FIXED ABRASIVE BUFF

BACKGROUND

Conventional buffs and buffing wheels (collectively “buffs”) are used to polish components formed from various metals, plastics, ceramics, among others. These conventional buffs are typically free of any fixed abrasive material and are generally used in a so-called buffing process to polish or surface finish components formed from various materials (e.g., metals, plastics, ceramics, etc.). Instead of containing a fixed abrasive material, abrasive buffing emulsions or compounds are externally applied to the working surface of the conventional buffs, and periodically reapplied, during polishing operations. These conventional buffs have various draw backs including high costs of maintaining and cleaning, high material waste during buffing, longer buffing time due to the repeated reapplication of the abrasive buffing emulsions or compounds, and costs and concerns associated with disposal of the abrasive buffing emulsions or compounds. Therefore, there continues to be a demand for improved fixed abrasive buffs that provide enhanced abrasive processing performance, efficiency, and improved surface quality.

SUMMARY

In one aspect, the present disclosure relates generally to a fixed abrasive buff that includes a central hub, a plurality of fabric layers affixed to the central hub, and an abrasive composition disposed throughout or embedded within the plurality of fabric layers. The abrasive composition includes a polymeric binder and a plurality of abrasive particles dispersed in the polymeric binder. A content of the abrasive particles at an outer edge of the plurality of fabric layers may be higher than the content of the abrasive particles at an inner edge of the plurality of fabric layers.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the features and advantages of the embodiments are attained and can be understood in more detail, a more particular description may be had by reference to the embodiments thereof that are illustrated in the appended drawings. However, the drawings illustrate only some embodiments and therefore are not to be considered limiting in scope, as there may be other equally effective embodiments.

FIG. 1 is an image of a fixed abrasive buff according to an embodiment of the disclosure.

FIG. 2 is a flowchart of a method 200 of forming a fixed abrasive buff according to an embodiment of the disclosure.

FIG. 3A is an image of an uncoated buff mounted to a rotation device prior to coating with an abrasive composition according to an embodiment of the disclosure.

FIG. 3B is an image of an uncoated buff submerged into and being rotated within an abrasive composition according to an embodiment of the disclosure.

FIG. 3C is an image of a fixed abrasive buff coated with and removed from the abrasive composition according to an embodiment of the disclosure.

FIG. 3D is an image of a fixed abrasive buff coated with the abrasive composition after spinning to remove the excess abrasive composition according to an embodiment of the disclosure.

FIG. 4A shows an apparatus having a pressurized air delivery device according to an embodiment of the disclosure.

FIG. 4B shows an image of a pressurized air delivery device according to an embodiment of the disclosure.

FIG. 5A is an image of a used control abrasive buff with no abrasive composition.

FIG. 5B is an image of a used sample fixed abrasive buff according an embodiment of the disclosure.

FIG. 6A is an image of a brass panel buffed by the control abrasive buff with no abrasive composition.

FIG. 6B is an image of a brass panel buffed by a sample fixed abrasive buff according to an embodiment of the disclosure.

FIG. 7 shows a chart providing comparative data of surface finish (Ra) versus time of a control fixed abrasive buff and an embodiment of a sample fixed abrasive buff.

FIG. 8 shows a chart providing comparative data of surface finish (Rz) versus time of a control fixed abrasive buff and an embodiment of a sample fixed abrasive buff.

FIG. 9 shows a chart providing comparative data of cumulative material removal versus time of a control fixed abrasive buff and an embodiment of sample fixed abrasive buff.

FIG. 10 shows a chart providing comparative data of surface finish (Ra) versus time of a control fixed abrasive buff and an embodiment of a sample fixed abrasive buff.

FIG. 11 shows a chart providing comparative data of surface finish (Rz) versus time of a control fixed abrasive buff and an embodiment of a sample fixed abrasive buff.

FIG. 12 shows a chart providing comparative data of cumulative material removal versus time of a control fixed abrasive buff and an embodiment of sample fixed abrasive buff.

FIG. 13 shows a chart providing comparative data of required power versus time of a control fixed abrasive buff and an embodiment of sample fixed abrasive buff.

FIG. 14 shows an image of a deconstructed sample fixed abrasive buff with sample strips removed.

The use of the same reference symbols in different drawings indicates similar or identical items.

DETAILED DESCRIPTION

Fixed Abrasive Buff

FIG. 1 shows an image of a fixed abrasive buff 100 according to an embodiment of the disclosure. The fixed abrasive buff 100 generally comprises a central hub 102, a plurality of fabric layers 104 affixed to the central hub 102, and an abrasive composition 106 disposed throughout or embedded within the plurality of fabric layers 104. The abrasive composition 106 comprises a polymeric binder and a plurality of abrasive particles dispersed in the polymeric binder. The abrasive composition 106 may generally be disposed throughout or embedded within the plurality of fabric layers 104, such that the abrasive composition 106 (including the abrasive particles) penetrates into and between the fibers of each of the plurality of fabric layers 104 of the fixed abrasive buff 100.

