Some of the results of an extensive quality improvement program for instrument panels are described. This includes the development of new improved test procedures. An example is given concerning the rheological characterization of the foils at elevated temperatures. The processing conditions are also evaluated. The effect of operation temperature and the choice of tool material for the thermoforming process is demonstrated. Furthermore, the effect of the temperature of the chemical reactants on the foaming operation is discussed.
The ageing characteristics of surface layers as well as padded products are elucidated. The degradation of ABS/PVC foils and sintered PVC is evaluated with respect to foam interaction, thickness of the material and temperature exposure.