In recent months we have seen more requirements for Silicone Foam and Closed Cell Silicone Sponge Enclosure Gaskets and Cushioning Pads requiring high strength pressure sensitive acrylic adhesives for bonding to powder coated metal surfaces and certain low surface energy plastics.
Secure lamination of acrylic pressure sensitive adhesives onto silicone rubber is not possible without priming the silicone rubber. Stockwell has developed primers that allow for lamination of 3M Corporations’ 9485 acrylic transfer film adhesive and 9490LE film supported acrylic adhesive onto silicone foam, closed cell silicone sponge and solid silicone rubber.
3M 9485 acrylic adhesive is .005” thick unsupported transfer film adhesive. Its ultimate bonding strength on stainless steel is 150 lbs / inch of width. 9485 withstands high temperature excursions for brief periods up to 400°F, and long term temperatures up to 300°F continuous without slumping or shearing. This adhesive is well suited for thick silicone sponge gaskets on most metal surfaces. Unsupported transfer film adhesives allow for bonding to contoured surfaces and permit forming corner radii using strips of gasketing.
3M 9490LE acrylic adhesive is .0067” thick film supported adhesive. This adhesive is formulated for secure bonding to most surfaces, including many low surface energy plastics and powder coated metal surfaces. 9490LE withstands high temperature excursions for brief periods up to 300°F, and long term temperatures up to 200°F. Film supported adhesive backings provide dimensional stability, which may benefit the assembly of thin-walled gaskets onto some enclosure designs.