Porous layer core manufacturing method for dental porcelain frame and dental porcelain frame manufacturing method

摘要

PROBLEM TO BE SOLVED: To enhance production stability and to make rapid production possible by having the polyvinyl alcohol(PVA) of an amt. to relieve the stress under firing down to the stress below the stress to the occurrence of crack accompanied with the ceramic molding on a refractory pattern. SOLUTION: Slip is formed by adding moisture to alumina powder raw material of, for example, 37m average particle size. The slip is cast onto the gypsum refractory pattern 1 and the surface thereof is subjected to coating 3 at, for example, 0.1 to 0.2mm thickness with an aq. soln. of, for example, 10wt.% PVA, by which a ceramic core material (ceramic core part) is formed. The PVA is used in the amt. to relieve the stress under firing down to the stress below the stress to the occurrence of crack in the ceramic core material (ceramic core part). The ceramic core material is fired by holding for 30 minutes at, for example, 150 deg.C, then heating up for 40 minutes to, for example, 1120 deg.C, followed by holding for 10 minutes at, for example, 1120 deg.C.