| 摘要 |
Valves (110) and other apparatus, methods of moulding and moulds (112) are provided for the moulding of materials such as injection or injection-compression moulding of molten thermoplastic materials. The valve includes a valve element/piston (126) that is orientated at 60 degrees relative to the mould's bounding wall (116) and that can reciprocate in a barrel (122) and that can rotate. The piston (126) h a leading face (128) that is also orientated at 60 degrees, so that the flow passage/melt channel (118) extends past the leading face (128) when the valve (110) is open and the leading face (128) forms part of the bounding wall of the mould cavity (114) when the valve is closed. The piston (126) is advanced or retracted a very short distance and is rotated through 180 degrees, to open and close the valve (110). The other apparatus include multiple flow passage and valve elements that feed single or multiple mould cavities to allow improved moulding of articles in conventional injection moulding machines through multiple flow passages. |
