A heated plunger used in the vacuum moulding of plastics which forces the plastic partially into the mould cavity before the vacuum is applied; the technique of using this device.
Origin
1950s; earliest use found in British Plastics.
Definition of plug assist in US English:
plug assist
noun
A heated plunger used in the vacuum moulding of plastics which forces the plastic partially into the mould cavity before the vacuum is applied; the technique of using this device.