A method for producing an abrasive tool or structure which includes the steps of mixing an abrasive composition containing abrasive particles and, preferably, friable particles, with a liquid, multi-stage, thermosetting resin and coating substantially all of the individual particles with the resin; curing the resin to the B-stage while the resin is in contact with the particles to form a fusible solid coating on the particles and forming individual particles coated with said B-stage resin, and placing said resin coated particles in a mold and heating the particles sufficiently to render the resin tacky and fusible and, concurrently, applying sufficient pressure to form a coherent mass of said particles and curing the resin to a hard infusible state to form a high tensile strength bond between said particles. An abrasive tool composed of abrasive particles and lightweight, easily crushable, friable particles uniformly dispersed throughout the abrasive particles, each of the particles being bonded together with a high strength bond formed by a thermosetting resin cured to a hard and infusible state.
Particles of garnet are intermixed with rubber compound in the formation of tire tread structures to increase traction with the road surface. The amount of garnet introduced into the tread structure is at least 10% by weight of garnet relative to the weight of rubber compound to obtain maximum traction. The size of the garnet particles that may be used ranges in size from 177 to 841 microns.
An improved process is disclosed for making grinding wheels wherein a vinyl resin, such as polystyrene, or other suitable thermoplastic material is incorporated in the refractory composition with an epoxy binder or other binder which cures in the proper temperature range. The flat surface grinding wheels made in accordance with the invention and used on double-disc grinders function more effectively and facilitate rapid grinding and their useful life can be increased at least 3 or 4 times.
According to the invention, the composition contains an abrasive material (12.5-37.5 vol.-%), a metallic filler (30-60 vol.-%), a mineral binder (5-30 vol.-%) and the balance is an organic binder. The mineral binder is constituted by at least one substance from a group of salts whose melting temperature corresponds to the temperature range of polymerization of the organic binder.
An abrasive for removing flashes of a molded product, which comprises synthetic resin particles, each particle having a plurality of cutting edges and of cracks capable of easily forming cleavages upon collision against a workpiece. A method for manufacturing such synthetic resin abrasive particles which comprises a step of intentionally forming a number of cracks in the resin particles.
Differentiation between grinding wheels which are dimensionally stable in use and which remove stock to specification tolerances and polishing wheels which are flexible and which primarily do not remove stock but which "fill the valleys with the hills" call for different development. This invention is directed to a polishing tool (wheel) comprising selected abrasive, filler and plastic elastomeric bond to produce a non-rigid solid tool (wheel) of minimum voids content, the cured elastomeric bond alone characterized by a Shore hardness of 45-55 but the completed tool face hardness is not in excess of about 96 "Shore A" hardness. The so limited polishing wheel is characterized by non-chattering, non-loading, aggressive and is yet non-smearing. It is arrived at by accurate volume control ratios of the components essentially present in the product.
