ABRASIVE ARTICLE HAVING A DROSS RIDGE AND METHOD OF FORMING SAME

BACKGROUND

1. Field of the Disclosure

The following is directed to abrasive articles, and particularly, abrasive articles having a dross ridge formed on an edge of a surface on the abrasive articles.

2. Description of the Related Art

Abrasive articles have been used to abrade and finish work-piece surfaces. Applications suitable for using abrasive articles include high stock removal from workpieces such as wood and metal, to fine polishing of ophthalmic lenses, fiber optics and computer read-write heads. In general, abrasive articles comprise a plurality of abrasive particles bonded either together (e.g., a bonded abrasive or grinding wheel) or to a backing (e.g., a coated abrasive article). For a coated abrasive article, there is typically a single layer, or sometimes a plurality of layers, of abrasive particles bonded to the backing. The abrasive particles can be bonded to the backing with a “make” coat and “size” coat, or as a slurry coat. Further, a supersize coat can be applied on the make coat or size coat to help extend the life of the abrasive particles.

Various configurations of abrasive articles are known, for example, discs, endless belts, sanding sponges, and the like. The configurations of the abrasive article will affect the intended use of the articles. For example, some abrasive articles are configured to be connected to a vacuum source during use, to remove dust and swarf from the abrading surface.

For generally all coated abrasive articles, the exposed tips of the abrasive particles abrade the workpiece during use. New abrasive particle surfaces are continuously being exposed to extend the life of the abrasive article. After a certain time, the abrasive particles will no longer have a sufficient amount of sharp abrading surfaces left, wherein the coated abrasive is considered to be worn out and is then typically discarded.

Although the manufacture and processing of coated abrasive articles using lasers for perforating or cutting the coated abrasive articles is known, there is still a need in the art for improved coated abrasive articles and methods for forming such abrasive articles using improved laser cutting methods.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure can be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings

FIG. 1 is a schematic cross-sectional side view of an abrasive article in accordance with an embodiment.

FIG. 2 is a schematic cross-sectional side view of an abrasive article in accordance with an embodiment.

FIG. 3 is a schematic cross-sectional side view of an abrasive article in accordance with an embodiment.

FIG. 4 is a schematic cross-sectional side view of an abrasive article in accordance with an embodiment.

FIG. 5 is a planar top view image of a portion of an abrasive article in accordance with an embodiment.

FIG. 6 is a planar top view image of a portion of an abrasive article in accordance with an embodiment

DETAILED DESCRIPTION

The following is directed to processes that can be suitable for forming abrasive articles, which can be useful in a variety of applications. Furthermore, the following includes description of abrasive articles including coated abrasive articles which can be useful in certain applications, including, for example, high stock removal from workpieces such as wood and metal, to fine polishing of ophthalmic lenses, fiber optics and computer read-write heads.

In particular, the following is directed to processes for forming an abrasive article having an edge on a surface of the abrasive article. Forming the edge can include forming a spatter ridge or a dross ridge that extends from at least a portion of the edge. As used herein, a spatter ridge is defined as the residue of resolidified melt on the impingement edge (i.e., the entrance edge) of a cut formed on or in the abrasive article. As used herein, a dross ridge canis defined as the residue of resolidified melt on the through-edge (i.e., the exiting edge) of a cut formed on or in the abrasive article.

In accordance with embodiments herein, forming the edge and resultant spatter ridge or dross ridge can include the use of a laser. Types of lasers that are considered suitable for use in accordance with embodiments herein can include lasers that are tunable, fixed wavelength, pulsed, continuous wave (CW), or a combination thereof. In certain instances, suitable lasers can include gas lasers (e.g. Helium-neon laser, Argon laser, Krypton laser, Xenon ion laser, Nitrogen laser, Carbon dioxide laser, Carbon monoxide laser, Excimer laser, and the like), chemical lasers (Hydrogen fluoride, Deuterium fluoride, Chemical oxygen-iodine, All gas-phase iodine laser, and the like), dye lasers, metal-vapor lasers (Helium-cadmium, Helium-mercury, Helium-selenium, Helium-silver, Strontium Vapor, Neon-copper, Copper vapor, Gold vapor, and the like), solid state lasers (e.g., ruby, Nd/YAG, NdCrYAG, ErYAG, Nd:YLF, Nd:YVO₄, Nd:YCOB, Ti:Sapphire, Tm:YAG, Yb:YAG, and the like) semiconductor lasers (semiconductor laser diodes, GaN, InGaN, AlGaInP, lead salt, Vertical cavity surface emitting, Quantum cascade, Hybrid silicon, and the like) and combinations thereof. In certain instances, suitable lasers include water pulse lasers, and fiber lasers, free electron lasers, and gas dynamic lasers. In certain embodiments, a suitable laser can include a pulsed infrared laser or an ultrafast pulsed laser.

Argon-ion lasers, carbon-monoxide lasers, and metal ion lasers, are gas lasers that generate deep ultraviolet wavelengths, such as helium-silver (HeAg) 224 nm and neon-copper (NeCu) 248 nm lasers. These lasers have particularly narrow oscillation linewidths of less than 3 GHz (0.5 picometers).

Chemical lasers are powered by a chemical reaction, and can achieve high powers in continuous operation. For example, in the hydrogen fluoride laser (2700-2900 nm) and the deuterium fluoride laser (3800 nm), the reaction is the combination of hydrogen or deuterium gas with combustion products of ethylene in nitrogen trifluoride.

Excimer lasers represent laser technology in the ultraviolet portion of the light spectrum offering the capability of pulsed short-wavelength lasers having high peak power. A leading example of an excimer laser is the krypton fluoride laser.

