| 摘要 |
A process for producing injection mouldings made of a foamed plastic, comprises charging an injection moulding machine with a mixture of plastic granules and a propellant, and mixing it in a worm unit. The mixture is subjected to pressure and plastified, and then a nozzle is opened to allow the material to enter the mould. Before the nozzle is opened the worm is pulled back for a short time to reduce the pressure in the front chamber of the cylinder, to allow pre-foaming. The worm is moved at high speed, and the plastified material is prevented from foaming in the worm unit by adjusting the worm rotational speed and temperature. |
