Simulation and optimization of vulcanization in the adhesion area in a 2K Thermoset-Thermoplastic product

Two component (2K) injection molding of thermoplastics is a well-known technique to obtain products that consist of two parts in different thermoplastic materials, each with specific properties, for example a stiff core with a soft rubber sealing. In many cases a thermoplastic elastomer is used for such a sealing. The be-havior of this thermoplastic materials and the injection molding of such a two component product can be predicted very well. However, for various applications, an elastomer cannot meet the required properties, such as resistance to acids or mechanical loads. In that case a thermoset rubber would be preferred. For such combinations, not much is known about the vulcanization quality of the rubber part in the adhesion zone. In this paper a PE-EPDM combination is investigated. Typical simulation software packages such as Autodesk Moldflow, do not provide a tool to predict the flow and curing of the thermoset in a 2K situation. However, with some modifications, it is possible to predict the temperatures and degree of vulcanization in function of time in and around the adhesion zone. This allows to optimize the mold and the process parameters to obtain a well vulcanized product on a thermoplastic product.status: publishe