Unique Adhesive Cuts Costs for Plastic Oil Pans
Removal of screw joints saves 20-25 percent per oil pan
Doug Smock, contributing editor -- Design News, 2010-01-28 13:31:49 EST
A unique government-industry research consortium in Germany is producing interesting
new materials technology, including a new silicone adhesive sealant for rapidly
emerging plastic oil plans.
The new adhesives replace solid gaskets, further extending the significant weight savings (around 40 percent) offered by injection molded pans, which have been under development in the U.S. and Europe for more than 20 years, but are just now breaking through into major production models.
DuPont and BASF have been leaders in developing plastic oil pans, and both companies have developed specialized grades of engineering plastics to meet the demand.
"Our selection of a particularly high-melt flow grade of Zytel nylon resin meant that we were able to manage the long flow distances at a comparably low injection pressure and despite some very low wall thicknesses," says Ralf Franz, development engineer at ElringKlinger, a German auto supplier.
Ford Motor is now using the first plastic oil pan designed for full exposure to the road environment and optimized to withstand road chemicals and stone impacts. A special waffle-design ribbing pattern can take multiple impacts unlike earlier plastic designs with sacrificial ribs.
BASF joined with Wacker in a Berlin-based research imitative called INPRO to develop an adhesive so strong that the integrity of the oil pan seal with aluminum engine blocks works under all common testing conditions. The tests included storage in oil and in a blow-by medium (a condensate found in the crankcase of gasoline engines) and thermal shock tests between temperatures of -40 and 150C.
Removal of the solid gasket and a number of screw joints translates into cost savings of 20 to 25 percent per oil pan. Importantly, the flange geometry is free of stresses. Compressive forces can develop when using a vulcanizable sealant that is formed in place.
The RTV-2 liquid silicone rubber can be easily machine applied, cures at room temperature, and has excellent resistance to oil, heat and blow-by gases. With its outstanding adhesive and sealing properties, this rubber grade will allow innovation in engine design. Its strength derives from an inorganic backbone that gives silicone elastomers not only greater heat resistance, but also better resistance to weathering, aging and chemicals than organic polymers.
INPRO Innovation Society for advanced production systems in the automotive industry is a joint venture between BASF, Siemens, ThyssenKrupp, Daimler and Volkswagen. Founded in 1983, the government of Berlin is also a partner.
Areas of focus are:
- Process simulation,
- Production systems and information processes,
- Manufacturing and automation technology, and
- Coatings and composite technologies.