding direction. Turning briefly to
A second set of samples (Sample B) are also tested according to the grinding test described above for Sample A. Notably, however, the shaped abrasive particles of Sample B have a sideways orientation on the backing relative to the grinding direction. Turning briefly to
Five samples are analyzed to compare the orientation of shaped abrasive particles. Three samples (Samples S1, S2 and S3) are made according to an embodiment. Sample S1 was made using at template and contacting process. The abrasive particles were disposed into and held in place by a template having a desired predetermined abrasive particle distribution. A backing substrate having a continuous make coat was contacted with the abrasive particles so that the abrasive particles were adhered to the make coat in the desired predetermined abrasive particle distribution. Samples S2 and S3 were made using a continuous electrostatic projection process. Shaped abrasive particles were projected onto a backing substrate having a discontinuous make coat. The make coat was previously applied as a predetermined distribution of a nonshadowing pattern of discrete circular adhesive contact areas (also called herein make coat “spots”). The pattern was phyllotactic pattern conforming to formula 1.1, described herein, (also called the pineapple pattern). The make coat for S2 and S3 comprised 17,000 circular adhesive contact regions distributed over the surface of the backing material. The make weight for the abrasive sample S2 and S3 was approximately 0.84 pounds per ream. The grain weight for samples S2 and S3 was approximately 17.7 pounds per ream. An image of the S2 and S3 sample is shown in
Another inventive coated abrasive embodiment was prepared in a similar manner to S2 and S3. The make coat was applied according to a discontinuous, non-shadowing distribution following the pineapple pattern; however the total number of discrete adhesive contact regions was 10,000. The make weight was approximately 1.6 lb./rm and the grain weight was approximately 19.2 lb./rm. Shaped abrasive particles (Cubitron II), as described above in Example 2, were then applied to the make coat contact regions. The inventive coated abrasive had an abrasive particle density (abrasive grain density) of 19 grains/cm2. X-ray analysis was conducted, similar to Example 2 above, to evaluate the orientation of the shaped abrasive particles of the inventive embodiment and a conventional comparative coated abrasive product.
The present application represents a departure from the state of the art. While the industry has recognized that shaped abrasive particles may be formed through processes such as molding and screen printing, the processes of the embodiments herein are distinct from such processes. Notably, the embodiments herein include a combination of process features facilitating the formation of batches of shaped abrasive particle having particular features. Moreover, the abrasive articles of the embodiments herein can have a particular combination of features distinct from other abrasive articles including, but not limited to, a predetermined distribution of shaped abrasive particles, utilization of a combination of predetermined orientation characteristics, groups, rows, columns, companies, macro-shapes, channel regions, aspects of the shaped abrasive particles, including but not limited to, aspect ratio, composition, additives, two-dimensional shape, three-dimensional shape, difference in height, difference in height profile, flashing percentage, height, dishing, half life change of specific grinding energy, and a combination thereof. And in fact, the abrasive articles of embodiments herein may facilitate improved grinding performance. While the industry has generally recognized that certain abrasive articles may be formed having an order to certain abrasive units, such abrasive units have traditionally been limited to abrasive composites that can be easily molded via a binder system, or using traditional abrasive or superabrasive grits. The industry has not contemplated or developed systems for forming abrasive articles from shaped abrasive particles having predetermined orientation characteristics as described herein. Manipulation of shaped abrasive particles in order to effectively control predetermined orientation characteristics is a non-trivial matter, having exponentially improved control of particles in three-space, which is not disclosed or suggested in the art. Reference herein to the term “the same” will be understood to mean substantially the same.
Item 1. A coated abrasive article comprising a backing; an adhesive layer disposed in a discontinuous distribution on at least a portion of the backing, wherein the discontinuous distribution comprises a plurality of adhesive contact regions having at least one of a lateral spacing or a longitudinal spacing between each of the adhesive contact regions; and at least one abrasive particle disposed on a majority of the adhesive contact regions, the abrasive particle having a tip, and there being at least one of a lateral spacing or a longitudinal spacing between each of the abrasive particles, and wherein at least 65% of the at least one of a lateral spacing and a longitudinal spacing between the tips of the abrasive particles is within 2.5 standard deviations of the mean.
Item 2. The coated abrasive article of item 1, wherein at least 55% of the abrasive particle tips are upright.
Item 3. The coated abrasive article of item 1, wherein the ratio of the variance to the mean is not greater than 35%.
Item 4. The coated abrasive article of item 1, wherein the discontinuous distribution is a non-shadowing pattern, a controlled non-uniform pattern, a semi-random pattern, a random pattern, a regular pattern, an alternating pattern, or combinations thereof.
Item 5. The coated abrasive article of item 2, wherein the at least one abrasive particle disposed on the majority of adhesive contact regions comprises a first shaped abrasive particle coupled to a first adhesive contact region in a first position; and a second shaped abrasive particle coupled to a second adhesive contact region; wherein the first shaped abrasive particle and second shaped abrasive particle are arranged in a controlled, non-shadowing arrangement relative to each other, the controlled, non-shadowing arrangement comprising at least two of a predetermined rotational orientation, a predetermined lateral orientation, and a predetermined longitudinal orientation.
Item 6. The coated abrasive article of item 1, wherein at least 65% of the at least one of the lateral spacing and the longitudinal spacing between the adhesive contact regions is within 2.5 standard deviations of the mean.
