| 摘要 |
Apparatus for making open-ended thermoplastic tubular articles, which are dimensionally stable up to elevated temperatures comprises a fixed, heated external mould (12) and cooled mandrel (10), which is vertically displaceable relative to the mould (12). An open-ended polymer tube is disposed between the mandrel and mould and both its ends clamped to restrain the tube axially. The polymer tube is radially expanded into contact with the hot mould and maintained in contact for a time sufficient to ensure dimensional stability, and then allowed to shrink back into contact with the cooled mandrel, which is maintained at a temperature below the glass transistion temperature of the polymer. The resulting article is then stripped from the mandrel. |
