Abrasive Articles and Methods of Forming Same

Abstract

The abrasive article includes a backing, a make coat overlying the backing, a plurality of abrasive particles overlying the backing and at least partially contained in the make coat, and a make coat thickness ratio (Tg / Ta) of 1.5 or less, where Tg is the average thickness of the make coat on the sides of the abrasive particles and Ta is the average thickness of the make coat.

Description

[Technical field]

[0001] The following is directed to abrasive articles, and specifically coated abrasive articles, and methods of forming coated abrasive articles. Summary of the Invention

[0002] According to one embodiment, an abrasive article includes a backing, a make coat overlying the backing, a plurality of abrasive particles overlying the backing and at least partially contained in the make coat, and a make coat thickness ratio (Tg / Ta) of 1.5 or less, where Tg is the average thickness of the make coat on the sides of the abrasive particles and Ta is the average thickness of the make coat. [Brief description of the drawings]

[0003] The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings. [Figure 1] 1 includes a cross-sectional image of a section of an abrasive article according to an embodiment. [Figure 2A] 1 includes a top view of a portion of a coated abrasive article according to an embodiment. [Figure 2B] 1 includes a top view of a portion of a coated abrasive article according to an embodiment. [Diagram 3] 1 includes an exemplary image of a portion of an abrasive article having randomly oriented abrasive particles. [Figure 4A] 1 includes a side view of abrasive particles on a backing according to an embodiment. [Figure 4B] 1 includes a side view of particles on a backing with an inclined angle according to an embodiment. [Figure 4C] Included is a top-down view of the particle in FIG. 4B. [Figure 4D] 1 includes a side view of particles on a backing with an inclined angle according to an embodiment. [Figure 4E] FIG. 4D includes a top-down view of the particle. [Figure 5A]1 includes a perspective view of a shaped abrasive particle according to an embodiment. [Figure 5B] 1 includes a top-down view of a shaped abrasive particle according to an embodiment. [Figure 6A] Includes images of 3-PT star abrasive particles. [Figure 6B] 6B includes a side view of the shaped abrasive particle of FIG. 6A. [Figure 6C] Includes images of 3-PT star abrasive particles. [Figure 7] 1 includes a perspective view of a shaped abrasive particle according to an embodiment. [Figure 8A] 1 includes a perspective view of a controlled height abrasive particle according to an embodiment. [Figure 8B] 1 includes a perspective view of an unshaped particle according to an embodiment. [Figure 9A] 1 includes a top down view of a coated abrasive article. [Figure 9B] 9A includes an image of FIG. 9A that has been edited to highlight the abrasive grains. [Figure 9C] 9B, which has been further edited to color-code the grains by orientation. [Figure 10] An image of an abrasive article having a pigmented make layer is included. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0004] The following is directed to methods of forming abrasive articles, such as fixed abrasive articles, and more specifically, coated abrasive articles. Abrasive articles can be used in a variety of material removal operations on a variety of workpieces.

[0005] FIG. 1 includes an image of a coated abrasive article 100 according to an embodiment. As shown in FIG. 1, the coated abrasive article 100 may include a backing 101. The coated abrasive article 100 may also include an adhesive layer, such as a make coat 105, overlying the backing. The coated abrasive article 100 may further include a plurality of abrasive particles 102 and 103. The coated abrasive article may also include a size coat 106 and a supersize coat 107. The make coat 105 may have an average thickness Ta. The make coat 105 may also include an average thickness Tg on the sides of the abrasive particles. An exemplary make coat thickness on the sides of the abrasive particles can be seen as dotted line 110 in FIG. 1.

[0006] In some embodiments, the make coat may include certain materials that may facilitate the manufacture or improve the performance of the abrasive article, hi some embodiments, the make coat may include wollastonite, PF resin, water, or combinations thereof.

[0007] In some embodiments, the make coat may have a particular viscosity that may facilitate the manufacture or improvement of the performance of the abrasive article. In some embodiments, the viscosity may be at least 3500 cps, or at least 3750 cps, or at least 4000 cps, or at least 4250 cps, or at least 4500 cps, or at least 4750 cps, or at least 5000 cps, or at least 5250 cps. In some embodiments, the viscosity may be 7000 cps or less, or 6750 cps or less, or 6500 cps or less, or 6250 cps or less, or 6000 cps or less, or 5750 or less. It will be appreciated that the make coat viscosity may be between any of the above minimum and maximum values ​​set forth above, including, for example, but not limited to, at least 3500 cps and 7000 cps or less, or at least 5000 cps and 6000 cps or less.

[0008] The average make coat thickness can be measured according to the following procedure: The abrasive article is cut down the middle to reveal a cross section. The article is then cut into 2 inch sections and mounted on an epoxy pack. Two 2 inch sections are then imaged and the make layer is identified by coloring the layer using imaging software. Figure 10 includes an exemplary image of an abrasive article with a colored make layer. Image analysis is used to overlay vertical grid lines to identify and isolate line sections that overlap the make layer. Each line section corresponds to a make coat thickness measurement. An average is taken of all sections. Approximately 150-200 overlapping line sections were made per 2 inch sample section, resulting in over 300 measurements for each sample.

[0009] The average make coat thickness near the upright grains can be measured according to the following procedure. The same cross-sectional image for the average make coat thickness can also be used for the average make coat thickness near the upright grains. Only upright grains showing a rectangular cross-sectional area with their short sides in contact with the make coat are considered. For example, in FIG. 1, grain 102 is considered but grain 103 is not considered. Furthermore, only isolated grains were considered. Upright grains in contact with another grain were not considered for the measurement of the average make coat thickness near the upright grains. The measurement was taken from the highest make point contacting the grain side to the lowest make point contacting the backing on both sides of the grain. The measurement line is perpendicular to the backing plane.

[0010] In some embodiments, the coated abrasive article may have a make coat of a particular average thickness, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, the average thickness Ta of the make coat may be at least 50 microns, or at least 60 microns, or at least 70 microns, or at least 80 microns, or at least 90 microns, or at least 100 microns, or at least 110 microns, or at least 120 microns, or at least 130 microns, or at least 140 microns, or at least 150 microns, or at least 160 microns. In other embodiments, the average thickness Ta of the make coat may be 1 mm or less, or 800 microns or less, or 700 microns or less, or 600 microns or less, or 500 microns or less, or 400 microns or less, or 300 microns or less, or 275 microns or less, or 250 microns or less, or 225 microns or less, or 200 microns or less. It will be appreciated that Ta may be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 50 microns and 800 microns or less, or at least 80 microns and 300 microns or less.

[0011] In some embodiments, the coated abrasive article may have a make coat of a particular average thickness Tg on the side of the abrasive particles, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, the Tg may be at least 50 microns, or at least 60 microns, or at least 70 microns, or at least 80 microns, or at least 90 microns, or at least 100 microns, or at least 110 microns, or at least 120 microns, or at least 130 microns, or at least 140 microns, or at least 150 microns. In other embodiments, the Tg may be 1 mm or less, or 800 microns or less, or 700 microns or less, or 600 microns or less, or 500 microns or less, or 400 microns or less, or 300 microns or less. It will be understood that the Tg may be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 50 microns and 800 microns or less, or at least 80 microns and 300 microns or less.

[0012] In some embodiments, the coated abrasive article may have a make coat with a particular thickness standard deviation STDT on the side of the abrasive particles, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, the STDT may be at least 1 micron, or at least 2 microns, or at least 3 microns, or at least 4 microns, or at least 5 microns, or at least 7 microns, or at least 10 microns, or at least 12 microns, or at least 15 microns, or at least 18 microns, or at least 20 microns, or at least 22 microns, or at least 25 microns, or at least 28 microns, or at least 30 microns. In other embodiments, the STDT may be 100 microns or less, or 90 microns or less, or 85 microns or less, or 80 microns or less, or 75 microns or less, or 70 microns or less, or 65 microns or less, or 60 microns or less, or 55 microns or less, or 50 microns or less, or 45 microns or less, or 40 microns or less, or 35 microns or less, or 30 microns or less, or 25 microns or less, or 20 microns or less, or 15 microns or less, or 10 microns or less. It will be appreciated that the STDT can be between any of the minimum and maximum values ​​set forth above, including, for example, but not limited to, at least 5 microns and not more than 100 microns, or at least 10 microns and not more than 45 microns.

[0013] In some embodiments, the coated abrasive article may have a make coat with a specific thickness standard deviation STDTg on the side of the abrasive particles, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, STDTg may be at least 1 micron, or at least 5 microns, or at least 10 microns, or at least 15 microns, or at least 20 microns, or at least 25 microns, or at least 30 microns. In other embodiments, STDTg may be 100 microns or less, or 90 microns or less, or 85 microns or less, or 80 microns or less, or 75 microns or less, or 70 microns or less, or 65 microns or less, or 60 microns or less, or 55 microns or less, or 50 microns or less, or 45 microns or less, or 40 microns or less, or 35 microns or less, or 30 microns or less. It will be understood that STDTg may be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 5 microns and 100 microns or less, or at least 10 microns and 45 microns or less.

[0014] In some embodiments, the coated abrasive article may have a make coat with a specific thickness ratio Tg / Ta, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, Tg / Ta may be 1.45 or less, or 1.43 or less, or 1.40 or less, or 1.38 or less, or 1.35 or less, or 1.33 or less, or 1.30 or less, or 1.28 or less, or 1.25 or less, or 1.23 or less, or 1.20 or less, or 1.18 or less, or 1.15 or less, or 1.13 or less, or 1.10 or less, or 1.08 or less, or 1.05 or less, or 1.03 or less. In other embodiments, Tg / Ta may be at least 0.70, or at least 0.80, or at least 0.90, or at least 0.98, or at least 1.00, or at least 1.03, or at least 1.05, or at least 1.08. It will be appreciated that Tg / Ta can be between any of the minimum and maximum values ​​set forth above, including, for example, but not limited to, at least 0.8 and no more than 1.45, or at least 0.98 and no more than 1.20.

[0015] Figure 2A includes a diagram of a portion of a coated abrasive article 200 according to an embodiment. As shown in Figure 2, the coated abrasive article 200 may include a backing 201 having a longitudinal axis 280 and a transverse axis 281. The abrasive article 200 may include a backing 201 having a major surface and an abrasive layer forming an abrasive surface overlying the major surface of the backing. The abrasive layer may form a single layer of abrasive particles 202 and 203 adhered to the major surface of the backing. Figure 2B also includes a diagram of a portion of a coated abrasive having abrasive particles 202 and 203.

[0016] In some embodiments, the abrasive particles may have a random rotational orientation relative to each other. The randomness of the rotational orientation is evaluated by creating a histogram or distribution of orientations measured from randomly sampled areas of a given abrasive article. The process for measuring the rotational orientation of particles on a substrate begins by obtaining a coated abrasive sample that does not contain a layer covering the particles, or by cleaning the coated abrasive sample to expose the particles so that they are clearly visible. If the coated abrasive article includes a layer (e.g., size coat, supersize coat, etc.) covering the particles, a gentle sandblasting operation can be performed to selectively remove the covering layer and expose the underlying abrasive particles. Care should be taken during the sandblasting operation to ensure that the particles are not damaged or displaced. The selective removal operation can be performed in stages to ensure that only the covering layer is removed, but the underlying particles are not damaged or altered.

[0017] After obtaining a sample with exposed particles, at least two randomly selected areas of the sample are imaged using a suitable device, such as a Cannon Powershot S110 camera with a resolution of 338 pixels / cm. From these images, the position and orientation of each particle relative to the edge of the sample is cataloged using MATLAB image analysis software. The orientation of the particle is based on the angle of the abrasive particle's major axis when viewed from above down relative to the edge of the coated abrasive. The same axes should be used to evaluate all sample images. The orientation of each particle is defined by an orientation angle between -90 degrees and +90 degrees. The orientation angles are then plotted on a plot of orientation angle (x-axis) versus degree (y-axis) to create a histogram of orientation angles. If the histogram has an essentially flat profile, with the degree for any given orientation angle being approximately the same as the degree for any other orientation angle, the histogram demonstrates that the particles generally do not have a primary orientation mode, and therefore the particles have a random orientation. Figure 3 includes an exemplary image of a portion of an abrasive article with randomly oriented abrasive particles.

[0018] It should be noted that while certain embodiments herein may have particles arranged in a random orientation, other embodiments may include particles arranged in a non-random or controlled distribution.

