Thermoformable core

Closed-cell thermoplastic polyester foam used as a structural sandwich core. It is thermoformable, recyclable and often manufactured with recycled content, and its fatigue and processing performance has made it a common choice in wind turbine blades and transport structures.

Core sheet cut with a grid of slits or kerfs, often combined with a scrim backing, so that it can conform to curved mould surfaces. The cuts also act as channels for resin flow during infusion, although they increase resin uptake and therefore the finished weight of the panel.

The forming of heated thermoplastic sheet over or into a mould using vacuum, air pressure or matched tooling, then cooling it to shape. Applications range from vacuum-formed cladding and rooflight components to the forming of consolidated thermoplastic composite blanks.

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.