Wacker presents coolant-resistant silicone at Fakuma

Wacker will present Elastosil LR 3822, an oil-exuding liquid silicone rubber with coolant-resistant properties, for the first time at Fakuma, the 30th international trade show for plastics processing. The material was developed specifically for e-mobility applications, with a focus on connector seals and sealing elements used in the cooling circuits of electric-vehicle traction batteries. Molded parts produced from the new liquid silicone rubber combine low compression set with high resilience, properties intended to support consistent sealing performance. Elastosil LR 3822 has a Shore A hardness of 60, a specification commonly used for sealing applications. Potential uses include weather pack connectors and sealing elements exposed to operating conditions in battery cooling systems.

Oil release supports automated assembly

After crosslinking, the elastomer continuously releases silicone oil from its surface. The resulting lubricant film facilitates the automated assembly of molded parts. According to Wacker, the silicone is also durable and tear-resistant. Once cured, it can be stretched by 270 percent without cracking or sustaining damage.

The material also retains flexibility at low temperatures. Its elasticity is maintained at temperatures down to -45°C, which is relevant for seals exposed to changing thermal conditions in vehicle applications.

Resistance to glycol-water coolant

Elastosil LR 3822 is Wacker's first oil-exuding liquid silicone rubber that also provides high coolant resistance. Tests showed that the material retained most of its mechanical properties after storage for 1,000 hours in a glycol-water mixture at 125°C.

The results are particularly reflected in the compression set, which measures the ability of a rubber component to return to its original thickness after prolonged compressive stress. Elastosil LR 3822 recorded a compression set of 44 percent. According to the company, this gives sealing elements sufficient resilience to maintain a consistently high level of sealing performance in the seal groove during operation.

Close-up of Elastosil LR 3822 glycol test

Self-adhesive silicone for hard-soft composites

At Fakuma, Wacker will also showcase Elastosil LR 5471, a self-adhesive silicone rubber that does not require thermal post-curing. The product cures into a silicone elastomer with an extremely low volatile content. This enables hard-soft composite components to be used in food, medical and baby-care applications without thermal post-treatment.