[0019] According to one embodiment, the abrasive particle 202 may cover the backing 201 at a first position that defines a width of the backing 201 and has a first rotational orientation relative to a transverse axis 281 that is perpendicular to the longitudinal axis 280. Specifically, the abrasive particle 202 may have a predetermined rotational orientation defined by a first rotational angle between a transverse axis 284 that is parallel to the transverse axis 281 and a dimension of the abrasive particle 202. Notably, references to dimensions herein may be references to a bisection axis 231 of the abrasive particle 202 that extends through a center point 221 of the abrasive particle 202 when viewed from above and below. Additionally, the predetermined rotational orientation may be defined as a minimum angle 241 with the transverse axis 284 that extends through the center point 221. As illustrated in FIG. 2A, the abrasive particle 202 may have a predetermined rotational angle defined as a minimum angle 241 between the bisection axis 231 and the transverse axis 284, where the transverse axis is parallel to the transverse axis 281. It will be appreciated that the transverse axis 281 may also be a radial axis if the backing 201 has a circular or elliptical shape. According to certain embodiments, the angle 241 defining the rotational orientation of the abrasive particles 202 relative to the transverse axis 284 may be any value within the range of at least 0 degrees and up to 90 degrees.

[0020] 2A, the abrasive particle 203 can be in a second position overlying the backing 201 and having a predetermined rotational orientation. Notably, the predetermined rotational orientation of the abrasive particle 203 can be characterized as the minimum angle between a transverse axis 285 parallel to the transverse axis 281 of the backing and a bisecting axis 232 of the abrasive particle 203 extending through a center point 222 of the abrasive particle 203. According to certain embodiments, the rotation angle 208 can be any value at least within the range of 0 degrees to 90 degrees.

[0021] According to certain embodiments, abrasive particle 202 may have a predetermined rotational orientation, as defined by rotation angle 241, that differs from the predetermined rotational orientation of abrasive particle 203, as defined by rotation angle 208. Specifically, the difference between rotation angle 241 and rotation angle 208 for abrasive particles 202 and 203 may define a predetermined rotational orientation difference. In certain cases, the predetermined rotational orientation difference may be any value within a range of at least 0 degrees and up to and including 90 degrees.

[0022] FIG. 2B includes a top view of a portion of a coated abrasive article according to an embodiment. As shown, the abrasive article 200 can include a plurality of abrasive particles disposed at different locations on the backing 201, with the abrasive particles 253 defining a random distribution of particles on the backing. Furthermore, the abrasive particles 253 have a random rotational orientation relative to one another such that the rotational orientation of the abrasive particles 253 varies randomly from particle to particle. According to one aspect, the random rotational orientation of the abrasive particles is such that the rotational angle of one abrasive particle in the group cannot be used to predict the rotational orientation of any of the directly neighboring particles. Thus, a group of abrasive particles with a random rotational orientation lacks any short-range (i.e., directly adjacent) or long-range order with respect to their rotational angles. It will be understood that any particles attached to a backing using the systems and processes of embodiments herein can have a random rotational orientation relative to one another.

[0023] Coated abrasive articles of embodiments herein may have at least a majority of the total content (weight or number) of abrasive particles on the backing that have a random rotational orientation. In still other cases, at least 10% of the total number of shaped abrasive particles, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or essentially all of the shaped abrasive particles have a random rotational orientation. In one embodiment, all of the abrasive particles on the backing have a random rotational orientation.

[0024] FIG. 4A includes a side view of abrasive particles on a backing according to an embodiment. The methods disclosed in the embodiments herein may facilitate the formation of coated abrasive articles with a particular distribution and orientation of abrasive particles. Of note, without wishing to be bound by a particular theory, it is noted that the projection speed and efficiency of the processes disclosed herein may facilitate improved control of the tilt angle of the abrasive particles adhered to the backing. To better understand these features, FIG. 4A provides a side view of three abrasive particles in various orientations. It will be understood that the coated abrasive articles of the embodiments herein may have various loadings of particles in the orientations shown, as described in more detail herein. The first particle 402 may have a particle axis 403 that extends at a particular tilt angle 404 relative to the surface of the backing 401. The particle axis 403 may be parallel to the longitudinal axis of the first particle 402, which defines the length of the first particle 402. The first particle 402 represents an upright oriented particle with a tilt angle 404 in the range of greater than 65 degrees to 90 degrees. The second grain 411 may have a grain axis 412 extending at a particular tilt angle 413 relative to the surface of the backing 401. The grain axis 412 may be parallel to a longitudinal axis of the second grain 411 that defines the length of the second grain 411. The second grain 411 represents a tilted oriented grain with a tilt angle 413 in a range of more than 5 degrees to 65 degrees. The third grain 421 may have a grain axis 422 extending at a particular tilt angle 423 relative to the surface of the backing 401. The grain axis 422 may be parallel to a longitudinal axis of the third grain 421 that defines the length of the third grain 421. The third grain 421 represents a flat oriented grain with a tilt angle 423 in a range of 0 degrees to 5 degrees or less (i.e., 5 degrees or less). FIG. 4B includes a side view of a grain on a backing with a particular tilt angle according to an embodiment. As shown, the grain 431 may be a shaped abrasive grain as described in embodiments herein. Particle 431 may have a longitudinal axis 436 as defined later in this application. Backing 433 may define a substantially flat surface and have an axis 434 extending perpendicular to the substantially flat surface of backing 433. Tilt angle 435 is the minimum angle between the flat surface of backing 433 and axis 432 extending parallel to longitudinal axis 436 of particle 431.A particular particle may have longitudinal axes along various surfaces, which may result in different tilt angles, in which case the axis that defines the maximum angle is the tilt angle.

[0025] Figure 4C includes a top-down view of the particle of Figure 4B. In certain cases, the top-down view may provide a suitable vantage point for identifying the direction of tilt and therefore may be suitable for measuring the tilt angle.

[0026] 4D includes a side view of a particle on a backing having a particular tilt angle according to an embodiment. As shown, the particle 441 may have a longitudinal axis 446 as defined later in this application. The particle 441 may be an abrasive particle, more specifically, a non-shaped abrasive particle. The backing 443 may define a substantially flat surface and have an axis 444 extending perpendicular to the substantially flat surface of the backing 443. The tilt angle 445 may be the minimum angle between an axis 442 extending parallel to the longitudinal axis 446 and the surface of the backing 443. It will be understood that certain particles, such as equiaxed particles, do not have a tilt angle.

[0027] 4E includes a top-down view of the particle of FIG. 4D. The top-down view can be used to assess the tilt angle of the particle. As shown, the top-down view may be the best view for assessing the tilt angle since the side view does not necessarily reliably identify the minimum angle. A combination of top and side views may be suitable for identifying and assessing the tilt angle 445.

[0028] In one embodiment, the coated abrasive article may include a plurality of abrasive particles in which the tilt angle of the abrasive particles is controlled, which may facilitate improved performance of the coated abrasive. For example, at least a portion of the shaped abrasive particles have a tilt angle of greater than 45 degrees. In a further embodiment, the portion is at least 10% of the total number of shaped abrasive particles, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or essentially all of the shaped abrasive particles have a tilt angle of greater than 45 degrees.

[0029] In some embodiments, the coated abrasive article may have a certain percentage of upright particles, which may facilitate improved performance and / or manufacturing of the abrasive article. Upright particles may be defined as particles having an inclination angle of 65-90 degrees. In some embodiments, the upright abrasive particles may comprise at least 10% of the total number of abrasive particles, or at least 20% or at least 30% or at least 40% or at least 50% or at least 55% or at least 57% or at least 60% or at least 62% or at least 65% or at least 67% or at least 70% or at least 72% or at least 75% or at least 77% or at least 80% or at least 82% or at least 85% or at least 87% or at least 90% of the total number of abrasive particles. In other embodiments, the upright abrasive particles may comprise 99.9% or less of the total number of abrasive particles, or 99% or less or 98% or less or 97% or less or 96% or less or 95% or less of the total number of abrasive particles. It will be appreciated that the percentage of upright particles can be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 20% and not more than 99%, or at least 50% and not more than 95%.

[0030] In some embodiments, the coated abrasive article may have a certain percentage of tilted particles, which may facilitate improved performance and / or manufacturing of the abrasive article. The tilted particles may be defined as particles having a tilt angle of 5 to 65 degrees. In some embodiments, the tilted abrasive particles may comprise at least 1% of the total number of abrasive particles, or at least 2%, or at least 3%, or at least 4%, or at least 5%, or at least 6%, or at least 7%, or at least 8%, or at least 9%, or at least 10%, or at least 11%, or at least 12%, or at least 13%, or at least 14%, or at least 15%, or at least 16%, or at least 17%, or at least 18%, or at least 20%, or at least 25% of the total number of abrasive particles. In another embodiment, the graded abrasive particles may comprise 90% or less of the total number of abrasive particles, or 85% or less, or 80% or less, or 75% or less, or 70% or less, or 65% or less, or 60% or less, or 55% or less, or 50% or less, or 45% or less, or 40% or less, or 35% or less, or 30% or less, or 25% or less, or 20% or less, or 18% or less, or 15% or less, or 12% or less, or 10% or less of the total number of abrasive particles. It will be understood that the percentage of graded particles may be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 5% and 80% or less, or at least 15% and 35% or less.

[0031] In some embodiments, the coated abrasive article may have a certain percentage of well-oriented grains, which may facilitate improved performance and / or manufacturing of the abrasive article. Well-oriented grains are defined as grains having a tilt angle of 5 to 90 degrees, and may include tilted grains and upright grains. In some embodiments, well-oriented abrasive grains may comprise at least 60% of the total number of abrasive grains, or at least 62% or at least 65% or at least 67% or at least 70% or at least 72% or at least 75% or at least 77% or at least 80% or at least 82% or at least 85% or at least 87% or at least 90% or at least 92% or at least 95% of the total number of abrasive grains. In other embodiments, well-oriented abrasive grains may be 99.9% or less, or 99% or less, or 98% or less, or 97% or less, or 96% or less, or 95% or less of the total number of abrasive grains. It will be appreciated that the percentage of well-oriented grains can be between any of the minimum and maximum values ​​set forth above, including, for example, but not limited to, at least 5% and no more than 80%, or at least 15% and no more than 35%.

[0032] In some embodiments, the coated abrasive article may have a certain percentage of fallen particles, which may facilitate improved performance and / or manufacturing of the abrasive article. Fallen particles may be defined as particles having a tilt angle of 0-5 degrees. In some embodiments, the fallen abrasive particles are at least 0.1% of the total number of abrasive particles, or at least 0.2% or at least 0.4% or at least 0.6% or at least 0.8% or at least 1% or at least 1.5% or at least 2% or at least 2.5% or at least 3% or at least 3.5% or at least 4% or at least 4.5% or at least 5% of the total number of abrasive particles. In other embodiments, the fallen abrasive particles may comprise 20% or less of the total number of abrasive particles, or 18% or less or 15% or less or 12% or less or 10% or less or 9% or less or 8% or less or 7% or less or 6% or less or 5% of the total number of abrasive particles. It will be appreciated that the percentage of fallen particles can be between any of the minimum and maximum values ​​set forth above, including, for example, but not limited to, at least 0.2% and no more than 15%, or at least 1% and no more than 9%.

[0033] In some embodiments, the coated abrasive article may have a certain percentage of inverted grains that may facilitate improved performance and / or manufacturing of the abrasive article. Inverted grains may be defined as grains that have a 5-90 degree inclination angle and a tip, corner, or apex that extends into the make coat and one or more flat surfaces, such as a base, opposite the tip at the other end of the abrasive grain. Only grains that have a tip at one end of their longitudinal axis and at least one flat surface at the opposite end of the longitudinal axis may be inverted. Exemplary grain shapes that may be inverted include triangles, three-pointed (3-PT) stars, pentagons, and pyramids. Grains that have flat surfaces at both ends of their longitudinal axis (e.g., rods or cylinders, rectangular prisms) and grains that have apexes at both ends of their longitudinal axis (e.g., toothpick, diamond, four-pointed (4-PT) stars) cannot be inverted. Inverted grains are not upright, tilted, fallen, or well oriented. In some embodiments, the inverted abrasive particles comprise at least 0.1% of the total number of abrasive particles, or at least 0.2%, or at least 0.4%, or at least 0.6%, or at least 0.8%, or at least 1%, or at least 1.5%, or at least 2%, or at least 2.5%, or at least 3%, or at least 3.5%, or at least 4%, or at least 4.5%, or at least 5% of the total number of abrasive particles. In other embodiments, the inverted abrasive particles may comprise 20% or less of the total number of abrasive particles, or 18% or less, or 15% or less, or 12% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less of the total number of abrasive particles. It will be appreciated that the percentage of inverted particles may be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 0.2% and 15% or less, or at least 1% and 9% or less.

