Injection molding is one of the most widely employed methods for the fabri- cating of polymer articles, being characterized by high production rates and accurately dimensioned products. The process includes the flow of polymer melt through a runner system and gates followed by injection into a cold mold, packing under high pressure, and subsequent cooling to solidification. Accordingly, during the injection-molding process the polymer undergoes simultaneous mechanical and therma! influences while in fluid, rubbery, and glassy states. Such effects introduce residual stresses and strains into the final product 1,2, resulting in highly anisotropic mechanical behavior 3#x2013;9 and warpage and shrinkage 10#x2013;13. Thus, understanding the factors governing the residual-stress development during molding is of great importance.
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