Injection Molding of Polymers and Polymer Composites: Process Modeling and Simulation

Abstract

For efficient and economic production of discrete parts with any material, it is always desirable to obtain the final product using one process alone, without secondary operations. This is called “net-shape” manufacturing. Injection molding is perhaps the best net-shape manufacturing process for materials that can be handled by this method. For polymers and some of their composites, injection molding can mass produce high-precision parts with complex geometry at very low cost. In engineering applications, some injection-molded plastic parts of intricate shape with tight tolerance can be snap-fitted together for easy assembly, while others can achieve extremely high quality to meet the optical functional requirements for such parts as optical lenses and information-storage disks.Since the oil crisis in the early 1970s, the use of polymers as an engineering material has been rapidly increasing to improve energy efficiency for both the processes themselves and the final products. Plastics still constitute one of the world's fastest growing industries. Polymeric materials and their composites offer various desirable properties including high strength-to-weight ratio, corrosion resistance, clarity, and others. Among all the polymer-processing methods, injection molding accounts for approximately one-third by weight of all the polymeric materials processed.