Blow moulding extruded parison - after conditioning and shaping in mould cavity

摘要

In blow moulding a molecularly orientated container with a neck portion, the extruded portion is heated and stretched in a mould upstream of the blow mould, the upstream mould having a cavity smaller than that of the blow mould, a cooled cavity and partable sections defining the neck finish, and the parison is then heated to a temp. at which it molecularly orientates with stretching in the blow mould. Several parisons are simultaneously heated prior to transfer to the blow mould.