Adhesive-Backed (PSA, Peel-and-Stick) Gasket Material

What peel-and-stick adds, and what it does not

A PSA lamination holds a sponge, foam, felt or thin rubber gasket on a door, lid, panel or housing while the assembly closes, and keeps it from falling out when the cover comes off for service. It is not the seal. The compressed gasket seals, and the adhesive only keeps it in place, so a gasket that leaks with adhesive leaks without it. The adhesive is put on by the sheet maker, and the gasket is cut from the laminated sheet with the liner still on.

The base sheet usually limits the gasket before the adhesive does. The cited acrylic holds 149 C long term and 204 C short term on steel [S1], but a neoprene sponge gives up long before that, so read the base sheet's own page for the service range. Where the base sheet runs hot or cold, silicone sponge with a silicone PSA is the usual pairing.

The three adhesive families

Every PSA on a gasket sheet is one of three chemistries, and the choice follows the base sheet and the surface it sticks to. Acrylics are the workhorse: they age well, resist solvents and heat, and bond to metals and most plastics. Rubber-based PSAs grab hardest at first touch and cost least, but age and soften with heat, so they suit temporary placement rather than long service. Silicone PSAs bond to silicone sheet, which nothing else holds, and serve the widest temperature span of the three families [S2].

Transfer tape, film-supported tape and foam tape

A transfer tape is adhesive alone on a liner, so the gasket keeps all of its flexibility; it is the usual lamination on foam and sponge. A film-supported (double-coated) tape carries the adhesive on a thin polyester film, which stops a soft, stretchy cut gasket from distorting as the liner comes off and holds its shape on installation. An acrylic foam tape is itself a soft, conformable core with adhesive on both faces, used where the tape must fill a gap as well as hold. The print names the construction when it matters; otherwise the sheet maker's standard lamination is quoted.

Surface energy and the silicone rule

PSA bonds by wetting the surface, so the surface decides the bond. Bare aluminum, steel and copper and most engineering plastics carry a surface energy above about 40 dynes/cm and take the general-purpose acrylics [S2]. Many powder-coated housings and the slick plastics, polyolefins and fluoropolymers among them, sit below that and need a low-surface-energy acrylic or a primer. Silicone sheet is the other trap: an acrylic PSA does not hold on silicone, so silicone sponge and solid silicone gaskets get a silicone PSA or an acrylic-silicone combination that presents acrylic to the metal and silicone to the sheet [S2]. Clean, dry surfaces and firm pressure at application matter as much as the adhesive; the 3M sheet reports the peel bond on steel still rising from 15 minutes to 72 hours of dwell [S1].

Ordering and cutting

Say which face gets the adhesive, or draw it, and name the tape if the print does. Adhesive-backed sheet is cut on the waterjet with the liner on, so each part arrives ready to peel and place. Kiss-cut parts that must stay on a continuous liner for hand or machine placement are not a waterjet job; they are cut by a converting partner and quoted from the same drawing, so say so on the request.