MANUFACTURE OF BATHTUB OF THERMOPLASTIC RESIN

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method allowing execution of a free design without any limitation on the wall thickness and projections of a bathtub causing no large strain or internal stress in the resin in the vicinity of a resin supply port in a product and reducing the cost of molds to be inexpensive. SOLUTION: In a manufacturing method of a bathtub of thermoplastic resin for which male and female molds having a cavity corresponding to a desired shape of the bathtub constituted of a bottom and an outer peripheral wall surface are used and which has a process of supplying molten thermoplastic resin of a volume for forming the bathtub into the cavity and a process of clamping the two molds and filling the supplied molten thermoplastic resin in the cavity of the molds, the bathtub of the thermoplastic resin is manufactured by supplying the molten thermoplastic resin so that at least 70 vol.% thereof be positioned between molding surfaces for forming the bottom of the bathtub and by conducting clamping so that a shear rate of the molten thermoplastic resin flowing between the molding surfaces for forming the outer peripheral wall surface be 50-5000 sec<-1> .