Scratch resistance of plastic parts is important property for automotive interior plastic components. Visible scratched surface will adversely affect aesthetic appearance of the parts.
Scratch visibility of the part is affected by many different parameters. Important ones are material, texture/grain and colour. Scratch visibility was studied on different materials like Polypropylene (PP) (various combinations of talc content), and Acrylonitrile Butadiene Styrene (ABS). The test specimens were made in different materials and with different textures and colours.
The test specimens were scratched at different loads by using Taber Multi finger scratch tester and Erichsen scratch pen. Load at which whitening was observed was recorded. Advance test techniques like image analyzer were used for studying surface appearance and width of scratch.
Since the degree of crystallinity of PP affects the scratch visibility, DSC (Differential scanning calorimeter) study was carried out to identify type of polypropylene used in these compounds. Heat of fusion (J/g) measured by DSC is related to % crystallinity of polypropylene which is known to affect scratch resistance.
Results are discussed for effect of materials, reinforcing fillers, textures and colours on scratch visibility.
Conclusions are drawn and scope of further work is defined.
The data generated and the results are useful as a guideline for improving the scratch resistance of interior automotive trims. The test techniques established are useful for selection of materials, colours and textures for interior trim parts.