ULTRASONICALLY ASSISTED HOT PLATE WELDING OF GLASS FIBER REINFORCED POLYPROPYLENE

摘要

Short glass fibers are commonly added to polymers to enhance their properties. When joining these materials, it is desirable to maintain the enhanced characteristics of the bulk material at the weld interface by orienting the fibers perpendicular to, and across the joint. However, in most conventional plastics welding processes, such as hot plate welding, the glass fibers tend to orient themselves parallel to the weld joint. In ultrasonic (US) welding, mechanical vibrations are used to generate heat via intermolecular friction. These same US vibrations are also used in many other processing functions, including mixing. The concept of using US vibrations to mix glass fibers in a molten polymer was considered as a possible solution for forcing glass fibers to bridge weld joints in hot plate welding applications. An investigation of the morphological and weld tensile strength properties resulting from the incorporation of US vibrations and the hot plate welding process was evaluated.