Reinforced plastics continuous pultrusion

Pultrusion is a process for producing continuous lengths of reinforced plastic shapes with constant cross-sectional area. Pultrusion equipment is commercially available from a number of manufactures (Table 21.6) and a diagram of a typical pultrusion system is shown in Figure 21.64. Figure 21.65 shows an 8 MT machine with a hand-over-hand gripper system. 

Embedment decorating n. A technique fur decorating reinforced-plastics articles in which a mat or web of fibrous material printed with a design is embedded in the surface of the article and covered with a transparent gel coat. The technique can be adapted for use in hand lay-up, continuous laminating, pultrusion, and matched-die molding. 

Since pultrusion is an automatic and continuous process for fabricating fiber reinforced plastics, a proper pulling velocity will optimize production rate and mechanical properties. 

Extrusion. The process of extrusion is closely related to pultrusion. In extrusion, the plastic material is pushed through a die under pressure rather than drawn through with continuous fiber-reinforcement materials. Random-oriented fiber-reinforcement materials can be used in the extrusion process if they are blended with the molten plastic before entering the die. Extrusion can be used only to produce structures that have a constant cross-sectional profile along their entire length, as determined by the die profile. Quite complex cross-sectional designs can be produced in this way, but they are essentially only two-dimensional. 

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