Method of Forming a Fixed Abrasive Buff

FIG. 2 shows a flowchart of a method 200 of forming a fixed abrasive buff 100 according to an embodiment of the disclosure. Method 200 may begin at block 202 by providing an uncoated buff comprising a central hub 102 and a plurality of fabric layers 104 affixed to the central hub 102. Method 200 may continue at block 204 by at least partially submerging the uncoated buff into an abrasive composition 106 having a polymeric binder and a plurality of abrasive particles. Method 200 may continue at block 206 by rotating the buff within the abrasive composition 106.

Method 200 may continue at block 208 by applying pressure to the plurality of fabric layers 104 to cause the plurality of fabric layers 104 to splay or separate each of the fabric layers from one another during the coating process. In some embodiments, the splaying of the plurality of fabric layers 104 may be accomplished by applying or directing pressurized air radially towards the plurality of fabric layers 104 to cause the plurality of fabric layers 104 to splay or separate from one another. In some embodiments, the splaying of the plurality of fabric layers 104 may be accomplished by pressing the plurality of fabric layers 104 against a sidewall of a container holding the abrasive composition 106 to cause the plurality of fabric layers 104 to splay or separate from one another.

In some embodiments, the steps at blocks 206 and 208 may be performed simultaneously, so as to continuously apply pressure to the plurality of fabric layers 104 to cause the plurality of fabric layers 104 to splay or separate from one another while rotating the buff within the abrasive composition 106 to coat the plurality of fabric layers 104 with the abrasive composition 106 to form a fixed abrasive buff 100. In some embodiments, rotating the buff within the abrasive composition 106 to coat the plurality of fabric layers 104 with the abrasive composition 106 may result in a higher concentration, higher content, and/or higher add-on or total weight of the abrasive composition 106 at an outer edge of the plurality of fabric layers 104 as compared to the concentration, content, and/or weight of the abrasive composition 106 at an inner edge, adjacent to the central hub 102, of the plurality of fabric layers 104. In some embodiments, method 200 may result in better penetration of the abrasive composition 106 into the plurality of fabric layers 104 of the fixed abrasive buff 100.

Method 200 may continue at block 210 by removing the fixed abrasive buff 100 from the abrasive composition 106 and rotating the fixed abrasive buff 100 to spin off excess abrasive composition 106. In some embodiments, the fixed abrasive buff 100 may be removed entirely from the abrasive composition 106 and rotated at a controlled rate to facilitate removal of excess abrasive composition. In at least one non-limiting embodiment, the rate of rotation may be controlled to facilitate other features of the fixed abrasive buff 100 as described in embodiments herein.

Method 200 may continue at block 212 by curing the abrasive composition 106 on the fixed abrasive buff 100. In some embodiments, curing the abrasive composition 106 may comprise allowing sufficient time for the abrasive composition 106 to harden and/or solidify. In other embodiments, curing the abrasive composition 106 may comprise a process that accelerates drying or induces curing, such as applying heat to (e.g., baking, etc.) the fixed abrasive buff 100. Without wishing to be tied to a particular theory, one or more process steps, including for example, but not limited to, the process of applying pressure to the plurality of fabric layers 104 may facilitate particular distributions of the abrasive particles in a given layer as well as differences in the distribution of abrasive particles from layer-to-layer.

FIGS. 3A to 3D show various steps of an embodiment in forming a fixed abrasive buff 100. FIG. 3A shows an uncoated buff comprising a central hub 102 and a plurality of fabric layers 104 affixed to the central hub 102 according to an embodiment of the disclosure. The uncoated buff is mounted to a rotation device via the central hub 102 and is suspended above a fixed container holding the abrasive composition 106. FIG. 3B shows the buff submerged into the abrasive composition 106 and being rotated to coat the plurality of fabric layers 104 with the abrasive composition 106. The plurality of fabric layers 104 are also being pressed against a sidewall of the fixed container holding the abrasive composition 106 to cause the plurality of fabric layers 104 to splay or separate from one another. However, in other embodiments, pressurized air may be radially applied to portions of the plurality of fabric layers 104 that are rotated out of the abrasive composition 106 to cause the plurality of fabric layers 104 to splay or separate from one another while being rotated through the abrasive composition 106. FIG. 3C shows the fixed abrasive buff 100 removed from the abrasive composition 106. FIG. 3D shows the fixed abrasive buff 100 coated with the abrasive composition 106 after spinning the fixed abrasive buff 100 to remove the excess abrasive composition 106. Once cured, the fixed abrasive buff will be ready for use in a buffing process to polish or surface finish a workpiece.

FIG. 4A shows an apparatus 150 having a pressurized air delivery device 152 for applying or directing compressed air to portions of the plurality of fabric layers 104 to cause the plurality of fabric layers 104 to splay or separate from one another while being rotated by a rotation device 154 through the abrasive composition 106. An uncoated buff may be mounted to the rotation device 154 via the central hub 102 and suspended at least partially within the abrasive composition 106. The pressurized air delivery device 152 may be connected to an air compressor or other compressed air delivery device. The pressurized air delivery device 152 may radially apply or direct pressurized air to portions of the plurality of fabric layers 104 that are rotated out of the abrasive composition 106 to cause the plurality of fabric layers 104 to splay or separate from one another while being rotated through the abrasive composition 106, which may result in a higher concentration, higher content, and/or higher weight of the abrasive composition 106 at an outer edge of the plurality of fabric layers 104 as compared to the concentration, content, and/or weight of the abrasive composition 106 at an inner edge, adjacent to the central hub 102, of the plurality of fabric layers 104. FIG. 4B shows an image of a pressurized air delivery device 152 according to an embodiment of the disclosure. In the embodiment shown, the pressurized air delivery device 152 comprises a plurality of air delivery holes. However, it will be appreciated that the number of air delivery holes in the pressurized air delivery device 152 may be selected based on the width, diameter, number of fabric layers 104, or other characteristics of the fixed abrasive buff 100.

