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

抄録

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 (φ_m, Ref. 1) and with finite element analysis. The alloy consists of two materials with different Young's modulus and different linear thermal expansion coefficient. φ_m is proportional to the difference of total strain and thermal strain. φ_m indicates the degree of restriction in thermal shrinkage in an injection molded part. In thermal stress analysis, φ_m 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 φ_m. It was found that blending two materials with high degree of dispersion reduces φ_m in macroscopic scale, and reduces possibility of disk buckling.