[0034] In some embodiments, the coated abrasive particles may have a particular ratio of standing particles (Pst) to slanted particles (Psl) (Pst / Psl) that may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, Pst / Psl may be at least 1 or at least 1.2 or at least 1.4 or at least 1.6 or at least 1.8 or at least 2.0 or at least 2.2 or at least 2.4 or at least 2.6 or at least 2.8 or at least 3.0 or at least 3.2 or at least 3.4 or at least 3.6 or at least 3.8 or at least 4.0 or at least 4.2 or at least 4.4 or at least 4.6 or at least 4.8 or at least 5.0 or at least 5.2 or at least 5.4 or at least 5.6. In other embodiments, Pst / Psl may be 100 or less or 95 or less or 90 or less or 80 or less or 70 or less or 60 or less or 50 or less or 40 or less or 30 or less or 20 or less or 10 or less. It will be appreciated that Pst / Psl can be between any of the minimum and maximum values ​​set forth above, including, for example and without limitation, at least 1.2 and not more than 95, or at least 2.0 and not more than 40.

[0035] In some embodiments, the coated abrasive particles may have a particular ratio of upright particles (Pst) to fallen particles (Pf) (Pst / Pf) that may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, Pst / Pf may be at least 2.0 or at least 2.2 or at least 2.4 or at least 2.6 or at least 2.8 or at least 3.0 or at least 3.2 or at least or at least 3.4 or at least 3.6 or at least 3.8 or at least 4.0 or at least 4.2 or at least 4.4 or at least 4.6 or at least 4.8 or at least 5.0 or at least 5.2 or at least 5.4 or at least 5.6 or at least 5.8 or at least 6.0 or at least 6.2 or at least 6.4 or at least 6.6 or at least 6.8 or at least 7.0 or at least 7.2 or at least 7.4 or at least 7.6 or at least 7.8 or at least 8.0. In other embodiments, Pst / Pf can be 1000 or less, or 800 or less, or 500 or less, or 200 or less, or 100 or less, or 95 or less. It will be appreciated that Pst / Pf can be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 2.0 and 500 or less, or at least 2.6 and 95 or less.

[0036] In some embodiments, the coated abrasive particles may have a particular ratio of tilted particles (Psl) to fallen particles (Pf) (Psl / Pf) that may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, Psl / Pf may be at least 1 or at least 1.2 or at least 1.4 or at least 1.6 or at least 1.8 or at least 2.0 or at least 2.2 or at least 2.4 or at least 2.6 or at least 2.8 or at least 3.0 or at least 3.2 or at least or at least 3.4 or at least 3.6 or at least 3.8 or at least 4.0 or at least 4.2 or at least 4.4 or at least 4.6 or at least 4.8 or at least 5.0 or at least 5.2 or at least 5.4 or at least 5.6. In other embodiments, Psl / Pf may be 100 or less or 95 or less or 90 or less or 80 or less or 70 or less or 60 or less or 50 or less or 40 or less or 30 or less or 20 or less or 10 or less or 8 or less or 6 or less. It will be appreciated that Psl / Pf can be between any of the minimum and maximum values ​​set forth above, including, for example, but not limited to, at least 2.0 and not more than 95, or at least 2.6 and not more than 70.

[0037] In some embodiments, the coated abrasive particles may have a particular ratio of upright particles (Pst) to inverted particles (Pi) (Pst / Pi) that may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, Pst / Pi may be at least 1, or at least 2.0, or at least 3.0, or at least 4.0, or at least 5.0, or at least 6, or at least 7, or at least 8, or at least 9, or at least 10, or at least 12, or at least 15, or at least 18, or at least 20, or at least 25, or at least 30, or at least 40, or at least 50. In other embodiments, Pst / Pi may be 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less, or 8 or less, or 6 or less. It will be appreciated that Pst / Pi may be between any of the minimum and maximum values ​​listed above, including, for example, but not limited to, at least 2.0 and 80 or less, or at least 6 and 20 or less.

[0038] In some embodiments, the coated abrasive particles may have a particular ratio of inclined grains (Psl) to inverted grains (Pi) (Psl / Pi) that may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, Psl / Pi may be at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1 or at least 1.2 or at least 1.4 or at least 1.6 or at least 1.8 or at least 2.0 or at least 2.2 or at least 2.4 or at least 2.6 or at least 2.8 or at least 3.0 or at least 3.2 or at least or at least 3.4 or at least 3.6 or at least 3.8 or at least 4.0 or at least 4.2 or at least 4.4 or at least 4.6 or at least 4.8 or at least 5.0 or at least 5.2 or at least 5.4 or at least 5.6. In another embodiment, Psl / Pi can be 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less, or 8 or less, or 6 or less, or 4 or less, or 3 or less, or 2 or less, or 1.5 or less. It will be appreciated that Psl / Pi can be between any of the minimum and maximum values ​​recited above, including, for example, but not limited to, at least 2.0 and 95 or less, or at least 2.6 and 70 or less.

[0039] In some embodiments, the coated abrasive particles may have a particular ratio of fallen particles (Pf) to inverted particles (Pi) (Pf / Pi) that may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, Pf / Pi may be at least 0.6, or at least 0.7, or at least 0.8, or at least 0.9, or at least 1, or at least 1.2, or at least 1.4, or at least 1.6, or at least 1.8, or at least 2.0, or at least 2.2, or at least 2.4, or at least 2.6, or at least 2.8, or at least 3.0, or at least 3.2, or at least 3.4, or at least 3.6, or at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4.8, or at least 5.0. In alternative embodiments, Pf / Pi can be 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less, or 8 or less, or 6 or less, or 4 or less, or 3 or less, or 2 or less, or 1.5 or less. It will be appreciated that Pf / Pi can be between any of the minimum and maximum values ​​recited above, including, for example, but not limited to, at least 2.0 and 95 or less, or at least 2.6 and 70 or less.

[0040] The embodiments herein refer to particles that may include abrasive particles, secondary particles, or any combination thereof. Various types of abrasive particles and / or secondary particles may be used with the abrasive articles described in the embodiments herein. FIG. 5A includes a perspective view of a shaped abrasive particle according to an embodiment. The shaped abrasive particle 500 may include a body 501 including a major surface 502, a major surface 503, and a side surface 504 extending between the major surfaces 502 and 503. As illustrated in FIG. 5A, the body 501 of the shaped abrasive particle 500 may be a thin-shaped body with the major surfaces 502 and 503 being larger than the side surface 504. Additionally, the body 501 may include a longitudinal axis 510 that extends from the apex to the base through a midpoint 550 on the major surface 502 or 503. The longitudinal axis 510 may define the longest dimension of the body along the major surface and through the midpoint 550 of the major surface 502.

[0041] If the midpoint of the major surface of the body is not readily apparent for a particular particle, one can view the major surface from top to bottom, draw a best fitting circle around the two-dimensional shape of the major surface, and use the center of the circle as the midpoint of the major surface. Figure 5B includes a top-down view of the shaped abrasive particle of Figure 5A. Notably, body 501 includes major surface 502 having a triangular two-dimensional shape. A circle 560 has been drawn around the triangle to facilitate locating midpoint 550 on major surface 502.

[0042] 5A, the body 501 may further include a transverse axis 511 that defines a width of the body 501 extending generally perpendicular to the longitudinal axis 510 on the same major surface 502. Finally, as shown, the body 501 may include a vertical axis 512, which in the context of a thin-shaped body may define a height (or thickness) of the body 501. In a thin-shaped body, the length of the longitudinal axis 510 exceeds the vertical axis 512. As shown, the thickness 512 may extend perpendicular to the plane defined by the longitudinal axis 510 and the transverse axis 511 along the side surface 504 between the major surfaces 502 and 503. It will be understood that references herein to the length, width, and height of an abrasive particle may be references to average values ​​taken from a suitable sampling size of a larger group of abrasive particles, including, for example, a group of abrasive particles fixed to a fixed abrasive.

[0043] 5A includes a diagram of a shaped abrasive particle having a two-dimensional shape as defined by the plane of the upper major surface 502 or major surface 503, which has a generally triangular two-dimensional shape. It will be understood that the shaped abrasive particles of the embodiments herein are not so limited and may include other two-dimensional shapes. For example, the shaped abrasive particles of the embodiments herein may include particles having a body having a two-dimensional shape as defined by the major surfaces of the body from the group of shapes including polygons, regular polygons, irregular polygons, irregular polygons with arcuate or curved sides or portions of sides, ellipses, numbers, Greek letters, Latin letters, Russian letters, Chinese characters, complex shapes having combinations of polygonal shapes, shapes including a central region and multiple arms (e.g., at least three arms) extending from the central region (e.g., star shapes), and combinations thereof. Particular polygonal shapes include rectangles, trapezoids, quadrilaterals, pentagons, hexagons, heptagons, octagons, nonagons, decagons, and any combination thereof. In other cases, the final formed shaped abrasive particles may have a body having a two-dimensional shape, such as an irregular quadrilateral, an irregular rectangle, an irregular trapezoid, an irregular pentagon, an irregular hexagon, an irregular octagon, an irregular nonagon, an irregular decagon, and combinations thereof. An irregular polygonal shape is one in which at least one of the sides defining the polygonal shape differs in dimension (e.g., length) relative to another side. As illustrated in other embodiments herein, the two-dimensional shape of a particular shaped abrasive particle may have a particular number of exterior vertices or corners. For example, the body of the shaped abrasive particle can have a two-dimensional polygonal shape when viewed in a plane defined by the length and width, the body including a two-dimensional shape having at least four outer vertices (e.g., a quadrilateral), at least five outer vertices (e.g., a pentagon), at least six outer vertices (e.g., a hexagon), at least seven outer vertices (e.g., a heptagon), at least eight outer vertices (e.g., an octagon), at least nine outer vertices (e.g., a nonagon), etc.

[0044] FIG. 7 includes a perspective view of a shaped abrasive particle according to another embodiment. Notably, shaped abrasive particle 700 may include a body 701 including a surface 702 and a surface 703, which may be referred to as end faces 702 and 703. The body may further include major faces 704, 705, 706, 707 extending between and bonded to end faces 702 and 703. The shaped abrasive particle of FIG. 7 is an elongated shaped abrasive particle having a longitudinal axis 710 extending along major face 705 through a midpoint 740 between end faces 702 and 703. For particles having a identifiable two-dimensional shape, such as the shaped abrasive particles of FIG. 5 and FIG. 7, the longitudinal axis is a dimension that is readily understood to define the length of the body through a midpoint on the major face. For example, in FIG. 7, the longitudinal axis 710 of shaped abrasive particle 700 extends between end faces 702 and 703 parallel to the edges that define the major faces as shown. Such a longitudinal axis is consistent with how the length of the rod is defined. Of note, the longitudinal axis 710 does not extend diagonally between the corner joining the end faces 702 and 703 and the edge defining the major surface 705, although such a line may define the maximum length dimension. To the extent that the major surface has undulations or minor imperfections from a perfectly flat surface, the longitudinal axis may be determined using a top-down two-dimensional image that ignores the undulations.

[0045] It will be appreciated that surface 705 is selected to illustrate longitudinal axis 710 because body 701 has a generally square cross-sectional profile as defined by end faces 702 and 703. Thus, surfaces 704, 705, 706, and 707 may be approximately the same size relative to one another. However, in the context of other elongated abrasive particles, surfaces 702 and 703 may have different shapes, e.g., rectangular, and thus at least one of surfaces 704, 705, 706, and 707 may be larger relative to the others. In such cases, the largest surface may define a major surface, and the longitudinal axis may extend through midpoint 740 along the largest of these surfaces and parallel to the edges that define the major surface. As further illustrated, body 701 may include a transverse axis 711 that extends perpendicular to longitudinal axis 710 within the same plane defined by surface 705. As further shown, the body 701 may further include a vertical axis 712 that defines the height of the abrasive particles, the vertical axis 712 extending in a direction perpendicular to the plane defined by the longitudinal axis 710 and the lateral axis 711 of the surface 705 .

[0046] It will be appreciated that, similar to the thin shaped abrasive particle of Figure 5, the elongated shaped abrasive particle of Figure 7 can have a variety of two-dimensional shapes, such as those defined for the shaped abrasive particle of Figure 5. The two-dimensional shape of the body 701 can be defined by the shape of the periphery of the end faces 702 and 703. The elongated shaped abrasive particle 700 can have any of the attributes of the shaped abrasive particles of the embodiments herein.

[0047] 8A includes a perspective view of a controlled height abrasive particle (CHAP), according to an embodiment. As shown, the CHAP 800 can include a body 801 including a first major surface 802, a second major surface 803, and a side surface 804 extending between the first major surface 802 and the second major surface 803. As shown in FIG. 8A, the body 801 can have a thin, relatively flat shape, with the first major surface 802 and the second major surface 803 being larger than the side surface 804 and being substantially parallel to one another. Additionally, the body 801 can include a longitudinal axis 810 extending through a midpoint 820 and defining a length of the body 801. The body 801 may further include a transverse axis 811 on the first major surface 802 that extends through a midpoint 820 of the first major surface 802 and is perpendicular to the longitudinal axis 810 and defines a width of the body 801 .

