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Capability of Scratch Testing − A View on the Influence of Injection Molding, Water Absorption, and Blend Systems of Polymeric Materials
Author(s) -
Moneke Martin,
Seeger Philipp,
Stengler Ralph
Publication year - 2019
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201800176
Subject(s) - indentation , materials science , composite material , scratch , thermoplastic polyurethane , molding (decorative) , brittleness , thermoplastic , enhanced data rates for gsm evolution , elastomer , telecommunications , computer science
Scratch tests have been performed on a set of different ductile and brittle thermoplastics to investigate the influence of injection molding, water absorption and blending on the indentation depth during scratching and hence the scratch resistance. For the measurements a universal surface tester (UST) has been used which allows to control the normal force between 10 and 1000 mN and the velocity between 0.01 and 2.5 mm/s during scratching while at the same time measuring the indentation depth with a sub‐micron resolution. It could be shown that the water uptake of polyamide 6.6 (PA6.6) doubles the indentation depth from approx. 10 microns to approx. 20 microns within the first 2 h. The indentation depth also strongly correlates with the position of measurement on an injection molded plate. Near the gate, the indentation depth measured in processing direction is always higher than at a position far from the gate. Similarly the indentation depth always is higher at the center compared to at the edge of the plate. For amorphous thermoplastics this surface anisotropy can be explained by the molecular orientation resulting from the flow and cooling processes during injection molding. When blending poly(methyl methacrylate) (PMMA) with thermoplastic polyurethane (TPU) the indentation depth increases with increasing TPU content. Overall, scratch testing proves to be a quick and easy tool to investigate surface related effects in plastics engineering and polymer science.