Method for injection-moulding a hollow product using a pressure variation between two gas volumes

摘要

A method is described for injection-moulding a product by means of the so-called gas-injection method. A special feature of the method is that in addition to the injection of gas into the product cavity (10) via a first gas inlet (51), gas is injected into a spill cavity (20) via a second gas inlet (52). The amount of material (1) flowing from and toward the spill cavity (20) can be controlled by the location of the second gas inlet (52). Moreover, a variant of the method prevents the formation of so-called dead ends. By means of another variant of the method in accordance with the invention it is possible to prevent the occurrence of so-called flow lines.