Production of polypropylene based interior trim parts used in the automotive industry by using chemical foaming additive with injection molding method and determining the features

This study aimed to lighten the polypropylene material used in the production of door panels of Toyota CH-R model vehicle using chemical foaming additive (CFA), and the effect of foaming additive on physical, thermal, and mechanical properties was investigated. By adding CFA in varying ratios (1%, 1.5%, and 2%) to PP material, PP material containing foam in its cross-section was obtained. Morphological properties such as foam cell sizes, cell density per unit volume, and skin layer thickness of the samples produced with foaming additive varying in weight were investigated. Depending on the foaming additive ratio, the change in mechanical properties was determined by tensile, flexural, impact, and hardness tests. Differential scanning calorimetry (DSC) analysis was carried out to examine its thermal properties. As a result of the studies, PP foam with closed cells was produced. With the increase in the amount of foam additive, a decrease in the particle density was achieved. While foam cell sizes and cell density per unit volume increased, the skin layer thickness decreased. When the effect of foam additive amount on mechanical properties is examined, generally, as the amount of foam additive increases, there is not much change in impact strength, tensile strength, and flexural strength values. Keywords: Cell morphology, foaming additive, polymer foam, injection molding