GB860920A - High speed frictional glossifying medium - Google Patents

Abstract

860,920. Flexible polishing materials. GENERAL PLYWOOD CORPORATION. May 6, 1959 [May 16, 1958], No. 15501/59. Class 140. [Also in Group XXIII] A frictional gasifying medium comprises a substantially unabrasive working face composed of adherently-bonded non-resilient, unabrasive, heat-insulating, expanded silicate particles which are derived from hydrated unexpanded silicate particles having the property of expanding from six to twenty times when heated to form a relatively light material of low density. The medium may comprise a flexible backing 10, a make coat 12 which adherently bonds a layer 11 of said particles to the backing, and a size coat 14 over the layer of particles. As shown in Fig. 3, the backing 30 may be coated with a presize coat 31 prior to application of the make coat 32. As shown in Fig. 4, an oversize or levelling coat 45, which may be deposited from a solution of alkali lignin, may be applied to the medium. The backing may be a greige or drills cloth, jeans or herringbone cloth. The presize coat may be of latex containing a mixture of butadiene-acrylonitrile copolymer and polyvinyl chloride. The expanded particles may be vermiculite, perlite, culsageeite, dudleyite, hallite, jeffersite, kerrite, lennilite, maconite, philadelphite, pyrosclerite, or vaalite, and may be in the graded size range - 10+180 mesh on Tyler standard screens. The make coat may be of animal glue or an oil-modified phenolic varnish. The size coat may be of animal glue or an oil modified phenolic varnish containing a melamine resin, and may contain finely-divided polishing materials or fillers such as cerium oxide, rouge of iron oxide, tripoli, silicon carbide, flint, emery, garnet, corundum, wollostonite, cryolite and various other siliceous materials.