Patent Application
20050233678
Many abrasive articles are used in conjunction with tools having a rotatable shaft. Examples of such abrasive articles include coated abrasive articles, surface conditioning articles, and abrasive brushes. Generally, the abrasive articles are attached to the rotatable shaft by one or more fastening devices (i.e., fasteners) affixed to the abrasive article. In order to remain affixed to the abrasive article during use the fasteners must be strongly adhered to the abrasive articles.
While there are many known methods for affixing fasteners, particularly metal fasteners, improvements are always desired, especially when the complexity or cost can be reduced.
In one aspect, the present invention relates to an attachable abrasive article comprising an abrasive member having an attachment device affixed thereto, the attachment device comprising:
In another aspect, the present invention relates to a method of making an attachable abrasive article, the method comprising:
In another aspect, the present invention relates to a method of abrading a surface, the method comprising:
In some embodiments, the abrasive member comprises a coated abrasive member, a surface conditioning member, or an abrasive brush member.
Fasteners may be affixed to abrasive members according to the present invention by processes that typically achieve a high degree of adhesion between the fastener and abrasive member without the need for thermosetting adhesives that typically result in aesthetically unattractive adhesive residue adjacent to the fastener. Further, methods according to the present invention are useful for bonding metal fasteners to non-metallic surfaces abrasive articles, and may, in some cases, provide stronger bonds between metallic fasteners and abrasive articles than achieved by current abrasives industry practice.
The present invention provides an abrasive article having an attachment device affixed thereto. The abrasive article may be any abrasive article to which an attachment device may be attached including, for example, coated abrasive articles, surface conditioning articles, and abrasive brushes.
In general, coated abrasive articles have abrasive particles secured to a backing. More typically, coated abrasive articles comprise a backing having two major opposed surfaces and an abrasive layer secured to a major surface. The abrasive layer is typically comprised of abrasive particles and a binder resin, wherein the binder resin serves to secure the abrasive particles to the backing.
Suitable abrasive particles include any abrasive particles known in the abrasive art. Exemplary useful abrasive particles include fused aluminum oxide based materials such as aluminum oxide, ceramic aluminum oxide (which may include one or more metal oxide modifiers and/or seeding or nucleating agents), and heat-treated aluminum oxide, silicon carbide, co-fused alumina-zirconia, diamond, ceria, titanium diboride, cubic boron nitride, boron carbide, garnet, flint, emery, sol-gel derived abrasive particles, and blends thereof. Preferably, the abrasive particles comprise fused aluminum oxide, heat-treated aluminum oxide, ceramic aluminum oxide, silicon carbide, alumina zirconia, garnet, diamond, cubic boron nitride, sol-gel derived abrasive particles, precisely shaped abrasive particles, agglomerate abrasive particles, or mixtures thereof.
The abrasive particles may be in the form of, for example, individual particles, abrasive composite particles, agglomerates (including erodible agglomerates), and mixtures thereof (e.g., having the same or different size and/or composition).
The abrasive particles typically have an average diameter of from about 0.1 to about 2000 micrometers, more preferably from about 1 to about 1300 micrometers, although other particles having other diameters can be used.
The backing may comprise a film, foam, fabric, sponge, or a combination thereof. Useful fabrics include woven and nonwoven fabrics, optionally having a treatment (e.g., a presize) thereon.
Coating weights for the abrasive particles may depend on, for example, the type of abrasive article (e.g., coated abrasive article or nonwoven abrasive article), the process for applying the abrasive particles, and the size of the abrasive particles, but typically range from about 5 to about 1350 grams per square meter.
In one embodiment of a coated abrasive article, the abrasive layer may comprise a make coat, optional size coat, and abrasive particles. Referring now to
In making such a coated abrasive article, a make coat comprising a first binder resin precursor is applied to a major surface of the backing. Abrasive particles are then at least partially embedded into the make coat (e.g., by electrostatic coating), and the first binder resin precursor is at least partially cured to secure the particles to the make coat. If utilized, an optional size coat comprising a second binder resin precursor (which may be the same or different from the first binder resin precursor) is then applied over the make coat and abrasive particles, followed by curing the binder resin precursors.