Abrasive Grain or Particle Distribution

In some embodiments, rotating the buff within the abrasive composition 106 to coat the plurality of fabric layers 104 with the abrasive composition 106 may result in a higher concentration, higher content, and/or higher weight of the abrasive composition 106 at an outer edge of the plurality of fabric layers 104 as compared to the concentration, content, and/or weight of the abrasive composition 106 at an inner edge, adjacent to the central hub 102, of the plurality of fabric layers 104. This may provide beneficial surface finish characteristics since more abrasive particles are disposed at the outer periphery of the plurality of fabric layers 104 of the fixed abrasive buff 100 where the majority of surface finishing of a workpiece occurs.

In some embodiments, the content of the abrasive particles at the outer edge of the plurality of fabric layers 104 may be higher than the content of the abrasive particles at the inner edge, adjacent to the central hub 102, of the plurality of fabric layers 104. In some embodiments, the content of the abrasive particles at the outer edge of the plurality of fabric layers 104 may be at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the content of the abrasive particles at the inner edge of the plurality of fabric layers 104. In some embodiments, the content of the abrasive particles at the outer edge of the plurality of fabric layers 104 may be not greater than 300%, not greater than 200%, not greater than 100%, not greater than 90%, not greater than 80%, not greater than 70%, not greater than 60%, or not greater than 50% higher than the content of the abrasive particles at the inner edge of the plurality of fabric layers 104. Further, it will be appreciated that the content of the abrasive particles at the outer edge of the plurality of fabric layers 104 may be between any of these minimum and maximum values, such as at least 10% to not greater than 300% higher than the content of the abrasive particles at the inner edge of the plurality of fabric layers 104, or even at least 50% to not greater than 100% higher than the content of the abrasive particles at the inner edge of the plurality of fabric layers 104. For example, in an embodiment, the content of the abrasive particles at the outer edge may be 0.639 grams, and the content of the abrasive particles at the inner edge may be 0.307 grams. The percentage is calculated using the following formula: (0.639−0.307)/0.639=0.52%. Thus, in this embodiment, the content at the outer edge is 52% higher than the content at the inner edge of the plurality of fabric layers 104.

In some embodiments, the add-on weight of the abrasive composition 104 at the outer edge of the plurality of fabric layers 104 may be higher than the add-on weight of the abrasive composition 104 at the inner edge, adjacent to the central hub 102, of the plurality of fabric layers 104. In some embodiments, the add-on weight of the abrasive composition 104 at the outer edge of the plurality of fabric layers may be at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the add-on weight of the abrasive composition 104 at the inner edge of the plurality of fabric layers 104. In some embodiments, the add-on weight of the abrasive composition 104 at the outer edge of the plurality of fabric layers may be not greater than 300%, not greater than 200%, not greater than 100%, not greater than 90%, not greater than 80%, not greater than 70%, not greater than 60%, or not greater than 50% higher than the add-on weight of the abrasive composition 104 at the inner edge of the plurality of fabric layers 104. Further, it will be appreciated that the add-on weight of the abrasive composition 104 at the outer edge of the plurality of fabric layers 104 may be between any of these minimum and maximum values, such as at least 10% to not greater than 300% higher than the add-on weight of the abrasive composition 104 at the inner edge of the plurality of fabric layers 104, or even at least 50% to not greater than 100% higher than the add-on weight of the abrasive composition 104 at the inner edge of the plurality of fabric layers 104. For example, in an embodiment, the add-on weight of the abrasive composition 104 at the outer edge may be 1.295 grams, and the add-on weight of the abrasive composition 104 at the inner edge may be 0.623 grams. Calculating (1.295−0.623)/1.295=0.52%. Thus, in this embodiment, the add-on weight of the abrasive composition 104 at the outer edge is 52% higher than the add-on weight of the abrasive composition 104 at the inner edge.

