WO2025149867A1

WO2025149867A1 - Abrasive articles, method of manufacture and use thereof

Info

Publication number: WO2025149867A1
Application number: PCT/IB2025/050080
Authority: WO
Inventors: Laura M. LARA RODRIGUEZ; Thomas J. Nelson; Tyler O. NAATZ; Jonathan J. O'hare; Nathan J. HERBST; Jingyi ZHAO; David E. Johnson; Nicole M. Sanborn; Ethan J. BERG; Paul N. Daveloose
Original assignee: 3M Innovative Properties Co
Current assignee: 3M Innovative Properties Co
Priority date: 2024-01-10
Filing date: 2025-01-03
Publication date: 2025-07-17
Anticipated expiration: 2026-07-10

Abstract

An abrasive article is presented that includes a backing and a plurality of abrasive article portions, each abrasive article portion being directly coupled to the backing. A first abrasive article portion comprises a first composition and a second abrasive article portion comprises a second composition. The first and second abrasive articles are coplanar such that first abrasive particles, of the first abrasive article, and second abrasive particles, of the second abrasive article, are configured to simultaneously contact a worksurface. The plurality of abrasive article portions are coupled to the backing by a coupling agent.

Description

ABRASIVE ARTICLES, METHOD OF MANUFACTURE AND USE THEREOF

BACKGROUND

Abrasive articles containing abrasive grains are useful for shaping, finishing, or grinding a wide variety of materials and surfaces such as wood, metals (e.g., especially non-ferrous metals such as aluminum that tend to clog grinding wheels), and flash.

A number of abrasive article options exist including those with abrasive elements coated on a backing as well as those with abrasive elements within a bonded or fiber matrix.

SUMMARY

An abrasive belt is presented that includes an abrading surface opposite a backside. The abrading surface comprises abrasive particles adhered to a backing. The abrasive belt also includes a first end having a portion of a first splice pattern and a second end having a portion of a second splice pattern. The first splice pattern is complementary to the second splice pattern. The first splice pattern comprises a lobe having a lobe circular portion and a receiving portion having a receiving circular portion. The lobe is defined by a line tangent to both the lobe circular portion and the receiving circular portion. The abrasive belt also includes a splice adhesive coupling the first splice pattern to the second splice pattern.

The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. It is to be understood, therefore, that the following description should not be read in a manner that would unduly limit the scope of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B illustrate schematics of an exemplary abrasive article that may benefit from embodiments disclosed herein. FIGS. 2A-2B illustrate an example composite abrasive article in accordance with embodiments herein.

FIG. 3 is a schematic of a processing step for forming composite abrasive articles in accordance with embodiments herein.

FIG. 4 illustrates a mixed-grade composite abrasive article in accordance with embodiments herein.

FIG. 5 illustrates a composite abrasive article kit in accordance with embodiments herein.

FIGS. 6A-6B is a schematic of a coated abrasive article.

FIGS. 7A-9D illustrate example belt splice patterns in accordance with embodiments herein.

FIGS. 10A-10D illustrate some example belt splice patterns and partial belt splice patterns in accordance with embodiments herein.

FIG. 11 illustrates a method of making an abrasive article in accordance with embodiments herein.

FIGS. 12A-15 illustrate abrasive article coupling schematics in accordance with embodiments herein.

FIGS. 16A-21C illustrate images of abrasive articles and performance described in greater detail in the Examples.

Repeated use of reference characters in the specification and drawings is intended to represent the same or analogous features or elements of the disclosure. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the disclosure. The figures may not be drawn to scale.

DETAILED DESCRIPTION

Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1%to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section.

In the methods described herein, the acts can be carried out in any order without departing from the principles of the disclosure, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%.

As used herein, the term "shaped abrasive particle," means an abrasive particle with at least a portion of the abrasive particle having a predetermined shape that is replicated from a mold cavity used to form the shaped precursor abrasive particle. Except in the case of abrasive shards (e.g. as described in US Patent Application Publication Nos. 2009/0169816 and 2009/0165394), the shaped abrasive particle will generally have a predetermined geometric shape that substantially replicates the mold cavity that was used to form the shaped abrasive particle. Shaped abrasive particle as used herein excludes abrasive particles obtained by a mechanical crushing operation. Suitable examples for geometric shapes having at least one vertex include polygons (including equilateral, equiangular, starshaped, regular and irregular polygons), lens- shapes, lune-shapes, circular shapes, semicircular shapes, oval shapes, circular sectors, circular segments, drop-shapes and hypocycloids (for example super elliptical shapes).

For the purposes of this invention, geometric shapes are also intended to include regular or irregular polygons or stars wherein one or more edges (parts of the perimeter of the face) can be arcuate (either of towards the inside or towards the outside, with the first alternative being preferred). Hence, for the purposes of this invention, triangular shapes also include three- sided polygons wherein one or more of the edges (parts of the perimeter of the face) can be arcuate. The second side may include (and preferably is) a second face. The second face may have a perimeter of a second geometric shape. For the purposes of this invention, shaped abrasive particles also include abrasive particles comprising faces with different shapes, for example on different faces of the abrasive particle. Some embodiments include shaped abrasive particles with different shaped opposing sides. The different shapes may include, for example, differences in surface area of two opposing sides, or different polygonal shapes of two opposing sides.

The shaped abrasive particles are typically selected to have an edge length in a range of from 0.001 mm to 26 mm, more typically 0.1 mm to 10 mm, and more typically 0.5 mm to 5 mm, although other lengths may also be used.

The shaped abrasive particle may have a “sharp portion” which is used herein to describe either a sharp tip or a sharp edge of an abrasive article. The sharp portion may be defined using a radius of curvature, which is understood in this disclosure, for a sharp point, to be the radius of a circular arc which best approximates the curve at that point. For a sharp edge, the radius of curvature is understood to be the radius of the curvature of the profile of the edge on the plane perpendicular to the tangent direction of the edge. Further, the radius of curvature is the radius of a circle which best fits a normal section, or an average of sections measured, along the length of the sharp edge. The smaller a radius of curvature, the sharper the sharp portion of the abrasive particle. Shaped abrasive particles with sharp portions are defined in U.S. Provisional Patent Application Ser. No. 62/877,443, filed on July 23, 2019, which is hereby incorporated by reference.

In the instance that the abrasive particles are precisely-shaped (e.g., into triangular platelets or conical particles), this effect of orientation can be especially important as discussed in U. S. Pat. Appl. Publ. No. 2013/0344786 Al (Keipert), incorporated by reference herein. As used herein, the term “alignment” is used to refer to a relative position of an abrasive particle on a backing, while the term “orientation” refers to a rotational position of the abrasive particle at the aligned position. For example, a triangle -shaped particle may have a “tip up” orientation or a “tip down” orientation with respect to the backing.

As used herein, the term shaped abrasive particle refers to a monolithic abrasive particle. As shown, shaped abrasive particle is free of a binder and is not an agglomeration of abrasive particles held together by a binder or other adhesive material.

FIGS. 1A and IB show an exemplary coated abrasive disc 100 according to the present disclosure, wherein shaped abrasive particles 130 are secured at precise locations and Z-axis rotational orientations to a backing 110. While shaped abrasive particles 130 are illustrated as triangular in shape, it is expressly contemplated that particles 130 may have other suitable shapes. Additionally, it is expressly contemplated that embodiments herein may have abrasive particles 130 deposited in a make coat 120 in a random pattern and / or aligned with random orientation. In some embodiments, abrasive particles 130 are precisely placed, e.g. in a repeating pattern across a backing 110. In some embodiments, abrasive particles 130 are oriented, for example by electrostatic or magnetic orientation methods.

Generally, a coated abrasive article 100 includes a plurality of abrasive particles embedded within a make coat that secures the particles to a backing. The backing may be formed from any known flexible coated abrasive backing, for example. Suitable materials for the backing include polymeric fdms, metal foils, woven fabrics, knitted fabrics, paper, nonwovens, foams, screens, laminates, combinations thereof, and treated versions thereof.

The abrasive particles 130 may be embedded within an abrasive layer, which can include multilayer construction having make 120 and size layers 140. Coated abrasive articles according to the present disclosure may include additional layers such as, for example, an optional supersize layer that is superimposed on the abrasive layer, or a backing antistatic treatment layer may also be included, if desired. Exemplary suitable binders can be prepared from thermally curable resins, radiation-curable resins, and combinations thereof.

Make layer 120 can be formed by coating a curable make layer precursor onto a major surface of backing 110. The make layer precursor may include, for example, glue, phenolic resin, aminoplast resin, urea-formaldehyde resin, melamine-formaldehyde resin, urethane resin, free-radically polymerizable polyfunctional (meth)acrylate (e.g., aminoplast resin having pendant a,P-unsaturated groups, acrylated urethane, acrylated epoxy, acrylated isocyanurate), epoxy resin (including bis- maleimide and fluorene-modified epoxy resins), isocyanurate resin, and mixtures thereof. Of these, phenolic resins are preferred.

Phenolic resins are generally formed by condensation of phenol and formaldehyde, and are usually categorized as resole or novolac phenolic resins. Novolac phenolic resins are acid-catalyzed and have a molar ratio of formaldehyde to phenol of less than 1: 1. Resole (also resol) phenolic resins can be catalyzed by alkaline catalysts, and the molar ratio of formaldehyde to phenol is greater than or equal to one, typically between 1.0 and 3.0, thus presenting pendant methylol groups. Alkaline catalysts suitable for catalyzing the reaction between aldehyde and phenolic components of resole phenolic resins include sodium hydroxide, barium hydroxide, potassium hydroxide, calcium hydroxide, organic amines, and sodium carbonate, all as solutions of the catalyst dissolved in water.

Resole phenolic resins are typically coated as a solution with water and/or organic solvent (e.g., alcohol). Typically, the solution includes about 70 percent to about 85 percent solids by weight, although other concentrations may be used. If the solids content is very low, then more energy is required to remove the water and/or solvent. If the solids content is very high, then the viscosity of the resulting phenolic resin is too high which typically leads to processing problems. Phenolic resins are well-known and readily available from commercial sources. Examples of commercially available resole phenolic resins useful in practice of the present disclosure include those marketed by Durez Corporation under the trade designation VARCUM (e.g., 29217, 29306, 29318, 29338, 29353); those marketed by Bostik, Inc. of Wauwatosa, Wisconsin under the trade designation AEROFENE (e.g., AEROFENE 295); and those marketed by Kangnam Chemical Company Ltd. of Seoul, South Korea under the trade designation PHENOLITE (e.g., PHENOLITE TD-2207).

The make layer precursor may be applied by any known coating method for applying a make layer to a backing such as, for example, including roll coating, extrusion die coating, curtain coating, knife coating, gravure coating, and spray coating.

The basis weight of the make layer utilized may depend, for example, on the intended use(s), type(s) of abrasive particles, and nature of the coated abrasive article being prepared, but typically will be in the range of from 1, 2, 5, 10, or 15 grams per square meter (gsm) to 20, 25, 100, 200, 300, 400, or even 600 gsm. The make layer may be applied by any known coating method for applying a make layer (e.g., amake coat) to a backing, including, for example, roll coating, extrusion die coating, curtain coating, knife coating, gravure coating, and spray coating.

Once the make layer precursor is coated on the backing, the triangular abrasive particles are applied to and embedded in the make layer precursor. The triangular abrasive particles are applied nominally according to a predetermined pattern and Z-axis rotational orientation onto the make layer precursor. Using known orientation methods, such as electrostatic or magnetic orientation, it is possible to orient the abrasive particles with respect to the backing in order to improve performance of the particles.

FIGS. 2A-2B illustrate an example composite abrasive article in accordance with embodiments herein. FIG. 2A illustrates a schematic of a number of abrasive article portions 210 coupled together to form an abrasive article 200. In the illustrated embodiment, each portion 210 includes a protrusion 202 that is received by an aperture 204. Portions 210 may meet at an interface 220. While one example of a shaped protrusion 202 is illustrated, it is expressly contemplated that, in embodiments herein, other coupling shapes, or no coupling shape at all, may be used.

FIG. 2B illustrates an example nonwoven compositive abrasive article.

FIG. 3 is a schematic of a processing step for forming composite abrasive articles in accordance with embodiments herein. Formation of disc-shaped abrasive articles often results in a significant amount of waste as, in many instances, a large sheet 310 is formed, from which abrasive articles 320 are cut. A significant portion of sheet 310 is then discarded. However, it is possible to, from what would otherwise be wasted abrasive material, to cut abrasive article portions 340. The amount of recovered material varies based on the disc size - smaller sized discs, for example, can be packed more closely than larger discs. In some embodiments, 50% of material that would be wasted can be converted into abrasive article portions 210.

