Scored core

A lightweight open-weave fabric used as a flexible carrier or stabiliser. In core materials it is bonded to one face of small core blocks so the sheet can drape over curved moulds, while in roofing membranes and coated fabrics a scrim acts as the reinforcing carrier that gives the sheet dimensional stability and tear resistance.

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.

A thermoplastic core material, such as PET foam or certain linear PVC foams, that can be softened with heat and formed to a curved shape before lamination. Thermoforming avoids the slits used in scored core, so the finished panel absorbs less resin and keeps a more uniform surface.

Closed-cell polyvinyl chloride foam supplied in sheet form as a structural sandwich core. Crosslinked grades offer higher stiffness and temperature resistance, while linear grades are tougher and more ductile; both are widely used in boat hulls and decks, wind turbine blades and vehicle panels.