In some embodiments, the total weight of the fixed abrasive buff 100 at the outer edge of the plurality of fabric layers 104 may be higher than the total weight at the inner edge, adjacent to the central hub 102, of the plurality of fabric layers 104. In some embodiments, the total weight of the fixed abrasive buff 100 at the outer edge of the plurality of fabric layers may be at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the total weight at the inner edge of the plurality of fabric layers 104. In some embodiments, the total weight of the fixed abrasive buff 100 at the outer edge of the plurality of fabric layers may be not greater than 300%, not greater than 200%, not greater than 100%, not greater than 90%, not greater than 80%, not greater than 70%, not greater than 60%, or not greater than 50% higher than the total weight at the inner edge of the plurality of fabric layers 104. Further, it will be appreciated that the total weight of the fixed abrasive buff 100 at the outer edge of the plurality of fabric layers 104 may be between any of these minimum and maximum values, such as at least 10% to not greater than 300% higher than the total weight of the fixed abrasive buff 100 at the inner edge of the plurality of fabric layers 104, or even at least 50% to not greater than 100% higher than the total weight of the fixed abrasive buff 100 at the inner edge of the plurality of fabric layers 104. For example, in an embodiment, the total weight of the abrasive composition 104 at the outer edge may be 1.901 grams, and the total weight of the abrasive composition 104 at the inner edge may be 1.229 grams. Calculating (1.901−1.229)/1.901=0.32%. Thus, in this embodiment, the total weight of the abrasive composition 104 at the outer edge is 32% higher than the total weight of the abrasive composition 104 at the inner edge.

Fabric Layers

The plurality of fabric layers 104 may generally be made from any number of various materials, including woven fabrics, nonwoven fabrics, or a combination thereof. The fabric layers 104 may be formed from a plurality of fibers or yarns, such as natural fibers or yarns, synthetic fibers or yarns, or a combination thereof. The natural fibers or yarns can comprise one or more types of natural fibers. In some embodiment, the natural fibers or yarns may comprise cellulose fibers or yarns, cotton fibers or yarns, flax fibers or yarns, hemp fibers or yarns, jute fibers or yarns, ramie fibers or yarns, sisal fibers or yarns, linen fibers or yarns, silk fibers or yarns, or a combination thereof. In a specific embodiment, natural fibers or yarns may consist essentially of cotton fibers or yarns. The synthetic fibers or yarns may comprise one or more types of synthetic fibers or yarns. In an embodiment, the synthetic fibers or yarns may comprise glass fibers or yarns, polymeric fibers or yarns, or a combination thereof. In a specific embodiment, the polymeric fibers or yarns may comprise acrylic fibers or yarns, nylon fibers or yarns, olefin fibers or yarns, polyester fibers or yarns, rayon fibers or yarns, modal fibers or yarns, or a combination thereof. In a specific embodiment, the synthetic fibers consist essentially of polyester fibers. In another specific embodiment, the synthetic fibers consist essentially of nylon fibers.

In some embodiments, the plurality of fabric layers 104 may comprise a woven fabric. The woven fabric can comprise a plurality of yarns, such as warp yarns and weft yarns. In some embodiments, the abrasive composition can be disposed at least partially within or between the yarns, such as between the warp and weft yarns. Further, in some embodiments, the abrasive composition can be disposed through the fabric between the yarns from a first side of the fabric to a second side of the fabric.

In some embodiments, the plurality of fabric layers 104 comprises a nonwoven fabric. As used herein the term “nonwoven fabric” refers to a web having a structure of individual fibers that are interlaid, but not in an identifiable manner such in a knitted fabric. In specific embodiments, the nonwoven fabric may comprise a spunbond fabric (also known as a “spunlaid” fabric) of spunbonded fibers, a meltblown fabric of meltblown fibers, or a combination thereof. In some embodiments, the abrasive composition may be disposed at least partially within or between the fibers of the nonwoven web. Further, in some embodiments, the abrasive composition may be disposed through the nonwoven fabric between the fibers of the web from a first side of the fabric to a second side of the fabric.

Number of Fabric Layers

The fixed abrasive buff 100 is generally formed by a plurality of fabric layers 104. In some embodiments, the fixed abrasive buff 100 may comprise at least 2 layers, at least 4 layers, at least 6 layers, at least 8 layers, at least 10 layers, at least 12 layers, at least 15 layers, at least 20 layers, or at least 25 layers. In some embodiments, the fixed abrasive buff 100 may comprise not greater than 100 layers, not greater than 50 layers, not greater than 25 layers, not greater than 20 layers, not greater than 15 layers, or not greater than 12 layers. Further, it will be appreciated that the fixed abrasive buff 100 may comprise may comprise a plurality of fabric layers 104 between any of these minimum and maximum values, such as at least 2 layers to not greater than 30 layers.

Abrasive Composition

The abrasive composition 106 may generally comprise a polymeric binder and a plurality of abrasive particles dispersed in the polymeric binder. The abrasive composition 106 may generally be disposed throughout or embedded within the plurality of fabric layers 104, such that the abrasive composition 106 (including the abrasive particles) penetrates into and between the fibers of each of the plurality of fabric layers 104 of the fixed abrasive buff 100. The abrasive composition 106 may be applied to the fixed abrasive buff 100 and comprise a beneficial add-on weight. In some embodiments, the add-on weight of the abrasive composition 106 may be at least 15 grams, at least 16 grams, at least 17 grams, at least 18 grams, at least 19 grams, at least 20 grams, at least 21 grams, at least 22 grams, at least 23 grams, at least 24 grams, or at least 25 grams.