FIG. 4 illustrates a mixed-grade composite abrasive article in accordance with embodiments herein. A backing 410 receives a number of abrasive article portions 420-440. Mixed grade composite abrasive article 400 includes a recloseable fastener backing 410 which entangles with the nonwoven abrasive article portions 420-440. In the embodiment illustrated in FIG. 4, the recloseable fastener backing 410 is a dual-lock™ backup pad. However, other recloseable fastening systems may be used. In some embodiments, abrasive article portions are permanently coupled to a backing, e.g. using an adhesive. Mechanical fasteners may also be used, in some embodiments. For example, a threated attachment at a disc center, a clamp that engages the disc, a T-S button or other mechanically recloseable fastener may be suitable in embodiments herein.

Abrasive articles are often sold in a number of grades - e.g. extra coarse, coarse, medium, fine, very fine and super fine. Each grade generally has a different volumetric cut rate and finish and are suited to different applications. However, there are many applications where a balance between cut rate and finish. It was surprisingly found, as illustrated in greater detail in the Examples, that a modular abrasive article with a combination of different grades resulted in a cut and finish in between the two. By combining different abrasive portions with different properties, a more tailored product may be provided.

Composite abrasive articles according to embodiments herein may be formed of any number of abrasive portions. While FIGS. 2 and 4 illustrate embodiments where eight abrasive portions form a composite abrasive articles, it is expressly contemplated that more, or fewer, may be used. For example, a first half portion having a first set of properties may be paired with a second half portion having a second set of properties. A first third portion may be paired with a second and third portion, to form an abrasive article having two or more abrasive compositions. Similarly, four quarter portions may be coupled to form an abrasive article having two, three, or four abrasive compositions. Five, six, seven, nine or more portions may be used to form an abrasive composite in accordance with embodiments herein.

While FIGS. 2 and 4 also illustrate embodiments where abrasive portions of equal size are used to form a composite, it is expressly contemplated that abrasive portions of different sizes may be used. For example, a half portion may be paired with two quarter portions, a third with two thirds, a quarter with six eighths, etc.

FIG. 5 illustrates a composite abrasive article kit in accordance with embodiments herein. A backing element 510 may be provided to couple a number of abrasive portions 520-540 together to form a composite abrasive article. Backing element 510 may couple to portions 520-540 in a permanent or removeable manner. A kit may come with adhesive, for example, in some embodiments. In other embodiments backing element 510 may have fastening elements, such as the recloseable elements of DualLock™, available from 3M Company of Minnesota. In some embodiments, portions 520-540 are adhered or otherwise coupled directly to adjacent portions, e.g. through adhesive, welding, etc.

FIG. 5 illustrates a kit 500 with abrasive portions of three different compositions, 520, 530 and 540. However, it is expressly contemplated that embodiments herein may have more, or fewer portions. Further, it is expressly contemplated that embodiments herein may have more, or fewer than three different compositions.

While FIGS. 2 and 4 illustrate nonwoven abrasive articles, it is expressly contemplated that coated abrasive articles, having any suitable backing, may also benefit from embodiments herein. Coated abrasive article portions may need to have the same thickness such that a surface of a composite abrasive article contacts a worksurface to be abraded.

FIG. 6 illustrates an example of a spliced abrasive article in accordance with embodiments herein.

Belt grinding is a process used to machine metals and other materials. Belt grinding can be used as a finishing process or a stock removal process, with belts coming in multiple grades and thicknesses. The belt moves over the surface to be processed and removed materials by contacting abrasive particles to the surface being processed.

Generally, abrasive belts are formed by coating abrasive particles on a backing material. The backing material is then coupled to itself, with a first end adhered to a second end, for example, to form an endless loop. The endless loop may then be aligned around one or more wheels which drive the belt in a machine direction over rotating wheels or pulleys. A surface to be processed contacts the belt while the belt is in motion. Some example configurations that abrasive belts described in embodiments herein may be suitable for include stroke-belt grinding, platen belt grinding, wide belt grinding, hackstand belt grinding or centerless belt grinding. The abrading operation may be conducted dry or wet.

FIG. 6 illustrates an example of a spliced abrasive article in accordance with embodiments herein. An abrasive article 600 is formed into an endless loop by splicing together a first end 610 to a second end 614 along a splice interface 612. As illustrated in FIG. 6A, belt 600 moves around two or more wheels 620

The coupling between the first and second ends, along the splice interface 612, must be strong enough such that, during use, the two sides do not split apart. A common method to increase a strength of the coupling along the splice interface is to increase an area of contact between the first and second ends. U.S. Pat. 5,487,707 to Sharf illustrates several different configurations to increase surface area. FIG. 6B is a reproduction of FIG. 2 of Sharf. A pattern of extending lobes is present on each of ends 642, 644. Each lobe of Sharf has a neck 646 coupled to a head 648.

However, there is a need to improve splice strength as splice breakage is still a significant source of premature belt failure. Particularly for smaller belts, such as 'A” by 18” file belts, it is suspected that the smaller contact wheels used providing more demanding stress as the belt navigates around the wheel. File belts also can see an increased temperature during use than wider belts, which makes splice integrity challenging.

An improved interface pattern is needed that reduces splice breakage. Described herein is an improved splice pattern that exhibits an improved splice strength. The pattern described herein exhibits a higher splice integrity even in smaller belt sizes.

FIG. 7A illustrates a splice pattern 700 that consists of lobes 702 alternating with receiving apertures 704. The pattern can be defined by a number of variables. The splice pattern may be at an angle, 6, from an edge 710 of a belt. The pattern may be defined, in part, by a line 720 extending from edge 710 at said 6, which marks half of a height 722, of each of the lobes 702. Each of the lobes 702 can be characterized as having a radius, R. A distance of 2d separates a center of a first lobe tip portion with a center of an adjacent lobe tip portion. It is noted that the “d” in 2d does not refer to the diameter of a circle with radius R. As illustrated in FIG. 7, in some embodiments 2d is less than four times R. However, it is expressly contemplated, and shown herein, that 2d may be greater than four times R. Center point C is defined, at least in part, by radius R. A distance, e, describes a distance from the centerline 720 and center point C.

In accordance with embodiments herein, the splice pattern 700 is defined by a tangent line 706 of the circular part of a first lobe 702, such that the same line 706 is tangent to the circular portion of aperture 704 (which, e.g. would receive a corresponding lobe 702 of a second end of a belt being spliced to the illustrated belt end). In some embodiments, a splice pattern includes a gap between a lobe 702 and a receiving cavity 704, for example to allow for adhesive to flow between lobe 702 and cavity edge 704. The relationships between the variables described herein may characterize either lobe 702, cavity 704 or, in the case of no gap, both.

Determining suitable values for the four parameters R, 2d, e, and 6 started with Equation 1, below: Equation 1 where N is the load capacity per unit width of belt, t is the thickness of the belt, R is radius of lobe structure, E is the elastic modulus, G is a geometrical ratio:

G = R/d Equation 2

Using Equation 3, a dimensionless load capacity M was defined to understand the influence of the geometrical ratio G. Equation 3

FIG. 7B illustrates an abrasive belt with a splice pattern having g=l .8, H= 2, R = 0.067 inch and 0=75.

Fig. 8A compares our results with the US5487707A patent, where G>0.5 and g<2. It indicates the major differences between them is our design have a smoother transition between each pattern. FIG. 8B illustrates the influence of geometric ratio G on the load capacity M. This indicates when G approaches 0.5, the splice pattern will be stronger and less likely to fracture.

It is noted that R is inversely related to the strength of the splice pattern. According to the mathematical relationships described herein, the load capacity per width of the splice pattern is linear to 1/R³. After determining R, d and e are obtained through two geometrical ratios: g=d/R Equation 4

H=e//? Equation 5

Where G = 1/g. It is recommended that 75° < 0 < 90° for the lobe structure geometry, which will enhance inter-locking strength as well as reducing the stress concentration.

When considering prior art splice patterns, such as that of FIG. 6B or other patterns described in U.S. Pat. 5,487,707 to Sharf, several differences are noted. Notably, embodiments herein utilize tangent lines to connect circles defining lobes and adjacent receiving apertures. This reduces a stress concentration at sharp transitions, e.g. the sharp reduction in width between head 648 and neck 646. The term “sharp,” as used herein, refers to a rapid change in a slope of a line connecting an arc defining a lobe tip to an arc defining a lobe valley. A transition may be characterized as “sharp” if a slope (e.g. “S” illustrated in FOG. 7A changes by more than 20%. In accordance with some embodiments herein a slope is substantially constant, e.g. does not change by more than 5%. Additionally it is noted that designs herein utilize a non-90° angle (e.g. 0) from a belt edge. The use of an angle further ensures interlocking between belt ends and reduces the risk of belt breakage because an individual lobe is less likely to experience a tensile slide unzip unless one of the lobes breaks.

FIGS. 9A-9D illustrate how variations of the geometrical ratios affects the splice shape. FIG. 9A illustrates an example of g* < 2. FIG. 9B illustrates an example of g* > 2. FIG. 9C illustrates an example where e = 1.2R. FIG. 9D illustrates an example where e = 2R.

As illustrated in the difference between the patterns of 9A and 9B, a g* value of less than 2 is preferred for creating interlocking properties. The ratio h* determines a length of each lobe. As a length of a lobe increases (e.g. as h* increases), a total friction force increases. However, longer lobes are more difficult to manufacture.

Interlocking strength depends in part on the local stress around the arc defining a lobe tip portion and the tangent transition.

As noted previously, belt failure occurs more frequently in belts with increasingly small diameters. However, splice patterns, as defined by the parameters herein, have dimensions that are not easily enlarged or shrunk to accommodate different belt thicknesses. This means that, for smaller belt sizes, a full unit of the splice pattern (e.g. one lobe and one receiving aperture for each belt end) will not be present. It has been surmised that the small splice interface area has been a contributing factor to failure of belts in these smaller sizes.

However, splice patterns herein have shown improved performance, even when a full splice pattern is not present. When considering prior art interface designs, such as those described in Sharf et al., a partial splice pattern would likely fail due to the stress around the sharp curves.

Splice patterns having improved performance may have a shape similar to that illustrated in FIGS. 7A and 8. The parameter values defining the pattern may depend on a number of factors including a use of the belt - as the radius of a contact wheel directly affects the force applied to the splice during use.

A ratio of radius, R, to Belt Width, W, is at least 0.001. In some embodiments, a ratio of R to belt width is at least 0.05. In some embodiments, a ratio of R to W is at least 0.1. In some embodiments, a ratio of Rto belt width is at least 0.15. In some embodiments, a ratio of Rto W is less than or equal to 0.2.

A ratio of d/R is at least 1.7. In some embodiments, a ratio of d/R is at least 1.75. In some embodiments, a ratio of d/R is at least 1.8. In some embodiments, a ratio of d/R is at least 1.85. In some embodiments, a ratio of d/R is at least 1.9. In some embodiments, a ratio of d/R less than or equal to 1.95. A ratio of e/R is at least 1.5. In some embodiments, a ratio of e/R is at least 1.6. In some embodiments, a ratio of e/R is at least 1.7. In some embodiments, a ratio of e/R is at least 1.8. In some embodiments, a ratio of e/R is at least 1.9. In some embodiments, a ratio of e/R is at least 2.0. In some embodiments, a ratio of e/R is at least 2.1. In some embodiments, a ratio of e/R is at least 2.2. In some embodiments, a ratio of e/R is at least 2.3. In some embodiments, a ratio of e/R is at least 2.4. In some embodiments, a ratio of e/R is at least 2.5.

FIGS. 10A-10C illustrate different schematics of belts having different portions of a splice pattern. It was surprisingly found that, even when only part of a splice pattern is present, fewer belt failure events occurred. This can be seen in Example 3 below. It is suspected that, as the pattern is close to parallel with a design of travel, that the bending of the lobes as the belt moves around a wheel is better tolerated.

FIGS 10A illustrates a splice pattern 1010 that includes a full lobe and a full aperture. FIGS. 10B, 10C and 10D each illustrates a partial splice pattern, 50% (1020), 30% (1030) and 14% (1040) of pattern 1010, respectively. However, while three example partial splice patterns are illustrated, it is expressly contemplated that other partial splice patterns may be used, depending on the selected parameters e, 2d, R and 6 and the belt size.

Partial splice patterns having improved performance may have a shape similar to that illustrated in FIG. 10A. The parameter values defining the pattern may depend on a number of factors including a use of the belt - as the radius of a contact wheel directly affects the force applied to the splice during use.

A ratio of radius, R, to belt width, W, is at least 0.1. In some embodiments, a ratio of R/belt width is at least 0.2. In some embodiments, a ratio of R/W is at least 0.3. In some embodiments, a ratio of R/W is at least 0.4. In some embodiments, a ratio of R/W is less than or equal to 0.5.

