Below is a brief introduction to some of the features and benefits of each category of foam. For more information, please contact us. A Marian sales representative would be more than happy to help customers determine the correct foam or sponge for their gasket application.

Silicone Sponge

• Maintains its flexibility across a wide temperature range (-50°C to 200°C).
• Superior flame resistance; low flame, smoke, and toxicity upon combustion.
• Resists environmental extremes like UV and ozone.
• Resilient to mechanical fatigue.
• Superior resistance to compression set and creep.

Recommended Products
Bisco Silicone Selection Guide

High Density Microcellular Urethane (Poron)

• Excellent compression set resistance, which enables durable and long-term performance for gasketing and sealing.
• Low outgassing and non-fogging features. Good resistance to many chemicals. Material does not become brittle and is non-corrosive to metal.
• Performs well over broad temperature ranges (-40ºC to 90 ºC).
• Flame retardant without the use of additives. Many materials meet flammability requirements of UL HBF and MVSS 302.
• Broad range of formulas and thicknesses.
• Thickness limitation of up to .500″

Recommended Products
Poron Selection Guide

Closed Cell EPDM Sponge

• Non-crystalline material. Contains no plasticizers that can migrate and lead to premature membrane failure.
• Can be formulated in a variety of combinations with other polymer modifiers.
• Performs well in the -40ºF to 175°F temperature range.
• Used in many applications that require water, UV, ozone, or indirect sunlight resistance (superior to neoprene in this regard).
• Does not meet UL flame rating without additives and will not withstand oil and fuels.

Closed Cell Neoprene Sponge

• Resists light oil contact, ozone, alkalis and acids.
• Generally serviceable from -40°F to 158°F continuous and can withstand 200°F intermittently.
• Good choice for general enclosure door gaskets.

Closed Cell Sponge Blend

• Produced from a blend of neoprene, EPDM, and SBR.
• Serviceable down to -70°F without cracking due to cold embrittlement.
• Normally meets UL94HF-1 flammability requirements.
• Oil resistance not as good as 100% neoprene sponge products.
• Good choice for general purpose sponge gaskets.

Light Density Polyester/Polyurethane Sponge or Foam

• Wide range of flexibility and rigidity.
• Often used for insulation.
• Thermoplastic polyurethane is commonly used in medical devices.
• Flexible polyurethane is sometimes used in automotive interiors.

XLPE or Cross-linked polyethylene

• Closed-cell, inert, stable, and lightweight.
• Low outgassing if punctured and compressed (the gas given off is air).
• Decent barrier qualities: thermal insulation and water permeation.
• Does not promote the growth of bacteria or fungus.
• Exposure of XLPE to salt water will have little effect on its properties.
• Cost-effective solution to many cushioning and sealing needs.

PVC (Vinyl) Foam

• Closed cell structure seals out air, moisture, light and dust when compressed at least 30%.
• UV resistant and resists most chemicals, acids, and solvents.
• Service temperature range of -40°F to 200°F.
• Inherently fire resistant.