For successful sealing in enclosure and gasket design, material selection is critical. A gasket’s primary task is to protect components and prevent failures and unplanned maintenance. Compressibility, environmental exposure, sealing effectiveness and specifications should be considered when selecting a material for gasket seal design. Effective sealing and gasketing materials must be able to withstand the effects of compression, manage damaging impact energy and seal out dust and particulate matter. Rogers offers a portfolio of high performance sealing and gasketing solutions that are highly compressible and conformable while resisting compression and stress relaxation. These unique materials effectively seal out dust, water and other contaminates for the life of the product.
Assembled housings or enclosures must ensure adequate gasket compression to provide the required level of seal. This compressibility enables the load to remain within required limits while accommodating a larger range of compressions. The seal or gasket needs to conform specifically to its surfaces, whether an aircraft, automobile or industrial enclosure. If the gasket leaks requires replacement, enclosure certification can be lost, resulting in lost time and increased expenses in addition to the damage incurred to the components. PORON® Polyurethane and BISCO® Silicone foams are highly compressible and conformable, effectively sealing for the life of the product. Both are available in a wide range of firmness and thickness options to ensure robust sealing design.
A significant factor in long-term sealing durability is the ability of the material to resist compression over time. Choosing materials with excellent Compression set (C-Set) retention helps keep a consistent closure force on a door or panel, creating a more durable seal. C-Set resistance is the ability of an elastomer to return to its original thickness after a compression load, under a specified time and temperature, is released. If a gasket takes a significant C-Set, sealing may be compromised due to the decreased thickness. This loss of thickness normally takes place over time and is not always evident during initial testing. PORON® polyurethane, BISCO® silicone and Griswold® cellular rubber materials provide excellent resistance to compression set, exhibiting excellent physical properties and sealing characteristics for the life of the product.
Environmental Considerations
Addressing environmental considerations -- outgassing, chemical and solvent resistance, temperature load, flammability and sealing standards -- can be a challenge when creating a successful seal or gasket. Both PORON® Polyurethanes and BISCO® Silicone foams are low-outgassing, non-fogging and contain no plasticizers or residual chemicals to contaminate devices. The materials will not become brittle and crumble and are non-corrosive to metal.
Aircraft Specifications - Aircraft are subject to some of the most stringent specifications in the transportation industry. All seals must meet Federal Aviation Regulations (FAR) flammability. BISCO® silicones reliably meet various FAR specifications and are specified to many OEM material specifications including Boeing and Airbus. Rogers is AS9100 certified and has been awarded multiple Boeing supplier Performance Excellence Awards.
Automotive –PORON® Urethanes and BISCO® Silicones are certified for use under several standards, including UL-508 (industrial control equipment), UL-1572 (HID lighting fixtures) and especially UL-50E (electrical enclosures), with testing done to the new periodic recompression standard. PORON cellular urethane products also meet environmental standards’ requirements for UL 50E electrical equipment, UL 508 industrial control equipment and UL JMST2 gasketing.
Enclosures Specifications - Seals must be resistant to temperature extremes and meet industry regulations.
Rogers’ specialty materials meet or exceed automotive specifications for flame resistance (FMVSS302), fogging (SAE-J 1756), Ford WSS-M2D496, Ford WSL-M99G163, General Motors GMW14196, General Motors GMW16392, Chrysler MS-AY549 and Chrysler MS-AY-556.Flammability & Sealing Standards - Rail cars are subject to very stringent specifications that are enforced by many national governing bodies of rail. Components used within the railcar must meet specific Flame, Smoke and Toxicity requirements depending on its usage and location. BISCO® silicones meet various national rail standards including NFPA 130 (US), BS 6853 (UK), DIN 5510 (Germany), EN 45545 (Europe) and NFF 16-101 (France).Rail Fire Safety Standards - Many PORON Urethane foams meet the flammability requirements of UL HBF and MVSS 302. In addition, PORON cellular urethane products meet environmental standards such as UL JMST2 gasketing, AMS 3568 Corrosion Resistance and ASTM G53 UV Resistance requirements.