A ratio of d/R is at least 1.7. In some embodiments, a ratio of d/R is at least 1.75. In some embodiments, a ratio of d/R is at least 1.8. In some embodiments, a ratio of d/R is at least 1.85. In some embodiments, a ratio of d/R is at least 1.9. In some embodiments, a ratio of d/R less than or equal to 1.95.

A ratio of e/R is at least 1.5. In some embodiments, a ratio of e/R is at least 1.6. In some embodiments, a ratio of e/R is at least 1.7. In some embodiments, a ratio of e/R is at least 1.8. In some embodiments, a ratio of e/R is at least 1.9. In some embodiments, a ratio of e/R is at least 2.0. In some embodiments, a ratio of e/R is at least 2.1. In some embodiments, a ratio of e/R is at least 2.2. In some embodiments, a ratio of e/R is at least 2.3. In some embodiments, a ratio of e/R is at least 2.4. In some embodiments, a ratio of e/R is at least 2.5 or 7iR_w/R whatever is larger, where R_w is the contact wheel. FIG. 11 illustrates a method of manufacturing an abrasive article in accordance with embodiments described herein. Method 1100 may be used, for example, to make a composite abrasive disc or an abrasive belt.

In block 1110, a backing is provided. The backing may have apre-treatmentpriorto the coating process, in accordance with some embodiments. Pre-treatments may help increase adhesion, reduce shelling, or reduce static, for example. The provided backing may also be untreated, however, in other embodiments. The backing may also have other features. The backing may be flexible or stiff, and may be made from any suitable material including, but not limited to nonwoven 1102, woven 1103, or fibrous material 1104. Other suitable backing materials are also expressly contemplated herein.

In block 1120, a make coat is provided. The make coat is typically provided in an uncured form such that deposited abrasive particles can embed. The make coat can be deposited on the backing in any number of suitable manners including, for example, spray coating, roll-coating, etc.

In block 1130, abrasive particles are embedded within the make coat. In accordance with embodiments herein, the abrasive particles may be crushed abrasive particles 1122, formed abrasive particles 1124, shaped abrasive particles, other abrasive particles 1128 or a combination thereof. Abrasive particles may be placed in one step, in some embodiments, or in multiple steps - e.g. a first set of abrasive particles deposited before a second set of abrasive particles.

In embodiments where the placed abrasive particles include shaped abrasive particles, the shaped abrasive particles may be triangular prisms, rod shaped, platey shaped, another polygonal shaped prism, or any other suitable shape. The first set of abrasive particles may be deposited and oriented on the backing using any suitable method, such as using electrostatic alignment, which orients the particles in an X-Y direction, but not in a Z direction. Alternatively, the first set of abrasive particles may be deposited and oriented using magnetic alignment. For example, the abrasive particles may include a magnetically responsive element or coating such that the particles, when exposed to a magnetic field, will orient in a desired orientation. For example, in one embodiment the particles orient such that corresponding faces of nearby particles are parallel to one another, and such that a sharp tip or edge is facing away from the backing. Alignment of abrasive particles may be accomplished using electrostatic coating or magnetic coating, as described in PCT Pat. Appl. Publ. Nos. WO2018/080703 (Nelson et al.), W02018/080756 (Eckel et al.), W02018/080704 (Eckel et al.), W02018/080705 (Adefris et al.), W02018/080765 (Nelson et al.), W02018/080784 (Eckel et al.), WO2018/136271 (Eckel et al.), WO2018/134732 (Nienaber et al.), W02018/080755 (Martinez et al.), W02018/080799 (Nienaber et al.), WO2018/136269 (Nienaber et al.), WO2018/136268 (Jesme et al.), WO2019/207415 (Nienaber et al.), WO2019/207417 (Eckel et al.), WO2019/207416 (Nienaber et al.), and U.S. Provisional Nos. 62/914,778 filed on October 14, 2019 and 62/875,700 filed July 18, 2019, and 62/924,956, filed October 23, 2019.

In some embodiments, the abrasive particles are magnetically responsive. In one embodiment, making particles magnetically responsive includes coating non-magnetically responsive particles with a magnetically responsive coating. However, in another embodiment, the particles are formed with magnetically responsive material, for example as recited in co-owned provisional patent U.S. 62/914778, filed on October 14, 2019. At least one magnetic material may be included within or coated to shaped abrasive particle. Examples of magnetic materials include iron; cobalt; nickel; various alloys of nickel and iron marketed as Permalloy in various grades; various alloys of iron, nickel and cobalt marketed as Fernico, Kovar, FerNiCo I, or FerNiCo II; various alloys of iron, aluminum, nickel, cobalt, and sometimes also copper and/or titanium marketed as Alnico in various grades; alloys of iron, silicon, and aluminum (about 85:9:6 by weight) marketed as Sendust alloy; Heusler alloys (e.g., Cu2MnSn); manganese bismuthide (also known as Bismanol); rare earth magnetizable materials such as gadolinium, dysprosium, holmium, europium oxide, alloys of neodymium, iron and boron (e.g., Nd2Fel4B), and alloys of samarium and cobalt (e.g., SmCo5); MnSb; MnOFe2O3; Y3Fe5O12; CrO2; MnAs; ferrites such as ferrite, magnetite; zinc ferrite; nickel ferrite; cobalt ferrite, magnesium ferrite, barium ferrite, and strontium ferrite; yttrium iron garnet; and combinations of the foregoing. In some embodiments, the magnetizable material is an alloy containing 8 to 12 weight percent aluminum, 15 to 26 wt% nickel, 5 to 24 wt% cobalt, up to 6 wt% copper, up to 1 % titanium, wherein the balance of material to add up to 100 wt% is iron. In some other embodiments, a magnetizable coating can be deposited on an abrasive particle 100 using a vapor deposition technique such as, for example, physical vapor deposition (PVD) including magnetron sputtering. Including these magnetizable materials can allow shaped abrasive particle to be responsive a magnetic field. Any of shaped abrasive particles can include the same material or include different materials.

The magnetic coating may be a continuous coating, for example that coats an entire abrasive particle, or at least coats an entire surface of an abrasive particle. In another embodiment, a continuous coating refers to a coating present with no uncoated portions on the coated surface. In one embodiment, the coating is a unitary coating - formed of a single layer of magnetic material and not as discrete magnetic particulates. In one embodiment, the magnetic coating is provided on an abrasive particle while the particle is still in a mold cavity, such that the magnetic coating directly contacts an abrasive particle precursor surface. In one embodiment, the thickness of the magnetic coating is at most equal to, or preferably less than, a thickness of the abrasive particle. In one embodiment, the magnetic coating is not more than about 20 wt.% of the final particle, or not more than about 10 wt.% of the final particle, or not more than 5 wt.% of the final particle. Magnetically aligning the abrasive particles with respect to each other generally requires two steps. First, providing the magnetizable abrasive particles described herein on a substrate having a major surface. Second, applying a magnetic field to the magnetizable abrasive particles such that a majority of the magnetizable abrasive particles are oriented substantially perpendicular to the major surface. Without application of a magnetic field, the resultant magnetizable abrasive particles may not have a magnetic moment, and the constituent abrasive particles, or magnetizable abrasive particles may be randomly oriented. However, when a sufficient magnetic field is applied the magnetizable abrasive particles will tend to align with the magnetic field. In favored embodiments, the ceramic particles have a major axis (e.g. aspect ratio of 2) and the major axis aligns parallel to the magnetic field. Preferably, a majority or even all of the magnetizable abrasive particles will have magnetic moments that are aligned substantially parallel to one another. As described above, abrasive particles described herein may have more than one magnetic moment, and will align with a net magnetic torque.

The magnetic field can be supplied by any external magnet (e.g., a permanent magnet or an electromagnet) or set of magnets. In some embodiments, the magnetic field typically ranges from 0.5 to 1.5 kOe. Preferably, the magnetic field is substantially uniform on the scale of individual magnetizable abrasive particles.

For production of abrasive articles, a magnetic field can optionally be used to place and/or orient the magnetizable abrasive particles prior to curing a binder (e.g., vitreous or organic) precursor to produce the abrasive article. The magnetic field may be substantially uniform over the magnetizable abrasive particles before they are fixed in position in the binder or continuous over the entire, or it may be uneven, or even effectively separated into discrete sections. Typically, the orientation of the magnetic field is configured to achieve alignment of the magnetizable abrasive particles according to a predetermined orientation, for example such that abrasive particles are parallel to each other and have cutting faces facing in a downweb direction.

Examples of magnetic field configurations and apparatuses for generating them are described in U. S. Patent No. 8,262,758 (Gao) and U. S. Pat. Nos. 2,370,636 (Carlton), 2,857,879 (Johnson), 3,625,666 (James), 4,008,055 (Phaal), 5,181,939 (Neff), and British (G. B.) Pat. No. 1 477 767 (Edenville Engineering Works Limited).

In another embodiment, the abrasive particles are oriented and placed using a tool. In some embodiments, patterned drop coating can be achieved using an alignment tool by methods analogous to that described in PCT Pat. Appl. Publ. Nos. 2016/205133 (Wilson et al.), 2016/205267 (Wilson et al.), 2017/007703 (Wilson et al.), 2017/007714 (Liu et al.). The method generally involves the steps of filling the cavities in a production tool each with one or more triangular abrasive particles (typically one or two), aligning the filled production tool and a make layer precursor-coated backing for transfer of the triangular abrasive particles to the make layer precursor, transferring the abrasive particles from the cavities onto the make layer precursor-coated backing, and removing the production tool from the aligned position. Thereafter, the make layer precursor is at least partially cured (typically to a sufficient degree that the triangular abrasive particles are securely adhered to the backing), a size layer precursor is then applied over the make layer precursor and abrasive particles, and at least partially cured to provide the coated abrasive belt. The process, which may be batch or continuous, can be practiced by hand or automated, e.g., using robotic equipment. It is not required to perform all steps or perform them in consecutive order, but they can be performed in the order listed or additional steps performed in between. The triangular abrasive particles can be placed in the desired Z-axis rotational orientation formed by first placing them in appropriately shaped cavities in a dispensing surface of a production tool arranged to have a complementary rectangular grid pattern, or other suitable pattern based on the shape of the abrasive particles.

Transfer coating using a tool having patterned cavities can be analogous to that described in U.S. Pat. Appln. Publ. No. 2016/0311081 Al (Culler et al.). In some embodiments, abrasive particles can be applied onto the make layer through a patterned mesh or sieve.

Examples of suitable abrasive particles include, but are not limited to: fused aluminum oxide; heat-treated aluminum oxide; white fused aluminum oxide; ceramic aluminum oxide materials such as those commercially available under the trade designation 3M CERAMIC ABRASIVE GRAIN from 3M Company, St. Paul, MN; brown aluminum oxide; blue aluminum oxide; silicon carbide (including green silicon carbide); titanium diboride; boron carbide; tungsten carbide; garnet; titanium carbide; diamond; cubic boron nitride; garnet; fused alumina zirconia; iron oxide; chromia; zirconia; titania; tin oxide; quartz; feldspar; flint; emery; sol-gel-derived abrasive particles; and combinations thereof. Of these, molded sol-gel derived alpha alumina abrasive particles are preferred in many embodiments. Abrasive material that cannot be processed by a sol-gel route may be molded with a temporary or permanent binder to form shaped precursor particles which are then sintered to form shaped abrasive particles, for example, as described in U. S. Pat. Appln. Publ. No. 2016/0068729 Al (Erickson et al.).

Examples of sol-gel-derived abrasive particles and methods for their preparation can be found in U. S. Pat. Nos. 4,314,827 (Leitheiser et al.); 4,623,364 (Cottringer et al.); 4,744,802 (Schwabel), 4,770,671 (Monroe et al.); and 4,881,951 (Monroe et al.). It is also contemplated that the abrasive particles could include abrasive agglomerates such, for example, as those described in U. S. Pat. Nos. 4,652,275 (Bloecher et al.) or 4,799,939 (Bloecher et al.). In some embodiments, first and / or abrasive particles may be surface-treated with a coupling agent (e.g., an organosilane coupling agent) or other physical treatment (e.g., iron oxide or titanium oxide) to enhance adhesion of the abrasive particles to the binder (e.g., make and/or size layer). The abrasive particles may be treated before combining them with the corresponding binder precursor, or they may be surface treated in situ by including a coupling agent to the binder.

Preferably, the abrasive particles are ceramic abrasive particles such as, for example, sol-gel- derived polycrystalline alpha alumina particles. Abrasive particles composed of crystallites of alpha alumina, magnesium alumina spinel, and a rare earth hexagonal aluminate may be prepared using solgel precursor alpha alumina particles according to methods described in, for example, U. S. Pat. No. 5,213,591 (Celikkaya et al.) and U. S. Pat. Appln. Publ. Nos. 2009/0165394 Al (Culler et al.) and 2009/0169816 Al (Erickson et al.).

