Heatsetting of thermoplastic tubular articles.

摘要

A polyethylene terephthalate (PET) body for a food container has open ends and is made by stretch blow moulding a hollow elongate parison of PET using pressurised gas which is admitted at one end only of the parison. Dimensional stability for the body at elevated temperatures is given to the body by use of a continuously heated mould against which the body is held by the pressurised gas. After heat-setting, the article is cooled within the mould by spraying water into its interior, and exhausting the pressurised gas through the end opposite to the end at which the gas was admitted. The departing gas caused turbulence in the water spray and removes most of the water from the article, so ensuring quick and efficient cooling. <IMAGE>