FORMING METHOD OF CRYSTALLINE THERMOPLASTIC RESIN SHEET, FORMING DIE USED THEREFOR, AND FORMED MOLDING

摘要

PROBLEM TO BE SOLVED: To provide a forming method for a crystalline thermoplastic resin sheet, with which the development of various failures due to poor mold releasing and the manufacturing yield of moldings can be improved better than ever, and a molding, which is formed by the molding method into a mat surface having a beautiful exterior appearance and a high class feeling and a poor sealing in a top sealing film hardly develops. SOLUTION: This forming method has a process W2 for forming the crystalline thermoplastic resin sheet S under heat with a forming die 2 having a top die 21 and a bottom die 22, the surface contacting with the molding S1 of both of which are finished to fine tongued and grooved surfaces having a center-line mean roughness Ra=4-18μm and a maximum height Rmax=40-170μm. The surface contacting with the tongued and grooved surfaces of the molding S1 are finished so as to be mat surfaces having a center-line means roughness Ra=3-8μm and a maximum height Rmax=30-80μm.