In addition to plastic technologies for reducing weight of car bodies, Dow Automotive has developed a novel bonding system for the structural bonding of aluminium roofs with steel car bodies. The new system uses BETAMATE™ 2-component PU adhesive technologies for bonding roof systems and car body in new BMW 7 Series. As per the company, this effective for both lightweight constructions and mounting processes, important factors for the hybrid construction of materials where significant weight reduction advantages only come into play through use of a combination of materials.
As against the presently used adhesive systems, the new 2K PU adhesive based bonding system is flexible enough to offset the different expansion coefficients of steel/aluminum combination while guaranteeing the necessary structural system stability at even higher temperatures, says the company. This benefit, the company says, is facilitated by the improved glass transition temperature (Tg) of the new 2-component (2K) PU adhesives. Together with BMW, Dow Automotive developed an improved 2K technology based on its BETAMATE 2K PU adhesive range which marks the first time a 2K bonding system has been directly used on the assembly line to assemble an aluminium roof module.