Submitted to: Journal of Environmental Polymer Degradation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 28, 1996
Publication Date: N/A
Interpretive Summary: Synthetic polystyrene loose-fill foam usually clings to the products packaged in this protective material. This annoying static cling does not occur when protective starch-based loose-fill foam is used. To quantify these observations, the electrical resistance characteristics, particularly specific surface resistance and static decay properties of commercial starch-based and expanded polystyrene foam products, was measured accordin to established electronic industry testing standards. The results show that polystyrene foam is an insulative material that easily builds up static charge, and starch foam, such as ECO-FOAM, is a static dissipative material that prevents the build up of static charges on the material surface. These properties are strongly influenced by water content and the structure and chemical composition of the starch in the loose-fill product.
Technical Abstract: The insulative character of expanded polystyrene loose-fill packing material supports the immobile triboelectric charge on its surface, causing static cling. One beneficial property of starch-based loose-fill is its antistatic behavior that prevents the build up of electrostatic charges on the foam surface, resulting in non static cling. This investigation explores the electrical resistance characteristics of plasticized starch materials such as commercial loose-fill. Electrical resistance standards used in this study to measure surface resistance and static decay properties are ASTM D 257-78, EOS/ESD S-11, and EIA 541. Following these established testing protocols, the electrical resistance of starch-based and expanded polystyrene loose-fill are quantified. Surface resistivity, measured at 12% r.h., of starch-based loose-fill products is less than 1.0 x 10**12 ohms per square characteristic of inherently static dissipative materials.