Pultrusion process equipment

The state of the art for many polymer processes is a simple time-temperature recipe for the process equipment. This is often a satisfactory solution for processes in which the process equipment temperature and the part temperature are nearly identical. Temperature control for pultrusion of thin cross-sections, for instance, can be satisfactorily based on the die and barrel temperatures. In processes where there is a major difference between the setpoint and the local conditions, it is now becoming more common to implement supervisory controllers which account for these differences. The autoclave curing of composites, for instance, may have large temperature lags between the autoclave and the part as is shown in Figures 15.3... 

Fig. 13. Clean injection die pultrusion process and equipment is producing structural elements such as beams for bridge decks and one-piece 224-cm by 297-cm floor panels for semitruck cab and sleeper. Courtesy of Glasforms Inc.

VE polyurethane resins have mechanical properties similar or superior to those of conventional VE and epoxies. Characteristics include a heat distortion temperature of 120C (248F). Ultimate elongation of an unreinforced molding compound without fillers is 5.5% tensile strength is 80 MPa and flexural strength 150 MPa. The resins can be custom-formulated. Applications include customized automobile parts, recreational vehicles, outdoor equipment, tubs/showers and electrical parts. The resins are suitable for standard molding processes some were specifically developed for pultrusion, RIM, foam, adhesive, and polymer concrete applications. 

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. 

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