Solid state lasers and dye type lasers represent laser technology that can span the infrared to the ultraviolet portion of the light spectrum, and also offer high peak power and high continuous power. One example of this type of laser is Nd:YVO₄or neodymium-doped yttrium vanadate laser, and its shorter wavelength harmonics.

In a specific embodiment, a laser for forming an abrasive article described herein is an infrared, or carbon dioxide (i.e., CO₂) laser.

In accordance with embodiments herein, a laser can be useful for cutting, penetrating, perforating, or otherwise assisting in converting an abrasive article into a finished abrasive article. The laser can operate by a process of flame cutting, fusion cutting, ablation (i.e., vaporization, whether by evaporation or sublimation, of a portion of material of the abrasive article), or combinations thereof. In some instances, the use of a laser for forming an edge of an abrasive article can result in hardened, raised, and/or sharp edges being formed on the surface of the abrasive article adjacent to edges made by the laser. In certain instances, the use of a laser for forming an abrasive article can form a spatter ridge or a dross ridge of residual particles that have been melted and resolidified on the edge of the abrasive article produced by the laser.

In certain instances, the laser can produce a beam of long wave infrared (LWIR) light with the principal wavelength chosen to operate between about 9 and about 12 micrometers. In an embodiment, the laser can produce a wavelength of not greater than about 12 micrometers, such as not greater than about 11 micrometers, not greater than about 10.6 micrometers, not greater than about 10.4 micrometers, not greater than about 10.2 micrometers, not greater than about 10 micrometers, not greater than about 9.8 micrometers, not greater than about 9.7 micrometers, not greater than about 9.6 micrometers, or even not greater than about 9.4 micrometers. In a an embodiment, the laser can produce a wavelength of at least about 9 micrometers, such as at least about 9.2 micrometers, at least about 9.3 micrometers, at least about 9.4 micrometers, at least about 9.5 micrometers, at least about 9.6 micrometers, at least about 9.7 micrometers, at least about 9.8 micrometers, at least about 9.9 micrometers, at least about 10 micrometers, at least about 10.2 micrometers, at least about 10.4 micrometers, or even at least about 10.5 micrometers. In a specific embodiment, the laser can produce a wavelength of about 9.2 micrometers to about 10.6 micrometers. In a specific embodiment, the laser can produce a wavelength of about 10.6 micrometers. In another specific embodiment, the laser can produce a wavelength of about 9.2 micrometers. It will be appreciated that the laser can be chosen to produce a wavelength within a range comprising any pair of the previous upper and lower limits.

In an embodiment, a laser suitable for forming abrasive articles described herein can include a particular average power. For example, a suitable laser can include an average power of at least about 1000 W, such as at least about 1250 W, at least about 1500 W, at least about 1750 W, at least about 2000 W, or even at least about 2250 W. Still, in other embodiments, a suitable laser can include an average power of not greater than about 2500 W, such as not greater than about 2250 W, not greater than about 2000 W, not greater than about 1750 W, not greater than about 1500 W, or even not greater than about 1250 W. It will be appreciated that the laser can include an average power within a range comprising any pair of the previous upper and lower limits.

In an embodiment, a cross-section of a laser beam (i.e., spot size) directed at a substrate to be cut can have a particular size, typically with an area. For example, the laser beam can be focused to a spot (where the laser beam contacts the abrasive article) such that a total of all portions of the spot, having an intensity of at least half of the average beam intensity, has an area of less than or equal to 0.3 square millimeters (mm²), less than about 0.1 mm², or even less than about 0.01 mm². In an embodiment, a laser trace rate (i.e., the rate at which the beam is scanned across a substrate) can be at least about 10 mm/sec, such as at least about 20 mm/sec.

Laser ablation of the material of the coated abrasive article can be achieved using a single trace (i.e, a single pass) of a laser beam or multiple superimposed traces (i.e., multiple passes over the same space). Alternative;y, multiple laser beams can be used simultaneously or sequentially. If multiple laser beams are used, they can have the same or different wavelengths. In an embodiment, individual components of a coated abrasive article can be sequentially removed using laser beams, each laser beam tuned to an absorbance band of a respective component (e.g., the backing, the abrasive layer, or a combination thereof). In another embodiment, individual components of an abrasive article are simultaneously removed using multiple laser beams tuned to an absorbance band of separate components of the abrasive article (e.g., the backing, the abrasive layer, or combinations thereof).

Additional lasers can also be used, for example, if additional components are present, such as multiple layers of an abrasive article. If multiple laser beams are used, their traces should typically be superposed to achieve maximum benefit, although this is not a requirement.

In a specific embodiment, a single laser is used, wherein a single trace or multiple traces are made. In another embodiment, multiple lasers are used, wherein each laser conducts either a single trace or multiple traces.

Laser ablation can be carried out such that it does not completely penetrate the coated abrasive article. In certain instances, laser ablation can be performed on the abrasive article such that it does penetrate completely through the abrasive article. Further, laser ablation can be carried out from any direction, e.g., from the “front” surface (i.e., the abrasive surface) to the “back” surface (the non-abrasive surface) or vice-versa. In an embodiment, laser ablation can be performed from the back surface of the abrasive article, such that the laser impinges or penetrates the back side (i.e., second surface of the abrasive article) before impinging or penetrating the front or upper side or surface (i.e., the first surface of the abrasive article). In certain instances, the laser can form at least one aperture that extends through the abrasive article (i.e., from the second surface of the abrasive article to the first surface of the abrasive article).