Polymeric Binder

The polymeric binder may generally be formed from a single polymer or a blend of polymers. In some embodiments, the polymeric binder may be formed from an epoxy composition, acrylic composition, a phenolic composition, a polyurethane composition, a phenolic composition, a polysiloxane composition, an acrylic latex composition, a thermoset rubber composition, a thermoset elastomer composition, a styrene butadiene rubber composition, an acrylonitrile-butadiene rubber composition, a polybutadiene composition, or a combination thereof. In some embodiments, the polymeric binder may comprise a self-crosslinking carboxylated styrene-butadiene composition. In other embodiments, the polymeric binder may comprise a carboxylated acrylic composition. In some embodiments, the polymeric binder may include one or more active filler particles, additives, one or more reaction constituents or polymer constituents, thickeners, solvents, plasticizers, chain transfer agents, catalysts, defoamers, stabilizers, dispersants, curing agents, rheology modifiers, reaction mediators and agents for influencing the fluidity of the dispersion, or any combination thereof. In some embodiments, the polymeric binder may be flexible after curing such that the plurality of fabric layers 104 has a “soft” hand, also known as a soft “drape”, so that the plurality of fabric layers 104 feels soft to the touch, is flexible, and conformable around a workpiece.

The polymeric binder can comprise a desirable glass transition temperature (T_g) that can contribute to beneficial abrasive properties. In some embodiments, the polymeric binder may comprise a glass transition temperature of at least −30° C., at least −25° C., at least −20° C., or at least −15° C. In some embodiments, the polymeric binder may comprise a glass transition temperature of not greater than 60° C., not greater than 50° C., not greater than 40° C., not greater than 30° C., not greater than 20° C., not greater than 10° C., not greater than 0° C., or not greater than −1° C. Further, it will be appreciated that the polymeric binder may comprise a glass transition temperature between any of these minimum and maximum values, such as at least −30° C. to not greater than 30° C.

The amount of polymeric binder in the abrasive composition may vary. In some embodiments, the abrasive composition may comprise at least 10 wt. % polymeric binder, at least 15 wt. %, at least 20 wt. %, at least 25 wt. %, at least 35 wt. %, or at least 50 wt. % polymeric binder. In some embodiments, the abrasive composition may comprise not greater than 80 wt. % polymeric binder, not greater than 75 wt. %, not greater than 70 wt. %, not greater than 65 wt. %, not greater than 60 wt. %, not greater than 55 wt. %, not greater than 50 wt. %, not greater than 40 wt. %, not greater than 35 wt. %, or not greater than 30 wt. % polymeric binder. Further, it will be appreciated that the amount of polymeric binder in the abrasive composition may be between any of these minimum and maximum values, such as at least 10 wt. % to not greater than 80 wt. % polymeric binder.

Abrasive Particles

The abrasive particles may include essentially single-phase inorganic materials, such as alumina, silicon carbide, silica, ceria, and/or harder, high performance superabrasive particles such as cubic boron nitride and diamond. Further, the abrasive particles may include engineered abrasives including macrostructures and particular three-dimensional structures. Aggregates may comprise abrasive aggregates and/or nonabrasive aggregates. In some embodiments, aggregates may include composite particulate materials, which can be formed through slurry processing pathways that include removal of the liquid carrier through volatilization or evaporation, leaving behind unfired (“green”) aggregates, that can optionally undergo high temperature treatment (i.e., firing, sintering) to form usable, fired aggregates.

The abrasive particles may be formed of any one of or a combination of abrasive particles, including silica, alumina (fused or sintered), zirconia, zirconia/alumina oxides, zirconium silicate, silicon carbide, garnet, diamond, cubic boron nitride, silicon nitride, ceria, titanium dioxide, titanium diboride, boron carbide, tin oxide, tungsten carbide, titanium carbide, iron oxide, chromia, flint, emery, or a combination thereof. For example, the abrasive particles and/or aggregates may be selected from a group consisting of silica, alumina, zirconia, silicon carbide, silicon nitride, boron nitride, garnet, diamond, co-fused alumina zirconia, ceria, titanium diboride, boron carbide, flint, emery, alumina nitride, and a blend thereof. In a specific embodiment, the abrasive particles consist essentially of silicon carbide.

The average particle size of the abrasive particles may vary. The particle size of the abrasive particles is typically specified to be the longest dimension of the abrasive particle. Generally, there is a range distribution of particle sizes. In some embodiments, the abrasive particles may comprise an average particle size of at least 5 micrometers, at least 10 micrometers, at least 15 micrometers, at least 20 micrometers, or at least 25 micrometers. In some embodiments, the abrasive particles may comprise an average particle size of not greater than 1500 micrometers, not greater than 1000 micrometers, not greater than 750 micrometers, not greater than 500 micrometers, not greater than 250 micrometers, not greater than 100 micrometers, or not greater than 50 micrometers. Further, it will be appreciated that abrasive particles may comprise an average particle size between any of these minimum and maximum values, such as 5 micrometers to not greater than 1500 micrometers, or even at least 10 micrometers to not greater than 50 micrometers.

