German chemical firm Wacker says it will be presenting an oil-exuding liquid silicone rubber (LSR) with coolant resistant properties at Fakuma, the 30th international trade show for plastics processing, to be held in October.
Elastosil LR 3822 was specifically designed for applications in the field of e-mobility with a focus on connector seals and sealing elements in the cooling circuit of EV traction batteries. Moulded parts made of the LSR are said to show a low compression set and high resilience. This makes it possible to manufacture sealing elements with high sealing performance.
It also offers processors a wide range of benefits. For example, the crosslinked elastomer continuously releases silicone oil from its surface. This creates a lubricant film that facilitates the machine assembly of moulded parts significantly. The silicone is also extremely durable and tear-resistant. After curing, the silicone rubber can be stretched by 270% without cracks or damage. Another advantage is its superior low-temperature flexibility. The elastomer retains its elasticity even at temperatures as low as –45°C.
The LSR is also the first oil-exuding product that also offers high coolant resistance. Tests show that the silicone maintains most of its mechanical properties even after being stored for 1,000 hours in a glycol-water mixture at 125 °C. This becomes especially evident when examining its compression set. This test records the ability for rubber parts to return to their original thickness after prolonged pressure stresses. With a compression set of 44%, sealing elements made of the LSR have sufficient resilience to ensure a consistently high level of sealing performance in the seal groove during operation. This makes the product the ideal material for elastic seals in the field of e-mobility.
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It has a Shore A hardness of 60, a specification commonly used in the sealing segment. Possible applications include weather packs or sealing elements in the cooling circuit of electric-vehicle batteries.