GB562815A - Improvements in or relating to metal-supported abrasive articles - Google Patents

Abstract

562,815. Abrasive wheels. ABBEY, A. (Carborundum Co.). Jan. 13, 1943, No. 675. [Class 60] A bonded abrasive body is secured to a rigid metal support by a tie bond comprising one or more members of a group consisting of a polymerised halogen substituted butadiene such as polychloroprene and polybromoprene, polymers of butadiene (polydivinyl), polychloroethylene, polyvinylchloride, polyvinyl acetate, polyethylene sulphide and/or copolymers of or incorporating any of said members. The copolymer may comprise a copolymer of butadiene with any members of the group containing styrene, acrylonitrile, methyl methacrylate, isobutylene, coumarone or indene, vinylidene chloride and chloromethacrylic ester or a copolymer of chloroprene and any members of the group consisting of acrylonitrile, styrene and methyl methacrylate. A filler material, such as carbon black, may be incorporated with the tie bond material. The grinding wheel shown in Fig. 2 consists of a bonded abrasive section 5 having a flat grinding surface 6 secured to a steel backing plate 8 by a layer of tie bond material 9. The abrasive section 5 may consist of crystalline aluminium oxide or silicon carbide bonded by a vitrefied ceramic material, a silicate or a resin or a rubber compound. Before applying the tie bond, the attachment surface 7 is cleaned and coated with one or more thin coatings of cement such as vulcanizable compounded polychloroprene dissolved in benzol or toluol and the wheel is then heated to 250‹ F. The backing plate is also cleaned and similarly coated on its attachment surface. A sheet of tie bond material, 1/32" to 1/16" in thickness, is placed on the backing plate and smoothed down by a roller to ensure complete contact and the abrasive section is placed on the tie bond while still hot. The assembly is then placed on a mandrel and subjected for about 30 minutes to a temperature of 290‹-300‹ in a hot press producing a pressure of 100-600 1bs. per square inch. A suitable composition of tie bond is polychloroprene 100 parts, calcined magnesia 4 parts, zinc oxide 5 parts, soft carbon black 200 parts, cotton seed oil 5 parts, sulphur 1 part, phenyl-beta-naphthylamine 2 parts by weight. Grinding rings or segments may be attached by similar tie bonds to steel supporting discs, centre rings or spindles.