Ceramic prods., esp. porcelain, contg. pattern of holes - made by shot blasting with glass beads prior to final baking

摘要

Ceramic prod. with pattern of holes is prepd. by (a) white-drying; (b) partial baking; (c) opt. glazing; (d) selectively covering the prod. with a mask and subjecting the exposed zones to a stream of granular particles to make the holes; and then (e) final baking. The partial baking is pref. at 600-1100 degrees C but may be omitted if the dried prod. has a similar hardness to the partly baked prod. The hard, white-dried prod. can be obtd. by adding a binder to the ceramic, thus eliminating the partial baking step. The granule particles are pref. glass beads, 40-250 (esp. 85-150) mu m dia. Used to produce decoration in the form of a pattern of holes, e.g. of fine porcelain tableware, e.g. on the edge of a plate. A simpler and easier process of making the holes as compared with conventional processes. The amt. of hand work and the number of defective prods. are reduced.