Numerical simulation of the multi-component injection moulding process

The versatility of the injection molding process can be increased by combining multiple polymers in one product. The multi-component injection molding process (MCIM) offers the possibility to inject 2 or 3 materials sequentially or simultaneously into a mold to make products that consist of e.g. a layered structure. For a successful application of this technique for geometrically complex products or multiple materials, the material distribution in the product has to be predicted. Numerical tools are described for calcg. the positions of material particles during the flow in the mold cavity. These tools make it possible to solve the inverse problem of predicting the injection sequence in MCIM given a required material distribution in the product. The simulations are validated using exptl. results of a co-injected strip with stiffener ribs. Furthermore the effect of a bifurcation of the midsurface on the material distribution is investigated numerically using a simplified model based on the local mass balanc

VI p (deel 4): Modelvorming en numerieke simulatie van het spuitgieten van reagerende polymeren

A review with 5 refs. Numerical simulation of injection molding of reactive materials may reveal crit. conditions. Calcns. on filling a rectangular mold with polyurethane correspond well with earlier result, except when the gel no. of the material at the end of the mold is high. It was concluded that it is almost essential that optimum process parameters are detd. by numerical simulation when large molds are to be filled with rapidly reacting material