Abstract
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 thermoviscoelatic 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.