[0048] The body 801 may further include a vertical axis 812 that may define the height (or thickness) of the body 801. As shown, the vertical axis 812 may extend along the side 804 between the first major surface 802 and the second major surface 803 in a direction generally perpendicular to the plane defined by the axes 810 and 811 on the first major surface. For a body of thin shape, such as the CHAP illustrated in FIG. 8A, the length may be equal to or greater than the width, and the length may exceed the height. It will be understood that references herein to the length, width, and height of an abrasive particle may refer to average values ​​taken from a suitable sampling size of abrasive particles from a batch of abrasive particles.

[0049] Unlike the shaped abrasive particles of Figures 5A, 5B, and 7, the CHAP of Figure 8A does not have an easily identifiable two-dimensional shape based on the perimeter of the first major surface 802 or the second major surface 803. Such abrasive particles can be formed in a variety of ways, including but not limited to, breaking a thin layer of material to form an abrasive particle having a controlled height, but irregularly shaped flat major surface. For such particles, the longitudinal axis is defined as the longest dimension on the major surface that extends through a midpoint on the surface. To the extent that the major surface has undulations, the longitudinal axis can be determined using a top-down two-dimensional image that ignores the undulations. Additionally, as described above in Figure 5B, a best fit circle can be used to identify the midpoint of the major surface to identify the longitudinal and transverse axes.

[0050] FIG. 8B includes a diagram of a non-shaped particle, which may be an elongated non-shaped abrasive particle, or a secondary particle, such as a diluent grain, filler, agglomerate, etc. The shaped abrasive particles may be formed through certain processes, including molding, printing, casting, extrusion, etc. The shaped abrasive particles may be formed such that each particle has surfaces and edges in substantially the same arrangement relative to each other. For example, a group of shaped abrasive particles generally has surfaces and edges in the same arrangement and orientation relative to each other and / or two-dimensional shapes. Thus, shaped abrasive particles have a relatively high shape fidelity and consistency in the arrangement of surfaces and edges relative to each other. Furthermore, constant height abrasive particles (CHAPs) may also be formed through certain processes that facilitate the formation of a thin shaped body that may have an irregular two-dimensional shape when viewed from above and below the major surface. The CHAPs may have a lower shape fidelity than shaped abrasive particles, but may have substantially flat and parallel major surfaces separated by side surfaces.

[0051] In contrast, non-shaped particles are formed through different processes and may have different shape attributes compared to shaped abrasive particles and CHAP. For example, non-shaped particles are typically formed by a grinding process, which forms a mass of material, which is then crushed and sieved to obtain abrasive particles of a certain size. However, non-shaped particles have surfaces and edges that are approximately randomly arranged, and generally lack any recognizable two- or three-dimensional shape in the arrangement of the surfaces and edges. Furthermore, non-shaped particles do not necessarily have a consistent shape relative to each other, and therefore have significantly lower shape fidelity compared to shaped abrasive particles or CHAP. Non-shaped particles are generally defined by randomly arranged surfaces and edges for each particle relative to other non-shaped particles.

[0052] FIG. 8B includes a perspective view of a non-shaped particle. The non-shaped particle 850 may have a body 851 including a generally random arrangement of edges 855 extending along the outer surface of the body 851. The body may further include a longitudinal axis 852 that defines the longest dimension of the particle. The longitudinal axis 852 defines the longest dimension of the body when viewed in two dimensions. Thus, unlike shaped abrasive particles and CHAPs, whose longitudinal axes are measured on the major surface, the longitudinal axis of a non-shaped particle is defined by the vertices on the body that are furthest from each other when the particle is viewed in two dimensions using an image or perspective that provides a view of the longest dimension of the particle. That is, while elongated particles as illustrated in FIG. 8B, non-shaped particles should be viewed in a perspective view that reveals the longest dimension in order to properly appreciate the longitudinal axis. The body 851 may further include a transverse axis 853 that extends perpendicular to the longitudinal axis 852 and defines the width of the particle. The horizontal axis 853 may extend perpendicular to the vertical axis 852 through a vertical axis midpoint 856 in the same plane used to identify the vertical axis 852. The abrasive particle may have a height (or thickness) as defined by a vertical axis 854. The vertical axis 854 may extend through the midpoint 856, but in a direction perpendicular to the plane used to define the vertical axis 852 and the horizontal axis 853. To assess the height, one may have to change the view of the abrasive particle to view the particle from a different perspective than used to assess the length and width.

[0053] In some embodiments, the plurality of abrasive particles 102 and 103 of the coated abrasive article may comprise shaped abrasive particles. In some embodiments, the shaped abrasive particles may be 3-PT star-shaped abrasive particles. The abrasive particles may have a length (l), a width (w), and a thickness (t), where width >= thickness and length >= thickness. The particles may have a primary aspect ratio based on the length:width of the body. The particles may have a secondary aspect ratio based on the length:thickness of the body. The particles may also have a tertiary aspect ratio based on the width:thickness of the body. The particles 102 and 103 may be elongated abrasive particles with a primary aspect ratio of greater than 1.1:1.

[0054] In some embodiments, the plurality of shaped abrasive particles may include a plurality of shaped abrasive particles having a 3-PT star-shaped two-dimensional shape when viewed in the plane of the length and width of the body. The body may include at least three exterior corners and at least four side sections, or at least five side sections, or at least six side sections. In some embodiments, the plurality of shaped abrasive particles may include a body having at least three exterior corners, the sum of the exterior corner angles being less than 180 degrees. In some embodiments, the plurality of shaped abrasive particles may include a body having at least three exterior corners, each of the exterior corners defining an angle less than 60 degrees, or less than 59 degrees, or less than 58 degrees, or less than 57 degrees, or less than 56 degrees, or less than 55 degrees. In some embodiments, the plurality of shaped abrasive particles may include a body having at least three exterior corners and at least three interior corners, each of the interior corners having an interior corner angle value that exceeds any of the exterior corner values ​​of any of the at least three exterior corners.

[0055] Outside corners can be identified using the "rubber band test": if a rubber band is stretched around the body of an abrasive particle, the corner that contacts the rubber band and causes it to deflect is an outside corner.

[0056] 6A includes a top view image of a 3-PT star-shaped abrasive particle according to certain embodiments. As shown, the shaped abrasive particle 600 may define a star-shaped body when viewed in two dimensions. Specifically, the shaped abrasive particle 600 may include a body 601 having a central portion 602 and a first arm 603, a second arm 604, and a third arm 605 extending from the central portion 602. The body 601 may have a length (l) measured as the longest dimension along a side of the particle, and a width (w) measured as the longest dimension of the particle between a midpoint 653 of the side, through a midpoint 690 of the body 601, to a first tip 606 of the first arm 603. The width may extend in a direction perpendicular to the length dimension. The body 601 may have a thickness (t) extending in a direction perpendicular to the top or first major surface 610 of the body 601 and defining a third side 656 between the top or first major surface 610 and the base surface 611, as illustrated in FIG. 6B, which is a side view of the image of the particle of FIG. 6A.

[0057] The shaped abrasive particle 600 may have a body 601 in the form of a 3-PT star defined by a first arm 603, a second arm 604, and a third arm 605 extending from a central portion 602. According to one particular embodiment, at least one of the arms, including for example the first arm 603, may have a midpoint width 613 that is less than the central portion width 612. The central portion 602 may be defined as the area between the midpoints 651, 652, and 653 of the first side 654, the second side 655, and the third side 656, respectively. The central portion width 612 of the first arm 603 may be the width of the dimension between the midpoints 651 and 652. The midpoint width 613 may be the width of a line at the midpoint between the line of the central portion width 612 and the tip 606 of the first arm 603 along the first axis 660. In certain cases, the midpoint width 613 can be about 90% or less, such as about 80% or less, about 70% or less, about 5% or less, or even about 60% or less, of the center portion width 612. Further, the midpoint width 613 can be at least about 10%, such as at least about 20%, at least about 30%, or even at least about 40% of the center portion width 612. It will be understood that the midpoint width 613 can have a width within a range between any of the above minimum and maximum percentages of the center portion width 612.

[0058] Additionally, the body 601 may have at least one arm, such as the first arm 603, having a tip width at the tip 606 of the first arm 603 that is less than the midpoint width 613. In such cases where the tip 606 is sharply formed, the tip width may be considered to be 0. In cases where the tip 606 has a radius of curvature, the tip width may be considered to be the diameter of a circle defined by the radius of curvature. According to an embodiment, the tip width 614 may be about 90% or less of the midpoint width 613, such as about 80% or less, or about 70% or less, or about 60% or less, or about 50% or less, or about 40% or less, or about 30% or less, or about 20% or less, or even about 10% or less. Additionally, in certain non-limiting embodiments, the tip width 614 may be at least about 1% of the midpoint width 613, such as at least about 2%, at least about 3%, at least about 5%, or even at least about 10%. It will be appreciated that the tip width 614 may have a width within a range between any of the minimum and maximum percentages noted above with respect to the midpoint width 613 .

[0059] As further shown, the body 601 can have a first arm 603 including a first tip 606 that defines a first tip angle 621 between a first side 654 and a second side 655. According to an embodiment, the first tip angle can be less than about 60 degrees, such as about 55 degrees or less, about 50 degrees or less, about 45 degrees or less, or even about 40 degrees or less. Additionally, the first tip angle can be at least about 5 degrees, such as at least about 8 degrees, at least about 10 degrees, at least about 15 degrees, at least about 20 degrees, at least about 25 degrees, or even at least about 30 degrees. The first tip angle can be within a range between any of the minimum and maximum values ​​listed above.

[0060] The body 601 can include a second arm 604 having a second tip 607 that defines a second tip angle 622 between a second side 655 and a third side 656. The second tip angle can be substantially the same as the first tip angle, such as within 5% of the numerical angle. Alternatively, the second tip angle can be substantially different relative to the first tip angle.

[0061] The body 601 can include a third arm 605 having a third tip 608 that defines a third tip angle 623 between a first side 654 and a third side 656. The third tip angle can be substantially the same as the first tip angle or the second tip angle, such as within 5% of the numerical angle. Alternatively, the third tip angle can be substantially different relative to the first tip angle or the second tip angle.

[0062] The body 601 may have a total angle that is the sum of the values ​​of the first tip angle, the second tip angle, and the third tip angle, which may be less than about 180 degrees. In other embodiments, the total angle may be about 175 degrees or less, such as about 170 degrees or less, about 15 degrees or less, about 150 degrees or less, such as about 140 degrees or less, about 130 degrees or less, about 125 degrees or less, or even about 120 degrees or less. Further, in one non-limiting embodiment, the body 601 may have a total angle of at least about 60 degrees, such as at least about 70 degrees, at least about 80 degrees, at least about 90 degrees, such as at least about 95 degrees, at least about 100 degrees, or even at least about 105 degrees. It will be understood that the total angle may be within a range between any of the minimum and maximum values ​​stated above.

[0063] As discussed herein, the body 601 can have a first side 654 extending between the first arm 606 and the third arm 608. In certain instances, the first side 654 can have an arcuate contour. For example, with momentary reference to FIG. 6C, a top view image of a shaped abrasive particle according to an embodiment is provided. Notably, the shaped abrasive particle of FIG. 6C can include a 3-PT star shape having a body 681 and an arcuate side 682 extending between two vertices. In certain instances, the side 682 can have a concave contour defining a curved portion extending inwardly toward a central portion 683 of the body 681.

[0064] 6A , the body 601 can have a first side 654 having a first side section 658 and a second side section 659. The first side section 658 can extend between the first tip 606 and the midpoint 651, and the second side section 659 can extend between the third tip 608 and the midpoint 651. The first side section 658 and the second side section 659 can define an interior angle 662, which can be an obtuse angle. For example, the interior angle 662 can be greater than about 90 degrees, such as greater than about 95 degrees, greater than about 100 degrees, greater than about 110 degrees, or even greater than about 120 degrees. Further, in one non-limiting embodiment, the interior angle 662 can be less than or equal to about 320 degrees, such as less than or equal to about 300 degrees, or even less than or equal to about 270 degrees. It will be understood that the interior angle can be within a range between any of the minimum and maximum values ​​discussed above.

[0065] The first side section 658 can extend over a substantial portion of the length of the first side 654. For example, the first side section 658 can extend over at least about 20%, such as at least about 25%, at least about 30%, at least about 35%, or even at least about 40% of the total length of the first side 654. Further, in one non-limiting embodiment, the first side section 658 can have a length (ls1) between the midpoint 651 and the first tip 606 that is about 80% or less, such as about 75% or less, about 70% or less, or even about 5% or less of the total length of the side 654. It will be understood that the length of the first side section 658 can be within a range between any of the minimum and maximum percentages discussed above.

