ELASTOSIL® RT 779 is an advance on ELASTOSIL® 76540, a silicone adhesive which was previously used for bonding both polyamide and aluminum oil pans. ELASTOSIL® RT 779 outscores its predecessor in terms of processing properties, storage stability and resistance to hot engine oil under dynamic loads.
This self-adhesive, condensation-curing two-part silicone rubber boasts a balanced range of rheological properties. It has a high green strength, but thins enough under shear to enable it to be readily processed on two-component mixing and metering equipment. ELASTOSIL® RT 779 also cures rapidly. Even if the container has been in protracted storage, the pot life is just five to ten minutes. Substantial improvements have also been made to the storage stability of the curing-agent component.
The adhesive-sealant provides very good long-term adhesion to aluminum and polyamide, without the need for priming. Just 20 minutes after mounting, the bond is strong enough to allow further operations on the engine and oil pan. This slashes cycle times in the production process. When fully cured, the adhesive has a bond strength far in excess of 0.25 megapascals. As the area of the adhesive surface is several thousand square millimeters, vehicle oil pans bonded with ELASTOSIL® RT 779 can still support a weight of over 100 kilograms after years of service. ELASTOSIL® RT 779 therefore exceeds all the relevant manufacturing specifications on the mounting of such parts.
As a result of the push to make vehicles lighter, more and more engine oil pans are being made from lightweight materials, such as aluminum and plastic. Until now, such components were bolted to the crankcase. The assembly was then additionally sealed with an adhesive-sealant.
Thanks to the new WACKER product, the oil pan can now be mounted and sealed in one operation. This slashes the time needed for mounting. Compared with conventional mounting methods, far fewer bolted joints and drilled holes are needed for the crankcase.
inpro Innovationsgesellschaft für fortgeschrittene Produktionssysteme in der Fahrzeugindustrie mbH, headquartered in Berlin, is a joint venture by the companies Daimler, Volkswagen, SABIC, Siemens and Thyssen-Krupp. Its objective is to drive forward innovations in automotive production and to transfer research results to industrial applications. inpro has about 100 employees who are currently working on developments in joining and materials technology, production testing technology, simulation technology and the digital factory.