摘要 |
<p>A process for blow moulding hollow thermoplastic members, comprises extruding tubular preforms through an annular gap nozzle, and then expanding them in a blow mould (5). The preforms that leave the nozzle swell, and are elongated by their own weight. The diameter of the preforms can be adjusted by adjusting the exit diameter of the nozzle. A process for blow moulding hollow thermoplastic members, comprises extruding tubular preforms through an annular gap nozzle, and then expanding them in a blow mould (5). The preforms that leave the nozzle swell, and are elongated by their own weight. The diameter of the preforms can be adjusted by adjusting the exit diameter of the nozzle. The blow mould has an extrusion press head (1) with a ring shaped nozzle (7), a plastic advancing unit (2) for moving the plastic melt through the head, and a programme controlled adjustment unit (3) for controlling the nozzle width.</p> |