Abrasive body and method for producing the same

Abstract

An abrasive body includes portions of first abrasive elements. The portions of first abrasive elements are bonded together by a first binder material. The first abrasive elements include abrasive particles bonded to a substrate by at least a second binder material. The portions of first abrasive elements are not agglomerated abrasive particles. The abrasive body has a maximum dimension, and the maximum dimension of the portions of first abrasive elements is less than 80% of the maximum dimension of the abrasive body. Methods of making the abrasive body are also disclosed.

Description

TECHNICAL FIELD

[0001] The present disclosure relates broadly to abrasive articles and methods of making the same. BACKGROUND

[0002] During the manufacture of abrasive finished products, waste material is typically generated during the conversion to the final form of the product, for example, as trim or scrap (e.g., converting a roll good to a disc). Such material is often discarded and sent out for disposal by incineration or landfill. Both processes can have adverse environmental impacts. SUMMARY

[0003] The present disclosure provides a practical use of this scrap by recycling it into abrasive bodies such as, for example, abrasive wheels and hand pads suitable for abrading a workpiece.

[0004] Thus, in one aspect, the present disclosure provides an abrasive body comprising a portion of a first abrasive element, wherein the portion of the first abrasive element is bonded together by a first binder material, and wherein the first abrasive element comprises abrasive particles bonded to a substrate by at least a second binder material, wherein the portion of the first abrasive element is not agglomerated abrasive particles, wherein the abrasive body has a maximum dimension, and wherein the maximum dimension of the portion of the first abrasive element is less than 80% of the maximum dimension of the abrasive body.

[0005] Abrasive bodies according to the present disclosure are suitable for abrading a workpiece. For example, the abrasive body can be in frictional contact with the workpiece and moved relative to the workpiece to abrade the workpiece.

[0006] In another aspect, the present disclosure provides a method of making an abrasive body, the method comprising:

[0007] combining a portion of a first abrasive element and a curable binder precursor, wherein the first abrasive element comprises abrasive particles bonded to a substrate by at least a second binder material; and

[0008] pressing and at least partially curing the curable binder precursor to provide the abrasive body, wherein the abrasive body has a maximum dimension, and wherein the maximum dimension of the portion of the first abrasive element is less than 80% of the maximum dimension of the abrasive body.

[0009] The features and advantages of the present disclosure will be further understood upon consideration of the detailed description and the appended claims, with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0010] Figure 1 is a schematic perspective view of an exemplary abrasive wheel 100 according to the present disclosure;

[0011] Figure 1Ais a schematic enlarged side view of the abrasive wheel 100;

[0012] Figure 2 is a perspective view of an exemplary nonwoven abrasive element 200;

[0013] Figure 2A is Figure 2 is an enlarged view of the area 2A of the nonwoven abrasive element 200 shown in

[0014] Figure 3 is a side view of an exemplary coated abrasive element 300;

[0015] Figure 4 is a schematic top cross-sectional view of an exemplary screen abrasive element 400;

[0016] Reference designators repeated in the description and drawings indicate elements with similar or the same function. It is to be understood that many other modifications and embodiments will be apparent to those skilled in the art in view of the foregoing description. The drawings can not be to scale. DETAILED DESCRIPTION

[0017] Figure 1 An exemplary abrasive body (i.e., shown as an abrasive wheel 100) having an optional central mandrel hole 130) according to one embodiment of the present disclosure is shown. Referring now to Figure 1A , the abrasive wheel 100 includes portions of first abrasive elements 110. The portions of first abrasive elements are bonded together by a first binder material 120.

[0018] The abrasive wheel 100 has a maximum dimension 140. The maximum dimension 112 of the portions of first abrasive elements 110 is less than 80% of the maximum dimension of the abrasive wheel. In many embodiments, the maximum dimension of the portions of first abrasive elements is less than 70%, less than 60%, less than 50%, less than 40%, less than 30%, less than 20%, less than 10%, or even less than 5% of the maximum dimension of the abrasive body. In many embodiments, the maximum dimension of the portions of first abrasive elements is at least 1%, at least 2%, at least 3%, at least 4%, at least 45%, or even at least 10% of the maximum dimension of the abrasive body. All possible combinations of the foregoing recited upper and lower maximum dimension limits can be used, although this is not required.

