2材料混合系ポリマーアロイのそりにおけるモルフォロジーの影響
War page and Morphology of a Part Injection Molded from Polymer Alloy
菊池博之・小山清人
Kikuchi, Hiroyuki / Koyama, Kiyohito
This investigation is a subset of study to explain warpage of a part molded from anisotropic and isotropic material, warpage of a part with internal void, and warpage of polymer alloy, in an integrated manner. Correlation between warpage of a disk injection molded from polymer alloy and the morphology of the material was investigated with warpage index (ψm, Ref.1) and with finite element analysis. The alloy consists of two materials with different Young's modulus and different linear thermal expansion coefficient. ψm is proportional to the difference of total strain and thermal strain. ψm indicates the degree of restriction in thermal shrinkage in an injection molded part. In thermal stress analysis, ψm is generated by thermal load which is proportional to the product of linear thermal expansion coefficient and temperature difference. Warpage of a part molded from polymer alloy was explained with ψm. It was found that blending two materials with high degree of dispersion reduces ψm in macroscopic scale, and reduces possibility of disk buckling.
Key words: Warpage index / Polymer alloy / Morphology / Finite element / Injection molding