Sätt och anordning att kristallisera och forma bottenpartiet hos en kopp eller koppliknande föremål

摘要

Crystallizable mainly amorphous thermoplastic material is crystallized at a temperature exceeding the glass transition temperature of the material (13) by subjecting the material at the elevated temperature to compressive forces. By means of these the material thickness as a rule is reduced by at least 20 %, preferably by at least 40 %. In a device for the application of the procedure a plunger (20) and a mould (30) are moved to a minimum distance at which the thermoplastic material (13) located between the plunger and the mould part is subjected to compressive forces. The plunger and/or the mould part are provided with elements (29, 39) for the setting and maintaining of a temperature specified in advance of the surfaces (23, 33) with which the plunger and the mould part respectively abut against the thermoplastic material.