In accordance with an embodiment, a method for forming an abrasive article as described herein can be initiated at a first step that includes providing an abrasive article having a first surface and a second surface spaced apart from the first surface. FIG. 1 is a schematic cross-sectional side view of an abrasive article 100 in accordance with an embodiment. As illustrated, the first surface 101 can be the top surface of the abrasive article, defined as the surface that is intended to contact a workpiece to perform stock removal polishing, sanding, abrading, or the like. As described herein, the first surface 101 can be an abrasive layer (i.e., a make coat having abrasive particles dispersed in the make coat—“an abrasive slurry”, or disposed on the surface of the make coat), a size coat, a supersize coat, or a combination thereof. In a particular instance, the first surface includes a supersize coat.

As also illustrated in FIG. 1, the second surface 108 of the abrasive article 100 can be spaced apart from the first surface 101 of the abrasive article 100. Moreover, the second surface 108 can be substantially parallel to the first surface 101. As described herein, the second surface can include a backing, an adhesive, an attachment system described herein, or the like.

In accordance with an embodiment, a method of forming an abrasive article can include directing the laser 150 toward the abrasive article 100 to impinge the second surface 108 before the first surface 101. The laser 150, which as used herein can refer to a laser beam, can be directed to a back surface (or second surface 108) or the abrasive article 100 such that it impinges, or otherwise penetrates the second surface 108 before the laser 150 impinges, or otherwise penetrates the front surface (or first surface 101) of the abrasive article 100. Referring briefly to FIG. 2, the laser 250 can be directed to a back surface (or second surface 208) or the abrasive article 200 such that it impinges, or otherwise penetrates the second surface 208 before the laser 250 impinges, or otherwise penetrates the front surface (or first surface 201) of the abrasive article 200. As discussed herein, and as will be appreciated, the laser 250 can include a focused beam that can form surfaces, such as surfaces 209 and 210, which can define a particular taper, such as tapered aperture 206.

In accordance with an embodiment, a method of forming an abrasive article can include forming an edge on the first surface of the abrasive article. For example, as illustrated in FIG. 1, edge(s) 102 can be formed on the first surface 101 of the abrasive article 100. In an embodiment, the edge(s) 102 can define at least a portion of the periphery 107 of the abrasive article 100. It will be appreciated that the periphery 107 can define a circumference of the abrasive article 100. In accordance with an embodiment, a method of forming an abrasive article can include forming one or more dross ridge(s) 103 extending from at least a portion of the edge(s) 102 of the periphery 107 and/or the aperture 106, as described herein.

After completing the forming process, an abrasive article is formed. The abrasive article can have certain features, which are described in greater detail in accordance with the embodiments described herein.

For example, referring back to FIG. 1 in accordance with embodiment described herein, the edge(s) 102 can define an aperture 106 formed in at least a portion of the abrasive article 100. In certain instances, the abrasive article 100 can include a plurality of apertures 106. In accordance with an embodiment, the number and configuration of apertures present can be dependent on the application for the abrasive article and the size of abrasive article. For example, there can be not greater than about 500 apertures disposed on the abrasive article, such not greater than about 400 apertures, not greater than about 300 apertures, not greater than about 200 apertures, not greater than about 100 apertures, not greater than about 50 apertures, or even not greater than about 40 apertures. In an embodiment, there can be at least about 40 apertures disposed on the abrasive article, such as at least about 50 apertures, at least about 10 apertures, at least about 200 apertures, at least about 300 apertures, at least about 400 apertures, or even at least about 500 apertures. It will be appreciated that the number of the plurality of apertures 106 can be within a range comprising any pair of the previous upper and lower limits

In accordance with an embodiment, the abrasive article can be a disc, and the shape of the plurality of apertures can include circles. However, other shapes of abrasive articles and/or apertures are considered within the scope of the embodiments described herein. For example, the abrasive article can include a shape defined by the periphery edge of a disc, a circle, an oval, a rectangle, a polygon two-dimensional shape, an endless belt, or a combination thereof.

In accordance with an embodiment, the edge defining one or more apertures can include the shape of a circle, a rectangle, an oval, a curve, a polygonal two-dimensional shape, or a combination thereof.

One or more apertures can have any placement within abrasive article, and they can occupy a particular percentage of the open area of the top surface (i.e. the first surface) of the abrasive article. In certain instances, the one or more apertures can occupy at least about 1% of the open area of the top surface of the abrasive article, such as at least about 10%, at least about 20%, at least about 30%, at least about 40%, at least about 50%, or even at least about 60%. In a embodiment, the one or more apertures can occupy not greater than 70% of the open area of the top surface of the abrasive article, such as not greater than about 60%, not greater than about 50%, not greater than about 40%, not greater than about 30%, not greater than about 20%, not greater than about 10%, or even not greater than about 1%. It will be appreciated that the one or more apertures can occupy a percentage of the first surface that is within a range comprising any pair of the previous upper and lower limits.

The individual openings of the apertures can include a particular size. For example, the size of the opening of the one or more apertures can be at least about 1 mm, such as at least about 5 mm, at least about 10 mm, at least about 20 mm, or even at least about 30 mm. In embodiments, the size of the opening of the one or more apertures can be not greater than about 30 mm, such as not greater than about 20 mm, not greater than about 10 mm, not greater than about 5 mm, or even not greater than about 1 mm. It will be appreciated that the size of the openings of the one or more apertures can be within a range comprising any pair of the previous upper and lower limits.

