Stretch blow receptacle and molding method of the same

摘要

Improve the strength of the stretch blow receptacle and make the heat resistant treatment easier, by making the receptacle wall cross-section multi-layered in view of crystalline density, and the crystalline density of the surface layer high density. The inventions concerns a thin plastic receptacle 2 molded by stretch blowing of a bottomed preform 1 in the longitudinal and transversal directions. The wall cross-section is composed of inside and outside surface layers 2 a whose crystalline density is high by stretching, a core layer 2 b presenting a lower density than the surface layers 2 a, and an intermediate layer 2 c presenting a graduated density between both layers 2 a, 2 b.