ABSTRACT
Pultrusion is a truly continuous process with an automated cut-off saw, a pultrusion line can run with virtually no attention except for occasional checking for glass breakouts and resin levels. The basic parts of the pultrusion process are reinforcement handling, resin impregnation, Pre-die forming, Shaping and cure of the resin and Pulling and cut-off. Pultrusion resins are predominantly unsaturated polyesters, but epoxies and silicones have been used in a few special purpose applications. If multiple layers are required, the pairs of roving and mat layers should be kept separate through the impregnation bath and combined thereafter. The pre-die formers need not be elaborate; bent wires or slotted plates are the most common pre-die formers. Glass-fiber surface mats have no strength in the wet state; they should be fed onto the laminate at the entrance to the curing die. Often resin technique will clear the die so that a smooth surface on the cured part is again restored.