Optionally, coated abrasive articles may further comprise, for example, a backsize (i.e., a coating on the major surface of the backing opposite the major surface having the abrasive coat), a presize or a tie layer (i.e., a coating between the abrasive coat and the major surface to which the abrasive coat is secured), and/or a saturant which coats both major surfaces of the backing. Coated abrasive articles may further comprise a supersize covering the abrasive coat. If present, the supersize typically includes grinding aids and/or anti-loading materials.
In another exemplary embodiment of a coated abrasive article according to the present invention, the abrasive layer has abrasive particles dispersed in a binder resin. In making such coated abrasive articles, a slurry comprising a first binder resin precursor and abrasive particles is typically applied to a major surface of the backing, and the binder resin precursor is then at least partially cured to form a binder resin. Optionally, a size coat may be present on the abrasive layer.
Referring now to
Further description of techniques and materials for making coated abrasive articles may be found in, for example, U.S. Pat. No. 4,314,827 (Leitheiser et al.); U.S. Pat. No. 4,518,397 (Leitheiser et al.); U.S. Pat. No. 4,588,419 (Caul et al.); U.S. Pat. No. 4,623,364 (Cottringer et al.); U.S. Pat. No. 4,652,275 (Bloecher et al.); U.S. Pat. No. 4,734,104 (Broberg); U.S. Pat. No. 4,737,163 (Larkey); U.S. Pat. No. 4,744,802 (Schwabel); U.S. Pat. No. 4,751,137 (Tumey et al.); U.S. Pat. No. 4,770,671 (Monroe et al.); U.S. Pat. No. 4,799,939 (Bloecher et al.); U.S. Pat. No. 4,881,951 (Wood et al.); U.S. Pat. No. 4,927,431 (Buchanan et al.); U.S. Pat. No. 5,498,269 (Larmie); U.S. Pat. No. 5,011,508 (Wald et al.); U.S. Pat. No. 5,078,753 (Broberg et al.); U.S. Pat. No. 5,090,968 (Pellow); U.S. Pat. No. 5,108,463 (Buchanan et al.); U.S. Pat. No. 5,137,542 (Buchanan et al.); U.S. Pat. No. 5,139,978 (Wood); U.S. Pat. No. 5,152,917 (Pieper et al.); U.S. Pat. No. 5,201,916 (Berg et al.); U.S. Pat. No. 5,203,884 (Buchanan et al.); U.S. Pat. No. 5,227,104 (Bauer); U.S. Pat. No. 5,328,716 (Buchanan); U.S. Pat. No. 5,366,523 (Rowenhorst 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. 5,429,647 (Larmie); U.S. Pat. No. 5,436,063 (Follett et al.); U.S. Pat. No. 5,490,878 (Peterson et al.); U.S. Pat. No. 5,492,550 (Krishnan et al.); U.S. Pat. No. 5,496,386 (Broberg et al.); U.S. Pat. No. 5,520,711 (Helmin); U.S. Pat. No. 5,549,962 (Holmes et al.); U.S. Pat. No. 5,551,963 (Larmie); U.S. Pat. No. 5,556,437 (Lee et al.); U.S. Pat. No. 5,560,753 (Buchanan et al.); U.S. Pat. No. 5,573,619 (Benedict et al.); U.S. Pat. No. 5,609,706 (Benedict et al.); U.S. Pat. No. 5,672,186 (Chesley et al.); U.S. Pat. No. 5,700,302 (Stoetzel et al.); U.S. Pat. No. 5,942,015 (Culler et al.); U.S. Pat. No. 5,954,844 (Law et al.); U.S. Pat. No. 5,961,674 (Gagliardi et al.); U.S. Pat. No. 5,975,988 (Christianson); U.S. Pat. No. 6,059,850 (Lise et al.); and U.S. Pat. No. 6,261,682 (Law), the disclosures of which are incorporated herein by reference.
Surface conditioning articles are abrasive articles that typically include a porous (e.g., a lofty open porous) polymer filament structure having abrasive particles bonded thereto by a binder resin. An exemplary attachable surface conditioning article is shown in
Referring now to
The fiber web may comprise continuous filaments (e.g., a spunbond fiber web) and/or staple fibers that may be crimped and/or entangled with one another. Exemplary fibers include polyester fibers, polyamide fibers, and polyaramid fibers.