In some embodiments, apertures can be arranged in a predetermined distribution. It will be appreciated that a predetermined distribution of first discrete regions can be defined by a combination of predetermined positions on a base plate that are purposefully selected. A predetermined distribution can include a pattern, such that the predetermined positions can define a two-dimensional array. An array can include have short range order defined by a unit of first discrete regions. An array can also be a pattern, having long range order including regular and repetitive units linked together, such that the arrangement can be symmetrical and/or predictable. An array can 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 controlled, non-uniform distribution, a controlled uniform distribution, and a combination thereof. In particular instances, a predetermined distribution can include a radial pattern, a spiral pattern, a phyllotactic pattern, an asymmetric pattern, a self-avoiding random distribution, a self-avoiding random distribution and a combination thereof. The predetermined distribution can be partially, substantially, or fully asymmetric. 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. In particular embodiments, the plurality of first discrete regions can be arranged in a row, a column, a circle, a square, a rectangle, or any combination thereof.

In accordance with an embodiment, a dross ridge 103 can be formed on the first surface 101. The dross ridge 103 can for formed to extend from at least a portion of the edge(s) 102. Thus, it will be understood that the dross ridge 103 can extend from at least a portion of the edge(s) 102 of the periphery 107 and/or the aperture 106. In particular, the dross ridge(s) 103 can extend from at least a portion of the edge(s) 102 by an average width 104. The average width 104 of the dross ridge 103 can be defined as the average distance between the edge 102 and an outer boundary 113 of the instant dross ridge 103 being measured extends in a direction in which the instant dross ridge 103 being measured extends perpendicularly from the edge 102. In certain instances, the average width 104 of the dross ridge 103 can be at least about 101 μm, such as at least about 110 μm, at least about 120 μm, at least about 130 μm, at least about 140 μm, at least about 150 μm, at least about 200 μm, at least about 250 μm, at least about 300 μm, at least about 350 μm, at least about 400 μm, or even at least about 450 μm. Still, in a embodiment, the dross ridge(s) 103 can include an average width 104 of not greater than about 500 μm, such as not greater than about 450 μm, not greater than about 400 μm, not greater than about 350 μm, not greater than about 300 μm, not greater than about 250 μm, not greater than about 200 μm, not greater than about 150 μm, not greater than about 140 μm, not greater than about 130 μm, not greater than about 120 μm, or even not greater than about 110 μm. It will be appreciated that the average width can be within a range comprising any pair of the previous upper and lower limits.

In accordance with an embodiment, the dross ridge(s) 103 can include a particular height, defined by the average highest point on the dross ridge(s) 103 measured from the first surface 101 as viewed from a cross section of the dross ridge(s) 103 defined by a direction in which the instant dross ridge(s) 103 being measured extends perpendicularly from the edge 102. In certain instances, the dross ridge(s) 103 can include a particular height of not greater than about 50 μm, such as not greater than about 40 μm, not greater than about 30 μm, not greater than about 20 μm, not greater than about 10 μm, or even not greater than about 5 μm. In a embodiment, the dross ridge(s) 103 can include a height of at least about 1 μm, such as at least about 5 μm, at least about 10 μm, at least about 20 μm, at least about 30 μm, or even at least about 40 μm. It will be appreciated that the height of the dross ridge can be within a range comprising any pair of the previous upper and lower limits.

In accordance with an embodiment, the dross ridge(s) 103 can include a ratio of height (h_dr) to ridge width (w_dr) of not greater than about 0.495 according to the equation h_dr/w_dr, such as not greater than about 0.45, not greater than about 0.40, not greater than about 0.35, not greater than about 0.30, not greater than about 0.25, not greater than about 0.20, not greater than about 0.15, not greater than about 0.10, or even not greater than about 0.05. In a embodiment, the dross ridge(s) 103 can include a ratio of height (h_dr) to ridge width (w_dr) of at least about 0.01, such as at least about 0.05, at least about 0.10, at least about 0.15, at least about 0.20, at least about 0.25, at least about 0.30, at least about 0.35, at least about 0.40, and at least about 0.45. It will be appreciated that the ratio of height (h_dr) to ridge width (w_dr) of the dross ridge can be within a range comprising any pair of the previous upper and lower limits.

In accordance with an embodiment, the intensity (W) of the laser being used to form the abrasive article can affect the width of the dross ridge(s). In some embodiments, the laser intensity can be at least about 300 W, such as at least about 500 W, at least about 750 W, at least about 1000 W, at least about 1250 W, at least about 1500 W, at least about 1750 W, or even at least about 2000 W, or even at least about 2250 W,. In other non-limiting embodiments, the laser intensity can be not greater than about 2500 W, such as not greater than about 2250 W, not greater than about 2000 W, not greater than about 1750 W, not greater than about 1500 W, not greater than about 1250 W, not greater than about 1000 W, not greater than about 750 W, or even not greater than about 500 W. It will be appreciated that the laser intensity can be within a range comprising any pair of the previous upper and lower limits.

In accordance with an embodiment, the laser head speed (in/s) of the laser can affect the width of the dross ridge(s). In some embodiments, the laser head speed (in/s) can be at least about 1, such as at least about 2, at least about 3, at least about 5, at least about 8, 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 65, at least about 70, at least about 75, at least about 80, at least about 85, at least about 90, at least about 100, at least about 150, at least about 200, at least about 250, at least about 300, at least about 350, at least about 400, at least about 450, or even at least about 500. In other non-limiting embodiments, the laser head speed (in/s) can be not greater than about 500, such as not greater than about 450, not greater than about 400, not greater than about 350, not greater than about 300, not greater than about 250, not greater than about 200, not greater than about 150, not greater than about 110, not greater than about 100, not greater than about 95, not greater than about 90, 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, 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, not greater than about 15, not greater than about 10, not greater than about 8, not greater than about 5, not greater than about 3, not greater than about 2, or even not greater than about 1. It will be appreciated that the laser head speed can be within a range comprising any pair of the previous upper and lower limits.

