Sheet moulding compoundSMC

A dough-like moulding compound of short chopped fibres, filler and thermosetting resin, shaped by compression or injection moulding. BMC suits complex, detailed parts such as electrical housings, reflectors and valve components.

A moulding process in which a charge of material, such as sheet moulding compound or a preheated thermoplastic blank, is placed in a heated matched metal mould and formed under press pressure. It offers short cycle times and good surface finish and is widely used for automotive panels and electrical components.

Fibre drawn from molten glass, the most widely used reinforcement for polymer composites. Different formulations, such as E-glass, E-CR glass, S-glass and AR glass, balance cost, strength, electrical performance and chemical resistance. It is the standard reinforcement in GRP laminates, including liquid applied GRP flat roofing systems.

A surface defect in which the pattern of the underlying reinforcement or core becomes visible on the finished face of a moulding, usually as a result of resin shrinkage during cure or post-cure. It is a particular concern on high-gloss gelcoated and painted panels.