PHYSICAL METHODS FOR EXAMINING AND COMPARING TRANSPARENT PLASTIC BAGSAND CLING FILMS

Methods are described which have been developed to allow forensic scie ntists to examine and compare the physical properties of transparent p lastic bags and cling films. These properties range from the character istics of the polymer film to the size, shape and design of the finish ed product. A polarization table, an optical bench providing a shadowg raph and Schlieren image and microscopic techniques were used. Knowled ge of the manufacturing process is needed to assess the observations m ade.