Plastics vessel moulded from stacking beaker - by heating on mandrel and expanding into mould under differential pressure

摘要

Stacking vessels are used which have, adjacent to their top, open end, a stacking shelf having a lower, outer stacking shoulder and an inner, upper stacking shoulder, which are used to secure the stacking vessel onto the mandrel; the stacking vessel is then heated (except for a portion of this retention rim) and is stretched to fit the inner surface of the mould. This arrangement enables a stacking vessel, without a specially formed beading around the rim, to be used.