Stretch blow container and molding method therefor

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 2a whose crystalline density is high by stretching, a core layer 2b presenting a lower density than the surface layers 2a, and an intermediate layer 2c presenting a graduated density between both layers 2a, 2b.