[0066] The second side section 659 can extend over a substantial portion of the length of the first side 654. For example, the second side section 659 can extend over at least about 20%, such as at least about 25%, at least about 30%, at least about 35%, or even at least about 40% of the total length of the first side 654. Furthermore, in one non-limiting embodiment, the second side section 659 can have a length (ls2) between the midpoint 651 and the third tip 608 that is about 80% or less, such as about 75% or less, about 70% or less, or even about 5% or less of the total length of the side 654 as a straight line between the first tip 606 and the third tip 608. It will be understood that the length of the second side section 659 can be within a range between any of the minimum and maximum percentages mentioned above.

[0067] The body 601 can include a first average side angle 631 between the sides 654, 655, and 656 and the top or first major surface 610. The body can also include a second side angle 632 between the sides 654, 655, and 656 and the second major or base surface 612.

[0068] In some embodiments, the abrasive particles may include a particular first side angle that may facilitate improved performance and / or manufacturing of the abrasive particles, hi some embodiments, the first side angle may be in the range of at least 70 degrees and no more than 94 degrees, or in the range of at least 80 degrees and no more than 93 degrees, or in the range of at least 83 degrees and no more than 92 degrees, or in the range of at least 85 degrees and no more than 91 degrees.

[0069] In some embodiments, the abrasive particles may include a particular second side angle that may facilitate improved performance and / or manufacturing of the abrasive particles, hi some embodiments, the second side angle may be in the range of at least 70 degrees and no more than 94 degrees, or in the range of at least 80 degrees and no more than 93 degrees, or in the range of at least 83 degrees and no more than 92 degrees, or in the range of at least 85 degrees and no more than 91 degrees.

[0070] Although the aforementioned body 601 in the shape of a 3-PT star is shown having a top surface 610 having a two-dimensional shape that is substantially the same as the two-dimensional shape of the base surface or second major surface 611 of the body 601 when viewed in the plane of the length and width of the body, other shapes are contemplated. For example, in one embodiment, the cross-sectional shape of the body at the base surface may define a base surface shape from the group consisting of a 3-PT star, a 4-PT star, a cross, a polygon, an ellipse, a number, a Greek letter, a Latin letter, a Russian letter, a complex shape having a combination of polygonal shapes, and combinations thereof. Additionally, the cross-sectional shape of the body at the top surface may differ from the base surface shape and define a top surface shape that may be selected from the group of a 3-PT star, a 4-PT star, a cross, a polygon, an ellipse, a number, a Greek letter, a Latin letter, a Russian letter, a complex shape having a combination of polygonal shapes, and combinations thereof.

[0071] In certain cases, the top surface shape may have an arcuate form of the base surface shape. For example, the top surface shape may define an arcuate 3-PT two-dimensional shape that defines arms with rounded ends. Specifically, the arms as defined at the base surface may have a smaller radius of curvature at their tips compared to the radius of curvature of the corresponding tips at the top surface.

[0072] It will be appreciated that, as described in other embodiments herein, at least one of the arms of body 601 may be formed with a twist such that the arm twists about a central axis. For example, first arm 603 may twist about axis 660. Additionally, body 601 may be formed such that at least one arm extends in an arcuate path from a central region.

[0073] In some embodiments, the plurality of shaped abrasive particles can define a first group of abrasive particles. In some embodiments, the first group of abrasive particles can include at least two different types of shaped abrasive particles, where the two different types of shaped abrasive particles differ from each other based on at least one characteristic selected from the group of particle size, two-dimensional shape, three-dimensional shape, composition, hardness, toughness, friability, density, grain size, agglomeration state, lateral position, longitudinal position, rotational orientation, or any combination thereof.

[0074] In some embodiments, the abrasive article may include a second group of abrasive particles that are different from the first group of abrasive particles. The second group of abrasive particles may differ from the first group of abrasive particles based on at least one characteristic selected from the group of particle size, two-dimensional shape, three-dimensional shape, composition, hardness, toughness, friability, density, grain size, agglomeration state, lateral position, longitudinal position, rotational orientation, or any combination thereof. In further embodiments, the second group of abrasive particles includes dilute abrasive particles. In another embodiment, the second group of particles may include randomly shaped or non-shaped abrasive particles.

[0075] The shaped abrasive particles may be formed through a particular process, including molding, printing, casting, extrusion, etc. The shaped abrasive particles may be formed such that each particle has surfaces and edges in substantially the same arrangement relative to each other. For example, a group of shaped abrasive particles generally have surfaces and edges in the same arrangement and orientation relative to each other and / or two-dimensional shape. Thus, the shaped abrasive particles have a relatively high shape fidelity and consistency in the arrangement of the surfaces and edges relative to each other. In contrast, non-shaped particles may be formed through a different process and have different shape attributes compared to shaped abrasive particles / for example, non-shaped particles are typically formed by a grinding process in which a mass of material is formed, which is then crushed and sieved to obtain abrasive particles of a certain size. However, non-shaped particles have surfaces and edges in a generally random arrangement, and generally lack any discernible two- or three-dimensional shape in the arrangement of the surfaces and edges. Furthermore, non-shaped particles do not necessarily have a consistent shape relative to each other, and therefore have significantly less shape fidelity compared to shaped abrasive particles. The non-shaped particles are generally defined by randomly positioned surfaces and edges for each particle relative to other non-shaped particles.

[0076] In some embodiments, the abrasive article may include a certain percentage of cracked abrasive particles, which may facilitate improved performance or manufacturing of the abrasive article. As defined herein, the cracks in the plurality of shaped abrasive particles include cracks visible at a magnification where the width of the particle is equal to 50% to 95% of the field of view. In some embodiments, the abrasive article may include a plurality of shaped abrasive particles having at least three inner corners, where 50% or less, or 45% or less, or 40% or less, or 35% or less, or 30% or less, or 25% or less, or 20% or less, or 18% or less, or 16% or less, or 14% or less, or 12% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2% or less, or 1% or less of the total number of shaped abrasive particles have cracks at the inner corners on the first major surface. In some embodiments, the abrasive article may include a plurality of shaped abrasive particles having at least three inner corners, where 50% or less, or 45% or less, or 40% or less, or 35% or less, or 30% or less, or 25% or less, or 20% or less, or 18% or less, or 16% or less, or 14% or less, or 12% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2% or less, or 1% or less of the total number of the shaped abrasive particles have cracks in the inner corners on the first major surface. In some embodiments, the abrasive article may include a plurality of shaped abrasive particles having a body with at least three inner corners, where at least 0.01%, or at least 0.5%, or at least 1%, or at least 2%, or at least 3%, or at least 4%, or at least 5%, or at least 8%, or at least 10% of the total number of the shaped abrasive particles have cracks in the inner corners on the first major surface. In some embodiments, the abrasive article may include a plurality of shaped abrasive particles having a body with at least three inner corners, where at least 0.01%, or at least 0.5%, or at least 1%, or at least 2%, or at least 3%, or at least 4%, or at least 5%, or at least 8%, or at least 10% of the total number of shaped abrasive particles have cracks in the inner corners on the second major surface. It will be understood that the percentage of the plurality of shaped abrasive particles having cracks in the inner corners may be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 0.5% and no more than 50%, or at least 5% and no more than 30%.

[0077] In some embodiments, the abrasive article may include a plurality of shaped abrasive particles of a particular material, which may facilitate the manufacture or improvement of the performance of the abrasive article. In some embodiments, the abrasive article may include a plurality of shaped abrasive particles including a ceramic material. In some embodiments, the abrasive article may include a plurality of shaped abrasive particles including at least one of a nitride, an oxide, a carbide, a boride, an oxynitride, an oxyboride, a diamond, a carbon-containing material, or any combination thereof. In some embodiments, the abrasive article may include a plurality of shaped abrasive particles including an oxide compound or composite, such as aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, chromium oxide, strontium oxide, silicon oxide, magnesium oxide, a rare earth oxide, or any combination thereof.

[0078] In some embodiments, the plurality of shaped abrasive particles may contain a particular percentage of alumina, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, the shaped abrasive particles may contain at least 80% by weight alumina, or at least 90% by weight alumina, or at least 91% by weight alumina, or at least 92% by weight alumina, or at least 93% by weight alumina, or at least 94% by weight alumina, or at least 95% by weight alumina, or at least 96% by weight alumina, or at least 97% by weight alumina. In some embodiments, the shaped abrasive particles may contain up to 99.5% by weight alumina, or up to 99% by weight alumina, or up to 98.5% by weight alumina, or up to 97.5% by weight alumina, or up to 97% by weight alumina, up to 96% by weight alumina, or up to 94% by weight alumina. It will be appreciated that the percentage of alumina in the plurality of shaped abrasive particles can be between any of the minimum and maximum values ​​recited above, including, for example, but not limited to, at least 80% and not more than 99% by weight, or at least 93% and not more than 97% by weight.

[0079] In some embodiments, each shaped abrasive particle of the plurality of shaped abrasive particles can have a particular density, which can facilitate improved manufacturing and / or performance of the abrasive article. In some embodiments, each shaped abrasive particle of the plurality of shaped abrasive particles can have a density of at least 95% of theoretical density.

[0080] In some embodiments, each shaped abrasive particle of the plurality of shaped abrasive particles may have a particular grain size, which may facilitate the manufacture and / or improvement of the performance of the abrasive particle. In some embodiments, each shaped abrasive particle of the plurality of shaped abrasive particles may have an average grain (crystallite) size of 1 micron or less, or 0.8 microns or less, or 0.6 microns or less, or 0.4 microns or less, or 0.2 microns or less, as measured according to the uncorrected intercept method. In some embodiments, each shaped abrasive particle of the plurality of shaped abrasive particles may have an average grain (crystallite) size of at least 0.01 microns or at least 0.05 microns. It will be understood that the grain size of the plurality of shaped abrasive particles may be between any of the minimum and maximum values ​​described above, including, for example, but not limited to, at least 0.01 microns and less than 1 micron, or at least 0.05 microns and less than 0.8 microns.

[0081] In some embodiments, the abrasive article may include a particular density of shaped abrasive particles that may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, the density of the shaped abrasive particles per square centimeter of the abrasive article is about 70 particles / cm. 2 Less than or equal to 65 particles / cm 2 Less than or equal to 60 particles / cm 2 Less than or equal to 55 particles / cm 2 Less than or equal to 50 particles / cm 2 In some embodiments, the density of the plurality of shaped abrasive particles per square centimeter of the abrasive article is at least 5 particles / cm 2 or at least 10 particles / cm 2 The density of the plurality of shaped abrasive particles may be, for example, but not limited to, at least 5 particles / cm 2 and 60 particles / cm 2 Less than or equal to 10 particles / cm 2and 50 particles / cm 2 It will be appreciated that the range may be between any of the minimum and maximum values ​​stated above, including:

[0082] In some embodiments, the abrasive article may include a particular density of well-oriented abrasive particles, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, the density of well-oriented abrasive particles per square centimeter of the abrasive article is at least 42 grains / cm. 2 or at least 43 grains / cm 2 or at least 44 grains / cm 2 or at least 45 grains / cm 2 or at least 46 grains / cm 2 or at least 47 grains / cm 2 or at least 48 grains / cm 2 or at least 49 grains / cm 2 or at least 50 grains / cm 2 or at least 51 grains / cm 2 or at least 52 grains / cm 2 or at least 53 grains / cm 2 or at least 54 grains / cm 2 In one embodiment, the density of well-oriented abrasive particles per square centimeter of the abrasive material can be 100 grains / cm 2 Less than or equal to 95 grains / cm 2 Less than or equal to 90 grains / cm 2 Less than or equal to 85 grains / cm 2 Less than or equal to 80 grains / cm 2 Less than or equal to 75 grains / cm 2 Less than or equal to 70 grains / cm 2 Less than or equal to 65 grains / cm 2 Less than or equal to 60 grains / cm 2 The density of well-oriented abrasive particles can be, for example, but not limited to, at least 42 particles / cm 2 and 60 particles / cm 2 Less than or equal to 49 particles / cm 2 and 70 particles / cm 2 It will be appreciated that the range may be between any of the minimum and maximum values ​​stated above, including:

[0083] In some embodiments, the abrasive article may include a make coat of a particular weight, which may facilitate improved performance and / or manufacturing of the abrasive article. In some embodiments, the abrasive article may include at least 1 lbs. / rm, or at least 2 lbs. / rm, or at least 3 lbs. / rm, or at least 4 lbs. / rm, or at least 5 lbs. / rm, or at least 6 lbs. / rm, or at least 7 lbs. / rm, or at least 8 lbs. / rm, or at least 9 lbs. / rm, or at least 10 lbs. / rm, or at least 11 lbs. / rm, or at least 12 lbs. / rm, or at least 13 lbs. / rm, or at least 14 lbs. / rm, or at least 15 lbs. / rm, or at least 16 lbs. / rm. In other embodiments, the abrasive article can include 20 lbs. / rm or less, or 19.5 lbs. / rm or less, or 19 lbs. / rm or less, or 18.5 lbs. / rm or less, or 18 lbs. / rm or less, or 17.5 lbs. / rm or less, or 17 lbs. / rm or less. It will be understood that the weight of the make coat can be between any of the minimum and maximum values ​​stated above, including, for example, at least 9 lbs. / rm and no more than 20 lbs. / rm, or at least 12 lbs. / rm and no more than 18.5 lbs. / rm.

