Effect of Increased Weight Reduction on Shrinkage of Injection-Molded Parts Using Microcellular Foaming Process

Abstract

Shrinkage is a common problem in injection-molded parts. This study finds a way to reduce the linear and volumetric shrinkage by using microcellular foaming process. Experiments were conducted by using unfilled and filled (25% short glass fiber reinforced) acetal copolymer samples to demonstrate the effect. The overall improvement in shrinkage was observed therefore the result of increasing weight reduction in the samples. Therefore weight reduction can be utilized to achieve higher-dimensional tolerances of polymer parts and filled polymer can be used if greater mechanical properties are also a matter of concern.

Keywords:

• Glass fiber
• Injection molding
• Microcellular foaming process
• Polymer
• Shrinkage