Patent Application
20230226664
The present disclosure broadly relates abrasive articles, and methods of making and using the same.
Abrasive articles having an abrasive layer disposed on a porous and/or perforated backing are especially useful for abrading applications (e.g., sanding auto body filler) where dust removal during use is desired.
Screen abrasives generally have an abrasive layer disposed on an open mesh substrate such as, for example, a wire screen, glass fiber woven mesh, unitary plastic mesh, or polymer fiber (e.g., polyimide fiber) woven mesh. Typically, the abrasive layer had abrasive particles dispersed in a binder material. Screen abrasive are typically used for applications where lots of dust may generated such as, for example, vehicle body repair and drywall sanding, because the porous nature of these products allows dust to pass through the screen abrasive and not load the abrasive layer thereby reducing abrading performance.
Certain coated abrasive articles (e.g., sandpaper, grinding discs, and abrasive belts) have a relatively dense planar backing (e.g., vulcanized fiber or a woven or knit fabric, optionally treated with a saturant to increase durability) on which make and size layers securing abrasive particles are disposed. These products are often more aggressive than corresponding screen abrasives (i.e., having the same shape, orientation, and type of abrasive particles); however, they can become loaded with swarf during use, thereby reducing abrading performance.
Composite abrasive articles according to the present disclosure combine abrading performance of the abovementioned coated abrasive articles with the dust removal benefits of screen abrasives.
In one aspect, the present disclosure provides a composite abrasive article comprising: an open mesh backing member having first and second major surfaces; and coated abrasive members secured to the first major surface of the open mesh backing member, wherein each coated abrasive member independently respectively comprises:
In another aspect, the present disclosure provides a method of making a composite abrasive article comprising:
providing an open mesh backing member having first and second major surfaces; and
securing coated abrasive members to the first major surface, wherein each coated abrasive member independently respectively comprises:
In yet another aspect, the present disclosure provides a method of using a composite abrasive article, the method comprising:
frictionally contacting the abrasive layer of at least one of the coated abrasive members of a coated abrasive article according to the present disclosure with a surface of a workpiece; and
moving at least one of the coated abrasive article or the workpiece relative to the other to abrade the surface of the workpiece.
As used herein:
the term “mesh” refers to a substantially two-dimensional screen which may be a woven fabric or unitary plastic sheet having closely spaced geometrically shaped openings (e.g., triangular, square, rectangular, round, hexagonal, or a combination thereof).
Features and advantages of the present disclosure will be further understood upon consideration of the detailed description as well as the appended claims.
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.
Referring now to
Various open mesh backings may be used including, for example, the woven open mesh backing 200 shown in
further comprising securing an attachment element to the second major surface of the open mesh backing member opposite the coated abrasive members.
Useful backings members may include wire screen, glass fiber woven mesh, unitary plastic mesh, or polymer fiber (e.g., polyimide fiber) woven mesh, for example as long as it has openings of sufficient size and quantity to make it porous enough for dust to pass through.
The attachment element may comprise, for example, a looped portion of a hook and loop fastening system, or stem-web (interlocking mechanical mushroom shaped features) fastener system. In some embodiments, the attachment element comprises nonwoven, woven or knitted loop material. In other embodiments, it comprises hook material, e.g., as described in U.S. Pat. No. 5,058,247 (Thomas et al.).
An exemplary embodiment of a useful coated abrasive member is depicted in
Coated abrasive members, which may be prepared from corresponding coated abrasive articles well-known in the abrasives art and/or marketed commercially.
The make and/or size layer can be formed by coating a curable precursor onto a major surface of the backing and curing it. The curable precursor may comprise, 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 α,β-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 curable precursor may be applied by any known coating method for applying a make or size layer to a backing, including roll coating, extrusion die coating, curtain coating, knife coating, gravure coating, spray coating, or screen printing, for example.
The basis weight of the make and size layers will also necessarily vary depending on the intended use(s), type(s) of abrasive particles, and nature of the coated abrasive member being prepared, but generally will be in the range of from 1 or 5 gsm to 300, 400, or even 500 gsm, or more.
In addition to other components, the make and/or size layers may further contain optional additives, for example, to modify performance and/or appearance. Exemplary additives include grinding aids, fillers, plasticizers, wetting agents, surfactants, pigments, coupling agents, fibers, lubricants, thixotropic materials, antistatic agents, suspending agents, and/or dyes.
If present, the optional supersize layer 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 disc. 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.
