Nanoscopic control of production tools for the polymer industry

Purpose and goal

The purpose was to develop measurement strategies in order to quantify the surface topography of tool for injection moulding of plastic components. The surfaces were prepared by a new method developed by InMold A/S. With this method, the surfaces are coated by a thin layer of HSQ (Hydrogen Silsesquioxane) which is then heat treated to form a hard, shiny and durable coating of fused silica. The project has led to increased knowledge about the HSQ-coating effects on various surface topographies and how it behaves on different substrates by the tests and surface analysis conducted.

Expected results and effects

The project has led to two conference papers, and knowledge about how the HSQ-layer should be measured and analysed. The preparation method works well for non-structured as well as structured tool surfaces, which generate more reflective plastic surfaces assumed to be hard to reproduce. The latter require a precise surface characterisation based on standardised surface parameters to prove its uniqueness and origin. The process is considered to result in shorter leadtimes and more well controlled injection moulding plastic surface topographies.

Planned approach and implementation

InMold A/S was the project leader. The work to characterise the surfaces has partially been delayed or just not carried out due to process-related factors. The main reason has been crazing (cracked layers) which gave rise to miss-leading measurement results. However, suggestions for measuring strategies have been developed which can be used regardless of the layer quality. Initial tribo-tests, layer thickness and hardness measurements have given promising results regarding the HSQ layer´s behaviour.