Investigation the effects of obstacle geometries and injection molding parameters on weld line strength using experimental and finite element methods in plastic injection molding

In this study, effects of injection parameters and weld line on the mechanical properties of polypropylene (PP) moldings were studied. To produce weld line at PP specimens, the obstacles having edge angle of 0°, 15° and 45° were designed. These obstacles were located at the center of the mold. The effects of both obstacles angles and the injection molding parameters such as melt temperature and packing pressure on the mechanical strength were investigated. Mechanical properties such as tensile strength and izod impact strength (notched) of the specimens were measured by test methods. The effect of molecular orientation on the mechanical properties of the specimens was discussed by Finite Element Analysis. Weld line tensile strength of injection molded specimens having obstacle edge angle (OEA) of 15° was obtained higher than the other obstacle edge angles.