Cavity pressure profile study during foam injection molding and its effect on cell formation of polypropylene/chemical blowing agent foam

Abstract

In the current scenario, many automotive and aerospace industries have exaggerated replacement of most of the metal parts with polymers to achieve the pursuit of lightweight thereby to reduce fuel consumption and carbon emission. Foam injection molding (FIM) is among one of the cost-effective approaches to produce lightweight polymer products. During FIM, stringent control over various processing parameters is crucial to ensure the precision and reliability of molded parts. This work aims toward the investigation of cavity pressure and its effect on microstructure or cell morphology in chemical blowing agent mixed polypropylene (PP) foams produced by FIM. In particular, effect of varying injection temperature, injection speed and plasticization parameters (screw rotation speed and back pressure) have been examined on the cavity pressure profiles and its conforming influence on cell nucleation and growth have been discussed acutely. The results of this study indicate that various process parameters significantly influence the trajectory of cavity pressure profile during FIM which in turn critically decides structural uniformity of foamed product.