The amount of abrasive particles in the abrasive composition may also vary. In some embodiments, the abrasive composition may comprise least 10 wt. % abrasive particles, at least 15 wt. %, at least 20 wt. %, at least 25 wt. %, at least 30 wt. %, at least 35 wt. %, at least 40 wt. %, at least 45 wt. %, at least 50 wt. %, at least 55 wt. %, or at least 60 wt. % abrasive particles. In some embodiments, the abrasive composition may comprise not greater than 75 wt. % abrasive particles, not greater than 70 wt. %, not greater than 65 wt. %, not greater than 60 wt. %, not greater than 55 wt. %, or not greater than 50 wt. % abrasive particles. The abrasive particles can be within a range of any minimum or maximum value noted above. Further, it will be appreciated that the amount of abrasive particles in the abrasive composition may be between any of these minimum and maximum values, such as at least 10 wt. % to not greater than 75 wt. % abrasive particles.

Examples

Sample fixed abrasive buffs were prepared according to methods disclosed herein. Two different abrasive compositions were used. The first uncured abrasive composition is shown in Table 1 below. While ranges are provided for some components, the components in the composition total 100%.

TABLE 1

First Abrasive Composition

Materials
Component
Weight %

Abrasive Powder
SiC ANSI 320, 29.2 μm
34.00-38.00

Thickener
Xantham Gum
0.10-1.00

Liquid
Water
25.00-29.00

Rovene 5550, 50% Solid
36.33

Wetting Agent
0.17

Defoamer
0.17

Total

100.00

The second uncured abrasive composition is shown in Table 2 below. It will be noted that the second abrasive composition comprises about 50% fewer abrasive particles. While ranges are provided for some components, the components in the composition total 100%.

TABLE 2

Second Abrasive Composition

Materials
Component
Weight %

Abrasive Powder
SiC ANSI 320, 29.2 μm
16.00-19.00

Thickener
Xantham Gum
0.25

Liquid
Water
60.00-65.00

Rovene 5550, 50% Solid
18.08

Wetting Agent
0.17

Defoamer
0.17

Total

100.00

Sample fixed abrasive buff, S1, was prepared according to methods disclosed herein, which included applying pressure to the plurality of fabric layers to cause the plurality of fabric layers to splay, and rotating the buff within the abrasive composition to coat the buff with the first abrasive composition. Control sample, C1, was prepared according to conventional methods without applying pressure to the plurality of fabric layers. The resulting weights of the samples are shown in Table 3 below.

TALBE 3

Sample Weights

Abrasive
Total Wt.
Uncoated Buff
Add-on Wt.

Sample
Composition
(grams)
Wt. (grams)
(grams)

Cl
First—Table 1
60.24
49.41
10.83

Si
First—Table 1
88.89
49.41
39.48

Sample S1 had higher weights of the abrasive composition than did the control sample C1. This can be attributed, at least in part, to the application of pressure to the plurality of fabric layers that caused the plurality of fabric layers to splay.

Additional sample buffs were created. All samples started with the same cotton fabric buff. Control sample (“C1”) remained uncoated with an abrasive composition, and instead used an abrasive buffing compound that was externally applied to the buff at 6000-7000 SFPM during buffing. The used control sample C1 is shown after buffing in FIG. 5A. Sample S1 was prepared using the same cotton fabric buff and was coated according to methods disclosed herein with the first abrasive composition in Table 1. Used sample S1 is shown after buffing in FIG. 5B.

The samples (C1, S1) were tested on brass panels that were 6 inches wide, 24 inches long, and 0.125 inches thick. The resultant brass panel buffed by C1 is shown in FIG. 6A. The resultant brass panel buffed by S1 is shown in FIG. 6B. Notably, the surface finish buffed by S1 appears to have a better surface finish.

FIG. 7 shows a chart providing comparative data of surface finish (Ra) of C1 and the S1. Most notably, S1 achieved a much better surface finish (Ra). FIG. 8 shows a chart providing comparative data of surface finish (Rz) of C1 and the S1. Most notably, S1 achieved a much better surface finish (Rz). FIG. 9 shows a chart providing comparative data of cumulative material removal (measured in grams) of C1 and S1. Most notably, S1 had a much higher cumulative material removal. Surprisingly and beneficially, S1 outperformed C1 in both surface finish (both Ra and Rz) and cumulative material removal rate.

Eight additional sample fixed abrasive cotton buffs were created and coated with an abrasive composition according to methods disclosed herein. The sample fixed abrasive buffs were analyzed untested for the weights of abrasive composition and abrasive grain or particle. The results are shown in Table 4 below.

TABLE 4

Abrasive Composition Sample Weights

Total Wt.
Total Wt.
Add-on Wt.
Abrasive

Sample
(grams)
(lb./ream)
(grams)
Content (grams)

Outer edge
1.901
39.802
1.295
0.639

Inner edge
1.229
25.728
0.623
0.307

Base cloth
0.606
12.686
NA
NA

Testing was conducted on additional fixed abrasive buffs. Control sample, C2, utilized a woven cotton buff and remained uncoated with an abrasive composition. Control sample, C3, utilized a woven cotton buff and was prepared according to conventional methods by applying an abrasive composition to the layers prior to formation of the buff. Sample fixed abrasive buff, S2, utilized a nonwoven buff and remained uncoated with an abrasive compound. Sample fixed abrasive buff, S3, utilized a nonwoven buff and was prepared according to methods disclosed herein, which included applying pressure to the plurality of fabric layers to cause the plurality of fabric layers to splay, and rotating the buff within the abrasive composition to coat the buff with the first abrasive composition.