[0084] In some embodiments, the coated abrasive article may include an abrasive surface that includes abrasive particles. In some embodiments, a certain percentage of the total surface area of ​​the abrasive surface may include a plurality of shaped abrasive particles. In some embodiments, 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less of the total surface area of ​​the abrasive surface includes a plurality of shaped abrasive particles. In some embodiments, at least 1%, or at least 5%, or at least 8%, or at least 10%, or at least 15%, or at least 20%, or at least 25%, or at least 30%, or at least 35%, or at least 40%, or at least 45%, or at least 50% of the total surface area of ​​the abrasive surface includes a plurality of shaped abrasive particles. It will be understood that the percentage of the total surface area of ​​the abrasive surface that includes a plurality of shaped abrasive particles may be between any of the minimum and maximum values ​​stated above, including, for example, but not limited to, at least 5% and no more than 50%, or at least 15% and no more than 80%.

[0085] Many different aspects and embodiments are possible. Some of these aspects and embodiments are described herein. After reading this specification, a person skilled in the art will understand that these aspects and embodiments are merely illustrative and do not limit the scope of the present invention. The embodiment may be according to any one or more of the embodiments listed below.

[0086] Embodiment Embodiment 1. An abrasive article comprising: Backing and A make coat covering the backing; a plurality of abrasive particles overlying the backing and at least partially contained in the make coat; and a make coat thickness ratio (Tg / Ta) of 1.5 or less, where Tg is the average thickness of the make coat on the sides of the abrasive particles and Ta is the average thickness of the make coat.

[0087] Embodiment 2. The abrasive article of embodiment 1, wherein the abrasive particles comprise shaped abrasive particles and / or elongated abrasive particles.

[0088] Embodiment 3. The abrasive article of embodiment 1, wherein the thickness ratio (Tg / Ta) is 1.45 or less, or 1.43 or less, or 1.40 or less, or 1.38 or less, or 1.35 or less, or 1.33 or less, or 1.30 or less, or 1.28 or less, or 1.25 or less, or 1.23 or less, or 1.20 or less, or 1.18 or less, or 1.15 or less, or 1.13 or less, or 1.10 or less, or 1.08 or less, or 1.05 or less, or 1.03 or less.

[0089] Embodiment 4. The abrasive article of embodiment 1, wherein the thickness ratio (Tg / Ta) is at least 0.70, or at least 0.80, or at least 0.90, or at least 0.98, or at least 1.00, or at least 1.03, or at least 1.05, or at least 1.08.

[0090] Embodiment 5. The abrasive article of embodiment 1, wherein the average thickness of the make coat at the sides of the grains (Tg) is at least 50 microns, or at least 60 microns, or at least 70 microns, or at least 80 microns, or at least 90 microns, or at least 100 microns, or at least 110 microns, or at least 120 microns, or at least 130 microns, or at least 140 microns, or at least 150 microns.

[0091] Embodiment 6. An abrasive article as described in embodiment 1, wherein the average thickness (Tg) of the make coat on the sides of the grains is 1 mm or less, or 800 microns or less, or 700 microns or less, or 600 microns or less, or 500 microns or less, or 400 microns or less, or 300 microns or less.

[0092] Embodiment 7. The abrasive article of embodiment 1, wherein the make coat comprises a thickness standard deviation at the sides of the abrasive particles (STDTg) of 100 microns or less, or 90 microns or less, or 85 microns or less, or 80 microns or less, or 75 microns or less, or 70 microns or less, or 65 microns or less, or 60 microns or less, or 55 microns or less, or 50 microns or less, or 45 microns or less, or 40 microns or less, or 35 microns or less, or 30 microns or less.

[0093] Embodiment 8. The abrasive article of embodiment 7, wherein the make coat comprises a lateral thickness standard deviation (STDTg) of the abrasive particles of at least 1 micron, or at least 5 microns, or at least 10 microns, or at least 15 microns, or at least 20 microns, or at least 25 microns, or at least 30 microns.

[0094] Embodiment 9. The abrasive article of embodiment 1, wherein the make coat has an average thickness (Ta) of at least 50 microns, or at least 60 microns, or at least 70 microns, or at least 80 microns, or at least 90 microns, or at least 100 microns, or at least 110 microns, or at least 120 microns, or at least 130 microns, or at least 140 microns, or at least 150 microns, or at least 160 microns.

[0095] Embodiment 10. The abrasive article of embodiment 1, wherein the average thickness (Ta) of the make coat is 1 mm or less, or 800 microns or less, or 700 microns or less, or 600 microns or less, or 500 microns or less, or 400 microns or less, or 300 microns or less, or 275 microns or less, or 250 microns or less, or 225 microns or less, or 200 microns or less.

[0096] Embodiment 11. The abrasive article of embodiment 1, wherein the make coat comprises a thickness standard deviation (STDT) of 100 microns or less, or 90 microns or less, or 85 microns or less, or 80 microns or less, or 75 microns or less, or 70 microns or less, or 65 microns or less, or 60 microns or less, or 55 microns or less, or 50 microns or less, or 45 microns or less, or 40 microns or less, or 35 microns or less, or 30 microns or less, or 25 microns or less, or 20 microns or less, or 15 microns or less, or 10 microns or less.

[0097] Embodiment 12. The abrasive article of embodiment 11, wherein the make coat comprises a standard deviation of thickness (STDT) of at least 1 micron, or at least 2 microns, or at least 3 microns, or at least 4 microns, or at least 5 microns, or at least 7 microns, or at least 10 microns, or at least 12 microns, or at least 15 microns, or at least 18 microns, or at least 20 microns, or at least 22 microns, or at least 25 microns, or at least 28 microns, or at least 30 microns.

[0098] Embodiment 13. The abrasive article of embodiment 1, wherein at least a portion of the abrasive particles comprise a random rotational orientation.

[0099] Embodiment 14. An abrasive article as described in embodiment 13, wherein a portion comprises at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 60%, or at least 70%, or at least 80%, or at least 90%, or essentially all, of the total number of abrasive particles having a random rotational orientation.

[0100] Embodiment 15. The abrasive article of embodiment 1, further comprising upright portions of abrasive particles having an upright orientation, wherein the upright portions comprise at least 10% of the total number of abrasive particles, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or at least 55%, or at least 57%, or at least 60%, or at least 62%, or at least 65%, or at least 67%, or at least 70%, or at least 72%, or at least 75%, or at least 77%, or at least 80%, or at least 82%, or at least 85%, or at least 87%, or at least 90% of the total number of abrasive particles.

[0101] Embodiment 16. An abrasive article as described in embodiment 15, wherein the upright portions are 99.9% or less of the total number of abrasive particles, or 99% or less, or 98% or less, or 97% or less, or 96% or less, or 95% or less of the total number of abrasive particles.

[0102] Embodiment 17. The abrasive article of embodiment 1, further comprising a slanted portion of abrasive particles having a tilted orientation, wherein the slanted portion comprises at least 1% of the total number of abrasive particles, or at least 2%, or at least 3%, or at least 4%, or at least 5%, or at least 6%, or at least 7%, or at least 8%, or at least 9%, or at least 10%, or at least 11%, or at least 12%, or at least 13%, or at least 14%, or at least 15%, or at least 16%, or at least 17%, or at least 18%, or at least 20%, or at least 25% of the total number of abrasive particles.

[0103] Embodiment 18. An abrasive article as described in embodiment 17, wherein the inclined portion is 90% or less of the total number of abrasive particles, or 85% or less, or 80% or less, or 75% or less, or 70% or less, or 65% or less, or 60% or less, or 55% or less, or 50% or less, or 45% or less, or 40% or less, or 35% or less, or 30% or less, or 25% or less, or 20% or less, or 18% or less, or 15% or less, or 12% or less, or 10% or less of the total number of abrasive particles.

[0104] Embodiment 19. The abrasive article of embodiment 1, further comprising upright portions (Pst) of the abrasive particles having a upright orientation and inclined portions (Psl) of the abrasive particles having an inclined orientation, and further comprising a ratio of upright portions to inclined portions (PSt / Psl) of at least 1, or at least 1.2, or at least 1.4, or at least 1.6, or at least 1.8, or at least 2.0, or at least 2.2, or at least 2.4, or at least 2.6, or at least 2.8, or at least 3.0, or at least 3.2, or at least 3.4, or at least 3.6, or at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4.8, or at least 5.0, or at least 5.2, or at least 5.4, or at least 5.6.

[0105] Embodiment 20. An abrasive article as described in embodiment 19, wherein the ratio of upright portions to inclined portions (PSt / Psl) is 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less.

[0106] Embodiment 21. The abrasive article of embodiment 1, further comprising a fallen portion of abrasive particles having a fallen orientation, wherein the fallen portion comprises at least 0.1% of the total number of abrasive particles, or at least 0.2%, or at least 0.4%, or at least 0.6%, or at least 0.8%, or at least 1%, or at least 1.5%, or at least 2%, or at least 2.5%, or at least 3%, or at least 3.5%, or at least 4%, or at least 4.5%, or at least 5% of the total number of abrasive particles.

[0107] Embodiment 22. An abrasive article as described in embodiment 21, in which the fallen portions are 20% or less of the total number of abrasive particles, or 18% or less, or 15% or less, or 12% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less of the total number of abrasive particles.

[0108] Embodiment 23. The abrasive article of embodiment 1, further comprising an upright portion (Pst) of the abrasive particles having an upright orientation and a fallen portion (Pf) of the abrasive particles having a fallen orientation, and further comprising a ratio of upright portions to fallen portions (PSt / Pf) of at least 2.0, or at least 2.2, or at least 2.4, or at least 2.6, or at least 2.8, or at least 3.0, or at least 3.2, or at least 3.4, or at least 3.6, or at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4.8, or at least 5.0, or at least 5.2, or at least 5.4, or at least 5.6, or at least 5.8, or at least 6.0, or at least 6.2, or at least 6.4, or at least 6.6, or at least 6.8, or at least 7.0, or at least 7.2, or at least 7.4, or at least 7.6, or at least 7.8, or at least 8.0.

[0109] Embodiment 24. An abrasive article as described in embodiment 23, wherein the ratio of upright portions to fallen portions (PSt / Pf) is 1000 or less, or 800 or less, or 500 or less, or 200 or less, or 100 or less, or 95 or less.

[0110] Embodiment 25. An abrasive article according to embodiment 1, further comprising an inclined portion (Psl) of the abrasive particles having an inclined orientation and a fallen portion (Pf) of the abrasive particles having a fallen orientation, and further comprising a ratio of the inclined portion to the fallen portion (PSl / Pf) of at least 1, or at least 1.2, or at least 1.4, or at least 1.6, or at least 1.8, or at least 2.0, or at least 2.2, or at least 2.4, or at least 2.6, or at least 2.8, or at least 3.0, or at least 3.2, or at least 3.4, or at least 3.6, or at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4.8, or at least 5.0, or at least 5.2, or at least 5.4, or at least 5.6.

[0111] Embodiment 26. An abrasive article as described in embodiment 25, wherein the ratio of the inclined portion to the fallen portion (PSl / Pf) is 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less, or 8 or less, or 6 or less.

[0112] Embodiment 27. The abrasive article of embodiment 1, further comprising a reverse portion of abrasive particles having a reverse orientation, wherein the reverse portion comprises at least 0.1% of the total number of abrasive particles, or at least 0.2%, or at least 0.4%, or at least 0.6%, or at least 0.8%, or at least 1%, or at least 1.5%, or at least 2%, or at least 2.5%, or at least 3%, or at least 3.5%, or at least 4%, or at least 4.5%, or at least 5% of the total number of abrasive particles.

[0113] Embodiment 28. An abrasive article as described in embodiment 27, wherein the inverted portion is 20% or less of the total number of abrasive particles, or 18% or less, or 15% or less, or 12% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less of the total number of abrasive particles.

