Pultrusion
Pultrusion is a continuous molding process using fiber reinforcements with thermosetting resin matrices.Pre-selected reinforcement materials,such as fiberglass roving,mat,woven fabrics or stitched fabric,are drawn through a resin bath in which all material is thoroughly impregnated with a liquid thermosetting resin.Typical resins included polyester,vinyl ester and phenolic. The wet-out fiber is formed to the desired geometric shape and pulled into a heated steel die.Once inside the die,the resin cure is initiated by controlling precise elevated temperatures.The laminated solidifies in the exact cavity shape of the die,as it is continuously pulled by the pultrusionmachine.Most any constant cross-section part can be pultruded.Pultrusion allows the designer to customize the selection of the resin system,the type and form of fiberglass reinforcements,and the placement of the reinforcements within the composite profile.