Abstract
The current veneering process for interior trim components in the premium car segment involves the use of aluminium or polymeric substrates with thin wood veneers hot embossed to the surface using thermoset adhesives. The alternative process of back injecting real wood veneers with engineering polymer materials is considered here. The main aim of this work was to trial a number of engineering polymeric materials in a simple geometry component. In addition the basic adhesion and dimensional performance was also assessed.
Five engineering polymers were selected and trialled for this process. A cross-section of the parts made were tested to an adhesion delamination test (DIN 53255), all of which passed the test successfully. Dimensional analysis of the mouldings show there is a distinct relationship between component distortion and the shrinkage value for that material, at both post injection moulding and post cooling.
A relationship between the veneer and low polymer shrinkage was shown. The blend polymer, PA + ABS with 15% glass filler performed ideally with dimensional data. This material had the lowest measured shrinkage value of 0.15% and produced the flattest test samples.
The worst dimensionally performing material with veneer was PA 66; which produced dimensional readings approximately three times worse than the PA + ABS 15% GF. This correlated with the polymer shrinkage values for this polymer being the highest recorded from this series of experiments.