[0019] In some preferred embodiments, the portions of the first abrasive elements comprise recycled scrap (e.g., edge trim, scrap, or off-spec material) generated during the manufacture of a finished abrasive article, such as, for example, a nonwoven abrasive article or a coated abrasive article. The portions of the first abrasive elements can have any shape or size subject to the above-described limitations regarding maximum size, which can fit within the desired volume of the abrasive body (e.g., in at least one orientation after compression). In some embodiments, the recycled scrap can comprise portions of used converted abrasive articles, such as, for example, nonwoven abrasive pads or discs, or coated abrasive discs, sheets, or belts. The portions of the first elements can have random shapes, predetermined shapes, or combinations thereof.

[0020] In many embodiments, the size and shape of the portions of the first abrasive elements will be heavily influenced by the recycling method used. Examples include shredding, slicing, and / or tearing to provide smaller sizes of the first abrasive elements suitable for recycling.

[0021] In addition to the portions of the first abrasive elements, the abrasive body can further comprise portions of, for example, second abrasive elements, third abrasive elements, or fourth abrasive elements. There is no particular upper limit to the number of types of abrasive elements that can be included in the abrasive body according to the present disclosure. Generally, these optional portions of additional abrasive elements are also independently subject to the same size limitations and embodiments as the portions of the first abrasive elements.

[0022] The portions of the first abrasive elements do not consist of individual agglomerated abrasive particles, although they can contain them as part of the larger abrasive elements. As used herein, the term “abrasive agglomerated particles” refers to particles that are agglomerates of abrasive particles in an organic or inorganic binder material (e.g., a glass or ceramic binder).

[0023] The first abrasive elements comprise abrasive particles bonded to a substrate by at least a second binder material. Depending on the substrate, different types of abrasive articles are contemplated.

[0024] Exemplary embodiments of suitable first abrasive elements are shown in Figures 2 to 4 as described below.

[0025] In some embodiments, the abrasive elements can comprise a lofty, resilient, open- celled nonwoven fibrous web having abrasive particles firmly bonded thereto.

[0026] Figure 2 Exemplary embodiments of such abrasive elements are shown in 2A as described below. Figure 2 and Figure 2AThe nonwoven abrasive article 200 includes a lofty, resilient, open- celled, low density fibrous web (substrate) 210 formed from entangled fibers 215. Abrasive particles 240 are secured to the fibrous web 210 on exposed surfaces of the fibers 215 by a binder material 250 that also bonds the fibers 215 to one another at points where they are in contact, thereby causing the cut points to be oriented outwardly relative to the fibers 215.

[0027] It is well known in the abrasive art to use nonwoven fibrous webs. Generally, the nonwoven fibrous web includes an entangled web of fibers. The fibers can include continuous fibers, staple fibers, or a combination thereof.

[0028] The fibrous web can be made using, for example, conventional air-laying, carding, stitch-bonding, spun-bonding, wet-laying, and / or melt-blowing processes. Air-laid fibrous webs can be prepared using equipment such as, for example, equipment available under the trade designation RANDO WEBBER from Rando Machine Company of Macedon, New York.

[0029] The nonwoven fibrous web is generally selected to be compatible with the adhering binder material and abrasive particles, while also being compatible with other components of the article, and generally can withstand some process conditions (e.g., temperature) such as those employed during application and curing of the curable binder precursor. The fibers can be chosen to influence properties of the abrasive article such as, for example, flexibility, resiliency, durability or shelf life, abrasion resistance, and finishing characteristics. Examples of suitable fibers include natural fibers, synthetic fibers, and mixtures of natural and / or synthetic fibers.

[0030] Prior to coating and / or impregnation with the curable binder material precursor, the weight per unit area (i.e., basis weight) of the nonwoven fibrous web is generally at least about 50 grams per square meter (gsm), at least about 100 gsm, or at least about 150 gsm; and / or less than about 600 gsm, less than about 500 gsm, or less than about 400 gsm, although greater and lesser basis weights can also be used. Additionally, the thickness of the fibrous web prior to impregnation with the curable binder precursor is generally at least about 3 mm, at least about 6 mm, or even at least about 10 mm; and / or less than about 100 mm, less than about 50 mm, or less than about 25 mm, although greater thicknesses and lesser thicknesses can also be used.