In accordance with an embodiment, the edge defining a periphery or one or more apertures of the abrasive article can in part define a third surface in contact between the first surface and the second surface. FIG. 2 is a schematic cross-sectional side view of a abrasive article 200 in accordance with an embodiment. As illustrated, the third surfaces 209 and 210 intersect the first 201 surface and second surface 208. In certain instances, the third surfaces 209 and 210 can intersect the first 201 surface and/or second surface 208 at a substantially normal (perpendicular) angle, as generally illustrated in FIG. 1. In other instances, the third surfaces 209 and 210 can intersect the first 201 surface and/or second surface 208 at substantially non-normal (non-perpendicular) angles. In particular instances, the third surfaces 210 can in part define the aperture 206, defining a tapered aperture 206. In more particular instances, the tapered aperture 206 can include a first edge 211 disposed on the first surface 201 and a second edge 212 disposed on the second surface 208, in which the second edge 212 includes a larger diameter than a diameter of the first edge 211.

An abrasive article according to embodiments described herein can include a particular arrangement of layers. FIG. 3 is a schematic cross-sectional side view of an abrasive article 300 in accordance with an embodiment. As illustrated, the abrasive article 300 can include an abrasive layer 314 secured to the first major surface 315 of the backing 310. The backing 310 can include a second major surface 325 spaced apart from the first major surface 315. In certain aspects, multiple layer backings can be used. For example, multiple layer backings can be laminates of one or more known backings materials, usually with an adhesive to hold the layers together. In other embodiments, the backing can include one or more treatments for sealing the backing and/or modifying a physical property of the backing.

In accordance with an embodiment, the first major surface 315 of the backing 310 can be the surface on which an abrasive layer 314 is disposed. Further, it will be appreciated that the first major surface 315 of the backing 310 can be the surface on which a make coat 316, a size coat 317, a supersize coat 319, or a combination thereof, are disposed.

In accordance with an embodiment, the second major surface 325 of the backing 310 can include an attachment system to enable securing the resulting abrasive article 300 to a tool or apparatus to facilitate use of the abrasive article 300. In particular instances, the second major surface 325 of the backing 310 can include a support pad, back up pad, hook and loop attachment system, an intermeshing attachment system, a threaded projection, or a combination thereof. It will be understood that securing an attachment system can include the use of, for example, pressure sensitive adhesive 360, a release liner 370, a slip resistant or frictional coating, or a combination thereof.

In accordance with an embodiment, backing 310 can be flexible or rigid. The backing 310 can be made of any number of various materials including those conventionally used as backings in the manufacture of coated abrasives. An exemplary flexible backing includes a polymeric film (for example, a primed film), such as polyolefin film (e.g., polypropylene including biaxially oriented polypropylene), polyester film (e.g., polyethylene terephthalate), polyamide film, or cellulose ester film; metal foil; mesh; foam (e.g., natural sponge material or polyurethane foam); cloth (e.g., cloth made from fibers or yarns comprising polyester, nylon, silk, cotton, poly-cotton or rayon); paper; vulcanized paper; vulcanized rubber; vulcanized fiber; nonwoven materials; a combination thereof; or a treated version thereof. Cloth backings may be woven or stitch bonded. In particular examples, the backing is selected from the group consisting of paper, polymer film, cloth, cotton, poly-cotton, rayon, polyester, poly-nylon, vulcanized rubber, vulcanized fiber, metal foil, organic material, synthetic material, nylon, para-aramid material, and a combination thereof. In other examples, the backing includes polypropylene film or polyethylene terephthalate (PET) film.

In certain aspects, the backing 310 can include multiple layers. For example, multiple layer backings can be laminates of one or more known backing materials, usually with an adhesive to hold the layers together. In other embodiments, the backing can include one or more treatments for sealing the backing and/or modifying a physical property of the backing 310. The backing 310 may optionally have at least one of a saturant, a presize layer or a backsize layer. The purpose of these layers is typically to seal the backing or to protect yarn or fibers in the backing. If the backing is a cloth material, at least one of these layers is typically used. The addition of the presize layer or backsize layer may additionally result in a “smoother” surface on either the front or the back side of the backing. Other optional layers known in the art can also be used (for example, a tie layer; see U.S. Pat. No. 5,700,302 (Stoetzel et al.), the disclosure of which is incorporated by reference).

An antistatic material may be included in a cloth treatment material. The addition of an antistatic material can reduce the tendency of the coated abrasive article to accumulate static electricity when sanding wood or wood-like materials. Additional details regarding antistatic backings and backing treatments can be found in, for example, U.S. Pat. No. 5,108,463 (Buchanan et al.); U.S. Pat. No. 5,137,542 (Buchanan et al.); U.S. Pat. No. 5,328,716 (Buchanan); and U.S. Pat. No. 5,560,753 (Buchanan et al.), the disclosures of which are incorporated herein by reference.

The backing may be a fibrous reinforced thermoplastic such as described, for example, in U.S. Pat. No. 5,417,726 (Stout et al.), or an endless spliceless belt, as described, for example, in U.S. Pat. No. 5,573,619 (Benedict et al.), the disclosures of which are incorporated herein by reference. Likewise, the backing may be a polymeric substrate having hooking stems projecting therefrom such as that described, for example, in U.S. Pat. No. 5,505,747 (Chesley et al.), the disclosure of which is incorporated herein by reference. Similarly, the backing may be a loop fabric such as that described, for example, in U.S. Pat. No. 5,565,011 (Follett et al.), the disclosure of which is incorporated herein by reference.