Alpha alumina-based abrasive particles can be made according to well-known multistep processes. Briefly, the method includes the steps of making either a seeded or non-seeded sol-gel alpha alumina precursor dispersion that can be converted into alpha alumina; fdling one or more mold cavities having the desired outer shape of the abrasive particle with the sol-gel, drying the sol-gel to form precursor abrasive particles; removing the precursor abrasive particles from the mold cavities; calcining the precursor abrasive particles to form calcined, precursor abrasive particles, and then sintering the calcined, precursor abrasive particles to form the abrasive particles. The process will now be described in greater detail.

Further details concerning methods of making sol-gel-derived abrasive particles can be found in, for example, U. S. Pat. Nos. 4,314,827 (Leitheiser); 5,152,917 (Pieper et al.); 5,435,816 (Spurgeon et al.); 5,672,097 (Hoopman et al.); 5,946,991 (Hoopman et al.); 5,975,987 (Hoopman et al.); and 6,129,540 (Hoopman et al.); and in U. S. Publ. Pat. Appln. No. 2009/0165394 Al (Culler et al.).

Examples of slurry derived alpha alumina abrasive particles can be found in WO 2014/070468, published on May 8, 2014. Slurry derived particles may be formed from a powder precursor, such as alumina oxide powder. The slurry process may be advantageous for larger particles that can be difficult to make using sol-gel techniques.

The abrasive particles may undergo a sintering process, such as the process described in U.S. Pat. 10400146, issued on September 3, 2019, for example. However, other processing techniques are expressly contemplated.

Ultra-fine grain shaped grains may be formed using techniques described in U.S. PAP 2019/0233693, published on August 1, 2019, or in WO 2018023177, published on December 20, 2018, or in WO 2018/207145, published on November 15, 2018.

Softer shaped grain particles, with Mohs hardness’ between 2.0 and 5.0, that can be used for non-scratch applications, can be made according to methods described in WO 2019/215539, published on November 14, 2019. In some preferred embodiments, the abrasive particles are precisely-shaped in that individual abrasive particles will have a shape that is essentially the shape of the portion of the cavity of a mold or production tool in which the particle precursor was dried, prior to optional calcining and sintering.

Abrasive particles used in the present disclosure can typically be made using tools (i.e., molds) cut using precision machining, which provides higher feature definition than other fabrication alternatives such as, for example, stamping or punching.

The shaped abrasive particles can have at least one sidewall, which may be a sloping sidewall. In some embodiments, more than one (for example two or three) sloping sidewall can be present and the slope or angle for each sloping sidewall may be the same or different. In other embodiments, the sidewall can be minimized for particles where the first and the second faces taper to a thin edge or point where they meet instead of having a sidewall. The sloping sidewall can also be defined by a radius, R (as illustrated in Fig 5B of US Patent Application No. 2010/0151196). The radius, R, can be varied for each of the sidewalls.

Specific examples of shaped particles having a ridge line include roof-shaped particles, for example particles as illustrated, in Fig. 4A to 4C of WO 2011/068714. Preferred, roof-shaped particles include particles having the shape of a hip roof, or hipped roof (a type of roof wherein any sidewalls facets present slope downwards from the ridge line to the first side. A hipped roof typically does not include vertical sidewall(s) or facet(s)).

Methods for making shaped abrasive particles having at least one sloping sidewall are for example described in US Patent Application Publication No. 2010/0151196.

Shaped abrasive particles can also include a plurality of ridges on their surfaces. The plurality of grooves (or ridges) can be formed by a plurality of ridges (or grooves) in the bottom surface of a mold cavity that have been found to make it easier to remove the precursor shaped abrasive particles from the mold.

The plurality of grooves (or ridges) is not particularly limited and can, for example, include parallel lines which may or may not extend completely across the side. Preferably, the parallel lines intersect with the perimeter along a first edge at a 90° angle. The cross-sectional geometry of a groove or ridge can be a truncated triangle, triangle, or other geometry as further discussed in the following. In various embodiments of the invention, the depth, of the plurality of grooves can be between about 1 micrometer to about 400 micrometers.

According to another embodiment the plurality of grooves include a cross hatch pattern of intersecting parallel lines which may or may not extend completely across the face. In various embodiments, the cross hatch pattern can use intersecting parallel or non-parallel lines, various percent spacing between the lines, arcuate intersecting lines, or various cross-sectional geometries of the grooves. In other embodiments the number of ridges (or grooves) in the bottom surface of each mold cavity can be between 1 and about 100, or between 2 to about 50, or between about 4 to about 25 and thus form a corresponding number of grooves (or ridges) in the shaped abrasive particles.

Methods for making shaped abrasive particles having grooves on at least one side are for example described in US Patent Application Publication No. 2010/0146867.

The shaped abrasive particles may also have one or more notches on one of the faces of the abrasive particle, as described in PCT Application Ser. No. IB2019/060861, filed on December 16, 2019.

Shaped abrasive particles can have an opening (preferably one extending or passing through the first and second side). Methods for making shaped abrasive particles having an opening are for example described in US Patent Application Publication No. 2010/0151201 and 2009/0165394.

Shaped abrasive particles can also have at least one recessed (or concave) face or facet; at least one face or facet which is shaped outwardly (or convex). Methods for making dish-shaped abrasive particles are for example described in US Patent Application Publication Nos. 2010/0151195 and 2009/0165394. Additionally, shaped abrasive particles may also have a multifaceted surface as described in U.S. Pat. 10,150,900, issued on December 11, 2018.

Shaped abrasive particles can also have at least one fractured surface. Methods for making shaped abrasive particles with at least one fractured surface are for example described in US Patent Application Publication Nos. 2009/0169816 and 2009/0165394.

Shaped abrasive particles can also have a cavity. Shaped abrasive particles may also include an aperture, such as that described in U.S. Pat. 8,142,532, issued on March 27, 2012, herein incorporated by reference.

Shaped abrasive particles can also have a low roundness factor. Methods for making shaped abrasive particles with low Roundness Factor are for example described in US Patent Application Publication No. 2010/0319269.

Shaped abrasive particles may have a second vertex on a second side, as described in U.S. 9,447,311, issued on September 16, 2016. Methods for making abrasive particles wherein the second side is a vertex (for example, dual tapered abrasive particles) or a ridge line (for example, roof shaped particles) are for example described in U.S. PAP 2012/022733, published on September 13, 2012.

Shaped abrasive particles may be formed to have sharp tips, such as those described in U.S. PAP 2019/0233693, published on August 1, 2019, or in U.S. Provisional Application with Serial No. 62/877443, filed on July 23, 2019. Shaped abrasive particles may also be formed to include a rake angle, such as those described in WO 2019/207423, published on October 31, 2019, or in WO 2019/207417, published on October 31, 2019, or in PCT Application Ser. No. IB 2019/059112, fded on October 24, 2019.

Shaped abrasive particles may also be formed to have a precision shaped portion and a nonshaped portion, such as a crushed portion, as described in U.S. Provisional Patent Application 62/833865, filed on April 15, 2019.

Shaped abrasive particles can also have a combination of one or more of shape features discussed herein, including a sloping sidewall, a groove, a recess, a facet, a fractured surface, a cavity, more than one vertex, sharp edges, a non-shaped portion, a notch, a rake angle and / or a low roundness factor.

As used herein in referring to triangular abrasive particles, the term "length" refers to the maximum dimension of a triangular abrasive particle. "Width" refers to the maximum dimension of the triangular abrasive particle that is perpendicular to the length. The terms "thickness" or "height" refer to the dimension of the triangular abrasive particle that is perpendicular to the length and width. For abrasive particles with shapes other than triangles, length refers to a longest dimension, and width refers to the maximum dimension perpendicular to the length, while thickness refers to a dimension perpendicular to both the length and width.

The shaped abrasive particles may have an elongated shape, such as that described in U.S. PAP 2019/0106362, published on April 11, 2019, or in WO 2019/069157, published on April 11, 2019. The elongate shape may be triangular-prism shaped, rod-shaped, or otherwise including one or more vertices along the perimeter.

The shaped abrasive particles may have a variable cross-sectional area along a length of the particle, such as those described in U.S. PAP 2019/0249051. For example, the shaped abrasive particles may be dogbone shaped, or otherwise have a cross sectional area that varies from a first end to a second end.

The shaped abrasive particles may have a tetrahedron shape, such as those described in WO 2018/207145, published on November 15, 2018, or those of U.S. Pat. No. 9,573,250, issued on February 21, 2017.

The shaped abrasive particles may also have a concave or convex portion, or may be defined as having one or more acute interior angles, such as those described in U.S. 10,301,518, issued on May 28, 2019.

The shaped abrasive particles may also include shape-on-shape particles, such as a plate on plate shaped particle as described in 8,728,185, issued on May 20, 2014. The shaped abrasive particles may also include shaped abrasive particles that have an irregular polygonal shape, as described in U.S. Provisional Patent Application 62/924956, filed on October 23, 2019.

The shaped abrasive particles may also be shaped to be self-standing abrasive particles, such that cutting portions are more likely to embed in a make coat, for example, in an orientation away from the backing, such as those described in PCT Application with Ser. No. IB 2019/060457, fded on December 4, 2019.

The abrasive particles are typically selected to have a length in a range of from 1 micron to 15000 microns, more typically 10 microns to about 10000 microns, and still more typically from 150 to 2600 microns, although other lengths may also be used.

The abrasive particles are typically selected to have a width in a range of from 0.1 micron to 3500 microns, more typically 100 microns to 3000 microns, and more typically 100 microns to 2600 microns, although other lengths may also be used.

Abrasive particles are typically selected to have a thickness in a range of from 0.1 micron to 1600 microns, more typically from 1 micron to 1200 microns, although other thicknesses may be used. In some embodiments, Abrasive particles may have an aspect ratio (length to thickness) of at least 2, 3, 4, 5, 6, or more.

Surface coatings for the abrasive particles may be used to improve the adhesion between abrasive particles and a binder in abrasive articles, or can be used to aid in electrostatic deposition of the abrasive particles. In one embodiment, surface coatings as described in U. S. Pat. No. 5,352,254 (Celikkaya) in an amount of 0.1 to 2 percent surface coating to abrasive particle weight may be used. Such surface coatings are described in U. S. Pat. Nos. 5,213,591 (Celikkaya et al.); 5,011,508 (Wald et al.); 1,910,444 (Nicholson); 3,041,156 (Rowse et al.); 5,009,675 (Kunz et al.); 5,085,671 (Martin et al.); 4,997,461 (Markhoff-Matheny et al.); and 5,042,991 (Kunz et al.). Additionally, the surface coating may prevent the abrasive particle from capping. Capping is the term to describe the phenomenon where metal particles from the workpiece being abraded become welded to the tops of the abrasive particles. Surface coatings to perform the above functions are known to those of skill in the art.

The abrasive particles may be independently sized according to an abrasives industry recognized specified nominal grade. Exemplary abrasive industry recognized grading standards include those promulgated by ANSI (American National Standards Institute), FEPA (Federation of European Producers of Abrasives), and JIS (Japanese Industrial Standard). ANSI grade designations (i.e., specified nominal grades) include, for example: ANSI 4, ANSI 6, ANSI 8, ANSI 16, ANSI 24, ANSI 36, ANSI 46, ANSI 54, ANSI 60, ANSI 70, ANSI 80, ANSI 90, ANSI 100, ANSI 120, ANSI 150, ANSI 180, ANSI 220, ANSI 240, ANSI 280, ANSI 320, ANSI 360, ANSI 400, and ANSI 600. FEPA grade designations include F4, F5, F6, F7, F8, F10, F12, F14, F16, F20, F22, F24, F30, F36, F40, F46, F54, F60, F70, F80, F90, F100, F120, F150, F180, F220, F230, F240, F280, F320, F360, F400, F500, F600, F800, F1000, F1200, F1500, and F2000. JIS grade designations include JIS8, JIS12, JIS16, JIS24, JIS36, JIS46, JIS54, JIS60, JIS80, JIS100, JIS150, JIS180, JIS220, JIS240, JIS280, JIS320, JIS360, JIS400, JIS600, JIS800, JIS1000, JIS1500, JIS2500, JIS4000, JIS6000, JIS8000, and JIS 10000. According to one embodiment of the present disclosure, the average diameter of the abrasive particles may be within a range of from 260 to 1400 microns in accordance with FEPA grades F60 to F24.

