EVOLUTION OF AN EXCELLENT LIGHTWEIGHTING TOOL - PUR SANDWICH COMPOSITES

摘要

This paper details how polyurethane spray sandwich technology, originally developed for automotive sunshades, has been optimized for use in more demanding automotive applications such as load floors. Polyurethane sandwich construction combines the light weight of a honeycomb core with the high strength of a fiber-reinforced polyurethane skin to produce load-bearing parts with very high flexural stiffness and excellent thermal properties, making it an attractive, lighter weight alternative to acrylonitrile butadiene styrene (ABS), polypropylene, sheet molding compound (SMC) and wood products. Sandwich construction parts can meet OEM-specific specifications for deflection and no permanent set at both room and elevated temperatures. The paper will present information on the deflection performance of different constructions with different systems to guide manufacturers on the best ways to hit specific targets such as cost, thickness or weight. The authors also explain how new formulations enable productivity improvements, including longer open times and shorter demolding times, which facilitate production of larger parts and reduce scrap. By matching core and facing materials, polyurethane spray sandwich construction technology can produce customized parts with the combination of lighter weight and stiffness needed to confidently replace heavier materials.