In accordance with an embodiment, the make coat 316 can include abrasive particle 318 embedded therein, and can further include a size coat 317 that can overlay the make coat 316 and abrasive particles 318. In particular instances, a supersize coat 319 can overlay the size coat 317. In some instances, a dross ridge 330a can be disposed directly adjacent to at least a portion of the edge 332 defining a periphery of the abrasive article 300. In still other instances, a dross ridge 330b can be disposed directly adjacent to at least a portion of the edge 134 defining the aperture 134.

In accordance with an embodiment, the make coat 316 or the size coat 317 may include one or more binders. The binder of the make coat 316 or the size coat 317 may be formed of a single polymer or a blend of polymers. For example, the binder may be formed from epoxy, acrylic polymer, or a combination thereof. In addition, the binder may include filler, such as nano-sized filler or a combination of nano-sized filler and micron-sized filler. In a particular embodiment, the binder is a colloidal binder, wherein the formulation that is cured to form the binder is a colloidal suspension including particulate filler. Alternatively, or in addition, the binder may be a nanocomposite binder including sub-micron particulate filler.

The binder generally includes a polymer matrix, which binds abrasive grains to the backing or compliant coat, if present. Typically, the binder is formed of cured binder formulation. In one exemplary embodiment, the binder formulation includes a polymer component and a dispersed phase.

The binder formulation may include one or more reaction constituents or polymer constituents for the preparation of a polymer. A polymer constituent may include a monomeric molecule, a polymeric molecule, or a combination thereof. The binder formulation may further comprise components selected from the group consisting of solvents, plasticizers, chain transfer agents, catalysts, stabilizers, dispersants, curing agents, reaction mediators and agents for influencing the fluidity of the dispersion.

The polymer constituents can form thermoplastics or thermosets. By way of example, the polymer constituents may include monomers and resins for the formation of polyurethane, polyurea, polymerized epoxy, polyester, polyimide, polysiloxanes (silicones), polymerized alkyd, styrene-butadiene rubber, acrylonitrile-butadiene rubber, polybutadiene, or, in general, reactive resins for the production of thermoset polymers. Another example includes an acrylate or a methacrylate polymer constituent. The precursor polymer constituents are typically curable organic material (i.e., a polymer monomer or material capable of polymerizing or crosslinking upon exposure to heat or other sources of energy, such as electron beam, ultraviolet light, visible light, etc., or with time upon the addition of a chemical catalyst, moisture, or other agent which cause the polymer to cure or polymerize). A precursor polymer constituent example includes a reactive constituent for the formation of an amino polymer or an aminoplast polymer, such as alkylated urea-formaldehyde polymer, melamine-formaldehyde polymer, and alkylated benzoguanamine-formaldehyde polymer; acrylate polymer including acrylate and methacrylate polymer, alkyl acrylate, acrylated epoxy, acrylated urethane, acrylated polyester, acrylated polyether, vinyl ether, acrylated oil, or acrylated silicone; alkyd polymer such as urethane alkyd polymer; polyester polymer; reactive urethane polymer; phenolic polymer such as resole and novolac polymer; phenolic/latex polymer; epoxy polymer such as bisphenol epoxy polymer; isocyanate; isocyanurate; polysiloxane polymer including alkylalkoxysilane polymer; or reactive vinyl polymer. The binder formulation may include a monomer, an oligomer, a polymer, or a combination thereof. In a particular embodiment, the binder formulation includes monomers of at least two types of polymers that when cured may crosslink For example, the binder formulation may include epoxy constituents and acrylic constituents that when cured form an epoxy/acrylic polymer.

The coated abrasive article can comprise a supersize coat 319 overlying the size coat 317. The supersize coat 319 can be the same as or different from the polymer binder composition or the size coat composition. The supersize coat 319 can comprise any conventional compositions known in the art that can be used as a supersize coat. In an embodiment, the supersize coat 319 comprises a conventionally known composition overlying the size coat composition. In another embodiment, the supersize coat 319 comprises the same ingredients as at least one of the size coat composition or the polymer binder composition of the abrasive layer. In a specific embodiment, the supersize coat comprises the same composition as the polymer binder composition of the abrasive layer or the composition of the size coat plus one or more grinding aids.

Suitable grinding aids can be inorganic based; such as halide salts, for example sodium cryolite, and potassium tetrafluoroborate; or organic based, such as sodium lauryl sulphate, or chlorinated waxes, such as polyvinyl chloride, or metal salts of fatty acids, such as zinc stearate or calcium stearate. In an embodiment, the grinding aid can be an environmentally sustainable material.

A particular embodiment includes cryolite and potassium tetrafluoroborate with particle size ranging from 1 micron to 80 microns, and most typically from 5 microns to 30 microns. The supersize coat can be a polymer layer applied over the abrasive grains to provide anti-glazing and anti-loading properties. In an embodiment, the dross ridge 330a and the dross ridge 330b can include material from the make coat 316, the size coat 317, the supersize coat 319, a recast material, a stearate, zinc stearate, and a combination thereof. It will be understood that because of the laser ablation process used in forming the edges defining a periphery or one or more apertures of the coated abrasive 300, the dross ridge 330a and the dross ridge 330b can include recast (e.g., melted and resolidified) material from any layer or portion of the coated abrasive article 300.

In an embodiment, the abrasive particles 318 can be dispersed throughout a binder secured to the backing 310. Such coated abrasive articles can have a desired topography imparted to the abrasive surface. For example, the abrasive layer 314 can comprise shaped abrasive composites, which, in at least some embodiments, are precisely-shaped, secured to the backing 310. Structured abrasive articles fall in this category.

