Mold for thermal conditioning a thermoplastic parison

摘要

An improved shell mold and method are provided for thermal conditioning a thermoplastic parison prior to blow molding the parison into a hollow container and especially a biaxially oriented container. The mold has an inner shell and an outer shell defining a passageway therebetween for a circulated heat transfer fluid. Heat transfer between the fluid and the parison is controlled to adjust the thermal history at different locations of the parison as it will be required by the mode of stretching and the blow out ratio at the different locations.