Samples C2, C3, S2, and S3 were tested on substantially similar brass workpieces. C2 and S2 were tested utilizing a bar compound applied to the buffs during buffing. C3 and S3 were tested as prepared.

FIG. 10 shows a chart providing comparative data of surface finish (Ra) of C2, C3, S2, and S3. Most notably, S3 achieved a much better surface finish (Ra) as compared to C2, C3, and S2. Additionally, S3 also achieved the better surface finish in a much shorter time as compared to C2, C3, and S2.

FIG. 11 shows a chart providing comparative data of surface finish (Rz) of C2, C3, S2, and S3. Most notably, S3 achieved a much better surface finish (Rz) as compared to C2, C3, and S2. Additionally, S3 also achieved the better surface finish in a much shorter time as compared to C2, C3, and S2.

FIG. 12 shows a chart providing comparative data of cumulative material removal (measured in grams) of C2, C3, S2, and S3. Most notably, S3 had a much higher cumulative material removal as compared to C2, C3, and S2.

FIG. 13 shows a chart providing comparative data of required power (measured in horsepower (Hp)) of C2, C3, S2, and S3. Most notably, S3 required much less power to achieve the desired surface finish (both Ra and Rz) while achieving a higher cumulative material removal as compared to C2, C3, and S2. Accordingly, S3 outperformed C2, C3, and S2 in both surface finish (both Ra and Rz) and cumulative material removal rate while requiring much less power to achieve these results.

Samples S3 was submitted for comparison of the amount of coating and abrasive grains or particles in the sample. Sample strips of 0.5 inches wide (measured circumferentially) and 1.25 inches long (measured radially) were cut from the deconstructed sample S3 as shown in FIG. 14. The sample weights of the sample strips were averaged and recorded. These sample strips were analyzed by subjecting the sample strips to a so-called “burn-off” process at 450 degrees Celsius for 10 hours.

The weight loss was recorded. It was noticed that sample strips had some inorganic residue (K—Cl phase) after the burn-off process. In order to find the accurate amount of abrasive grains (SiC garins), the ash remaining from the burn-off process was treated with 10% by volume of hydrochloric acid (HCl). The amount of remaining abrasive grains was recorded. Results shown in Table 5 below.

TABLE 5

Abrasive Composition Sample Weights

Wt. %

Coating
Inorganic
Wt. %
Grain
Grain In

Sample
(Resin&
Residue
Inorganic
After
Coating

Weight
Grain)
After
Coating
HCl
After

Sample
(g)
(g)
Burnoff (g)
(g)
(g)
HCl (g)

Outer Edge
1.9190
1.313
0.9083
69.2
0.8972
68.3

Inner Edge
1.2442
0.6382
0.4409
69.1
0.4289
67.2

As shown in Table 5, the outer edges had a higher overall weight and a higher overall abrasive composition coating. As a result, the outer edges had a higher concentration of abrasive grains at the outer edges (0.8972 g) as compared to the concentration of abrasive grains at the inner edges (0.4289 g). Most notably, the outer edges contained about 52.19% higher concentration at the outer edges for the tested sample S3.

It will be appreciated that embodiments of an abrasive article are disclosed herein that may include one or more of the following embodiments:

Embodiment 1. A fixed abrasive buff, comprising: a central hub; a plurality of fabric layers affixed to the central hub; and an abrasive composition comprising a polymeric binder and a plurality of abrasive particles dispersed in the polymeric binder, wherein a content of the abrasive particles at an outer edge of the plurality of fabric layers is higher than the content of the abrasive particles at an inner edge of the plurality of fabric layers.

Embodiment 2. The fixed abrasive buff of embodiment 1, wherein the content of the abrasive particles at the outer edge of the plurality of fabric layers is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the content of the abrasive particles at the inner edge of the plurality of fabric layers.

Embodiment 3. The fixed abrasive buff of embodiment 1, wherein the add-on weight of the abrasive composition at the outer edge of the plurality of fabric layers is higher than the add-on weight of the abrasive composition at the inner edge of the plurality of fabric layers.

Embodiment 4. The fixed abrasive buff of embodiment 3, wherein the add-on weight of the abrasive composition at the outer edge of the plurality of fabric layers is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the add-on weight of the abrasive composition at the inner edge of the plurality of fabric layers.

Embodiment 5. The fixed abrasive buff of embodiment 1, wherein the total weight of the fixed abrasive buff at the outer edge of the plurality of fabric layers is higher than the total weight at the inner edge of the plurality of fabric layers.

Embodiment 6. The fixed abrasive buff of embodiment 5, wherein the total weight of the fixed abrasive buff at the outer edge of the plurality of fabric layers is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the total weight at the inner edge of the plurality of fabric layers.

Embodiment 7. The fixed abrasive buff of any of embodiments 1 to 6, wherein the inner edge is adjacent the central hub, and wherein the outer edge is radially furthest from the central hub.