Item 7. The coated abrasive article of item 1, wherein the adhesive layer has a substantially uniform thickness that is less than the d50 height of the at least one abrasive particle.
Item 8. The coated abrasive article of item 1, wherein the width of each of the discrete adhesive contact regions is substantially equal to the d50 width of the at least one abrasive particle.
Item 9. The coated abrasive article of item 1 further comprising:
a second adhesive layer disposed in a discontinuous distribution over the first adhesive layer, wherein the second adhesive layer covers a smaller surface area than the first adhesive layer and does not extend beyond the first adhesive layer.
Item 10. The coated abrasive article of item 1, 5, or 9, wherein at least one abrasive particle is disposed on each adhesive contact region.
Item 11. A method of making a coated abrasive article comprising applying an adhesive composition to a backing using a continuous screen printing process, wherein the adhesive composition is applied as a discontinuous distribution comprising a plurality of discrete adhesive contact regions having at least one of a lateral spacing and a longitudinal spacing between each of the adhesive contact regions, disposing at least one abrasive particle onto each of the discrete adhesive contact regions, the abrasive particle having a tip and there being at least one of a lateral spacing or a longitudinal spacing between each of the abrasive particles and curing the binder composition.
Item 12. The method of item 11, wherein at least 65% of the at least one of a lateral spacing and a longitudinal spacing between the tips of the adhesive particle is within 2.5 standard deviations of the mean.
Item 13. A coated abrasive article comprising a backing; a make coat disposed on the backing in a predetermined distribution; and a plurality of shaped abrasive particles, wherein the predetermined distribution comprises a discontinuous pattern of a plurality of discrete contact regions, wherein at least one shaped abrasive particle of the plurality of shaped abrasive particles is disposed on each of the discrete contact regions, and wherein the ratio of make weight to grain weight is in a range of 1:40 to 1:1.
Item 14. A coated abrasive article comprising a backing; a make coat disposed on the backing in a predetermined distribution; and a plurality of shaped abrasive particles, wherein the predetermined distribution comprises a discontinuous pattern of a plurality of discrete contact regions, wherein at least one shaped abrasive particle of the plurality of shaped abrasive particles is disposed on each of the discrete contact regions, and wherein the number of discrete contact regions is in a range of 1000 to 40,000, and wherein greater than 50% of the shaped abrasive particles are in an upright position.
Item 15. The coated abrasive article of item 14, wherein the discrete contact regions have an adjacent spacing in a range of 0.5 to 3 times the average length of the shaped abrasive particle.
Item 16. The coated abrasive article of item 14, wherein the discrete contact regions have an adjacent spacing in a range of 0.2 mm to 2.2 mm.
Item 17. The coated abrasive article of item 14, wherein the discontinuous make coat covers at least 1% to 95% of the backing.
Item 18. The coated abrasive article of item 14, wherein the discrete contact regions have an average diameter in a range of 0.3 mm to 20 mm.
Item 19. The coated abrasive article of item 14, wherein 4% to 85% of the backing is bare.
Item 20. The coated abrasive of item 14, wherein greater than 75% of the shaped abrasive particles are in an upright position.
The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended items are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following items and their equivalents, and shall not be restricted or limited by the foregoing detailed description.
The Abstract of the Disclosure is provided to comply with Patent Law and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the items. In addition, in the foregoing Detailed Description of the Drawings, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the itemed embodiments require more features than are expressly recited in each item. Rather, as the following items reflect, inventive subject matter may be directed to less than all features of any of the disclosed embodiments. Thus, the following items are incorporated into the Detailed Description of the Drawings, with each item standing on its own as defining separately itemed subject matter.
This application is a continuation of and claims priority to U.S. Non-Provisional patent application Ser. No. 16/202,801, entitled “ABRASIVE PARTICLES HAVING PARTICULAR SHAPES AND METHODS OF FORMING SUCH PARTICLES,” naming inventors Anuj SETH, et al., filed on Nov. 28, 2018, which is a continuation of and claims priority to U.S. Non-Provisional patent application Ser. No. 15/261,142, entitled “ABRASIVE PARTICLES HAVING PARTICULAR SHAPES AND METHODS OF FORMING SUCH PARTICLES,” naming inventors Anuj SETH, et al., filed on Sep. 9, 2016, now U.S. Pat. No. 10,179,391, which is a continuation of and claims priority to U.S. Non-Provisional patent application Ser. No. 14/231,019, entitled “ABRASIVE PARTICLES HAVING PARTICULAR SHAPES AND METHODS OF FORMING SUCH PARTICLES,” naming inventors Anuj SETH, et al., filed on Mar. 31, 2014, now U.S. Pat. No. 9,457,453, which claims priority to and the benefit of U.S. Provisional Patent Application No. 61/806,741 entitled “ABRASIVE PARTICLES HAVING PARTICULAR SHAPES AND METHODS OF FORMING SUCH PARTICLES,” naming inventors Anuj SETH, et al., filed on Mar. 29, 2013, of which these applications are assigned to the current assignee hereof and incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 61806741 | Mar 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16202801 | Nov 2018 | US |
| Child | 16859336 | US | |
| Parent | 15261142 | Sep 2016 | US |
| Child | 16202801 | US | |
| Parent | 14231019 | Mar 2014 | US |
| Child | 15261142 | US |
