MICROWAVES FOR RASTER IMAGING OF LOCAL ANISOTROPIES IN POLYMER MATERIALS

Local anisotropies in polymer parts result from orientation effects of molecular chains, short fibers, or imbedded particles. These anisotropies determine the mechanical behaviour of the materials for different directions [1]. In the case of fiber reinforced polymers the strength depends on fiber orientation with respect to the applied stress direction. If one stress direction predominates, the fibers should preferably be aligned to it. But also shrinkage, e.g of molecular polymers, depends on material anisotropies. Therefore it is really important and of high industrial relevance to characterize the local orientation in polymer materials in a fast and nondestructive way.