Embodiment 8. The fixed abrasive buff of embodiment 1, wherein the plurality of fabric layers comprises a woven fabric, a nonwoven fabric, or a combination thereof.

Embodiment 9. The fixed abrasive buff of embodiment 8, wherein the plurality of fabric layers comprises at least 2 layers, at least 4 layers, at least 6 layers, at least 8 layers, at least 10 layers, at least 12 layers, at least 15 layers, at least 20 layers, or at least 25 layers to not greater than 100 layers, not greater than 50 layers, not greater than 25 layers, not greater than 20 layers, not greater than 15 layers, or not greater than 12 layers.

Embodiment 10. The fixed abrasive buff of embodiment 1, wherein the abrasive composition is dispersed on or in each of the plurality of fabric layers.

Embodiment 11. The fixed abrasive buff of embodiment 1, wherein the abrasive composition comprises: 10 wt. % to 80 wt. % of the polymeric binder; and 20 wt. % to 90 wt. % of abrasive particles.

Embodiment 12. The fixed abrasive buff of embodiment 11, wherein the polymeric binder comprises a self-crosslinking carboxylated styrene-butadiene composition.

Embodiment 13. The fixed abrasive buff of embodiment 11, wherein the abrasive particles comprise silicon carbide.

Embodiment 14. The fixed abrasive buff of embodiment 13, wherein the abrasive particles comprise an average particle size of at least 5 micrometers, at least 10 micrometers, at least 15 micrometers, at least 20 micrometers, or at least 25 micrometers.

Embodiment 15. The fixed abrasive buff of embodiment 14, wherein the abrasive particles comprise an average particle size of not greater than 500 micrometers, not greater than 250 micrometers, not greater than 100 micrometers, or not greater than 50 micrometers.

Embodiment 16. A method of forming a fixed abrasive buff, comprising: providing an uncoated buff comprising a central hub and a plurality of fabric layers affixed to the central hub; applying pressure to the plurality of fabric layers to cause the plurality of fabric layers to splay; and rotating the buff within an abrasive composition to coat the buff with the abrasive composition.

Embodiment 17. The method of embodiment 16, wherein a content of the abrasive particles at an outer edge of the plurality of fabric layers is higher than the content of the abrasive particles at an inner edge of the plurality of fabric layers.

Embodiment 18. The method of embodiment 17, wherein the content of the abrasive particles at the outer edge of the plurality of fabric layers is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the content of the abrasive particles at the inner edge of the plurality of fabric layers.

Embodiment 19. The method of any of embodiments 16 to 18, wherein the add-on weight of the abrasive composition at the outer edge of the plurality of fabric layers is higher than the add-on weight of the abrasive composition at the inner edge of the plurality of fabric layers.

Embodiment 20. The method of embodiment 19, wherein the add-on weight of the abrasive composition at the outer edge of the plurality of fabric layers is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the add-on weight of the abrasive composition at the inner edge of the plurality of fabric layers.

Embodiment 21. The method of any of embodiments 16 to 20, wherein the total weight of the fixed abrasive buff at the outer edge of the plurality of fabric layers is higher than the total weight at the inner edge of the plurality of fabric layers.

Embodiment 22. The method of embodiment 21, wherein the total weight of the fixed abrasive buff at the outer edge of the plurality of fabric layers is at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, or at least 50% higher than the total weight at the inner edge of the plurality of fabric layers, or a combination thereof.

Embodiment 23. The method of any of embodiments 16 to 22, applying pressure to the plurality of fabric layers is accomplished by applying pressurized air towards the plurality of fabric layers, pressing the plurality of fabric layers against a sidewall of a container holding the abrasive composition, or a combination thereof.

Embodiment 24. The method of any of embodiments 16 to 23, further comprising: removing the fixed abrasive buff from the abrasive composition; rotating the fixed abrasive buff to spin off excess abrasive composition; and curing the abrasive composition on the fixed abrasive buff.

Embodiment 25. The fixed abrasive buff of any of embodiments 1 to 15 or the method of any of embodiments 16 to 24, wherein an add-on weight of the abrasive composition is at least 15 grams, at least 16 grams, at least 17 grams, at least 18 grams, at least 19 grams, at least 20 grams, at least 21 grams, at least 22 grams, at least 23 grams, at least 24 grams, or at least 25 grams.

This written description uses examples to disclose the embodiments, including the best mode, and also to enable those of ordinary skill in the art to make and use the invention. The patentable scope is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Note that not all of the activities described above in the general description or the examples are required, that a portion of a specific activity may not be required, and that one or more further activities may be performed in addition to those described. Still further, the order in which activities are listed are not necessarily the order in which they are performed.

In the foregoing specification, the concepts have been described with reference to specific embodiments. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the invention as set forth in the claims below. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of invention.

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 may include other features not expressly listed or inherent to such process, method, article, or apparatus. 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).

Also, the use of “a” or “an” are 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 unless it is obvious that it is meant otherwise.

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 may 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.

After reading the specification, skilled artisans will appreciate that certain features are, for clarity, described herein in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, references to values stated in ranges include each and every value within that range.

FIXED ABRASIVE BUFF

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