[0114] Embodiment 29. The abrasive article of embodiment 1, further comprising upright portions (Pst) of the abrasive particles having a upright orientation and inverted portions (Pi) of the abrasive particles having an inverted orientation, and further comprising a ratio of upright portions to inverted portions (PSt / Pi) of at least 1, or at least 2.0, or at least 3.0, or at least 4.0, or at least 5.0, or at least 6, or at least 7, or at least 8, or at least 9, or at least 10, or at least 12, or at least 15, or at least 18, or at least 20, or at least 25, or at least 30, or at least 40, or at least 50.

[0115] Embodiment 30. An abrasive article as described in embodiment 29, wherein the ratio of upright portions to inverted portions (PSt / Pi) is 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less, or 8 or less, or 6 or less.

[0116] Embodiment 31. The abrasive article of embodiment 1, further comprising a slanted portion (Psl) of the abrasive particles having a tilted orientation and a reversed portion (Pi) of the abrasive particles having a reversed orientation, further comprising a ratio of slanted portion to reversed portion (PSl / Pi) of at least 0.6 or at least 0.7 or at least 0.8 or at least 0.9 or at least 1 or at least 1.2 or at least 1.4 or at least 1.6 or at least 1.8 or at least 2.0 or at least 2.2 or at least 2.4 or at least 2.6 or at least 2.8 or at least 3.0 or at least 3.2 or at least or at least 3.4 or at least 3.6 or at least 3.8 or at least 4.0 or at least 4.2 or at least 4.4 or at least 4.6 or at least 4.8 or at least 5.0 or at least 5.2 or at least 5.4 or at least 5.6.

[0117] Embodiment 32. An abrasive article as described in embodiment 30, wherein the ratio of the inclined portion to the inverted portion (PSl / Pi) is 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less, or 8 or less, or 6 or less, or 4 or less, or 3 or less, or 2 or less, or 1.5 or less.

[0118] Embodiment 33. The abrasive article of embodiment 1, further comprising a fallen portion (Pf) of the abrasive particles having a fallen orientation and an inverted portion (Pi) of the abrasive particles having an inverted orientation, and further comprising a ratio of fallen portions to inverted portions (Pf / Pi) of at least 0.6, or at least 0.7, or at least 0.8, or at least 0.9, or at least 1, or at least 1.2, or at least 1.4, or at least 1.6, or at least 1.8, or at least 2.0, or at least 2.2, or at least 2.4, or at least 2.6, or at least 2.8, or at least 3.0, or at least 3.2, or at least 3.4, or at least 3.6, or at least 3.8, or at least 4.0, or at least 4.2, or at least 4.4, or at least 4.6, or at least 4.8, or at least 5.0.

[0119] Embodiment 34. The abrasive article of embodiment 33, wherein the ratio of fallen portions to inverted portions (Pf / Pi) is 100 or less, or 95 or less, or 90 or less, or 80 or less, or 70 or less, or 60 or less, or 50 or less, or 40 or less, or 30 or less, or 20 or less, or 10 or less, or 8 or less, or 6 or less, or 4 or less, or 3 or less, or 2 or less, or 1.5 or less.

[0120] Embodiment 35. An abrasive article according to embodiment 1, further comprising an upright portion (Pst) of the abrasive particles having a upright orientation and an inclined portion (Psl) of the abrasive particles having an inclined orientation, and further comprising a well-oriented proportion represented by the sum of the upright portion (%) and the inclined portion (%) relative to all abrasive particles (i.e., 100%), wherein the well-oriented proportion is at least 60%, or at least 62%, or at least 65%, or at least 67%, or at least 70%, or at least 72%, or at least 75%, or at least 77%, or at least 80%, or at least 82%, or at least 85%, or at least 87%, or at least 90%, or at least 92%, or at least 95%.

[0121] Embodiment 36. An abrasive article as described in embodiment 35, in which the proportion of well oriented particles is 99.9% or less, or 99% or less, or 98% or less, or 97% or less, or 96% or less, or 95% or less.

[0122] 37. At least 42 grains / cm 2 or at least 43 grains / cm 2 or at least 44 grains / cm 2 or at least 45 grains / cm 2 or at least 46 grains / cm 2 or at least 47 grains / cm 2 or at least 48 grains / cm 2 or at least 49 grains / cm 2 or at least 50 grains / cm 2 or at least 51 grains / cm 2 or at least 52 grains / cm 2 or at least 53 grains / cm 2 or at least 54 grains / cm 2 2. The abrasive article of embodiment 1, further comprising a coverage density of well-oriented grains of

[0123] 38. 100 grains / cm 2 Less than or equal to 95 grains / cm 2 Less than or equal to 90 grains / cm 2 Less than or equal to 85 grains / cm 2 Less than or equal to 80 grains / cm 2Less than or equal to 75 grains / cm 2 Less than or equal to 70 grains / cm 2 Less than or equal to 65 grains / cm 2 Less than or equal to 60 grains / cm 2 38. The abrasive article of embodiment 37, comprising the following well-oriented grain coverage density:

[0124] Embodiment 39. The abrasive article of embodiment 1, wherein the make coat comprises a make coat add-on weight of 20 lbs. / rm or less, or 19.5 lbs. / rm or less, or 19 lbs. / rm or less, or 18.5 lbs. / rm or less, or 18 lbs. / rm or less, or 17.5 lbs. / rm or less, or 17 lbs. / rm or less.

[0125] Embodiment 40. The abrasive article of embodiment 39, wherein the make coat comprises a make coat add-on weight of at least 1 lbs. / rm, or at least 2 lbs. / rm, or at least 3 lbs. / rm, or at least 4 lbs. / rm, or at least 5 lbs. / rm, or at least 6 lbs. / rm, or at least 7 lbs. / rm, or at least 8 lbs. / rm, or at least 9 lbs. / rm, or at least 10 lbs. / rm, or at least 11 lbs. / rm, or at least 12 lbs. / rm, or at least 13 lbs. / rm, or at least 14 lbs. / rm, or at least 15 lbs. / rm, or at least 16 lbs. / rm.

[0126] Embodiment 41. An abrasive article as described in embodiment 1, wherein the abrasive particles comprise shaped abrasive particles or elongated abrasive particles, each of the shaped abrasive particles or elongated abrasive particles comprising a body having a length (l), a width (w), and a thickness (t), wherein the width>thickness and the length>thickness.

[0127] Embodiment 42. An abrasive article according to embodiment 41, wherein the shaped abrasive particles have a 3-PT star two-dimensional shape when viewed in the length and width plane of the body.

[0128] Embodiment 43. An abrasive article as described in embodiment 41, wherein each of the shaped abrasive particles or elongated abrasive particles of the plurality of shaped abrasive particles or elongated abrasive particles comprises a body including a first major surface, a second major surface opposite the first major surface, and a side surface extending between the first major surface and the second major surface, wherein the body includes at least three outer corners, and the side surface includes at least four side sections, or at least five side sections, or at least six side sections.

[0129] Embodiment 44. An abrasive article as described in embodiment 41, wherein the plurality of shaped abrasive particles or elongated abrasive particles comprises an average side angle between the side and the first major surface within the range of at least 70 degrees and not more than 94 degrees, or at least 80 degrees and not more than 93 degrees, or at least 83 degrees and not more than 92 degrees, or at least 85 degrees and not more than 91 degrees.

[0130] Embodiment 45. An abrasive article as described in embodiment 41, wherein the plurality of shaped abrasive particles or elongated abrasive particles comprises an average side angle between the side and the second major surface within the range of at least 70 degrees and not more than 94 degrees, or at least 80 degrees and not more than 93 degrees, or at least 83 degrees and not more than 92 degrees, or at least 85 degrees and not more than 91 degrees.

[0131] Embodiment 46. An abrasive article as described in embodiment 41, wherein each of the shaped abrasive particles or elongated abrasive particles of the plurality of shaped abrasive particles or elongated abrasive particles comprises a body having at least three outer corners, the sum of the angles of the outer corners being less than 180 degrees.

[0132] Embodiment 47. An abrasive article as described in embodiment 46, wherein each of the shaped abrasive particles or elongated abrasive particles of the plurality of shaped abrasive particles or elongated abrasive particles comprises a body having at least three outer corners, each of the outer corners defining an angle of less than 60 degrees, or less than 59 degrees, or less than 58 degrees, or less than 57 degrees, or less than 56 degrees, or less than 55 degrees.

[0133] Embodiment 48. An abrasive article as described in embodiment 41, wherein each of the shaped abrasive particles or elongated abrasive particles of the plurality of shaped abrasive particles or elongated abrasive particles comprises a body having at least three outer corners and at least three inner corners, each of the inner corners having an inner corner angle value that exceeds any of the outer corner values ​​of any of the at least three outer corners.

[0134] Embodiment 49. An abrasive article as described in embodiment 41, wherein each of the shaped abrasive particles or elongated abrasive particles of the plurality of shaped abrasive particles or elongated abrasive particles comprises a body having at least three inner corners, and wherein 50% or less, or 45% or less, or 40% or less, or 35% or less, or 30% or less, or 25% or less, or 20% or less, or 18% or less, or 16% or less, or 14% or less, or 12% or less, or 10% or less, or 9% or less, or 8% or less, or 7% or less, or 6% or less, or 5% or less, or 4% or less, or 3% or less, or 2% or less, or 1% or less of the total number of the plurality of shaped abrasive particles or elongated abrasive particles have cracks at the inner corners.

[0135] Embodiment 50. The abrasive article of embodiment 49, wherein each of the shaped abrasive particles or elongated abrasive particles of the plurality of shaped abrasive particles or elongated abrasive particles comprises a body having at least three inner corners, and at least 0.01%, or at least 0.5%, or at least 1%, or at least 2%, or at least 3%, or at least 4%, or at least 5%, or at least 8%, or at least 10% of the total number of the plurality of shaped abrasive particles or elongated abrasive particles have cracks at the inner corners.

[0136] Embodiment 51. The abrasive article of embodiment 41, wherein the abrasive particles comprise a ceramic material.

[0137] Embodiment 52. The abrasive article of embodiment 51, wherein the abrasive particles comprise at least one of a nitride, an oxide, a carbide, a boride, an oxynitride, an oxyboride, diamond, a carbon-containing material, or any combination thereof.

[0138] Embodiment 53. The abrasive article of embodiment 51, wherein the abrasive particles comprise an oxide compound or composite, such as aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, chromium oxide, strontium oxide, silicon oxide, magnesium oxide, rare earth oxide, or any combination thereof.

[0139] Embodiment 54. The abrasive article of embodiment 51, wherein the abrasive particles comprise at least 80% by weight alumina, or at least 90% by weight alumina, or at least 91% by weight alumina, or at least 92% by weight alumina, or at least 93% by weight alumina, or at least 94% by weight alumina, or at least 95% by weight alumina, or at least 96% by weight alumina, or at least 97% by weight alumina.

[0140] Embodiment 55. An abrasive article as described in embodiment 51, wherein the abrasive particles comprise 99.5% by weight or less of alumina, or 99% by weight or less of alumina, or 98.5% by weight or less of alumina, or 97.5% by weight or less of alumina, or 97% by weight or less of alumina, or 96% by weight or less of alumina, or 94% by weight or less of alumina.

[0141] Embodiment 56. The abrasive article of embodiment 1, wherein the abrasive particles have an average density of at least 95% of theoretical density.

[0142] Embodiment 57. An abrasive article as described in embodiment 1, wherein the abrasive particles have an average grain (crystallite) size of 1 micron or less, or 0.8 microns or less, or 0.6 microns or less, or 0.4 microns or less, or 0.2 microns or less, as measured according to the uncorrected intercept method.

[0143] Embodiment 58. An abrasive article as described in embodiment 57, wherein each shaped abrasive particle or elongated abrasive particle of the plurality of shaped abrasive particles or elongated abrasive particles comprises an average grain (crystallite) size of at least 0.01 microns or at least 0.05 microns.

[0144] Embodiment 59. The areal density of abrasive particles per square centimeter of the abrasive article is about 70 particles / cm2 Less than or equal to 65 particles / cm 2 Less than or equal to 60 particles / cm 2 Less than or equal to 55 particles / cm 2 Less than or equal to 50 particles / cm 2 2. The abrasive article of embodiment 1, which can be:

[0145] Embodiment 60. The surface density is at least 5 particles / cm 2 or at least 10 particles / cm 2 60. The abrasive article of embodiment 59, wherein

[0146] Embodiment 61. The abrasive article of embodiment 1, further comprising an abrasive surface comprising abrasive particles and at least one adhesive layer, wherein 90% or less, or 80% or less, or 70% or less, or 60% or less, or 50% or less, or 40% or less, or 30% or less, or 20% or less of the total surface area of ​​the abrasive surface comprises abrasive particles.

[0147] Embodiment 62. The abrasive article of embodiment 1, wherein at least 1%, or at least 5%, or at least 8%, or at least 10%, or at least 15%, or at least 20%, or at least 25%, or at least 30%, or at least 35%, or at least 40%, or at least 45%, or at least 50% of the total surface area of ​​the abrasive surface comprises abrasive particles.

