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Pressure build‐up during the packing stage of injection molding
Author(s) -
Chung TaiShung
Publication year - 1985
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760251208
Subject(s) - materials science , isothermal process , shrinkage , compressibility , molding (decorative) , newtonian fluid , viscosity , blow molding , pressure gradient , composite material , stage (stratigraphy) , mechanics , equation of state , thermodynamics , mold , physics , geology , paleontology
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.