Mfg. complicated shaped PTFE articles - by moulding in cavity defined by porous polyurethane elements to increase dimensional accuracy

摘要

Complex articles are mfd. from granular PFTE which is compacted by opposed plungers introduced into a mould sleeve by pressing the PTFE in the presence of mould cavity defining elements which are made from elastic and porous polyurethane having a vol. porosity of 40-85%. Elements are stripped from the article which is semi-finished. Used for making valve membranes, beakers, bellows, sealing rings. Dimensional accuracy is increased and quality improved whilst article range is expanded.