Federal-Mogul Corporation has developed a novel elastomeric material, called K16, that eliminates a costly and energy-intensive curing process used throughout the industry. Federal-Mogul’s first application of the new molding technique eliminates the oven post-cure process from the production of elastomeric seals for UNIPISTON bonded hydraulic clutch pistons.
This enables the company to reduce the environmental footprint of its manufacturing operations with significant reductions in CO2 emissions and natural gas consumption. Federal-Mogul believes it is the first company to develop such a system for manufacturing high-performance-rubber products.
UNIPISTON bonded pistons convert hydraulic pressure into the mechanical force needed to engage clutch packs in automatic and dual-clutch transmissions. The production of bonded piston seals has required that the parts are baked, or cured, in an oven for up to 12 hours at approximately 175 °C. By eliminating the oven post cure process, Federal-Mogul calculates that the annual natural gas consumption at its Frankfort, Ind., plant alone will decrease by 40 billion BTUs and prevent nearly 2000 tons of CO2 emissions from entering the atmosphere annually. This reduction in energy use is equivalent to the energy used by approximately 370 average single-family detached homes in the United States for an entire year.
The finished K16 seal meets or exceeds the performance of previous seals both in terms of wear resistance and life expectancy and is based on proven long-chain elastomers.
According to Federal-Mogul’s global director Sealing Technology and Innovation, Larry Brouwer, the company intends to expand K16 technology for other product applications such as gaskets for oil pans or valve and engine covers or virtually any other sealing application.
Elastomers are normally formed by cross-linking millions of polymer molecules through vulcanization, which is traditionally carried out in two steps. In the first step, known as press cure, the elastomeric compound is forced into a mold that defines the desired shape. In this step, vulcanization is initiated by subjecting the compound to heat and pressure. Until now, the second step of vulcanization occurred during oven post cure, during which the compound is kept at a constant, elevated temperature for an extended period of time.
Federal-Mogul’s search for more environmentally friendly processes led us to a combination of polymer chemistries and press cure conditions that produced the right elastic properties without energy-intensive curing or the use of expensive rubbers. We developed a process monitoring and control system that adjusts the press cure time to compensate for any variation in temperature or material characteristics. This is the key to stabilizing the cross-links between the polymers without a post-cure stage.—Larry Brouwer
The successful introduction of K16 on the company’s UNIPISTON product range is in production for several major OEMs. Plans are underway to integrate this at Federal-Mogul facilities around the world.