Prediction of weldline strength for injection molded short-glass-fiber composites

This paper provides a modified rule-of-mixtures relationship which allows for the calculation of weldline strength as a function of the area fraction between skin and core layers. The effects of fiber length and fiber orientation within the skin and core layers on the weldline strength of injection molded short-glass-fiber reinforced polypropylene have been studied in detail. The present theory is then applied to exiting experimental results and the agreement is found to be satisfactory.