The fiber web may be reinforced with an optional scrim (e.g., a woven or nonwoven scrim), for example, by needletacking, stitchbonding, and/or adhesive bonding (e.g., using glue or a hot melt adhesive).
Further description of techniques and materials for making surface conditioning articles may be found in, for example, U.S. Pat. No. 2,958,593 (Hoover et al.); U.S. Pat. No. 4,018,575 (Davis et al.); U.S. Pat. No. 4,227,350 (Fitzer); U.S. Pat. No. 4,331,453 (Dau et al.); U.S. Pat. No. 4,609,380 (Barnett et al.); U.S. Pat. No. 4,991,362 (Heyer et al.); U.S. Pat. No. 5,554,068 (Carr et al.); U.S. Pat. No. 5,712,210 (Windisch et al.); U.S. Pat. No. 5,591,239 (Edblom et al.); U.S. Pat. No. 5,681,361 (Sanders); U.S. Pat. No. 5,858,140 (Berger et al.); U.S. Pat. No. 5,928,070 (Lux); U.S. Pat. No. 6,017,831 (Beardsley et al.); U.S. Pat. No. 6,207,246 (Moren et al.); and U.S. Pat. No. 6,302,930 (Lux), the disclosures of which are incorporated herein by reference.
Useful forms of attachable coated abrasive and surface conditioning articles according to the present invention include, for example, discs, pads, and sheets.
In another embodiment of the present invention, the attachable abrasive article may be an abrasive brush having an attachment device affixed thereto. An exemplary attachable abrasive brush is shown in
Exemplary attachable abrasive brushes that can be prepared according to the present invention include radial brushes, right angle brushes, cup brushes, and flap brushes. Further description of techniques and materials for making abrasive brushes may be found in, for example, U.S. Pat. No. 6,261,156B1 (Johnson et al.); U.S. Pat. No. 5,983,434 (Eichinger et al.); abrasive brushes such as flap brushes as described, for example, in U.S. Pat. No. 5,554,068 (Carr et al.), and unitary brushes as described, for example, in U.S. Pat. Publication 2002/0065031A1 (Chou et al.), published May 30, 2002, the disclosures of which are incorporated herein by reference.
The attachment device includes a fastener having a flange thereon, wherein the flange has a peripheral edge. The attachment device may comprise any dimensionally stable material. For example, the attachment device may comprise metal, plastic, reinforced plastic, ceramic, glass-ceramic, fiber composite, thermoset, wood, and combinations thereof.
The fastener may be any fastener known in the abrasive arts for fastening an abrasive article to a rotatable shaft, including quick change fasteners such as, for example, a “snap-on” fastener, a threaded post, a threaded recess (e.g., a threaded fastener nut as described in U.S. Pat. No. 4,245,438 (van Buren, Jr.)), a Tinnerman nut (e.g., as described in U.S. Pat. No. 2,156,002 (Tinnerman)), the disclosures of which patents are incorporated herein by reference.
For example, as shown in
In another embodiment, shown in
The flange may be circular, polygonal (e.g., hexagonal or octagonal), or another shape. The flange may be continuous or may have at least one discontinuity formed therein. The discontinuity may comprise a perforation, which may be circular, in the shape of a slit (e.g. linear or arcuate) or another shape. The discontinuity may have one or more angular edges, non-angular edges, or a combination thereof. The discontinuity may also comprise a slot or notch (e.g., a linear or arcuate slot or notch) extending inwardly from the peripheral edge of the flange. For example, as shown in
The flange may have at least one embossed feature formed therein. For example, the flange may have pins, ribs, bumps, wells, troughs, or a combination thereof formed therein or thereon (e.g., as shown in
Thermoplastic material is disposed on at least a portion of the surface of the flange opposite the fastener, at least a portion of surface of the flange adjacent to the fastener, and optionally the peripheral edge of the flange. Preferably, the thermoplastic material contacts substantially all of the surface of the flange opposite the fastener, at least a portion of surface of the flange adjacent to the fastener, and optionally the peripheral edge of the flange.
