ExxonMobil Chemical’s Santoprene™ thermoplastic vulcanizate (TPV) 8291-85TL bonds directly to metal to simplify weatherseal fabrication. This grade is suitable for virtually any automotive weatherseal application where metal and TPV surfaces can be joined in a co-extrusion process.
Santoprene TPV 8291-85TL is used as a tie layer between a TPV and the metal portions of a weatherseal. Because of a strong cohesive chemical bond with the metal, it eliminates solvent-based primer and adhesive systems as well as the volatile organic compounds (VOCs) they generate.
Elastomer-to-metal weatherseal applications typically have relied on a combination of thermoset rubber and commercial adhesives to create a bond. Adhesive systems can be complex to apply, generally requiring mechanical cleaning or sand blasting, chemical vapor degreasing, solvent wiping, and masking to prevent excess primer or adhesive, both of which can affect sealing functionality and aesthetics.
“This specialty grade can significantly cut labor costs by reducing the number of steps involved compared with an adhesive bonding system,” said Lisa Dimitrijevs, market manager, automotive weatherseals, ExxonMobil Chemical. “We expect it will create many TPV-to-metal application opportunities.”
Santoprene TPV 8291-85TL creates a consistent bond enabling the manufacture of high quality parts with complex designs. Bonding successfully to cold rolled steel, galvanized steel, stainless steel, aluminum, copper and more, Santoprene TPV 8291-85TL can be used in automotive weatherseal applications including metal supported belt line seals or division bars, lower sash seals and door trim. Other non-automotive applications include sealing devices, grips and sound dampening panels.
The adhesion strength of Santoprene TPV 8291-85TL to stainless steel and aluminum is comparable to using a commercial adhesive system. In tests on finished coextruded profiles, peel strengths of 30 to 55 pounds per linear inch were obtained.
Automotive weatherseal applications benefit from Santoprene TPV because it offers reduced weight, lower system costs, design flexibility and recyclability with the equivalent long-term sealing performance and weatherability of thermoset rubber.
ExxonMobil Chemical is a technology leader in TPV bonding grades and weatherseal systems. It has a broad portfolio of Santoprene TPVs that bond to rubber, plastics and metal, providing innovative multi-functional sealing system solutions.
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