Abstract: A non-cellular polyurethane polishing and finishing wheel is disclosed having a molded annular matrix reinforced at the inner circumference by a circumferential reinforcing means. The radially outer portion of the matrix is free to deform during use and is formed of a flexible elastomeric polyurethane having a no-grain Shore A durometer hardness from about 30 to about 55 and a high tensile strength. Proper distribution of the abrasive refractory grains is achieved by employing a polyurethane prepolymer having a high viscosity of 2000 to 6000 centipoises at the curing temperature, and the curing agent is selected to provide the required flexibility and tensile strength and also to effect curing rapidly so that the abrasive grains remain in position during curing. The polyurethane composition preferably contains up to 100 parts of finely divided abrasive material, 3 to 20 parts of mica, and up to 10 parts of molybdenum disulfide per 100 parts by weight of the polyurethane prepolymer.

Abstract: A solid polyurethane polishing and finishing wheel is disclosed having a molded annular matrix reinforced at the inner circumference by a series of axially spaced annular fibrous members embedded in the matrix. The radially outer portion of the matrix is free to deform during use and is formed of a flexible elastomeric polyurethane having a no-grain Shore A durometer hardness from about 30 to about 55 and a high tensile strength. Proper distribution of the abrasive refractory grains is achieved by employing a polyurethane prepolymer having a high viscosity of 2000 to 6000 centipoises at the curing temperature, and the curing agent is selected to provide the required flexibility and tensile strength and also to effect curing rapidly so that the abrasive grains remain in position during curing. The polyurethane composition contains up to 100 parts of finely divided abrasive material, 3 to 20 parts of mica, and up to 10 parts of molybdenum disulfide per 100 parts by weight of the polyurethane prepolymer.