Experimental and Numerical Studies on the Deformation of a Flexible Wire in an Injection Moulding Process

Abstract

The application of thermoplastic materials is state of the art due to their fast cycle times in production and large freedom of shaping. To enhance the performance and functionality, additional materials or elements are embedded into the bulk material. While typically fibres are added for mechanical reinforcement, recent research also focusses on the integration of conductor wires to integrate electrical functions. During the manufacturing process, the interaction with the thermoplastic melt can lead to breakage or undesired deformation of the flexible elements respectively wires. For a proper process and component design, this local fluid-structure-interaction must be understood and considered. There are different numerical approaches to meet this challenge. In the present work, the suitability of established modelling techniques and solvers is evaluated and compared with experimental investigations. For this purpose, solid flexible wires are overmoulded with polypropylene using an injection moulding testing set-up. In the experimental investigations, the deflection of the wire is evaluated for different process settings. For the numerical simulations, solvers from ABAQUS and Moldflow including the Wire Sweep Module and the Core Shift Module are used. The comparison of the simulations and the experiments shows, that the different solver’s results clearly deviate from each other and the experiment depending on the wire length. While some approaches seem to be very promising, it can be concluded that the longer the wire, the worse the simulation quality.