Design of a Micro Injection Moulding Machine for Thermosetting Moulding Materials

W. Michaeli, T. Kamps
Institute of Plastics Processing at RWTH Aachen University, 52056 Aachen, Germany
A De Grave, T. Eriksson, H.N. Hansen
Department of Manufacturing Engineering and Management, Technical University of Denmark, 2800 Kgs., Lyngby, Denmark

Abstract

Demoulding micro structured surfaces and micro parts is an important issue in replication of micro technology based components. In this paper a state of the art on ways to improve demoulding of microstructured parts both in polymer moudling and metal injection moulding is presented. The approach is described and simulation methods are shown in relation to previously existing studies. The approach chosen is the investigation of the influence of the demoulding angle on the demouldability of polymer mouldings. The design is based on a number of micro sized cones with different slope angle placed on a flat metal surface. A mould design is proposed and simulated. The design is based on a number of micro sized cones with different slope angle placed on a flat metal surface. A method for characterization of the mould using Laser Scanning Confocal Microscopy (LSCM) and Atomic Force Microscopy (AFM) to verify the slope angle and the straightness quality of the slope is discussed. Initial mould filling simulations using a 2½ D mesh show that a real 3D simulation were performed.

Micro products made of thermosetting polymers enable innovative applications since thermoplastics do not always yield the desired properties: thermosetting moulding grades offer advantages in thermal durability and chemical resistance in comparison to thermoplastic resins. Processing smallest quantities of polymeric material for applications in micro system technology require high process accuracies, e.g. in the volume of plasticised material and injection dynamics. Alternative machine concepts especially designed for micro injection moulding meet these requirements by means of special constructive setups mostly by using a plunger for injection. An appropriate micro injection moulding machine prototype is available at IKV Aachen. A new design of the plasticising and injection unit specially designed for thermosetting moulding materials is presented in this paper.