[0148] Embodiment 63. The abrasive article of embodiment 1, wherein the abrasive particles comprise a first group of abrasive particles and a second group of abrasive particles.

[0149] Embodiment 64. The abrasive article of embodiment 63, wherein the first group of abrasive particles comprises at least two different types of shaped abrasive particles, and the two different types of shaped abrasive particles differ from each other based on at least one characteristic selected from the group of particle size, two-dimensional shape, three-dimensional shape, composition, hardness, toughness, friability, density, grain size, agglomeration state, lateral position, longitudinal position, rotational orientation, or any combination thereof.

[0150] Embodiment 65. The abrasive article of embodiment 63, further comprising a second group of abrasive particles that are different from the first group of abrasive particles.

[0151] Embodiment 66. The abrasive article of embodiment 65, wherein the second group of abrasive particles comprises diluent abrasive particles.

[0152] Embodiment 67. The abrasive article of embodiment 65, wherein the second group of abrasive particles comprises randomly shaped abrasive particles.

[0153] Embodiment 68. The abrasive article of embodiment 65, wherein the second group of abrasive particles differ from the first group of abrasive particles based on at least one characteristic selected from the group of particle size, two-dimensional shape, three-dimensional shape, composition, hardness, toughness, friability, density, grain size, agglomeration state, lateral position, longitudinal position, rotational orientation, or any combination thereof.

[0154] Embodiment 69. A coated abrasive having the features of embodiment 1, comprising a backing having a major surface and an abrasive layer forming an abrasive surface overlying the major surface of the backing, the abrasive layer forming a substantially single layer of abrasive particles adhered to the major surface of the backing by one or more layers of adhesive.

[0155] Embodiment 70. An abrasive article comprising: Backing and A make coat covering the backing; a plurality of abrasive particles overlying the backing and at least partially contained in the make coat; and a standard deviation in thickness of the make coat (STDTg) on ​​a side of the plurality of abrasive particles of at least 1 micron or less than 60 microns.

[0156] Embodiment 71. The abrasive article of embodiment 66, further comprising any one or any combination of the claims or embodiments herein.

[0157] Embodiment 72. A process for forming a coated abrasive article, comprising: Providing a backing; and forming a make coat over the backing; disposing a plurality of abrasive particles over the backing and at least partially contained in the make coat; a standard deviation in thickness of the make coat (STDTg) on ​​a side of the plurality of abrasive particles of at least 1 micron or less than 60 microns.

[0158] Embodiment 73. The abrasive article of embodiment 1, wherein the make coat comprises wollastonite, PF resin, water, or a combination thereof.

[0159] Embodiment 74. The abrasive article of embodiment 1, wherein the make coat comprises a viscosity of at least 3500 cps, or at least 3750 cps, or at least 4000 cps, or at least 4250 cps, or at least 4500 cps, or at least 4750 cps, or at least 5000 cps, or at least 5250 cps.

[0160] Embodiment 75. The abrasive article of embodiment 1, wherein the make coat comprises a viscosity of 7000 cps or less, or 6750 cps or less, or 6500 cps or less, or 6250 cps or less, or 6000 cps or less, or 5750 or less.

[0161] Embodiment 76. The process described in embodiment 72, wherein the abrasive article is an abrasive article described in embodiment 1+70 or 73-75. EXAMPLES

[0162] Example 1 Sample 1 and Comparative Sample 1 were prepared according to the following procedure with the specifications outlined in Table 1. The backing was saturated with 20.5 lbs. / rm of the following composition. Latex: 63.85% ○ Cab-o-sil: 0.98% ○ Defoamer: 0.44% Wetting agent: 0.24% ○Calcium carbonate: 31.93% Dye (reddish / pink): 2.56%

[0163] The saturated backing was backfilled with 7.1 lbs. / rm of the following composition: ○PF resin: 59.13% ○ Defoamer: 0.3% Wetting agent: 0.66% Solmod Tamol 165A: 2.01% Wollastonite: 19.71% ○Red dye: 0.21% ○Wed:17.98%

[0164] The make coat is applied to the saturated and backfilled backing via two roll coating. The make coat thickness is controlled by the nip gap to achieve the desired add-on weight. Abrasive particles are then applied to the wet make and backing via electrostatic coating. The backing, make, and grain are then cured in an oven according to the cure schedule in Table 1. The size coat and supersize coat are applied and cured similarly to the make coat according to the specifications in Table 1.

[0165] [Table 1]

[0166] Conventional Sample 1 was 3M™ Cubitron™ II Cloth Belt 984F 36+ grit.

[0167] The average make coat thickness was measured according to the following procedure. The sample was cut down the middle to reveal a cross section. The sample was then cut into 2 inch sections and mounted on an epoxy pack. The two 2 inch sections were then imaged and the make layer was identified by coloring the layer using imaging software. FIG. 10 includes an exemplary image of an abrasive article including a colored make layer. Image analysis was used to overlay vertical grid lines to identify and isolate line sections that overlap the make layer. Each line section corresponds to a make coat thickness measurement. An average was taken of all sections. Approximately 150-200 overlapping line sections were made per 2 inch sample section, resulting in over 300 measurements for each sample.

[0168] The average make coat thickness near the upright grains was measured according to the following procedure. The same cross-sectional images for the average make coat thickness were also used for the average make coat thickness near the upright grains. Only upright grains showing a rectangular cross-sectional area with the short side in contact with the make coat were considered. For example, in FIG. 1, grain 102 is considered, but grain 103 is not considered. Furthermore, only isolated grains were considered. Upright grains in contact with another grain were not considered for the measurement of the average make coat thickness near the upright grains. The measurement was taken from the highest make point contacting the grain side to the lowest make point contacting the backing on both sides of the grain. The measurement line was perpendicular to the backing plane. The results of the measurements of the average make coat thickness and the average make coat thickness near the upright grains can be seen in Table 2 below.

[0169] [Table 2]

[0170] Example 2 Samples 2 and 3, as well as Comparative Sample 2, were prepared according to the method for Sample 1 above and the specifications in Table 3. No size coat or supersize coat was applied. Sample 2 is essentially the same as Sample 1 without the size coat or supersize coat.

[0171] Regenerated Cubitron grain was regenerated according to the following procedure: 3M™ Cubitron™ II Cloth Belt 984F 36+ grit was obtained. The belt was burned until only abrasive grains and ash remained. The abrasive grains and burn-off were then immersed in a 400 ml glass beaker filled with hydrochloric acid. Enough acid was used to just cover the grain burn-off. The contents were boiled for 10 minutes and then allowed to cool. The solution was then diluted with DI water and the liquid was then discarded. The beaker containing the abrasive grains was then dried at 60-70°C for 2 hours. The grains and remaining ash were then transferred to a 250 ml Erlenmeyer flask. 50% hydrofluoric acid was added to the flask so that the abrasive grains were just covered. The grains were allowed to soak for 30 minutes. The acid was then diluted with DI water and the liquid was discarded. The flask was then dried at 60-70°C for 2 hours. The flask and contents were then cooled to room temperature and the regenerated acid washed grains were removed.

[0172] Conventional Sample 2 was prepared by removing the size coat and supersize coat from Conventional Sample 1 via sandblasting.

[0173] [Table 3]

[0174] The grain orientation in Sample 2, Sample 3, Comparative Sample 2, and Conventional Sample 2 was measured by the following procedure.

[0175] Images of each sample were taken using a z-stacking microscope. An exemplary image can be seen in FIG. 9A. The sample images include visible make coat 901 and abrasive grains, e.g., 902, 903, 904, 905. ImageJ software was used to threshold and identify grains, e.g., 902, 903, 904, 905. Covering grains were manually segmented as needed. An exemplary image of the abrasive edited to identify grains can be seen in FIG. 9B. Grains were color coded and counted by orientation based on the criteria in Table 2 below. An exemplary image with colored coated grains can be seen in FIG. 9C. Grain 902 is upright orientation, grain 903 is tilted orientation, grain 904 is tipped orientation, and grain 905 is inverted orientation. Grain orientation data can be seen in Table 3 below. Images were taken from a 3.2 cm section of each sample. 2 It contained a surface area of

[0176] [Table 4]

[0177] [Table 5]

[0178] As can be seen from Table 5, Samples 2 and 3 had a greater percentage of grains in the desired orientation compared to the Comparative and Conventional Samples. Sample 2 contained a significantly greater number of upright grains compared to all other samples.

[0179] This application represents a departure from the prior art. Although certain publications disclose that it is desirable to orient shaped abrasive particles in a certain orientation, these publications do not allow for the degree of orientation as disclosed in this application. Of note, it is clear that conventional coated abrasives have a significant portion of abrasive particles that are placed in an undesirable orientation. The industry continues to desire possible systems and methods for achieving a higher degree of control over the orientation of abrasive particles in coated abrasives. The systems and methods disclosed herein allow for the formation of coated abrasive articles with a higher degree of control over the orientation of particles on a backing for the creation of coated abrasive articles. Furthermore, the systems and methods herein can facilitate improved fine-tuning control over a certain orientation, such as control over upright, tilted, tipped, and inverted orientation of grains.

[0180] The subject matter disclosed above should be considered illustrative rather than limiting, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments that fall within the true scope of the invention. Accordingly, to the maximum extent permitted by law, the scope of the invention should be determined by the broadest permissible interpretation of the following claims and their equivalents, and should not be restricted or limited by the foregoing detailed description.

[0181] The Abstract is submitted with the understanding that it is provided for purposes of complying with patent law and will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure.

[0182] This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to fewer than all features of any of the disclosed embodiments. Accordingly, the following claims are incorporated into the Detailed Description, with each claim standing on its own as defining separately claimed subject matter.

Claims

1. 1. An abrasive article comprising: Backing and a make coat covering the backing; a plurality of abrasive particles overlying the backing and at least partially contained within the make coat; and a make coat thickness ratio (Tg / Ta) of 1.5 or less, where Tg is the average thickness of the make coat on the sides of the abrasive particles and Ta is the average thickness of the make coat.

2. The abrasive article of claim 1 , wherein the abrasive particles comprise shaped abrasive particles and / or elongated abrasive particles.

3. 2. The abrasive article of claim 1, wherein the average thickness (Tg) of the make coat on the sides of the grains is 1 mm or less.

4. 2. The abrasive article of claim 1, wherein the make coat comprises a lateral standard thickness deviation (STDTg) of the abrasive particles of 100 microns or less.

5. 2. The abrasive article of claim 1, wherein the make coat has an average thickness (Ta) of 1 mm or less.

6. 10. The abrasive article of claim 1, wherein the make coat comprises a standard deviation in thickness (STDT) of 100 microns or less.

7. 10. The abrasive article of claim 1, further comprising an upright portion of abrasive particles having an upright orientation, said upright portion comprising at least 10% of the total number of said abrasive particles.

8. 2. The abrasive article of claim 1, further comprising an upright portion of the abrasive grain having an upright orientation (Pst) and an inclined portion of the abrasive grain having an inclined orientation (Psl), and further comprising a ratio of the upright portion to the inclined portion (PSt / Psl) of at least 1.

9. 2. The abrasive article of claim 1, further comprising an upright portion (Pst) of the abrasive particles having an upright orientation and a fallen portion (Pf) of the abrasive particles having a fallen orientation, and further comprising a ratio of the upright portion to the fallen portion (PSt / Pf) of at least 2.

0.

10. 2. The abrasive article of claim 1, further comprising an upright portion (Pst) of the abrasive particles having an upright orientation and an inclined portion (Psl) of the abrasive particles having an inclined orientation, and further comprising a well-oriented proportion represented by the sum of the upright portion (%) and the inclined portion (%) relative to all of the abrasive particles (i.e., 100%), wherein the well-oriented proportion is at least 60%.

11. At least 42 grains / cm ２ 10. The abrasive article of claim 1, further comprising a coating density of well oriented grains of

12. 10. The abrasive article of claim 1, wherein the make coat comprises a make coat add-on weight of 20 lbs. / rm or less.

13. 2. The abrasive article of claim 1, wherein the abrasive particles comprise shaped or elongated abrasive particles, each of the shaped or elongated abrasive particles comprising a body having a length (l), a width (w), and a thickness (t), where width>thickness and length>thickness.

14. 14. The abrasive article of claim 13, wherein the shaped abrasive particles have a 3-PT star two-dimensional shape when viewed in the length and width plane of the body.

15. 14. The abrasive article of claim 13, wherein each of the shaped or elongated abrasive particles of the plurality of shaped or elongated abrasive particles comprises a body having at least three exterior corners, the sum of the angles of the exterior corners being less than 180 degrees.

Images