Development of the layered structure in a double-gated glass fiber-reinforced polypropylene injection molding: Experimental and simulated results

QUINTANA, MC; FRONTINI, MP

JOURNAL OF REINFORCED PLASTICS AND COMPOSITES

SAGE PUBLICATIONS LTD

Año: 2018

0731-6844

The present study aims to experimentally validate numerical simulation of fiber orientation distribution performed bymolding simulation software Moldex3D in a double-gated injection-molded glass fiber-filled (40 wt%) polypropylene box,by making a detailed comparison of predicted and experimentally measured fiber orientation distribution data.The modeling approach evaluated in this work consists in the implementation of the Folgar?Tucker rotary diffusionmodel with the invariant-based optimal fitting closure approximation for the fourth-order orientation tensor. Thespecimen used has a weld line in the center and sharp corners. This investigation characterizes in detail the developmentof the through-thickness layered structure at distinctive locations of the specimen. The sensitivity of fiber orientationdistribution and the layered structure to changes upon injection time and melt temperature is also evaluated. The boxesdisplay the typical layered laminate structure, with fibers aligned in the main flow direction near the walls (shell layer) andless oriented in the middle plane (core layer). The boxes injected at the lowest melt temperature display an additionalskin layer. Unfortunately, simulation fails in predicting the five layers structure developed under these latter conditions.The grade of fiber orientation is deemed to be independent of process parameters but not the layered structure.