PROCESS AND DEVICE FOR INJECTION MOULDING OF PREFORMS, PREFORMS AND THEIR USE

摘要

A process is disclosed for processing a plastic mass which crystallizes in a given temperature range. In order to prevent the preform from becoming cloudy because of crystallization, the moulding mass is quenched. This process prevents such cloudiness at least in the injection area of the preform, as the whole moulding mass is maintained during the whole working cycle, up to the injection area, at a temperature that is higher than the temperature TCC, under which the moulding mass begins to crystallize. An injection moulding system for implementing this process has a highly heat conductive nozzle core inside the injection nozzle, a highly heat conductive area in immediate proximity of the injection outlet and a heat insulating gap between the nozzle point or core and the moulded body.