Process for producing resin model and process of lost wax precision casting with the resin model

摘要

A process for producing a resin model for use in lost wax precious casting, comprising at least a hardened resin layer forming step of injecting two-pack reaction hardening type urethane resin solution (A) of 1 to 3 minutes of a working life, through a casting port (4) of a resin model forming mold (2) furnished with internal space (3) whose configuration is identical with that of product, into the internal space (3) in a volume amounting to 5 to 20% of the volume of the internal space (3), closing the casting port (4) and rotating the resin model forming mold (2); a resin model forming step of repeating the hardened resin layer forming step 3 to 6 times at intervals of 3 to 4 minutes so as to effect laminating of hardened resin layers (11), thereby obtaining resin model (12) having internal space (30) provided at a core region thereof; and a demolding the resin model (12) from the resin model forming mold (2).