Alternatively, the abrasive particles can be graded to a nominal screened grade using U. S.A. Standard Test Sieves conforming to ASTM E-l l "Standard Specification for Wire Cloth and Sieves for Testing Purposes". ASTM E-l l prescribes the requirements for the design and construction of testing sieves using a medium of woven wire cloth mounted in a frame for the classification of materials according to a designated particle size. A typical designation may be represented as -18+20 meaning that the abrasive particles pass through a test sieve meeting ASTM E-l l specifications for the number 18 sieve and are retained on a test sieve meeting ASTM E-l l specifications for the number 20 sieve. In one embodiment, the abrasive particles have a particle size such that most of the particles pass through an 18 mesh test sieve and can be retained on a 20, 25, 30, 35, 40, 45, or 50 mesh test sieve. In various embodiments, the abrasive particles can have a nominal screened grade of: -18+20, -20+25, -25+30, -30+35, -35+40, -40+45, -45+50, -50+60, -60+70, -70+80, -80+100, -100+120, - 120+140, -140+170, -170+200, -200+230, -230+270, -270+325, -325+400, -400+450, -450+500, or - 500+635. Alternatively, a custom mesh size can be used such as -90+100.

Once the first and second abrasive particles have been embedded in the make layer precursor, it is at least partially cured in order to preserve orientation of the mineral during application of the size layer precursor. Typically, this involves B-staging the make layer precursor, but more advanced cures may also be used if desired. B-staging may be accomplished, for example, using heat and/or light and/or use of a curative, depending on the nature of the make layer precursor selected.

In block 1140, the abrasive article material is further processed. For example, one or more additional coating, such as a size and / or a supersize coating may be applied over the abrasive particles. The abrasive article material may also be converted into the abrasive article shape. For example, composite abrasive article portions may be laser cut or stamped out of one or more sheets of abrasive material. However, it is expressly contemplated that other suitable methods can be used to produce the desired shape of abrasive articles. In another example, the abrasive article material may be converted into belts by laser cutting a sheet of abrasive article material to size. Processing the abrasive article material may also include forming coupling features - such as the protrusion and apertures described in the formation of composite abrasive articles or the interlacing lobe features.

In some embodiments, a size layer is coated over the embedded particles. The size layer precursor is applied over the at least partially cured make layer precursor and abrasive particles. The size layer can be formed by coating a curable size layer precursor onto a major surface of the backing. The size layer precursor may include for example, glue, phenolic resin, aminoplast resin, ureaformaldehyde resin, melamine-formaldehyde resin, urethane resin, free -radically polymerizable polyfunctional (meth)acrylate (e.g., aminoplast resin having pendant a,P-unsaturated groups, acrylated urethane, acrylated epoxy, acrylated isocyanurate), epoxy resin (including bis-maleimide and fluorene- modified epoxy resins), isocyanurate resin, and mixtures thereof. If phenolic resin is used to form the make layer, it is likewise preferably used to form the size layer. The size layer precursor may be applied by any known coating method for applying a size layer to a backing, including roll coating, extrusion die coating, curtain coating, knife coating, gravure coating, spray coating, and the like. If desired, a presize layer precursor or make layer precursor according to the present disclosure may be also used as the size layer precursor.

The basis weight of the size layer will also necessarily vary depending on the intended use(s), type(s) of abrasive particles, and nature of the coated abrasive belt being prepared, but generally will be in the range of from 1 or 5 gsm to 300, 400, or even 500 gsm, or more. The size layer precursor may be applied by any known coating method for applying a size layer precursor (e.g., a size coat) to a backing including, for example, roll coating, extrusion die coating, curtain coating, and spray coating.

Once applied, the size layer precursor, and typically the partially cured make layer precursor, are sufficiently cured to provide a usable coated abrasive article. In general, this curing step involves thermal energy, although other forms of energy such as, for example, radiation curing may also be used. Useful forms of thermal energy include, for example, heat and infrared radiation. Exemplary sources of thermal energy include ovens (e.g., festoon ovens), heated rolls, hot air blowers, infrared lamps, and combinations thereof.

In addition to other components, binder precursors, if present, in the make layer precursor and/or presize layer precursor of coated abrasive belts according to the present disclosure may optionally contain catalysts (e.g., thermally activated catalysts or photocatalysts), free-radical initiators (e.g., thermal initiators or photoinitiators), curing agents to facilitate cure. Such catalysts (e.g., thermally activated catalysts or photocatalysts), free-radical initiators (e.g., thermal initiators or photoinitiators), and/or curing agents may be of any type known for use in coated abrasive belts including, for example, those described herein. In addition to other components, the make and size layer precursors may further contain optional additives, for example, to modify performance and/or appearance. Exemplary additives include grinding aids, fdlers, plasticizers, wetting agents, surfactants, pigments, coupling agents, fibers, lubricants, thixotropic materials, antistatic agents, suspending agents, and/or dyes.

Exemplary grinding aids, which may be organic or inorganic, include waxes, halogenated organic compounds such as chlorinated waxes like tetrachloronaphthalene, pentachloronaphthalene, and polyvinyl chloride; halide salts such as sodium chloride, potassium cryolite, sodium cryolite, ammonium cryolite, potassium tetrafluoroborate, sodium tetrafluoroborate, silicon fluorides, potassium chloride, magnesium chloride; and metals and their alloys such as tin, lead, bismuth, cobalt, antimony, cadmium, iron, and titanium. Examples of other grinding aids include sulfur, organic sulfur compounds, graphite, and metallic sulfides. A combination of different grinding aids can be used.

Exemplary antistatic agents include electrically conductive material such as vanadium pentoxide (e.g., dispersed in a sulfonated polyester), humectants, carbon black and/or graphite in a binder.

Examples of useful fillers for this disclosure include silica such as quartz, glass beads, glass bubbles and glass fibers; silicates such as talc, clays, (montmorillonite) feldspar, mica, calcium silicate, calcium metasilicate, sodium aluminosilicate, sodium silicate; metal sulfates such as calcium sulfate, barium sulfate, sodium sulfate, aluminum sodium sulfate, aluminum sulfate; gypsum; vermiculite; wood flour; aluminum trihydrate; carbon black; aluminum oxide; titanium dioxide; cryolite; chiolite; and metal sulfites such as calcium sulfite.

Additionally, in some embodiments, a supersize coat is applied over the size coat. The supersize coat may include fillers, grinding aids, lubricants, or suitable other materials.

Optionally a supersize layer may be applied to at least a portion of the size layer. If present, the supersize typically includes grinding aids and/or anti-loading materials. The optional supersize layer may serve to prevent or reduce the accumulation of swarf (the material abraded from a workpiece) between abrasive particles, which can dramatically reduce the cutting ability of the coated abrasive belt. Useful supersize layers typically include a grinding aid (e.g., potassium tetrafluoroborate), metal salts of fatty acids (e.g., zinc stearate or calcium stearate), salts of phosphate esters (e.g., potassium behenyl phosphate), phosphate esters, urea-formaldehyde resins, mineral oils, crosslinked silanes, crosslinked silicones, and/or fluorochemicals. Useful supersize materials are further described, for example, in U. S. Pat. No. 5,556,437 (Lee et al.). Typically, the amount of grinding aid incorporated into coated abrasive products is about 50 to about 400 gsm, more typically about 80 to about 300 gsm. The supersize may contain a binder such as for example, those used to prepare the size or make layer, but it need not have any binder. Further details concerning the construction of coated abrasive articles comprising an abrasive layer secured to a backing, wherein the abrasive layer includes abrasive particles and make, size, and optional supersize layers are well known, and may be found, for example, in U. S. Pat. Nos. 4,734,104 (Broberg); 4,737,163 (Larkey); 5,203,884 (Buchanan et al.); 5,152,917 (Pieper et al.); 5,378,251 (Culler et al.); 5,417,726 (Stout et al.); 5,436,063 (Follett et al.); 5,496,386 (Broberg et al.); 5,609,706 (Benedict et al.); 5,520,711 (Helmin); 5,954,844 (Law et al.); 5,961,674 (Gagliardi et al.); 4,751,138 (Bange et al.); 5,766,277 (DeVoe et al.); 6,077,601 (DeVoe et al.); 6,228,133 (Thurber et al.); and No. 5,975,988 (Christianson).

In block 1150, the abrasive article is formed. For example, a number of composite abrasive article portions are coupled to a backing - for example using an adhesive 1152, or a mechanical attachment 1154. The mechanical attachment may be a recloseable attachment, such as DualLock™, available from 3M Company of Minnesota. Other attachment mechanisms 1156 may also be used, including welding.

In another example, forming an abrasive belt may also include applying an adhesive 1152, which may include any suitable adhesive, such as any of: urea formaldehyde resins, silicone resins, unsaturated polyesters, polyurethanes, bisamide polyesters, epoxy polyesters, epoxy polamides, bisketenes, epoxy resins, hyde glues, acrylate resins, styrene-polyesters, phenolic resins, polyamides and combinations thereof. However, in some embodiments a polyolefin-based splice adhesive is used, such as that described in U.S. Provisional Patent Application having Serial No. 63/611028, filed December 15, 2023.

In some embodiments, the backside of each end of the abrasive belt (opposite the abrasive particles) is scuffed to increase surface area. The lobes of the first end may then be interlaced with the lobes of the second end, and the adhesive may be applied. A splice tape may be placed such that the adhesive is between the backside of the abrasive belt and the splice tape. The adhesive may be applied directly to the backing, the splice tape, or both. In some embodiments the backside-adhesive-splice tape is then subjected to a heat-pressing step to facilitate curing of the adhesive. Additional heating steps may be used.

Abrasive articles in embodiments herein may be used in an abrading operation for a workpiece. The abrading operation may include urging the workpiece against the abrasive article (or vice versa) such that the abrasive particles contact the workpiece surface. Examples of workpiece materials include metal, metal alloys, steel, steel alloys, aluminum, exotic metal alloys, ceramics, glass, wood, wood-like materials, composites, painted surfaces, plastics, reinforced plastics, stone, and/or combinations thereof. The workpiece may be flat or have a shape or contour associated with it. Exemplary workpieces include metal components, plastic components, particleboard, camshafts, crankshafts, furniture, and turbine blades.

FIGS. 12A-12B illustrate a splice pattern resulting in a two-hinge system for an abrasive belt in accordance with embodiments herein. FIG. 12A illustrates a splice pattern 1200 with a series of alternating lobes and apertures that creates an interlocking splice. Using a pattern like pattern 1200, as discussed above, spreads out the stress on an abrasive belt, such as belt 1210 across two hinge locations, illustrated as hinge locations 1202 and 1204, which correspond to hinge locations 1212 and 1214. Having two hinge locations instead of a single splice may spread the stress on the belt across a greater area, increasing the ability of the belt to withstand stress. However, as illustrated in FIGS. 13- 15, embodiments herein are not limited to two hinge locations. Splice patterns herein can be designed to have 2, 3, 4 or even more hinge locations.

FIGS. 13A-13D illustrate splice patterns resulting in multi -hinge systems for an abrasive belt in accordance with embodiments herein.

FIG. 13A illustrates a splice pattern 1300 that results in a three-hinge system, having a first hinge 1302 formed along a line defined by shallowest point of each of a plurality of apertures. A second hinge 1304 is formed along a line defined by the height of a first lobe 1310. A third hinge 1306 is formed by the inclusion of a second lobe 1312, having a different profile than the first lobe 1310. The first and second lobes may differ in one or more of their height, their radius, or distance from a centerline. Illustrated in FIG. 13 A, lobes 1312 are similar to lobes 1310, but have a different height, which results in the positioning of the third hinge 1306.

FIG. 13B illustrates a splice pattern 1320 which has a four-hinge system formed by lobes 1332 and 1334. A hinge span 1349 is defined as a longest distance between two hinges present in a hinge pattern, e.g. hinge 1322 and 1324, for splice pattern 1320. A first hinge 1322 is positioned, in pattern 1320, at the deepest point of an aperture along the splice pattern. A second hinge 1324 is positioned, in pattern 1320, at the height of a lobe that is farthest away from the first hinge 1322. A third hinge 1326 is formed along a line defined by shallower apertures present between lobes 1332 and 1334. A fourth hinge 1328 is formed along a line defined by the topmost point of lobe 1336.

A belt having a splice pattern such as that illustrated in any of FIGS. 13A-13D may be considered as having a hinge area defined by the width of the belt and the hinge span defined by the hinges formed by the pattern of lobes and apertures.

As illustrated in FIGS. 19-21, increasing a number of hinge locations reduces a maximum stress experienced at any point along the splice pattern, spreading the stress out over a greater portion of the hinge area formed by the splice pattern. FIG. 13C illustrates another example of a splice pattern 1340 which also results in a four-hinge system. Splice pattern 1340 has two different sized lobes - with lobes 1352 having a greater height than lobes 1354. Splice pattern 1340 also includes two different aperture depths - with aperture 1356 being shallower than aperture 1358. This results in a hinge space defined by first hinge 1342 and second hinge 1344, with intervening hinges 1346 and 1348.

