Abstract
Keywords - aesthetical coverstock, soft touch, injected technology, automotive interior trim, RIM skins
Today the use of polyurethane systems to produce aesthetical coverstock for car interior applications is experiencing a very rapid growth; reasons for this are both economical and functional. In fact the characteristics of polyurethane (PU) systems allow achieving very appealing targets such as:
- better grain retention if compared to the thermoformed foils;
- better and customized soft feeling if compared with thermoplastic alternatives such as TPO or PVC;
- cost effective solutions if compared with the main thermoplastic options as TPO, TPU and PVC;
- reduced emissions and fogging combined with high mechanical properties and ageing resistance.
Furthermore the possibility to use aromatic polyurethane systems offers a much cheaper and better performing solution if compared to the polyurethane aliphatic alternative. The research made by The Dow Chemical Company brought to the definition of a wide variety of suitable PU systems covering a broad range of hardnesses.
This article covers the most recent developments made by Dow in the definition of a new family of soft touch polymers. These new polymers can be successfully applied with both injected and spray technologies. In particular as far as the injected technology is concerned the final applied density ranges from 1050 g/l to 700 g/l with a wall thickness of 0.8 mm or down to 400 g/l with wall thickness up to 15 mm.
The new soft touch skin technology developed by Dow allows producing in a single shot, parts with different softness degrees depending on the mold thickness. This new technology can be successfully applied to all different types of substrates. If combined with the LDRRIM substrate developed by Dow, it provides 100% polyurethane based automotive interior trim solutions with an integrated soft touch.