WACKER Launches ELASTOSIL LR 3822 to Ease EV Battery Coolant Seal Assembly
The new liquid silicone rubber continuously releases oil to reduce friction during automated assembly while resisting coolant degradation.
German chemicals maker WACKER has introduced ELASTOSIL LR 3822, a new liquid silicone rubber designed specifically for connector seals and sealing elements within the cooling circuits of electric vehicle traction batteries.
What Happened
WACKER describes ELASTOSIL LR 3822 as the first oil-exuding silicone rubber product that also resists coolant. The cured elastomer continuously releases silicone oil from its surface, creating a lubricating film on the molded part. This feature addresses a common manufacturing hurdle: silicone rubber has a high coefficient of friction, making dry seals difficult to feed, position, and press home on automated assembly lines. The oil bleed eases this machine assembly process.
The material demonstrates durability under harsh thermal conditions. According to the company, samples stored for 1,000 hours in a glycol-water mixture at 125° C retained most of their mechanical properties. After this exposure, the compression set measured 44%, a metric WACKER states leaves sealing elements with enough resilience to maintain high sealing performance in the seal groove. The product page rates the grade’s compression set in contact with coolant fluids as extremely low.
Technically, compression set records how much of its original thickness a rubber part recovers after prolonged compression. In hot glycol-water circuits, a seal that takes a permanent set loses the contact pressure necessary to keep joints tight. Groove designs rely on the elastomer staying squeezed against both sealing faces for the life of the battery pack.
Why It Matters
For EV manufacturers, this development targets efficiency in battery production and long-term reliability of thermal management systems. By reducing friction during assembly, the new material could streamline automated processes for battery connector seals, which are critical for maintaining coolant integrity in traction batteries. The specification of Shore A 60 hardness is noted by WACKER as commonly used in the sealing segment, while the material’s ability to stretch by 270% without cracks and remain elastic at temperatures as low as -45° C supports its use in varied environmental conditions.
The product is supplied as a paste-like two-component compound mixed in a 1:1 ratio. WACKER’s product page indicates a minimum pot life of three days at room temperature for the mixed components, along with reduced volatile content and short curing times. Applications named include battery coolant connectors, molded automotive seals, radiator-system gaskets, and weather packs.
The Bottom Line
WACKER’s ELASTOSIL LR 3822 offers a specialized solution for EV battery cooling circuits by combining oil-exuding lubrication with coolant resistance. The material is available in 20 kg pails and 200 kg drum kits, aiming to improve assembly ease and sealing durability in electric vehicle traction batteries.