In accordance with an embodiment, the coated abrasive article 300 can have a particular grit size. In some embodiments, the abrasive article 300 can have a grit size that is at least about P100, such as at least about P200, at least about P300, at least about P400, at least about P500, at least about P600, at least about P700, at least about P800, at least about P900, at least about P1000, at least about P1100, at least about P1200, at least about P1300, at least about P1400, or even at least about P1500. In other non-limiting embodiments, the abrasive article 300 can have a grit size that is not greater than about P1500, such as not greater than about P1400, not greater than about P1300, not greater than about P1200, not greater than about P1100, not greater than about P1000, not greater than about P900, not greater than about P800, not greater than about P700, not greater than about P600, not greater than about P500, not greater than about P400, or even not greater than about P300. It will be appreciated that the grit size can be within a range comprising any pair of the previous upper and lower limits.

Referring now to FIG. 4, which is a schematic cross-sectional side view of an abrasive article in accordance with an embodiment. A coated abrasive article 400 (a structured abrasive article) can have an abrasive layer 414 that comprises shaped abrasive composites 420 secured to a first major surface 415 of backing 410. Shaped abrasive composites 420 comprise abrasive particles 418 dispersed in the binder 450. Optional supersize coat 419 can overlay the abrasive layer 414. The dross ridge 430a can be disposed adjacent to the peripheral edge 432 and the dross ridge 430b can be disposed adjacent to the aperture (perforation) 434. Optional pressure-sensitive adhesive layer 460 can be disposed on the second major surface 425 of the backing 410 opposite the first major surface 415. Optional release liner 470 can be disposed on the optional pressure-sensitive adhesive layer 460.

FIG. 5 is a planar top view image of a portion of an abrasive article having a dross ridge 502 including a width (w_dr) formed by a laser in accordance with an embodiment. FIG. 6 is a planar top view image of a portion of an abrasive article having a dross ridge 602 including a width (w_dr) formed by a laser in accordance with an embodiment.

EXAMPLE

Three abrasive article samples were processed with a laser to create dross ridges in the abrasive article samples. A laser having an intensity of 1000 W was directed at three abrasive article samples, each having a grit size of P600. The laser impinged abrasive article samples 1, 2, and 3 at head speeds of 100 in/s, 500 in/s, and 15 in/s, respectively. The resulting widths of the dross ridges formed by the laser processing are shown below in TABLE 1. In particular, the combination of a laser intensity of 1000 W and a laser head speed of 15 in/s provided a dross ridge having an average width of 121 μm.

TABLE 1

Grit size P600

Sample #
1
2
3

Laser Intensity (W)
1000

Laser Head Speed (in/s)
100
50
15

Average width (μm)
87
85
121

Standard Dev.
13
23
17

n
15
15
15

As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but can include other features not expressly listed or inherent to such process, method, article, or apparatus. As used herein, the phrase “consists essentially” of or “consisting essentially of” means that the subject that the phrase describes does not include any other components that substantially affect the property of the subject.

Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

The use of “a” or “an” is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise.

Further, references to values stated in ranges include each and every value within that range. When the terms “about” or “approximately” precede a numerical value, such as when describing a numerical range, it is intended that the exact numerical value is also included. For example, a numerical range beginning at “about 25” is intended to also include a range that begins at exactly 25.

As used herein, the phrase “average particle diameter” can be reference to an average, mean, or median particle diameter, also commonly referred to in the art as D50.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent not described herein, many details regarding specific materials and processing acts are conventional and can be found in textbooks and other sources within the scintillation and radiation detection arts.

In the foregoing, reference to specific embodiments and the connections of certain components is illustrative. It will be appreciated that reference to components as being coupled or connected is intended to disclose either direct connection between said components or indirect connection through one or more intervening components as will be appreciated to carry out the methods as discussed herein. As such, the above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Moreover, not all of the activities described above in the general description or the examples are required, that a portion of a specific activity can not be required, and that one or more further activities can be performed in addition to those described. Still further, the order in which activities are listed is not necessarily the order in which they are performed.

The disclosure is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing disclosure, certain features that are, for clarity, described herein in the context of separate embodiments, can also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, can also be provided separately or in any subcombination. Still, inventive subject matter can be directed to less than all features of any of the disclosed embodiments.

Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that can cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims.

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 claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

Item 1. An abrasive article comprising:

a first surface having an edge; and

a dross ridge formed on the first surface, the dross ridge extending from at least a portion of the edge by an average width of at least about 101 μm and not greater than about 500 μm.

Item 2. The abrasive article of item 1, wherein the edge defines an aperture, wherein the edge defines a periphery of the abrasive article.

Item 3. An abrasive article, comprising:

a first surface having an edge, wherein the edge defines an aperture; and

a dross ridge formed on the first surface, the dross ridge extending from at least a portion of the edge of the aperture by an average width of at least about 101 μm and not greater than about 500 μm.

Item 4. The abrasive article of any one of the above items wherein the edge has a shape of a circle, a rectangle, an oval, a curve, a polygonal two-dimensional shape, or a combination thereof.

Item 5. The abrasive article of any one of the above items, wherein the average width of the dross ridge is defined as the average distance between the edge and an outer boundary of the dross ridge measured in a direction in which the dross ridge extends perpendicularly from the edge.

Item 6. The abrasive article of any one of the above items, wherein the dross ridge includes a material of a make material, a size material, a supersize material, a recast material, a stearate, zinc stearate, calcium stearate, or a combination thereof.

Item 7. The abrasive article of any one of the above items, wherein the dross ridge is formed by infrared laser, wherein the dross ridge is formed by CO2 laser.