[0031] In many cases, as is known in the abrasive arts, it is useful to apply a pre-bond resin to the nonwoven web prior to coating with the curable binder material precursor. The pre-bond resin, for example, serves to help maintain the integrity of the nonwoven web during handling. Examples of pre-bond resins include phenolic resins, polyurethane resins, hide glue, acrylic resins, urea-formaldehyde resins, melamine formaldehyde resins, epoxy resins, latex, and combinations thereof.

[0032] In many embodiments, after coating the curable binder material precursor, for example, using any suitable method known in the art, the abrasive particles adhere to the curable binder material precursor, which is then cured to form the nonwoven abrasive element. Examples of curable binder material precursors include phenolic resins, polyurethane resins, hide glue, acrylic resins, urea-formaldehyde resins, melamine formaldehyde resins, epoxy resins, latex, and combinations thereof.

[0033] In other embodiments, the abrasive particles are pre-dispersed in the curable binder material precursor prior to coating and curing.

[0034] The abrasive particles can be the result of a crushing operation (e.g., crushed abrasive particles that have been sorted by shape and size) or the result of a forming operation (i.e., formed abrasive particles), in which an abrasive precursor material is shaped (e.g., molded), dried, and converted to a ceramic material. Combinations of crushed produced abrasive particles and formed operation produced abrasive particles can also be used. The abrasive particles can be in the form of, for example, individual particles, agglomerates, composite particles, and mixtures thereof.

[0035] The abrasive particles should have sufficient hardness and surface roughness to function as a crushed abrasive particle in an abrasive process. Preferably, the abrasive particles have a Mohs hardness of at least 4, at least 5, at least 6, at least 7, or even at least 8.

[0036] Suitable abrasive particles include, for example, crushed abrasive particles including: fused alumina, heat treated alumina, white fused alumina, ceramic alumina materials such as those commercially available from 3M Company, St. Paul, Minnesota, under the trade designation 3M CERAMIC ABRASIVE GRAIN, brown alumina, blue alumina, 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, chromium oxide, zirconia, titania, tin oxide, quartz, feldspar, chert, emery, sol-gel derived ceramic (e.g., alpha alumina), and combinations thereof. Examples of sol-gel derived abrasive particles from which the abrasive particles can be isolated and methods of making the same 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 can include abrasive agglomerates such as, for example, those described in U.S. Pat. Nos. 4,652,275 (Bloecher et al.) or 4,799,939 (Bloecher et al.). In some embodiments, the abrasive particles can be surface treated or otherwise physically treated (e.g., iron oxide or titanium oxide) with a coupling agent (e.g., an organosilane coupling agent) to enhance adhesion of the crushed abrasive particles to the bond. The abrasive particles can be treated prior to their incorporation with the bond, or they can be surface treated in situ by including the coupling agent into the bond.

[0037] Preferably, the abrasive particles (and especially the abrasive particles) comprise ceramic abrasive particles, such as, for example, sol-gel prepared polycrystalline alpha alumina particles. Sol-gel alpha alumina particle precursors can be used to prepare ceramic abrasive particles composed of crystallites of alpha alumina, magnesium aluminate spinel, and rare earth hexaaluminate according to the methods described in, for example, U.S. Patent No. 5,213,591 (Celikkaya et al.) and U.S. Published Patent Application Nos. 2009 / 0165394 Al (Culler et al.) and 2009 / 0169816 Al (Erickson et al.). Further details regarding methods of making sol-gel derived abrasive particles can be found in, for example, U.S. Patents 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 U.S. Published Patent Application No. 2009 / 0165394 Al (Culler et al.).