Suitable abrasive particles may include any known abrasive particles or materials commonly used in abrasive articles. Examples of useful abrasive particles include, for example, fused aluminum oxide, heat treated aluminum oxide, white fused aluminum oxide, black silicon carbide, green silicon carbide, titanium diboride, boron carbide, tungsten carbide, titanium carbide, diamond, cubic boron nitride, garnet, fused alumina zirconia, sol gel abrasive particles, silica, iron oxide, chromia, ceria, zirconia, titania, silicates, metal carbonates (such as calcium carbonate (e g, chalk, calcite, marl, travertine, marble and limestone), calcium magnesium carbonate, sodium carbonate, magnesium carbonate), silica (e.g., quartz, glass beads, glass bubbles and glass fibers) silicates (e.g., talc, clays, (montmorillonite) feldspar, mica, calcium silicate, calcium metasilicate, sodium aluminosilicate, sodium silicate) metal sulfates (e.g., calcium sulfate, barium sulfate, sodium sulfate, aluminum sodium sulfate, aluminum sulfate), gypsum, aluminum trihydrate, graphite, metal oxides (e.g., tin oxide, calcium oxide), aluminum oxide, titanium dioxide) and metal sulfites (e.g., calcium sulfite), metal particles (e.g., tin, lead, copper), plastic abrasive particles formed from a thermoplastic material (e.g., polycarbonate, polyetherimide, polyester, polyethylene, polysulfone, polystyrene, acrylonitrile-butadiene-styrene block copolymer, polypropylene, acetal polymers, polyvinyl chloride, polyurethanes, nylon), plastic abrasive particles formed from crosslinked polymers (e.g., phenolic resins, aminoplast resins, urethane resins, epoxy resins, melamine-formaldehyde, acrylate resins, acrylated isocyanurate resins, urea-formaldehyde resins, isocyanurate resins, acrylated urethane resins, acrylated epoxy resins), and combinations thereof. The abrasive particles may also be agglomerates or composites that include additional components, such as, for example, a binder. Criteria used in selecting abrasive particles used for a particular abrading application typically include abrading life, rate of cut, substrate surface finish, grinding efficiency, and product cost.
Useful abrasive particles also include shaped abrasive particles (e.g., precisely-shaped abrasive particles). Details concerning such abrasive particles and methods for their preparation can be found, for example, in U.S. Pat. No. 8,142,531 (Adefris et al.); U.S. Pat. No. 8,142,891 (Culler et al.); and U.S. Pat. No. 8,142,532 (Erickson et al.); and in U.S. Pat. Appl. Publ. No. 2012/0227333 (Adefris et al.); 2013/0040537 (Schwabel et al.); and 2013/0125477 (Adefris).
Further details concerning coated abrasive discs comprising an abrasive layer secured to a backing, wherein the abrasive layer comprises abrasive particles and make, size, and optional supersize layers are well known, and may be found, for example, in U.S. Pat. No. 4,734,104 (Broberg); U.S. Pat. No. 4,737,163 (Larkey); U.S. Pat. No. 5,203,884 (Buchanan et al.); U.S. Pat. No. 5,152,917 (Pieper et al.); U.S. Pat. No. 5,378,251 (Culler et al.); U.S. Pat. No. 5,417,726 (Stout et al.); U.S. Pat. No. 5,436,063 (Follett et al.); U.S. Pat. No. 5,496,386 (Broberg et al.); U.S. Pat. No. 5,609,706 (Benedict et al.); U.S. Pat. No. 5,520,711 (Helmin); U.S. Pat. No. 5,954,844 (Law et al.); U.S. Pat. No. 5,961,674 (Gagliardi et al.); U.S. Pat. No. 4,751,138 (Bange et al.); U.S. Pat. No. 5,766,277 (DeVoe et al.); U.S. Pat. No. 6,077,601 (DeVoe et al.); U.S. Pat. No. 6,228,133 (Thurber et al.); and U.S. Pat. No. 5,975,988 (Christianson).
The coated abrasive member(s) may be secured to the porous backing member by any suitable method including, for example, stitchbonding, interlocking fasteners (e.g., mushroom-type, hooked), welding (e.g., spin welding), and/or adhesive bonding with a layer of adhesive. Useful adhesives may include glue, hot melt adhesives (e.g., styrene-butadiene polymers), latex adhesives, pressure-sensitive adhesives (e.g. acrylic pressure-sensitive adhesives), and/or thermosetting adhesives (e.g., epoxy, acrylic, or polyurethane adhesives).
Composite abrasive articles according to the present disclosure can be readily made by adhering the coated abrasive members to the open mesh backing member randomly or according to a predetermined pattern, for example. The coated abrasive members may have any shape and or size suitable for manufacture of the composite abrasive articles. Exemplary shapes may include triangles, squares, hexagons, circles, ellipses, rectangles, and/or random shapes. In some embodiments, coated abrasive members comprise material from scrap in commercial production of a coated abrasive product.
In a first embodiment, the present disclosure provides a composite abrasive article comprising:
an open mesh backing member having first and second major surfaces; and
coated abrasive members secured to the first major surface of the open mesh backing member, wherein independently each coated abrasive member respectively comprises:
In a second embodiment, the present disclosure provides a composite abrasive article according to the first embodiment, wherein each of the coated abrasive members is independently secured to the first major surface by at least one respective adhesive layer sandwiched therebetween.
In a third embodiment, the present disclosure provides a composite abrasive article according to the first or second embodiment, further comprising an attachment element secured to the second major surface of the open mesh backing member and disposed opposite the coated abrasive members.
In a fourth embodiment, the present disclosure provides a composite abrasive article according to any of the first to third embodiments, wherein the coated abrasive members comprise a make layer, a size layer, and optionally a supersize layer.