FIG. 13D illustrates another example of a splice pattern 1360 which has a hinge span extending from hinge 1362 to hinge 1364, with intervening hinges 1366 and 1368. Splice pattern 1360 is formed by a plurality of lobes that alternate between longer lobes 1372 and shorter lobes 1374, with corresponding apertures 1376 and 1378 therebetween. It is noted that splice pattern 1360 has spacings between adjacent hinges that are unequal - e.g. while a spacing between hinges 1362 and 1366 is the same as a spacing between 1368 and 1364, a larger spacing exists between adjacent hinges 1366 and 1368. However, it is expressly contemplated that, for a four-hinge system having three hinge spaces, that all three hinge spaces may be the same, in some embodiments, or may all be different, in some embodiments.

As used herein, the term first hinge may represent a first hinge point that separates the body 1380 of an abrasive belt from a splice section 1385 of the abrasive belt. The splice section 1385 may be the same as the hinge area.

FIG. 14 illustrates a stepped splice patterns for an abrasive belt in accordance with embodiments herein. FIGS. 13A-13D illustrate a number of different splice patterns where a hinge area extends perpendicularly along a width of an abrasive belt. FIG. 14 illustrates another embodiment of a splice pattern where a hinge area extends at an angle across a width of a belt.

The illustrated abrasive belt of FIG. 14 has a belt body portion 1440 and a splice portion 1445. Splice pattern 1400 includes a hinge area 1446 at an angle 1448 with respect to a moving direction 1410 of an abrasive belt. Splice pattern 1400 illustrates a plurality of lobes that all have the same height, interspersed with apertures all having the same depth. Each lobe is a different distance from an abrasive belt body 1440, e.g. with a first lobe being a first distance 1442 from a boundary between the belt portion 1440 and the splice portion 1445, and a second lobe being a second distance 1444 from the boundary between the belt portion 1440 and the splice portion 1445.

It is noted that, while FIG. 14 illustrates an embodiment where an offset 1420 between adjacent lobes is the same across the entire splice portion 1445. However, it is expressly contemplated that, in some embodiments, a number of differently-sized offsets 1420 may be present. For example, a first offset and a second offset, of different size, may alternate across splice portion 1445. Other patterns are expressly contemplated, such as a first offset appearing twice, then a second offset appearing once or twice, etc. Additionally, more than two offset sizes may be present in some embodiments, for example three distinctly sized offsets may be present, or four, or even more.

Similarly, in some embodiments, an offset is not present after each lobe. For example, an offset may only be present, in some embodiments, after every two or every three lobes. Other patterns are expressly contemplated.

The concept of an offset, as illustrated in FIG. 14, may also be combined with different sized lobes and / or apertures, as illustrated in FIG. 13. Such a combination could increase a hinge area 1446, and a number of hinges within the hinge area, spreading stress across a greater area.

FIG. 15 illustrates splice patterns having lobes with apertures in accordance with embodiments herein. In some embodiments herein, one or more lobes in a splice pattern may have an aperture extending therethrough. An aperture may increase penetration of adhesive between the splice portion of the belt and the splice tape, which may improve the strength of the spliced portion of the belt. FIG. 15 illustrates an example splice pattern 1500 which shows three different embodiments of potential apertures. It is expressly contemplated that apertures 1510, 1520 and 1530 represent only a small portion of aperture shapes that may be suitable. A circular or ovular aperture 1510 may be used, in some embodiments. In some embodiments, a slot 1520 may be used. However, it is expressly contemplated that, while apertures 1510, 1520 remove material from the abrasive belt to form an aperture, that a slit 1530 may be sufficient for some embodiments.

Comparing FIG. 15 to FIGS. 9A-9D, it is noted that FIGS. 9A-9D has the splice pattern angled with respect to the edge of the belt. However, it may be easier to manufacture the design of FIG. 15, while still obtaining the benefits of having an angled splice pattern.

Apertures may be cut into one or more lobes of a splice pattern by any suitable cutting tool. A laser may be used to make one or more perforations, slits, or remove any suitably sized and shaped aperture. Apertures may be punched or cut out using other suitable technology as well.

Objects and advantages of this disclosure are further illustrated by the following non-limiting examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.

An abrasive article includes a backing and a plurality of abrasive article portions is presented. Each abrasive article portion is directly coupled to the backing. A first abrasive article portion includes a first composition and a second abrasive article portion includes a second composition. The first and second abrasive articles are coplanar such that first abrasive particles of the first abrasive article and second abrasive particles of the second abrasive article are configured to simultaneously contact a worksurface. The plurality of abrasive article portions are coupled to the backing by a coupling agent. The abrasive article may include first abrasive particles with a first average size and second abrasive particles with a second average size, where the first average size differs from the second average size.

The abrasive article may include a first abrasive grade in the first abrasive article portion and a second abrasive grade in the second abrasive article portion, where the first and second abrasive grades differ.

The abrasive article may include first abrasive particles of a first particle type and second abrasive particles of a second particle type, where the first and second particle types are different. The first abrasive particle type may be crushed, platey, formed, or shaped.

The abrasive article may include a first abrasive particle density in the first abrasive article portion and a second abrasive particle density in the second abrasive article portion, where the first and second particle densities differ.

The abrasive article may include a first make coat composition in the first abrasive article portion and a second make coat composition in the second abrasive article portion, where the first and second make coat compositions differ.

The backing of the abrasive article may include a nonwoven material.

The backing of the abrasive article may include a polymeric film, a metal foil, a woven fabric, a knitted fabric, a paper, a nonwoven, a foam, a screen, or a laminate.

The backing of the abrasive article may include a backup pad.

The coupling agent of the abrasive article may be a mechanical coupling agent.

The coupling agent of the abrasive article may include an adhesive.

The first abrasive article portion may be coupled to the second abrasive article portion.

The first abrasive article portion may have a first interlocking feature that interacts with a second interlocking feature of the second abrasive article.

The first abrasive article portion may be mechanically coupled to the second abrasive article portion.

Adhesive may couple the first abrasive article portion to the second abrasive article portion.

The first abrasive article portion and the second abrasive article portion may be discrete portions.

The first abrasive article portion may be directly coupled to the backing and indirectly coupled to the second abrasive article portion.

The first interlocking feature may include a protrusion or aperture.

The plurality of abrasive article portions may include at least four abrasive article portions.

The plurality of abrasive article portions may include at least six abrasive article portions. The plurality of abrasive article portions may include an odd number of abrasive article portions.

The first abrasive article portion may include a first worksurface-contacting area that is larger than a second worksurface-contacting area of the second abrasive article portion.

A kit for forming a composite abrasive article is presented that includes a backing, a first abrasive article portion, a second abrasive article portion that is different from the first abrasive article portion in at least one property, and a coupling agent configured to couple the first and second abrasive article portions to the backing such that abrasive surfaces of the first and second pluralities of abrasive article portions are coplanar.

The coupling agent in the kit may include an adhesive.

The coupling agent in the kit may include a mechanical coupling component.

A surface of the backing in the kit may include the mechanical coupling agent.

The mechanical coupling agent in the kit may be configured to allow for attachment and removal of the first plurality of abrasive article portions.

The abrasive property in the kit may include an abrasive particle portion surface area configured to contact a worksurface, where the first abrasive article portion includes a surface area larger than the second abrasive article portion.

The abrasive property in the kit may be an abrasive particle size.

The abrasive property in the kit may be a type of abrasive particle, where the type includes crushed, formed, platey, or shaped.

The abrasive property in the kit may be a density of abrasive particles.

The abrasive property in the kit may be an abrasive grade.

The first and second abrasive article portions in the kit may be discrete and uncoupled.

The first abrasive article portion in the kit may include a first interlocking feature, and the second abrasive article portion may include a second interlocking feature. When coupled to the backing, the first interlocking feature is configured to interact with the second interlocking feature.

The first interlocking feature in the kit may include an aperture or a protrusion.

The first abrasive particle portion in the kit may be directly coupled to the second abrasive particle portion.

A first abrasive disc in the kit, including a first composition of the first abrasive article portion, may have a first abrasive cut rate. A second abrasive disc, including a second composition of the second abrasive article portion, may have a second abrasive cut rate. A composite abrasive article, including the first and second abrasive particle portions, may have a third abrasive cut rate, different from the first or second abrasive cut rates. A first abrasive disc in the kit, including a first composition of the first abrasive article portion, may impart a first surface finish. A second abrasive disc, including a second composition of the second abrasive article portion, may impart a second surface finish. A composite abrasive article, including the first and second abrasive particle portions, may impart a third surface finish, different from the first or second abrasive surface finishes.

The backing in the kit may include a nonwoven material.

The backing in the kit may include a polymeric film, a metal foil, a woven fabric, a knitted fabric, a paper, a nonwoven, a foam, a screen, or a laminate.

The backing in the kit may include a backup pad.

The kit may further include a third abrasive article portion, which is different from the first or second abrasive article portions.

The kit may include a plurality of the first abrasive article portions.

A method of abrading a surface is presented that includes contacting an abrasive article to a worksurface. The abrasive article is a composite abrasive article that includes a backing, a first portion having a first composition with a first plurality of abrasive particles, and a second portion having a second composition with a second plurality of abrasive particles. The first and second portions are coplanar and are coupled to the backing. The method also includes moving the abrasive article with respect to the worksurface such that a portion of the worksurface is removed.

The worksurface may be urged against the abrasive article.

The abrasive article may be urged against the worksurface.

The first plurality of abrasive particles may be larger, on average, than the second plurality of particles.

The first plurality of abrasive particles may be a first particle type of abrasive particle, different from a second particle type of the second plurality of abrasive particles. The first particle type may include crushed, formed, platey, or shaped particles.

A first particle density of the first portion may differ from a second particle density of the second portion.

The first portion may have a first make coat composition and the second portion may have a second make coat composition, different from the first make coat composition.

The first abrasive article portion may include a first worksurface-contacting area that is larger than a second worksurface -contacting area of the second abrasive article portion.

The composite abrasive particle may include a third portion, having a third composition different from the first or second portions.

The first portion may be directly coupled to the second portion. The first portion may be mechanically coupled to the second portion.

The first portion may be directly coupled to the backing.

The first portion may be permanently coupled to the backing.

The first portion may be removably coupled to the backing.

The backing may include a nonwoven material.

The backing may include a polymeric film, a metal foil, a woven fabric, a knitted fabric, a paper, a nonwoven, a foam, a screen, or a laminate.

The backing may include a backup pad.

A first abrasive disc, including the first composition, may have a first initial cut rate. A second abrasive disc, including the second composition, may have a second initial cut rate. The composite abrasive disc may have a composite initial cut rate, different from either the first or the second initial cut rate.

An abrasive belt is presented that includes an abrading surface opposite a backside. The abrading surface includes abrasive particles adhered to a backing. The belt has a first end with a portion of a first splice pattern and a second end with a portion of a second splice pattern. The first splice pattern is complementary to the second splice pattern. The first splice pattern includes a lobe having a lobe circular portion and a receiving portion having a receiving circular portion. The lobe is defined by a line tangent to both the lobe circular portion and the receiving circular portion. A splice adhesive couples the first splice pattern to the second splice pattern.

The first splice pattern may be defined by a centerline equidistant from a lobe tip to a receiving portion depth. The centerline may be angled, at an angle, with respect to an edge of the abrasive belt, where the angle is less than 90°.

The angle may be greater than about 60°.

The angle may be greater than about 70°. g may be less than about 2, where g is defined as half of a distance, 2d, from a first center of a first lobe circular portion to a second center of a second lobe circular portion, divided by a radius, R, of the lobe circular portion.

H may be greater than about 0.8 and less than about 1.4, where H is defined by e, a distance from a lobe center to the centerline, divided by a radius, R, of the lobe circular portion.

The first splice pattern may be offset from the second splice pattern.

The portion of the first splice pattern may be less than one repeating unit of the splice pattern.

The belt diameter may be less than 2 inches.

The first end may be coupled directly to a splice tape and the second end may be coupled directly to the splice tape. The abrasive particles may include crushed abrasive particles, formed abrasive particles, platey abrasive particles, or shaped abrasive particles.

The abrasive particles may be coupled to the backing by a make coat.

A size coat may be applied over the abrasive particles.

The lobe may be a first lobe, and the splice pattern may include a second lobe. The first lobe may include a first height, the second lobe may include a second height, and the first and second heights may be different.

The lobe may be a first lobe, and the splice pattern may include a second lobe. The first lobe may include a first radius, the second lobe may include a second radius, and the first and second radii may be different.

The receiving portion may be a first receiving portion, and the splice pattern may include a second receiving portion. The first receiving portion may include a first depth, the second receiving portion may include a second depth, and the first and second depths may be different.

