Pressure build-up during the packing stage of injection molding

✍ Scribed by Tai-Shung Chung

• Publisher: Society for Plastic Engineers
• Year: 1985
• Tongue: English
• Weight: 442 KB
• Volume: 25
• Category: Article
• ISSN: 0032-3888
• DOI: 10.1002/pen.760251208

✦ Synopsis

Abstract

A thorough study of an isothermal fluid motion within the mold cavity during the packing stage is presented. The fluid is considered Newtonian, and its compressible behavior is assumed to obey the Spencer‐Gilmore equation of state. Mathematical results indicate that the pressure built up during the packing stage is strongly dependent on the melt viscosity and the boundary of the cavity. The effects of pressure gradient and distribution, during this stage, on the shrinkage of the final products are also discussed.