Degassing

A closed-mould process in which dry reinforcement is laid into a mould, sealed under a vacuum bag, and liquid resin is drawn through the fibre stack by vacuum alone. It achieves higher fibre content and lower void levels than open moulding, with much lower workshop emissions.

The proportion of a cured laminate's volume occupied by trapped air or volatiles rather than fibre or resin. Elevated void content degrades interlaminar shear strength and fatigue performance, so it is controlled through debulking, vacuum and cure pressure and checked by testing or non-destructive inspection.

The length of time a mixed, reactive resin or adhesive remains usable in the mixing vessel before it thickens beyond application. Pot life shortens as temperature and mixed quantity increase, because the curing reaction generates its own heat.

The heat released by a thermosetting resin as it cures. In thick sections or large mixed volumes the temperature rise can be severe enough to cause discolouration, cracking or degradation, so laminate thickness per pass and mixing quantities are managed to control it.