The receiving portion may be a first receiving portion, and the splice pattern may include a second receiving portion. The first receiving portion may include a first circular portion having a first center point and a first distance from the first center point to a centerline of the splice pattern. The second receiving portion may include a second receiving portion, where the second receiving portion includes a second circular point having a second center point and a second distance from the second center point to the centerline of the splice pattern. The first and second distances may be different.

The splice pattern may include a hinge area defined by a first hinge and a second hinge. The hinge area may be further defined by a third hinge positioned between the first and second hinges.

A first distance from the first and third hinge may differ from a second distance from the third hinge to the second hinge.

The lobe may be a first lobe, and the splice pattern may include a second lobe, where the second lobe is offset from the first lobe.

The first lobe and the second lobe may differ in at least one of height or radius of the lobe circular portion.

The lobe may include an aperture.

The aperture may include a slit extending throughout a thickness of the abrasive belt.

The aperture may include a removed area of the abrasive belt.

The aperture may be wholly contained within the lobe circular portion.

The aperture may extend to a perimeter of the lobe.

The aperture may extend beyond the lobe circular portion. A method of abrading a workpiece includes contacting the workpiece to an endless abrasive belt. The endless abrasive belt includes a splice, where the splice includes a splice pattern that is free of sharp transitions. The endless abrasive belt is in motion about one or more contact wheels.

The splice pattern may be defined by circles and tangent lines to said circles.

The splice pattern may include a portion of a repeating pattern including alternating lobes and valleys, g, for the repeating pattern, may be less than about 2, where g is defined by d/R, where d is half a distance from a first center of a first circular portion of a first lobe and a second center of a second circular portion of a second lobe, and R is a radius of the first circular portion.

The splice pattern may be at an angle with respect to an edge of the endless belt, where the angle is less than 90°.

The angle may be greater than 60°.

The angle may be greater than 70°.

The splice pattern may include a portion of a repeating pattern including alternating lobes and valleys. H, for the repeating pattern, may be less than about 1.4, where H is defined as e/R, where e is a distance from a center of a first center of a first circular portion of a first lobe and a centerline, the centerline being equidistant from a lobe tip and a valley vertex.

H may be greater than about 0.8.

At the splice, a first splice pattern of a first belt end may be offset from a second splice pattern of a second belt end.

The splice may include less than one repeating unit of a splice pattern.

The belt diameter may be less than 2 inches.

A first belt end may be coupled directly to a splice tape and a second belt end may be coupled directly to the splice tape.

The abrasive particles may include crushed abrasive particles, formed abrasive particles, platey abrasive particles, or shaped abrasive particles.

The abrasive particles may be coupled to the backing by a make coat.

A size coat may be applied over the abrasive particles.

The splice pattern may include a first lobe and a second lobe, where the first lobe includes a first height, the second lobe includes a second height, and the first and second heights are different.

The splice pattern may include a first lobe and a second lobe, where the first lobe includes a first radius, the second lobe includes a second radius, and the first and second radii are different.

The splice pattern may include a first receiving portion and a second receiving portion, where the first receiving portion includes a first depth, the second receiving portion includes a second depth, and the first and second depths are different. The splice patern may include a first receiving portion and a second receiving portion, where the first receiving portion includes a first circular portion having a first center point and a first distance from the first center point to a centerline of the splice patern. The second receiving portion includes a second receiving portion, where the second receiving portion includes a second circular point having a second center point and a second distance from the second center point to the centerline of the splice patern. The first and second distances are different.

The splice patern may include a hinge area defined by a first hinge and a second hinge.

The hinge area may be further defined by a third hinge positioned between the first and second hinges.

The splice patern may include a first lobe and a second lobe, where the second lobe is offset from the first lobe with respect to a body of the endless abrasive belt.

The splice patern may include a first lobe and a second lobe, where the first lobe and the second lobe differ in at least one of height or radius of the lobe circular portion.

The splice patern may include a lobe, where the lobe includes an aperture.

The aperture may include a removed area of the abrasive belt.

The aperture may be wholly contained within the lobe circular portion.

The aperture may extend to a perimeter of the lobe.

The aperture may extend beyond the lobe circular portion.

An endless abrasive belt is presented that includes a flexible backing having a first end and a second end. The first and second ends are coupled at a splice, where the first end includes a first interlocking feature and the second end includes a second interlocking feature. The first and second interlocking features are free of sharp transitions, and one of the first and second interlocking features is in line with a direction of travel of the endless abrasive belt. The first interlocking feature is partially defined by a partial circular portion and a tangent line to the circular portion. The endless abrasive belt also includes an abrasive surface opposite a backside, where the abrasive surface includes abrasive particles coupled to the backing. A splice tape is applied to the backside.

The first interlocking feature may be a portion of a splice patern, where the splice patern includes a first lobe defined by a circular portion having a radius R. A center of the first lobe is spaced apart from a center of a second lobe by a distance 2d. A centerline of the splice patern is angled with respect to an edge of the flexible backing. The centerline is defined as a line passing through the first and second lobes at half of a height of each of the first and second lobes. A body of the first lobe may be defined by first and second tangent lines on opposing sides of the circular portion extending along the height of the first lobe.

A ratio of d/R for the first lobe may be less than 2.

A ratio of e/R may be at least about 0.8 and less than about 1.4, where e is defined as a distance from a center of the circular portion to the centerline.

The centerline may be angled at an angle that is less than about 90°.

The angle may be less than about 80°.

The angle may be greater than about 70°.

The angle may be greater than about 75°.

The first interlocking feature may be offset from the second interlocking feature, and a splice adhesive may fill a gap created by the offset.

The belt diameter may be less than 2 inches.

The first end may be coupled directly to the splice tape and the second end may be coupled directly to the splice tape.

The abrasive particles may be coupled to the backing by a make coat.

A size coat may be applied over the abrasive particles.

The interlocking feature may include a first lobe and a second lobe.

The first lobe may include a first height, the second lobe may include a second height, and the first and second heights may be different.

The first lobe may include a first radius, the second lobe may include a second radius, and the first and second radii may be different.

The interlocking feature may include a first receiving portion and a second receiving portion.

The first receiving portion may include a first depth, the second receiving portion may include a second depth, and the first and second depths may be different.

The first receiving portion may include a first circular portion having a first center point and a first distance from the first center point to a centerline of the splice pattern. The second receiving portion may include a second receiving portion, where the second receiving portion includes a second circular point having a second center point and a second distance from the second center point to the centerline of the splice pattern. The first and second distances may be different.

The splice pattern may include a hinge area defined by a first hinge and a second hinge. The hinge area may be further defined by a third hinge positioned between the first and second hinges. A first distance from the first and third hinge may differ from a second distance from the third hinge to the second hinge.

The second lobe may be offset from the first lobe.

The first lobe and the second lobe may differ in at least one of height or radius of a lobe circular portion.

The interlocking feature may include an aperture.

The aperture may include a removed area of the abrasive belt.

The interlocking feature may include a lobe having a lobe circular portion, and the aperture may be wholly contained within the lobe circular portion.

The interlocking feature may include a lobe, and the aperture may extend to a perimeter of the lobe.

The interlocking feature may include a lobe having a lobe circular portion, and the aperture may extend beyond the lobe circular portion.

An abrasive belt is presented that includes a first end and a second end coupled together at a splice. The first end includes a splice pattern and the second end includes a complementary splice pattern. The splice pattern interlocks with the complementary splice pattern. The splice pattern includes at least part of a lobe, at least part of a lobe receiving portion, and a hinge area including a first hinge defined by a depth of the lobe receiving portion and a second hinge defined by a height of the lobe. The abrasive belt also includes a first major surface including abrasive particles coupled to a backing and a splice tape applied to a second major surface, the second major surface being opposite the first major surface.

The splice pattern may be free of sharp transitions.

The splice pattern may include a third hinge positioned between the first and second hinges.

The lobe may be a first lobe and the height may be a first height, and the third hinge may be defined by a second height of a second lobe, the second height being different from the first height.

The lobe receiving portion may be a first lobe receiving portion, the depth may be a first depth, and the third hinge may be defined by a second lobe receiving portion having a second depth, the second depth being different from the first depth.

A first space between the first hinge and the third hinge may be different from a second space between the third hinge and the second hinge.

The abrasive belt may further include a fourth hinge positioned between the first and second hinges. The abrasive belt may further include a belt edge extending from the first end to the second end, and the splice pattern may be angled with respect to the belt edge.

The abrasive belt may further include a belt edge extending from the first end to the second end, and the splice pattern may be substantially parallel with respect to the belt edge.

The lobe may be a first lobe, and the abrasive belt may further include at least part of a second lobe, where the second lobe is offset from the first lobe with respect to the first end of the abrasive belt.

The splice pattern may include a first lobe defined by a circular portion having a radius R. A center of the first lobe is spaced apart from a center of a second lobe by a distance 2d. A centerline of the splice pattern is angled with respect to an edge of the flexible backing. The centerline is defined as a line passing through the first and second lobes at half of a height of each of the first and second lobes.

EXAMPLES

Example 1

3.75 inch diameter discs were made using 2 types of nonwoven web: SC AMED & SC CRS. Using the die depicted in FIG. 2A, segments of web were die cut, along with complete discs of the same diameter.

3.75 inch diameter back up pads obtained from Terhorst Manufacturing, Minot, ND (type 27 design made from hytrel with an outer diameter of about 3.75 inches (95.25 mm) and an inner diameter of about 5/8 inch (15.87 mm) were scuffed with 7447 Scotch-Brite hand pad, then flame treated lightly with a Bunsen burner.

3M™ Scotch-Weld™ Urethane Adhesive DP605NS used to adhere the pieces into the BUP. The assembled discs were left to cure overnight before testing.

A robotic automated test was used to compare the cut performance and finish of the working piece. A right angle grinding tool was attached to a servo motor. Abrasive tests were performed 8000 rpm, 8 ° and 30 mm/sec traverse speed, 10 Newtons downward force, and a total of 10 passes onto a 300S SS substrate.

The cut rate comparison is depicted in FIG. 16A. It is noted that the modular segmented discs have comparable cut rate & finish to the complete discs.

More importantly, the modular discs alternating coarse and medium pieces of web showed an intermediate cut rate between their counterparts. A similar behavior is depicted in FIG. 16B, for the finish measurements in the stainless-steel workpiece.

All the modular discs tested were able to withstand the same unit pressure and rotational speed of the test. The results are illustrated in FIGS. 16A-16B. Example 2

FIG. 17A illustrates a representation of an exemplary designs of Sharf et al. FIG. 17B illustrates an exemplary design of an embodiment herein. The two designs can be approximated by the illustrations of FIGS. 17C (corresponding to 17A) and FIG. 17D (corresponding to 17B).

According to the beam deflection equation (Equation 6 below) and the geometry of a contact wheel for a belt being designed. Equation 6

Where Rw is the radius of the bending wheel, h is the thickness of the belt, I is the bending inertia, E is the Young’s modulus and w is the nominal length shown in FIGS. 13C and 13D.

The bending ineria of the beam can be calculated using Equation 7 below: Equation 7

Equations 6 and 7 can be combined to form Equation 8, which provides the bending reaction force for the schematic of FIG. 13D: Equation 8

The Sharf model of FIG. 13C, can be regarded as bending two separate beams, one with length L, and width (1- ? )w. and one with length 0.5L and width (2? )w. The bending reaction force, then, is provided by Equation 9 below.

Fi = 0.75 0.5

Equation 9

As Fl will be larger than F2, the design of FIG. 17C will experience a larger reaction bending force under the same bending deflection, which is more likely to experience bending detach.

Based on the above analysis, an FEA analysis was conducted with the model illustrated in FIG. 17E. The results are illustrated in FIG. 17F. The design of FIG. 17B experienced less reaction force than that of FIG. 13A under the same bending displacement, illustrating that the design of FIG. 17B is less rigid and more flexible than that of FIG. 17A.

The theoretical stress experienced by both designs is illustrated in FIGS. 17G-1 and 17G-2 (corresponding to the design of FIG. 17A) and FIGS. 17G-3 and 17G-4 (corresponding to the design of FIG. 17B). FIGS. 17G-1 and FIGS. 17G-3 illustrate the mises stress while FIGS. 17G-2 and 17G-4 illustrate the maximum principal stress of the overall assembly. Example 3

For Example 3, belts were converted to match the splice geometry in FIG. 10B and were processed using the same procedure to make Comparative Example 3.

For Comparative Example 3, Durable Flex AMED belt was obtained from 3M Company and cut to a geometry of 3” (7.62 cm) width by 18” (45.72 cm) long at an angle of 67 degrees to form a parallelogram shape. A splice adhesive solution was prepared by first making a 20% solids mix of Desmocoll 176 (Available from Convestro AG) in methyl ethyl ketone.

