AN EXPERIMENTAL-STUDY OF POLYMER-FILLER REDISTRIBUTION IN INJECTION-MOLDED PARTS

The migration of filler particles in polymer composite materials durin g the injection molding process is investigated. Results indicate that during injection, particle concentration becomes non-uniform in the m olded part. Experiments were conducted with polystyrene filled with no n-rigid (rubber) and rigid (calcium carbonate) particles. A plasma etc hing technique has been used to determine the local concentration of r ubber particles in the molded part. An ashing technique was employed t o determine the average concentration of calcium carbonate at various regions of the molded part. The experimental results show that process variables like injection speed, particle size, particle concentration , and nature of filler determine the final filler distribution in the polymer matrix.