New technologies improve plastic/metal hybrids.Two new bonding and material technologies have been introduced to expand the use of hybrid plastic/metal composites for automotive applications. Such hybrids have been made by overmolding stamped sheet metal with injection molded plastic (typically nylon). Up to now, it has been usual practice to mechanically lock the two materials together by injecting plastic through holes in the metal. Bayer MaterialScience Bayer MaterialScience (BMS) is an independent subgroup within Bayer AG. It was created as part of the restructuring of Bayer AG from the former business group Bayer Polymers, with certain of its activities being spun off to Lanxess AG. , Pittsburgh, now says it can improve the joining of hybrid materials by using thermoactivated adhesives based on its Dispercoll U polyurethane dispersions. A 100-micron layer of the water-based PUR dispersion is first applied to the metal insert and dried. Later, during injection molding injection molding n. A manufacturing process for forming objects, as of plastic or metal, by heating the molding material to a fluid state and injecting it into a mold. , the hot melt of the thermoplastic A polymer material that turns to liquid when heated and becomes solid when cooled. There are more than 40 types of thermoplastics, including acrylic, polypropylene, polycarbonate and polyethylene. material activates the adhesive to bond to the plastic. Good initial strength is achieved at 70 to 80 C and a crosslinking reaction ensures final bond strength. Tel: (412) 777-2000 * PTDirect: 468PT Meanwhile, Lanxess Corp., Pittsburgh, is extending the definition of such overmolded "hybrids" by replacing the metal with thermoplastic composite sheet, creating an all-plastic part. Lanxess is working with Bond-Laminates GmbH in Brilon, Germany, which makes Tepex reinforced sheet from glass, carbon, or aramid Aramid fibers are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic rated body armor fabric, and as an asbestos substitute. The name is a shortened form of "aromatic polyamide". fabric embedded Inserted into. See embedded system. in nylon. The sheet is first thermoformed and then reheated to just below its melting point melting point, temperature at which a substance changes its state from solid to liquid. Under standard atmospheric pressure different pure crystalline solids will each melt at a different specific temperature; thus melting point is a characteristic of a substance and before being encapsulated with more nylon via injection molding. Because the sheet is preheated, good adhesion is said to result. Lanxess maintains that the process is economical because tooling investment for thermoforming is less costly than for metal, particularly in small- to medium-size production. Lanxess: (412) 809-1000/PTDirect: 411NZ * Bond-Laminates: +49 2961-96628-0/www.bond- laminates.com [ILLUSTRATION OMITTED] |
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