Ultra-Thin Silicone Rubber Gaskets with Adhesive Backing

Stockwell Elastomerics offers two ultra-thin silicone materials:

• BISCO® HT-6000 – cast liquid silicone rubber (LSR)
• ESS4722 – platinum cured, high consistency rubber (HCR)

Rogers BISCO® HT-6000 Series Silicone Rubber

Stockwell Elastomerics developed the capability to laminate 3M™ Adhesive Transfer Tape 9667MP onto very thin BISCO® HT-6000 series silicone rubber from Rogers Corporation. The HT-6000 series is liquid silicone rubber, cast as thin as .010″ and .020″ thick – which is considered too thin and stretchy for conventional adhesive lamination processes. Utilizing proprietary laminating processes, Stockwell Elastomerics laminates .002″ thick 3M9667MP adhesive onto these thin silicone materials for display gaskets and sealing gaskets used in ruggedized portable devices.

Where Are HT-6000 Ultra-Thin Silicone Gaskets Being Used?

Designers of rugged hand-held and portable devices are challenged to design the units lighter, thinner and capable of passing stringent IP ratings. Thin, sponge gaskets used for dust and incidental moisture cannot effectively seal out water or withstand immersion. In particular, the HT-6210 (10 durometer Shore A) and HT-6220 (20 durometer Shore A) are very soft, providing positive sealing with minimal closure force. The 3M9667MP acrylic adhesive backing adheres to most plastic housings and stamped metals.

Rogers Corporation is well known for casting PORON® cellular urethane and BISCO® silicone foams. A similar technology is used to cast HT-6000 liquid silicone rubber (LSR) in thicknesses including .010″, .020″, .032″, .062″ and .125″ thick. These ‘LSR’ silicones are platinum cure grades, known for their purity and resiliency. See the chart below for the properties of these materials.

BISCO® HT-6000

* The 3M9667MP acrylic adhesive is also clear

ESS4722 Series Platinum Catalyzed HCR Solid Silicone

Stockwell Elastomerics has developed the ESS4722 product family of ultra-thin platinum cured solid silicone, designed to maintain higher tensile strength and higher tear strength compared to traditional silicone foam or sponge material. This material comes in a 20 and a 30 durometer option for applications that require low closure force as well as a nonoptically clear, translucent, 40 durometer option. Due to this series being a platinum catalyzed high consistency rubber (HCR), its low durometer options display low oil secretion.

Stockwell Elastomerics offers this material in 36″ widths at continuous lengths. Standard thickness options range from 0.010″ to 0.125″ with different thicknesses available upon request. Pre-production and full production parts made from ESS4722 series material can be waterjet cut or die cut, with or without an adhesive backing.

ESS4722

* The 3M9667MP acrylic adhesive is also clear

3M™ 9667MP Adhesive Backing

3M™ high performance acrylic adhesive 200MP is selected for ultra-thin gaskets because the .002″ thick 3M9667MP adhesive does not add excessive thickness to the design stack-up. This adhesive provides excellent adhesion to metal and high surface energy plastics. Despite being an unsupported transfer film adhesive, 3M9667MP provides some dimensional stability and initial repositionability for placement accuracy when bonding the ultra-thin silicone gaskets onto plastics. The 78# polycoated Kraft paper release liner is moisture proof to withstand water jet cutting, and relatively thick (.0057″) for kiss cutting using die cutting and flash cutting processes.

BISCO® and PORON® are registered trademarks of Rogers Corporation.
3M™ is a registered trademark of 3M Company.