Item 8. The abrasive article of any one of the above items, wherein the dross ridge further includes a height defined by the average highest point on the ridge measured from the first surface as viewed from a cross section of the dross ridge defined by a direction in which the dross ridge extends perpendicularly from the edge.

Item 9. The abrasive article of any one of the above items, wherein the height of the dross ridge is not greater than about 50 μm and at least about 1 μm

Item 10. The abrasive article of item 8, wherein the dross ridge includes a ratio of height (h_dr) to ridge width (w_dr) of not greater than about 0.495 according to the equation h_dr/w_dr.

Item 11. The abrasive article of any of the above items, further comprising a backing, wherein the backing includes at least one of a woven material, non-woven material, fiber material, an organic material, a synthetic material, nylon, carbon fiber, a para-aramid material, or combinations thereof.

Item 12. The abrasive article of item 11, further comprising an abrasive layer secured to the backing, wherein the abrasive layer includes abrasive particles

Item 13. The abrasive article of item 12, wherein the abrasive particles include a D50 of not greater than about 30 μm.

Item 14. The abrasive article of any one of the above items, wherein the abrasive article is a coated abrasive article.

Item 15. The abrasive article of any one of the above items, wherein the abrasive article includes a make coat, a size coat, a supersize coat, or a combination thereof.

Item 16. The abrasive article of any one of the above items, wherein the first surface is at least one of an abrasive layer, a make coat, a size coat, a supersize coat, or a combination thereof.

Item 17. A method of forming an abrasive article, comprising:

providing an abrasive article having a first surface and a second surface spaced apart from the first surface;
forming an edge on the first surface; and
forming a dross ridge on the first surface, the dross ridge extending from at least a portion of the edge by an average width of at least about 101 μm and not greater than about 500 μm.

Item 18. The abrasive article of item 17, wherein the edge defines an aperture, wherein the edge defines a periphery of the abrasive article.

Item 19. The method of item 17, wherein forming the ridge includes forming a ridge with a laser.

Item 20. The method of item 19, wherein the infrared laser has a maximum average power of at least about 1000 w.

Item 21. The method of any one of items 19 or 20, wherein forming the ridge includes directing the laser toward the abrasive article to impact the second surface before the first surface.

Item 22. The method of any one of items 19 or 20, wherein forming a dross ridge on the first surface of the abrasive article includes forming an aperture that extends from the second surface of the abrasive article to the first surface of the abrasive article.

Item 23. A coated abrasive article comprising:

a backing material having a first major surface and a second major surface spaced apart from the first major surface;
an abrasive layer disposed on the first major surface;
a size coat disposed on the abrasive layer;
a supersize coat disposed on the size coat,
at least one aperture extending through the backing material, abrasive layer, size coat, and supersize coat, and a dross ridge disposed on a portion of the coated abrasive article directly adjacent to at least a portion of the edge of the aperture, wherein the dross ridge has an average width ranging from 101 μm to 500 μm.

Item 24. The coated abrasive article of item 23, wherein the dross ridge has a maximum average height of less than 40 μm above the portion of the first surface on which the dross ridge is disposed.

Item 25. The coated abrasive article of item 23, wherein the ratio of the dross ridge average width (w_dr) to the dross ridge maximum average height (h_dr) is not greater than 0.495.

Item 26. An abrasive article comprising:

a first surface having an edge; and

a dross ridge formed on the first surface, the dross ridge extending from at least a portion of the edge by an average width of at least about 101 μm and not greater than about 500 μm.

Item 27. The abrasive article of claim 26, wherein the edge defines an aperture.

Item 28. The abrasive article of claim 26, wherein the average width of the dross ridge is defined as the average distance between the edge and an outer boundary of the dross ridge measured in a direction in which the dross ridge extends perpendicularly from the edge.

Item 29. The abrasive article of claim 26, wherein the dross ridge comprises a recast material.

Item 30. The abrasive article of claim 26, wherein the dross ridge further includes a height defined by the average highest point on the dross ridge measured from the first surface as viewed from a cross section of the dross ridge defined by a direction in which the dross ridge extends perpendicularly from the edge.

Item 31. The abrasive article of claim 30, wherein the height of the dross ridge is not greater than about 50 μm and is at least about 1 μm.

Item 32. The abrasive article of claim 30, wherein the dross ridge includes a ratio of height (h_dr) to dross ridge width (w_dr) of not greater than about 0.495 according to the equation h_dr/w_dr.

Item 33. The abrasive article of claim 26, wherein the first surface comprises an abrasive layer that is secured to a backing, and wherein the abrasive layer includes abrasive particles.

Item 34. The abrasive article of claim 33, wherein the abrasive particles have a D50 of not greater than about 30 μm.

Item 35. The abrasive article of claim 33, wherein the abrasive layer comprises a make coat, a size coat, a supersize coat, or a combination thereof.

Item 36. A method of forming an abrasive article, comprising:

providing an abrasive article having a first surface and a second surface spaced apart from the first surface; forming an edge on the first surface; and forming a dross ridge on the first surface, the dross ridge extending from at least a portion of the edge by an average width of at least about 101 μm and not greater than about 500 μm.

Item 37. The method of claim 36, wherein forming the dross ridge includes forming a dross ridge with a laser.

Item 38. The method of claim 37, wherein the laser has a maximum average power of at least about 1000 watts.

Item 39. The method of claim 37, wherein forming the dross ridge includes directing the laser to impact the second surface before the first surface.

Item 40. The method of claim 36, wherein forming the dross ridge on the first surface of the abrasive article includes forming an aperture that extends from the second surface of the abrasive article to the first surface of the abrasive article.

ABRASIVE ARTICLE HAVING A DROSS RIDGE AND METHOD OF FORMING SAME

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