Internal adhesion promoters allow a rigid thermoplastic or metal component to be overmolded with the silicone rubber. In suitable applications, the process can eliminate separate substrate surface treatment and simplify high-volume production.

In company testing, the material achieved adhesion strength of 28 N/mm on PBT under ISO 813. WACKER reported comparable performance on PET. Those results are supplier-generated and should be confirmed using each processor’s substrate, molding conditions and component design.

WACKER reports a specified volatile content below 0.4% in its compliance testing and says molded parts can meet recommendations from Germany’s Federal Institute for Risk Assessment for silicones used in food-contact applications without a separate production postcure.

The company reports elongation at break of up to 570% and tear strength of 38 N/mm under ASTM D624 B. Intended applications include cookware gaskets and scrapers, medical-mask liners, therapeutic devices and soft components for pacifiers and baby bottles.

ELASTOSIL LR 5471 is an addition-curing, two-component material available in Shore A hardness grades of 40 and 50. It is intended for overmolding and co-molding processes.

WACKER will present the material at FAKUMA 2026, scheduled for Oct. 12–16 in Friedrichshafen, Germany.

Learn more about the self-adhesive liquid silicone rubber.

The material is relevant to PCI readers following adhesives and sealants and technologies that combine substrate adhesion, elastomer performance and simplified component processing.