熱可塑性樹脂の成形過程で生ずる残留応力

Abstract

本報では、熱可塑性樹脂の射出成形下での残留応力の発生機構について述べた。最初に、熱粘弾性力学モデルを用いてこの発生機構を定性的に説明した。つぎに、ポリプロピレン(PP)樹脂板を種々の保圧条件で成形し、それらの残留応力に直接影響する熱粘弾性特性を注意して測定した。最後に、逐次除去法によりPP樹脂板の残留応力を測定した。種々の保圧条件で、これらの残留応力と熱粘弾性力学モデルによる数値とを比較し、上記の熱粘弾性特性、射出成形した熱可塑性樹脂の残留応力の発生機構を定量的に論じた。

This paper describes the generation mechanism of residual stress in thermoplastic resins under injection molding. First, the generation mechanism is qualitatively explained by using a thermoviscoelastic model. Second, PolyPropylene (PP) resin plates are molded under various dwelling conditions, and these thermoviscoelastic properties which have a direct effect on their residual stresses are carefully measured. Finally, the residual stresses in PP resin plates are measured by a layer removal method. By comparing these residual stresses under various dwelling conditions with the numerical ones by the thermoviscoelastic model the thermoviscoelastic properties mentioned above, the generation mechanism of residual stress in thermoplastic resins under injection molding is discussed quantitatively.