DescriptionOpen cell polyurethane foams can be used as storage material for ink in a stamp. The ability of the foam for ink storage and release are determined by the morphological structure, the mechanical properties and the polymer material. Important parameters are the homogeneity of the ink distribution within the foam reservoir since this has influence on quality of stamping. Usually a layer is mounted on top of the reservoir to improve the stamp image. 3D methods have been applied already to investigate cell morphology of cellular materials non-destructively. X-ray computed tomography has shown to be a suitable technique to determine pore size distribution, particle location or input data for mechanical simulations. Also in-situ deformation testing under pressure has been performed while CT scanning to learn about the mechanisms of mechanical deformation. In this study the distribution and storage behaviour of ink in different polymeric foam materials will be investigated. CT scans are performed using a sub-µm-CT device at resolutions of a few microns per voxel. Scanning time for such a system at the required resolution usually is up to two hours. The procedure of ink penetration after application is a finished in a few seconds. To be able to visualize the penetration itself it is necessary to reduce scan time. This decreases image quality and induces artifacts into the CT-data. Nevertheless it is possible to get information about the penetration depth and the long term behaviour of ink storage. Another possibility is to analyse projection images instead of 3D volumetric images. An automatic application of ink inside the CT scanner ensures that the imaging starts before ink penetration. An important role plays the way how the polyurethane foam and the top layer are joined together. Different ways of joining will be applied and results of the 3D analysis generated. A correlation between cell morphology of different polymeric foams and ink penetration speed, depth and 3D distribution will be determined.
|Period||13 Sep 2011|
|Event title||Euromat 2011: null|