Non-destructive characterisation of polymers during injection moulding with ultrasonic attenuation measurement

摘要

A non-destructive ultrasonic attenuation measurement is adopted to characterise the state ofnpolymers in the cavity during injection moulding. According to the relationship between ultrasonicnattenuation behaviours and polymer viscosity, elasticity transition as well as crystallisation, thenevolution of ultrasonic attenuations for an amorphous polymer (general purpose polystyrene) andna crystalline polymer (polypropylene) were discussed. Experimental results show that thenultrasonic attenuation measurement can not only provide information of the amorphous polymernon filling start, filling stop, elasticity transition and detachment from the mould, but can also extractninformation of crystallisation for the crystalline polymer throughout the injection moulding process.nThe ultrasonic attenuation measurement is a potential candidate technology to characterise thenstate of polymers in the cavity and thereby optimise the injection moulding process for perfectnproducts.