Stampable polypropylene composites

At 21.9 MPa stress load, the mega-coupled composite exhibits a much steeper strain versus time behavior than stampable polypropylene composite and fails after about 46.5 hr. However, this creep behavior is exceptional compared with the corresponding uncoupled GFRP, which fails almost immediately as reported by Silverman (33). This trend indicates that the mega-coupled stress trans-... 

Recendy, storm doors have been constmcted of advanced thermoplastic composites. Stampable, glass-mat reinforced polypropylene sheet is used to create a high strength outer skin. These compression molded skins are welded together using a friction or ultrasonic process then injection molded with a polyurethane foam core to produce an insulated structure. New technology for window frames incorporate the pultrusion of frame channels to produce a thermoset composite channel that can be filled with fiber glass for further insulation enhancement (12,31,33,34,48,49,54—56,60—67). 

Silverman characterized flexural creep resistance at 120°C (33) and room temperature impact resistance (34) for test specimens from injection-molded composites of chopped fibers versus machined specimens from compression molded continuous long GFR polypropylene sheets. His concepts of glass fiber reinforcement in stampable composites tend to mirror many of the attributes related to megacoupling of short GFRP. 

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