In a fifth embodiment, the present disclosure provides a composite abrasive article according to any of the first to fourth embodiments, wherein the coated abrasive members are arranged according to a predetermined pattern.
In a sixth embodiment, the present disclosure provides a composite abrasive article according to any of the first to fifth embodiments, wherein the coated abrasive members are compositionally the same.
In a seventh embodiment, the present disclosure provides a composite abrasive article according to any of the first to sixth embodiments, wherein the coated abrasive members have the same shape and size.
In an eighth embodiment, the present disclosure provides a composite abrasive article according to any of the first to seventh embodiments, wherein said at least one respective adhesive layer comprises hot melt adhesive.
In a ninth embodiment, the present disclosure provides a composite abrasive article according to any of the first to eighth embodiments, wherein said at least one respective adhesive layer comprises thermosetting adhesive.
In a tenth embodiment, the present disclosure provides a composite abrasive article according to any of the first to ninth embodiments, the open mesh backing member comprises a woven mesh.
In an eleventh embodiment, the present disclosure provides a composite abrasive article according to any of the first to ninth embodiments, wherein the open mesh backing member comprises a unitary plastic sheet or belt.
In a twelfth embodiment, the present disclosure provides a method of making a composite abrasive article, the method comprising:
providing an open mesh backing member having first and second major surfaces; and
securing coated abrasive members to the first major surface, wherein each coated abrasive member independently respectively comprises:
In a thirteenth embodiment, the present disclosure provides a method according to the twelfth embodiment, wherein said securing coated abrasive members to the first major surface is accomplished with adhesive.
In a fourteenth embodiment, the present disclosure provides a method according to the twelfth or thirteenth embodiment, wherein the open mesh backing member further comprises an attachment element opposite the coated abrasive members.
In a fifteenth embodiment, the present disclosure provides a method of using a composite abrasive article, the method comprising:
frictionally contacting the abrasive layer of at least one of the coated abrasive members of the coated abrasive article of any of the first to eleventh embodiments with a surface of a workpiece; and
moving at least one of the coated abrasive article or the workpiece relative to the other to abrade the surface of the workpiece.
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.
Unless otherwise noted, all parts, percentages, ratios, etc. in the Examples and the rest of the specification are by weight.
Table 1, below, reports abbreviations of certain materials used in the Examples.
To the non-abrasive side of ABR, was applied a 0.076 mm thick layer of ADH using a #3 wire wound rod from RD Specialties, Webster N.Y. Discs (25 mm diameter) were cut from the resulting ADH/ABR composite and adhered to the non-loop side of a 152 mm diameter NET disc such that approximately 33% of the NET disc area was covered with 25 mm ABR discs. With the LAM at the “5 mil” setting, the NET/ABR composite was passed through the LAM nip. The sample was rotated 90 degrees and fed through the LAM nip again. The laminated construction was allowed to cool before testing.
The procedure of Example 1 was repeated, except that the ADH/ABR composite was cut into triangles of dimensions 25 mm×25 mm×35 mm.
Loop-backed abrasive discs (6-inch (15.24 cm)), obtained as 3M Hookit Purple Clean Sanding Abrasive Disc 334U from 3M Company. The discs had a paper-based backing.
Abrasive performance testing was performed on 18 inches long by 24 inches wide (45.7 cm by 61 cm) black painted cold roll steel test panels having NEXA AOEM type clearcoat, obtained from ACT Laboratories, Inc., Hillsdale, Mich. For testing purposes, the abrasive discs were attached to a 6-inch (15.2 cm) backup pad commercially available as 3M #05551 Purple Cleansand Painters pad from 3M Company. The tool was disposed over an X-Y table, with the test panel secured to the X-Y table.
For testing purposes, the abrasive discs were attached to the backup pad. Sanding was performed using a dual action axis of a servo controlled motor operating at 6000 rpm. The dual action axis had a 3/16 inch (4.76 mm) stroke length. The servo-driven sanding mechanism was disposed over an X-Y table and the abrasive article held at an angle of 2.5 degrees against the panel at a load of 13 lbs (5.91 kg). The tool was then set to traverse in the X direction along the width of the panel at the rate of 2.53 inches/second (6.4 cm/second) and in Y direction at the rate of 20 inches/second (50.8 cm/second) along the length of the panel. Seven such passes along the width of the panel, evenly spaced, were completed for ½ of the length the panel. One sanding cycle was a minute long and sanded ½ of a new test panel. Each test was a total of four sanding cycles, such that the test lasted a total of four minutes and sanded a total of 2 full panels. The mass of the panel was measured before and after each cycle to determine the mass loss from the clearcoat layer of the AOEM panel after each cycle. Total cut was determined as the cumulative mass loss at the end of the test.
Using this Sanding Test Procedure, Examples 1 & 2 and Comparative Example A were tested for total cut. Results are reported in Table 2, below.
All cited references, patents, and patent applications in this application are incorporated by reference in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in this application 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.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/054217 | 5/17/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63027687 | May 2020 | US |
