High resolution X-ray computed tomography of fibre and particle filled polymers

X-ray computed tomography (XCT) provides a volumetric map of a specimen in three dimensions, generated from a set of radiographs. Due to the speed and quality of measurement, XCT systems with cone beam geometry and matrix detectors have become widely used. Continuous improvements in the quality and performance of Xray tubes and devices have led to cone beam XCT systems which can now achieve spatial resolutions down to 1 μm and even below. We report on the application of high-resolution X-ray computed tomography for the characterisation of various fibre-reinforced and particle fibre-reinforced polymeric materials. Due to their specific and outstanding properties for, for example, lightweight or packaging materials, they are widely used in the automotive, aeronautic, electronics, building, textile and leisure industries, as well as in medicine and agriculture. Fillers (particles and fibres) can be classified as inorganic, cellulose and polymeric fillers. We compare the different polymeric material systems and discuss the advantages and limitations of XCT for the characterisation of these systems. Due to varying density differences the contrast between the fibres and the polymeric matrix can be very good with, for example, glass- or talcum-reinforced polymers, or rather poor, as in the case of polymeric fillers within a polymeric matrix. Quantitative data can be extracted from the XCT-data. By applying various 3D-filters the following quantitative information and values can be extracted from the XCTdata: - filler percentage - 3D-geometry of the fillers (diameter, surface, volume) - fibre length distribution - fibre orientation (orientation tensor) - 3D filler distribution - filler interconnectivity