[0038] In some embodiments, the abrasive particles that can be used (especially in the case of the abrasive particles) can be shaped abrasive particles, which can be found in U.S. Patents 5,201,916 (Berg); 5,366,523 (Rowenhorst (Re 35,570)) and 5,984,988 (Berg). U.S. Patent No. 8,034,137 (Erickson et al.) describes alumina abrasive particles that have been formed into a particular shape, which are then crushed to form fragments that retain a portion of their initial shape features. In some embodiments, the abrasive particles are precisely shaped (i.e., the shape of the particles is at least partially determined by the shape of the cavities in the production tool used to make them). Details regarding such abrasive particles and methods of making them can be found in, for example, U.S. Patent Nos. 8,142,531 (Adefris et al.), 8,142,891 (Culler et al.); and 8,142,532 (Erickson et al.); and U.S. Patent Application Publications 2012 / 0227333 (Adefris et al.); 2013 / 0040537 (Schwabel et al.) and 2013 / 0125477 (Adefris).

[0039] Further details regarding nonwoven abrasive articles and methods of making them can be found, for example, in U.S. Patent Nos. 2,958,593 (Hoover et al.); 4,227,350 (Fitzer), 4,991,362 (Heyer et al.); 5,712,210 (Windisch et al.); 5,591,239 (Edblom et al.); 5,681,361 (Sanders), 5,858,140 (Berger et al.); 5,928,070 (Lux), 6,017,831 (Beardsley et al.); and U.S. Patent Application Publication Nos. 2006 / 0041065 Al (Barber, Jr.) and 2018 / 0036866 (Alkas et al.). Many such nonwoven abrasive articles are known and commercially available.

[0040] Exemplary embodiments of coated abrasive articles according to the present disclosure are shown in Figure 3 Referring now to Figure 3 Coated abrasive article 300 has a backing 320 and an abrasive layer 330. The abrasive layer 330 includes abrasive particles 340 secured to a major surface 370 of the backing 320 (substrate) by a make coat 350 and a size coat 360.

[0041] Coated abrasive elements can include a make coat, a size coat, and abrasive particles disposed between the make coat and the size coat on a backing (substrate), and can also include an optional top coat overlying the abrasive layer, or if desired, can include a backing antistatic treatment layer. In some embodiments, the abrasive particles are dispersed in a binder material, typically as a slurry, coated onto the backing.

[0042] For example, useful backings include those known in the art for making coated abrasive articles. Typically, the backing has two opposed major surfaces, but this is not necessarily so.

[0043] The make coat and / or the size coat are formed by at least partially curing a corresponding curable precursor material. Examples of curable precursor materials that can be used in make coat and / or size coat precursor compositions include free-radically polymerizable monomers and / or oligomers, epoxy resins, acrylic resins, polyurethane resins, phenolic resins, urea-formaldehyde resins, melamine-formaldehyde resins, aminoplast resins, cyanate ester resins, or combinations thereof. Useful binder precursors include thermally curable resins and radiation curable resins that can be cured, for example, by heat and / or by exposure to radiation. Additional details regarding size coat precursors can be found in U.S. Patent No. 4,588,419 (Caul et al.), U.S. Patent No. 4,751,138 (Tumey et al.), and U.S. Patent No. 5,436,063 (Follett et al.).

[0044] The make layer and / or size layer precursor composition can also include additives such as, for example, fibers, lubricants, wetting agents, surfactants, pigments, dyes, anti-static agents (e.g., carbon black, vanadium oxide, and / or graphite), coupling agents (e.g., silanes, titanates, and / or zirconates), plasticizers, and / or suspending agents. The amounts of these optional additives are selected to provide the preferred properties. Coupling agents can improve adhesion to abrasive particles and / or fillers. The curable composition can be thermally cured, radiation cured, or a combination thereof.

[0045] The make layer and / or size layer precursor composition can also include filler materials, diluent abrasive particles (e.g., as described below), or grinding aids, typically in the form of particulate materials. Typically, the particulate materials are inorganic materials. Examples of fillers that can be used in the present disclosure include: metal carbonates (e.g., calcium carbonate (e.g., chalk, calcite, marl, travertine, marble, and limestone), calcium magnesium carbonate, sodium carbonate, magnesium carbonate), silicas (e.g., quartz, glass beads, glass bubbles, and glass fibers) silicates (e.g., talc, clays, (montmorillonite) feldspar, mica, calcium silicate, calcium metasilicate, sodium aluminate, sodium silicate) metal sulfates (e.g., calcium sulfate, barium sulfate, sodium sulfate, sodium aluminum sulfate, aluminum sulfate), gypsum, vermiculite, wood flour, aluminum trihydrate, carbon black, metal oxides (e.g., calcium oxide (lime), aluminum oxide, titanium dioxide), and metal sulfites (e.g., calcium sulfite).

