Sponge rubber seals

Unlike cellular rubber, sponge rubber is a mixed-cell, elastic foam based on various rubbers such as CR (chloroprene rubber), NR (natural rubber), NBR (nitrile rubber), EPDM (ethylene-propylene-diene rubber) and other synthetic variants. At Rehm Dichtungen Ehlers GmbH, sponge rubber based on EPDM is available in rolls and sheets.

Sponge rubber seal

Sponge rubber materials available from Rehm Dichtungen Ehlers GmbH

If you need highly elastic material with high restoring forces and good resistance to weathering and ozone as a sealing material or insulation material, you can fall back on sponge rubber based on EPDM. The material is available in sheet and roll form. Due to our different manufacturing processes, you can not only purchase yard goods from us, but also individual products, such as cut-to-size, seals or flat seals or strips.

Sponge rubber EPDM

Import quality, open-pored

Technical data sheet:

Sponge rubber EPDM


Hardness [Shore A] ISO 7619-1 50 35°
Density [g/cm³] ISO 1183 Approx. 0.8
Elongation at break [%] ISO 37-S2 150
Operating temp. range [%] -20° to +70° C

The properties of sponge rubber as a sealing material

When propellant gases are added, the base material rubber is turned into sponge rubber. The surface is smooth, the cells are open on the inside. As a result, the surface is protected against foreign influences and has good sealing properties.
The material is particularly suitable for outdoor use.

The advantages and material properties of sponge rubber at a glance

Depending on the choice of base, sponge rubber made of EPDM has a number of good material properties. In general, the foamed material is excellently suited as a seal, as it adapts to the respective surface conditions and thus seals well. Thanks to its closed, smooth surface, sponge rubber is resistant to moisture. The closed outer skin of the material also results in a very high abrasion resistance. However, if the structure of the outer skin is damaged, the material loses this ability due to the open pores inside. Seals and gaskets made of sponge rubber also have good damping properties and high compressibility.

Other good material properties include:

  • High pressure elasticity
  • good resilience
  • positive cold behaviour
  • Air permeability
  • Ageing resistance
  • High formability
  • Temperature resistance between -40° C and +90° C
  • Weather resistance

EPDM foam rubber is also highly resistant to ageing, ozone, weathering and light, which is mainly due to the EPDM content. A disadvantage is the very poor bondability of the material. Depending on the chosen base material, there are individual, special adhesives that are particularly suitable where no high mechanical or thermal forces act.

Differentiation of sponge rubber seals from cellular rubber

Both sponge rubber and cellular rubber belong to the group of foamed materials. However, both sealing materials differ with regard to some properties and characteristics. While sponge rubber is a mixed-cell material characterised by high pressure elasticity and good resilience, cellular rubber is a closed-cell sealing material. The mixed-cell material requires a closed outer skin in order to function as a sealing material. This is not the case with cellular rubber, as the material is airtight and watertight.

Areas of application for sponge rubber seals

Foam rubber can be used in a variety of ways as a sealing and insulating material and is processed by us, with the help of our various manufacturing processes, in the form of cut-to-size parts, stamped parts or water-jet cut seals. For example, the sealing material is used as a door seal, protective mat, anti-slip mat or insulating underlay. The material also offers a cost-effective solution for sealing large openings in containers, tanks and housings.

We will be happy to answer whether the material is also suitable for your application purposes. Please contact our customer service for comprehensive advice.


What are sponge rubber seals?
Unlike cellular rubber, sponge rubber is a mixed-cell, elastic foam that is manufactured on the basis of various synthetic rubbers.
Can sponge rubber gaskets also be equipped with self-adhesive?
Due to the outer skin, sponge rubber gaskets are difficult to fit with a self-adhesive film. However, this is possible with special adhesives. After finishing, the single-sided self-adhesive sponge rubber sheets are processed into your self-adhesive seals using our various manufacturing processes - water jet cutting, plotting and punching. The primary purpose of the bonding is as an assembly aid.
What are the properties of foam rubber?
Sponge rubber made of EPDM is highly elastic and adapts to all surface conditions. Due to the closed surface structure, the material is weather and ozone resistant and therefore possible for outdoor use.
What resistances do sponge rubber seals offer?
Sponge rubber seals based on EPDM are resistant to ageing, ozone, weathering and light. Furthermore, the foamed material has a temperature resistance in the temperature range between -20 degrees and +70 degrees Celsius.
Which foam rubber is available from Rehm Dichtungen?
At Rehm Dichtungen Ehlers GmbH, we stock EPDM-based sponge rubber in thicknesses from 2 mm to 40 mm as standard.
In which forms can sponge rubber be obtained from Rehm Dichtungen?
Just as with all our gasket materials, we use the material to make you the right gaskets using our various manufacturing processes - water jet cutting, plotting, punching. In addition to the manufactured sponge rubber seals, we can also cut the sponge rubber sheets or sponge rubber strips to the desired length and width. Finally, you can also purchase sheets from us for your own production as yard goods. In principle, all products available from us for this material can also be equipped with self-adhesive on one side to aid assembly.
How does sponge rubber differ from cellular rubber?
While sponge rubber is a mixed-cell elastic foam that is additionally equipped with an outer skin to act as a sealing material, cellular rubber, on the other hand, is closed-cell.
Where is the foam rubber data sheet?
The data sheet for our sponge rubber EPDM can be found in the download area under Service. Alternatively, you can fold out the material in the text above, as the technical data sheet can also be found there.