NUMERICAL-SIMULATION OF THE MULTICOMPONENT INJECTION-MOLDING PROCESS

The versatility of the injection moulding process can be increased by combining multiple polymers in one product. The multi-component inject ion moulding process (MCIM) offers the possibility to inject two or th ree materials sequentially or simultaneously into a mould to make prod ucts that consist of e.g. a layered structure. For a successful applic ation of this technique for geometrically complex products or multiple materials, the material distribution in the product has to be predict ed In this paper numerical tools are described for calculating the pos itions of material particles during the flow in the mould cavity. Thes e tools make it possible to solve the inverse problem of predicting th e injection sequence in MCIM given a required material distribution in the product. The simulations are validated using experimental results of a co-injected strip with stiffener ribs. Furthermore the effect of a bifurcation of the midsurface on the material distribution is inves tigated numerically using a simplified model based on the local mass b alance.