[0046] The make layer and / or size layer precursor composition can also be modified by various additives (e.g., fibers, lubricants, wetting agents, surfactants, pigments, dyes, anti-static agents (e.g., carbon black, vanadium oxide, and / or graphite), coupling agents (e.g., silanes, titanates, zirconates, etc.), plasticizers, suspending agents). Catalysts and / or initiators can be added to thermosetting resins; for example, in accordance with conventional practice, and depending on the resin used.

[0047] The abrasive particles described herein are generally suitable for inclusion in coated abrasive elements.

[0048] Optionally, a top size layer can cover the size layer. For example, the top size layer can contain load resisting additives and / or grinding aids.

[0049] Further details regarding coated abrasive articles and how they are made are well known and described in, for example, U.S. Patents 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 5,975,988 (Christianson).

[0050] In some embodiments, the first abrasive element comprises a porous substrate having abrasive particles secured thereto by at least one binder material.

[0051] In some embodiments, the porous substrate comprises an open mesh web backing (substrate), which can be woven or nonwoven, having opposing first and second major surfaces and a plurality of openings extending from the first major surface to the second major surface. An abrasive layer comprising a plurality of abrasive particles dispersed in or bound to a binder material, such as a make layer and size layer or a slurry layer, is secured to at least a portion of the first major surface of the backing, in some embodiments, the entire backing can be coated with the abrasive layer. The binder and abrasive particles can be selected, for example, from those described elsewhere herein.

[0052] Referring now to Figure 4 The screen abrasive element 412 comprises an open mesh web backing 418 covered by an abrasive layer. The open mesh web backing 418 has a plurality of openings 424. The abrasive layer comprises a make layer 432, abrasive particles 430, and a size layer 434. A plurality of openings 414 extend through the screen abrasive element 412. Further details regarding web or screen abrasive articles and how they are made can be found in, for example, U.S. Patent 7,329,175 (Rambosek et al.).

[0053] Similar constructions involving a porous matrix, such as, for example, a porous foam or a perforated polymeric film, are also known and described in, for example, U.S. Patent 5,849,051 (Beardsley et al.).

[0054] Many other types or abrasive elements not described herein can also be suitable for use in the present disclosure. Abrasive bodies according to the present disclosure can be prepared by a method in which portions of first abrasive elements and a curable first binder material precursor are typically placed under pressure in a circular mold and cured, for example by heating and / or a spontaneous chemical reaction. Depending on the applied pressure and porosity of the components in the mold, the density of the resulting abrasive body can vary widely, for example depending on its intended use. Abrasive bodies that can be produced in this way can include, for example, deburring wheels, polishing wheels, hybrid wheels, grinding wheels, sanding blocks, and abrasive hand pads.

[0055] Details are within the ability of those of ordinary skill in the art and will typically depend on the curable binder material precursor chosen. The curable first binder material precursor can be any of the curable binder precursor materials described herein, including, for example, phenolic resins, polyurethane resins, casein, acrylic resins, urea-formaldehyde resins, melamine-formaldehyde resins, epoxy resins, and combinations thereof.

[0056] Optionally, in addition to what can be present in portions of one or more abrasive elements, abrasive bodies according to the present disclosure can contain additives such as abrasives, fillers, secondary abrasive particles (for example, abrasive particles as described above), pore formers, and reinforcing fibers and scrims.

[0057] The objects and advantages of the present disclosure are further illustrated by the following non-limiting examples, but the specific materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this disclosure.

