Double shot molding

Energy Savings via Stack Molding and Double Shot Holding C7.S)... 

Two-shot injection molding n. Confusingly, this term has been used in the literature for two processes that are distinctly different. One is described under double-shot molding. In the other process, one first injects a metered amount of one material into a single-cavity mold. As this material just begins to chill against the cold mold surfaces, a second material is injected. This fills the interior and forces the first material outward to the cavity surfaces. The second polymer, usually a reclaimed material forms the interior of the finished article, while the virgin material first injected forms the outer shell and surface of the article. 

The term coinjection can denote different products, such as sandwich construction, double-shot injection, multiple-shot injection, structural foam construction, two-color molding, and inmolding. Whatever its designation, a sandwich configuration has been made in which two or more plastics are laminated together to take advantage of the different properties each plastic contributes to the structure. 

Insert Molding n The process by which components may be molded into a part. See Double-Shot Molding. 

Pig. 6. Filling of a double-gated injection mold with polypropylene, (a) Experiment using a series of short shots and (b) simulation. -I-I-I-I-I-I—I- = Computed weld line. Reproduced from Ref. 28. Courtesy of Elsevier Science Publishers. 

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