After affixing the attachment means to an abrasive member, some of the thermoplastic material is disposed between, and affixed to, at least a portion of flange and the abrasive article.
Any thermoplastic material may be used as long as the attachment device does not consist of the same material. Typically, the thermoplastic is selected such that it adheres, preferably strongly adheres, to the abrasive article and preferably to the fastener, although if mechanically affixed to the fastener the thermoplastic need not adhere to the fastener. Useful thermoplastics include, for example, polyamides (e.g., polyhexamethyleneadipamide, polyhexamethylenesebacamide, polycaprolactam, and mixtures thereof), acrylics (e.g., copolymers of acrylic acid or methacrylic acid with alkyl acrylates), polycarbonates, polyurethanes, polyimides, polyesters (e.g., polyethylene terephthalate), polyolefins (e.g., polyethylene, polypropylene, and mixtures thereof), polyethers, and mixtures thereof.
The fastener is generally attached to the abrasive article by mechanically and/or adhesively affixing thermoplastic to the fastener, and subsequently bonding the thermoplastic to the abrasive article. Preferably, the thermoplastic forms a plate of sufficient size to at least substantially cover the surface of the flange bonded to the abrasive article, although the thermoplastic may have other forms such as, for example, a rod or block. The plate may be circular, polygonal, or any other shape, and may have protrusions such as for example pins, ribs, spring clips, or a combination thereof that may be adapted to engage the fastener.
Suitable methods for affixing thermoplastic to the fastener include molten methods such as, for example, injection molding thermoplastic onto the fastener or at least partially immersing the fastener into molten thermoplastic. Referring now to
Thermoplastic may be applied to the fastener by a variety of known methods including, for example, powder coating, injection molding, and immersion or dip coating in molten polymer or solution of polymer in a solvent. By applying thermoplastic to the fastener in the molten or dissolved state, secure bonding of the thermoplastic to the fastener is typically achieved. If applying molten thermoplastic to the fastener, the thermoplastic is preferably chosen such that, when cooled, it will form a strong adhesive bond to the fastener, especially if there is no mechanical engagement between the thermoplastic plate and the fastener. For example, thermoplastics comprising polyamide (e.g., nylon 6 or nylon 6,6), polyacrylate, polycarbonate, polyurethane, or a combination thereof typically strongly adhere to metallic substrates such as steel, iron, aluminum, titanium, and/or tin. Additionally, in such processes unwanted extraneous thermoplastic that is deposited onto the fastener may optionally be removed, for example, by abrasion or ablation.
Suitable methods for affixing thermoplastic to the fastener also include mechanical methods such as, for example, screws or snap on spring clips (e.g., integrally molded onto a thermoplastic disc), hot or cold rivets, and combinations thereof.
An exemplary embodiment of an attachment device having thermoplastic mechanically affixed to a fastener having a flange is shown in
The attachment device is typically attached to the abrasive article by one or more welding techniques in which the thermoplastic is heated until it becomes at least partially softened or molten, and then cooled while in contact with the abrasive article, thereby forming an adhesive and optionally mechanical bond. Suitable techniques known in the thermoplastic welding art include, for example, ultrasonic welding, infrared welding, vibration welding, and frictional welding (including spin welding). Welding may also be accomplished as a stepwise process in which at least a portion of the thermoplastic is heated until it is at least partially softened or melted, and then the softened or melted thermoplastic is bonded to the abrasive article. Of the abovementioned techniques, at least spin welding is typically simple, effective, and convenient.
The fastener may be attached to any portion of the abrasive article, although it is typically attached to a portion that is centrally located on an axis of rotational symmetry and not intended for abrading an article.
During abrading of a workpiece, attachable abrasive articles according to the present invention are typically used in combination with a tool having a rotatable shaft such as, for example, a grinder or an electric drill. Accordingly, the fastener portion of the attachment device is typically mounted on the rotatable shaft of the tool. To assist in attaching the attachable abrasive article to the rotatable shaft, the shaft may have a complementary fastener mounted thereon and adapted to engage the fastener on the attachment device.
Various modifications and alterations of this invention may be made by those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrative embodiments set forth herein.