[0058] Example 1

[0059] Nonwoven abrasive waste resulting from converting Scotch-Brite A Medium nonwoven abrasive from a roll into a disc was fed into a Cumberland / John Brown rotor cutting tool with a 0.5 inch (1.27 cm) screen to obtain a chopped waste. The chopped waste was saturated with a polyurethane solution containing 32 parts by weight of a ketoxime blocked poly-1,4-butanediol (obtained as Adiprene BL-31 from Lanxess, Pittsburgh, Pennsylvania) and 6 parts by weight (pbw) of an amine curing agent (obtained as Kayahard AA from Nippon Kayaku Co. Inc., Tokyo, Japan) and 9 pbw of propylene glycol monomethyl ether acetate (obtained as Arcosolv PM Acetate from Arco Chemical Co., Houston, Texas) and 6 pbw of synthetic hydrocarbon wax (obtained as MP-22 VF from Micro Powders, Inc., Tarrytown, New York) and 47 pbw of nonwoven abrasive waste. The saturated waste was placed in a rectangular tray and manipulated into a visually uniform 1 inch (2.5 cm) tall shape. The 1 inch (2.5 cm) tall stack was folded in half to provide a 2 inch (5.1 cm) tall shaped form and placed in another flexible tray with a release liner made of polytetrafluoroethylene. The entire assembly was placed in a heated hydraulic press at 275 °F (135 °C, 10,000 psi (69 MPa)) compressed to 0.5 inch (1.3 cm) and then held for 15 minutes to produce an abrasive plate. The plate was removed from the press and further cured in a convection air oven at 275 °F (135 °C) for 3 hours. The plate was removed and a grinding wheel having a 3 inch (7.6 cm) diameter and a 0.375 inch diameter (0.953 cm) center hole was cut from the plate.

[0060] The grinding wheel was mounted on a mandrel of an air-powered tool rotating at 25,000 revolutions per minute. The rotating wheel was brought against carbon steel, stainless steel, and aluminum metal plates and was found to be useful for edge deburring, removing milling marks, and polishing the surfaces of the metal plates.

[0061] All cited references, patents and patent applications in this application, are incorporated by reference in their entirety. In the event of an inconsistency between the incorporated references and the present application, the present application shall control. The foregoing description shall not be construed to limit the scope of the present disclosure as defined by the claims below and all equivalents thereof.

Claims

1. An abrasive body comprising a recycled waste portion of a first abrasive element, wherein the recycled waste portions of the first abrasive element are bonded together by a first adhesive material, and wherein each recycled waste portion of the first abrasive element comprises a substrate and abrasive particles bonded to the substrate by at least a second adhesive material, wherein the recycled waste portion of the first abrasive element is not an agglomerated abrasive particle, wherein the abrasive body has a maximum size, and wherein the maximum size of each recycled waste portion of the first abrasive element is less than 80% of the maximum size of the abrasive body.

2. The abrasive body according to claim 1, wherein the substrate comprises a loosely elastic open-pore nonwoven fiber web.

3. The abrasive body according to claim 1, wherein the substrate comprises a porous woven mesh or a porous nonwoven loose fabric.

4. The abrasive body according to claim 1, wherein the substrate comprises a polymer film, a woven or knitted fabric, or a porous elastic foam.

5. The abrasive body according to any one of claims 1 to 4, wherein each of the recycled waste portions of the first abrasive element is randomly shaped.

6. A method for preparing an abrasive body, the method comprising: The recycled waste portion of a first abrasive element is combined with a curable binder material precursor, wherein each of the recycled waste portions of the first abrasive element comprises a substrate and abrasive particles bonded to the substrate by at least a second binder material; as well as The curable binder material precursor is pressed and at least partially cured to provide the abrasive body, wherein the abrasive body has a maximum size, and wherein the maximum size of each of the recycled waste portions of the first abrasive element is less than 80% of the maximum size of the abrasive body.

7. The method of claim 6, wherein the substrate comprises a bulky, elastic, open-cell nonwoven fiber web.

8. The method of claim 6, wherein the substrate comprises a porous woven web or a porous nonwoven loose fabric.

9. The method of claim 6, wherein the substrate comprises a polymer film, a woven or knitted fabric, or a porous elastic foam.

10. The method of claim 6, further comprising configuring a reinforcing sparse cloth to contact the portion of the first abrasive element and the curable adhesive material precursor.

11. The method according to any one of claims 6 to 10, wherein each of the recycled waste portions of the first abrasive element is randomly shaped.

Images