GB697556A - Heavy duty flexible abrasive articles - Google Patents

Abstract

697,556. Abrasive tools. BAY STATE ABRASIVE PRODUCTS CO. June 29, 1951 [June 29, 1950], No. 15514/51. Class 60. A flexible abrasive article, such as a pad, belt or disc, comprises a flexible, fibrous backing, a number of flexible loops or filaments 20 projecting from one face of the backing, and a layer 12 of bonded abrasive granules surrounding and embedding the loops, the layer having a substantially uniform thickness several times greater than the diameter of a single abrasive grain and an outer face which is substantially free of deep random irregularities. The Figures show a disc in which the backing consists of a base 14 secured by an adhesive such as a heathardenable phenolic resin to a layer 16 of fibrous or plastic material. The fibrous material may be cellulose, glass, asbestos or wool while the plastic material may be natural, synthetic or silicone rubber, neoprene or polymerised vinyl compounds. The base 14 is preferably vulcanized fibre. The loops or filaments 20, which may be free-ended, may be of cotton, linen, silk or nylon or may be formed from steel, bronze or monel wire. The loops, which are about “ inch high and spaced # inch to <SP>3</SP>/ 16 inch apart, are formed by a sewing machine. The disc is assembled by placing a mass of loose abrasivebond inix in an annular cavity in the bottom of a cylindrical metal mould. A stiffening disc 24 having its upper face coated with adhesive is placed at the centre of the mould and the layer 16 and loops 20 which.have previously been stiffened by the application of a solution of latex, polyvinyl alcohol or the like is then placed over the abrasive. After the application of further adhesive, the base 14 is placed in position and the disc is cold pressed for half an hour at 600 pounds per sq. in. This process is followed by pressing at a lower pressure and a temperature of 320‹ F. The abrasive-bond mix may consist of abrasive granules pre-coated with a liquid phenolic resin and subsequently coated with a dry, powdered, reactive, phenolic resin. Mixtures of heat-sealing resinoid powder and abrasive granules or cold-moulding mixtures may also be used. The face of the tool is provided with a pattern of grooves 26 to prevent loading and, in the case of discs, the centre may be depressed, as shown, or flat.