Prototype tooling for producing small series of polymer microparts

Layer-based manufacture of three-dimensional functional models and concept prototypes play a crucial role in the early assessment and verification of product designs. Any change of design, which is frequently needed during product development, causes the development costs to rise significantly. However, there is a limited set of materials available for layer-based manufacturing, especially for producing polymer microcomponents. Therefore, for fabricating small batches of microcomponents in the required material it is necessary to develop rapid tooling process chains, e.g. for low-pressure injection moulding. This paper investigates the moulding performance of µSL inserts as a function of tool geometry in combination with the effects of process factors. Condition monitoring techniques applied to the µ-IM process have been carried out to provide information that can be used to optimize the process. It was found that small batches of parts with fine details and relatively high aspect ratio structures can be produced and that reduced pressure loads and in particular the decrease of the µSL inserts layer thickness can extend the tool life.