Self-Bonding Liquid Silicone Rubber Technology for Various Rigid Substrates

Liquid silicone rubber (LSR) typically displays superior physical properties relative to other soft or flexible materials (e.g. thermoplastic elastomers), but highly efficient production of rigid parts with silicone rubber over-molded as a flexible coating has been difficult to achieve based on the adhesion characteristics of silicone elastomers. Historically this difficulty has been overcome by incorporating external adhesion promoters and/or mechanical locks into the manufacturing process of the part. Based on recent work, the need for external adhesion promoters or mechanical fasteners has been eliminated by the development of new LSR formulations that exhibit primer-less adhesion to a large variety of substrates. This paper will describe three new self-bonding LSR grades and includes adhesion data for a variety of different rigid substrates used in automotive applications.