Then a catalyst premix solution of 6 g of 2-ethyl imidazole and 6 g of ethyl acetate was mixed and added to 3.79 liters of splice adhesive solution to make a catalyzed splice adhesive. 50 g of catalyzed splice adhesive and 5.5 g of Desmodur RE (Bayer Material Science) was added and hand mixed using a spatula for 2 minutes prior to application. About 1.5 g of the adhesive solution was applied evenly to the nonabrasive side of both terminal ends and the butt joint interface and allowed to partially dry for 20 minutes. Splice tape was then applied (Sheldahl T1641 Blue, 67 degree angle and 1” wide (25.4 mm)) to the partially dried splice adhesive and the two terminal ends were abutted together then pressed at 4 tons of force for 30 seconds using a heated press (Biko type PNP-450) with heated upper and lower platens set at 225 degrees F (107° C) and 220 degrees F (104° C) respectively. Spliced belts were then further slit down to produce belts of 1/8” (3.2 mm) wide.

Each of the Example 3 and Comparative Example 3 1/8” (3.2 mm) x 18” (45.72 cm) belts were individually mounted on a pneumatic 3M fde belt tool model 28367 using contact arm with model 28369 and ran for 15 seconds. The pneumatic fde belt was powered using 90 psi (621 kPa) air line of 1/4" (0.635 cm) diameter. The belt was free spinning meaning it was not in contact with a workpiece.

FIGS. 18A-18B illustrates how, after 15 seconds of running, a hinge is opening up for the comparative example belt (18A), but not for the example belt (18B). Comparative Example three failed after 18 seconds. Example 3 was still intact after 10 minutes of running.

FIGS. 19A-C present a series of Finite Element Analysis (FEA) with meshes illustrating that multi-hinge belts are better than two-hinge belt configurations when it comes to spreading out the stress on the splice portion. FIG. 19A features relatively shorter lobes, FIG. 19B shows relatively longer lobes, and FIG. 19C combines longer lobes with short fingers. These figures are produced using the following parameters (defined in FIG. 7A): 0 = 90 degrees, R = 82 mil, e = 100 mil (shorter lobes), el = 200 mil (longer lobes), and d = 71.34 mil.

FIG. 20 illustrates the overall loading geometry and sample dimensions. The combination of two 7-inch long, 1-inch wide lobe belts forms a 14-inch long connected belt, with a 3-inch roller coaster indenting and contacting the lobes on top. The maximum indentation in the contact direction is 30 mm, and the connected belt is fixed at both ends along its length. FIGS. 21A-C display the corresponding FEA results of Max Principal Stress distribution. Stress values exceeding the peak value (9 MPa) are grayed out, indicating high tensile stress region, to maintain consistent color coding for comparison. For the two-hinge lobes, Figure 21A shows that short lobes exhibit high tensile stress concentration at both ends and the middle, while Figure 2 IB indicates that longer lobes concentrate tensile stress in the middle, increasing the likelihood of breakage. In contrast, the four-hinge lobe case in FIG. 21C exhibits a more uniform stress distribution. The tensile stress in FIG. 21C is similar to that of the short lobes, with high-stress concentrations being more discontinuously distributed.

All cited references, patents, and patent applications in the above application for letters patent are herein incorporated by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control. The preceding description, given in order to enable one of ordinary skill in the art to practice the claimed disclosure, is not to be construed as limiting the scope of the disclosure, which is defined by the claims and all equivalents thereto.

Claims

What is claimed is:

1. An abrasive belt comprising: an abrading surface opposite a backside, wherein the abrading surface comprises abrasive particles adhered to a backing; a first end, comprising a portion of a first splice pattern; a second end, comprising a portion of a second splice pattern; wherein the first splice pattern is complementary to the second splice pattern; and wherein the first splice pattern comprises a lobe having a lobe circular portion and a receiving portion having a receiving circular portion, and wherein the lobe is defined by a line tangent to both the lobe circular portion and the receiving circular portion; and a splice adhesive coupling the first splice pattern to the second splice pattern.

2. The abrasive belt of claim 1, wherein the first splice pattern is defined by a centerline equidistant from a lobe tip to a receiving portion depth, and wherein the centerline is angled, at an angle, with respect to an edge of the abrasive belt, wherein the angle is less than 90°.

3. The abrasive belt of any of claims 1-2, wherein g is less than about 2, wherein g is defined as half of a distance, 2d, from a first center, of a first lobe circular portion, to a second center, of a second lobe circular portion, divided by a radius, R, of the lobe circular portion.

4. The abrasive belt of any of claims 1-3, wherein H is greater than about 0.8 and less than about 1.4, wherein H is defined by e, a distance from a lobe center to the centerline, divided by a radius, R, of the lobe circular portion.

5. The abrasive belt of any of claims 1-4, wherein the portion of the first splice pattern is less than one repeating unit of the splice pattern.

6. The abrasive belt of claim 1, wherein a belt diameter is less than 2 inches.

7. The abrasive belt of any of claims 1-6, wherein the first end is coupled directly to a splice tape and the second end is coupled directly to the splice tape.

8. The abrasive belt of any of claims 1-7, wherein the lobe is a first lobe, and wherein the splice pattern comprises a second lobe, wherein the first lobe comprises a first height, the second lobe comprises a second height, and wherein the first and second heights are different.

9. The abrasive belt of any of claims 1-8, wherein the lobe is a first lobe, and wherein the splice pattern comprises a second lobe, wherein the first lobe comprises a first radius, the second lobe comprises a second radius, and wherein the first and second radii are different.

10. The abrasive belt of any of claims 1-9, wherein the receiving portion is a first receiving portion, and wherein the splice pattern comprises a second receiving portion, wherein the first receiving portion comprises a first circular portion having a first center point and a first distance from the first center point to a centerline of the splice pattern, the second receiving portion comprises a second receiving portion, wherein the second receiving portion comprises a second circular point having a second center point and a second distance from the second center point to the centerline of the splice pattern, and wherein the first and second distances are different.

11. The abrasive belt of any of claims 1-10, wherein the splice pattern comprises a hinge area defined by a first hinge and a second hinge, and wherein the hinge area is further defined by a third hinge positioned between the first and second hinges.

12. The abrasive belt of any of claims 1-11, wherein the lobe comprises an aperture.

13. The abrasive belt of claim 12, wherein the aperture is wholly contained within the lobe circular portion.

14. The abrasive belt of claim 13, wherein the aperture extends to a perimeter of the lobe.

15. A method of abrading a workpiece, the method comprising: contacting the workpiece to an endless abrasive belt, the endless abrasive belt comprising a splice, wherein the splice comprises a splice pattern, the splice pattern being free of sharp transitions; and wherein the endless abrasive belt is in motion about one or more contact wheels.

16. The method of claim 15, wherein the splice pattern is defined by circles and tangent lines to said circles.

17. The method of claim 15 or 16, wherein the splice pattern comprising a portion of a repeating pattern comprising alternating lobes and valleys, wherein g, for the repeating pattern, is less than about 2, wherein g is defined by d/R, wherein d is half a distance from a first center of a first circular portion of a first lobe and a second center of a second circular portion of a second lobe, and wherein R is a radius of the first circular portion.

18. The method of any of claims 15-17, wherein the splice pattern comprising a portion of a repeating pattern comprising alternating lobes and valleys, wherein H, for the repeating pattern, is less than about 1.4, wherein H is defined as e/R, where e is a distance from a center of a first center of a first circular portion of a first lobe and a centerline, the centerline being equidistance from a lobe tip and a valley vertex.

19. The method of any of claims 15-18, wherein H is greater than about 0.8.

20. The method of any of claims 15-19, wherein the splice comprises less than one repeating unit of a splice pattern.

21. The method of claim 20, wherein a belt diameter is less than 2 inches.

22. The method of any of claims 15-21, wherein a first belt end is coupled directly to a splice tape and a second belt end is coupled directly to the splice tape.

23. The method of any of claims 15-22, wherein the splice pattern comprises a first lobe and a second lobe, wherein the first lobe comprises a first height, the second lobe comprises a second height, and wherein the first and second heights are different.

24. The method of any of claims 15-23, wherein the splice pattern comprises a first lobe and a second lobe, wherein the first lobe comprises a first radius, the second lobe comprises a second radius, and wherein the first and second radii are different.

25. The method of any of claims 15-24, wherein the splice pattern comprises a hinge area defined by a first hinge and a second hinge, wherein the hinge area is further defined by a third hinge positioned between the first and second, and wherein a first distance from the first and third hinge differs from a second distance from the third hinge to the second hinge.

26. The method of any of claims 15-25, wherein the splice pattern comprises a first lobe and a second lobe, wherein the second lobe is offset from the first lobe with respect to a body of the endless abrasive belt.

27. The method of any of claims 15-26, wherein the splice pattern comprises a lobe, and wherein the lobe comprises an aperture.

28. An endless abrasive belt comprising: a flexible backing having a first end and a second end, the first and second ends being coupled at a splice, wherein the first end comprises a first interlocking feature and the second end comprises a second interlocking feature, wherein the first and second interlocking features are free of sharp transitions, and wherein one of the first and second interlocking features is in line with a direction of travel of the endless abrasive belt, wherein the first interlocking feature is partially defined by a partial circular portion, and a tangent line to the circular portion; an abrasive surface opposite a backside, the abrasive surface comprising abrasive particles coupled to the backing; and a splice tape applied to the backside.

29. The endless abrasive belt of claim 28, wherein the first interlocking feature is a portion of a splice pattern, the splice pattern comprising a first lobe defined by a circular portion having a radius R, wherein a center of the first lobe is spaced apart from a center of a second lobe by a distance 2d, wherein a centerline of the splice pattern is angled with respect to an edge of the flexible backing, wherein the centerline is defined as a line passing through the first and second lobes at half of a height of each of the first and second lobes.

30. The endless abrasive belt of claim 29, wherein a body of the first lobe is defined by first and second tangent lines, on opposing sides of the circular portion extending along the height of the first lobe.

31. The endless abrasive belt of claim 29, wherein the centerline is angled at an angle that is less than about 90°.

32. The endless abrasive belt of any of claims 28-31, wherein the first interlocking feature is offset from the second interlocking feature, and wherein a splice adhesive fills a gap created by the offset.

33. The endless abrasive belt of any of claims 28-32, wherein a belt diameter is less than 2 inches.

34. The endless abrasive belt of any of claims 28-33, wherein the interlocking feature comprises a first lobe and a second lobe, wherein the first lobe comprises a first height, the second lobe comprises a second height, and wherein the first and second heights are different.

35. The endless abrasive belt of claim 34, wherein the first lobe comprises a first radius, the second lobe comprises a second radius, and wherein the first and second radii are different.

36. The endless abrasive belt of any of claims 28-35, wherein the interlocking feature comprises a first receiving portion and a second receiving portion.

37. The endless abrasive belt of claim 36, wherein the first receiving portion comprises a first circular portion having a first center point and a first distance from the first center point to a centerline of the splice pattern, the second receiving portion comprises a second receiving portion, wherein the second receiving portion comprises a second circular point having a second center point and a second distance from the second center point to the centerline of the splice pattern, and wherein the first and second distances are different.

38. The endless abrasive belt of any of claims 28-37, wherein the splice pattern comprises a hinge area defined by a first hinge and a second hinge, and wherein the hinge area is further defined by a third hinge positioned between the first and second hinges.

39. The abrasive belt of claim 38, wherein the first lobe and the second lobe differ in at least one of height or radius of a lobe circular portion.

40. An abrasive article comprising: a backing; a plurality of abrasive article portions, each abrasive article portion being directly coupled to the backing; wherein a first abrasive article portion comprises a first composition and a second abrasive article portion comprises a second composition, and wherein the first and second abrasive articles are coplanar such that first abrasive particles, of the first abrasive article, and second abrasive particles, of the second abrasive article, are configured to simultaneously contact a worksurface; and wherein the plurality of abrasive article portions are coupled to the backing by a coupling agent.

41. A kit for forming a composite abrasive article, the kit comprising: a backing; a first abrasive article portion; a second abrasive article portion, the second abrasive article portion being different from the first abrasive article portion in at least one property; a coupling agent configured to couple the first and second abrasive article portions to the backing such that abrasive surfaces of the first and second pluralities of abrasive article portions are coplanar.

42. A method of abrading a surface, the method comprising: contacting an abrasive article to a worksurface, wherein the abrasive article is a composite abrasive article comprising: a backing; a first portion having a first composition, the first composition comprising a first plurality of abrasive particles; a second portion having a second composition, the second composition comprising a second plurality of abrasive particles; wherein the first and second portions are coplanar; and wherein the first portion and second portions are coupled to the backing; and moving the abrasive article with respect to the worksurface such that a portion of the worksurface is removed.