Semi Open Cell EPDM Sponge Washers

Semi Open Cell EPDM Sponge Washers

Semi Open Cell EPDM Sponge Washers

Here at Advanced Seals & Gaskets Ltd we manufacture and supply 1000’s of washers produced from a variety of EPDM sponge materials, in various densities, grades and in various different products cut from the material, including semi open cell EPDM sponge washers. 

One of the EPDM sponge grades we can offer is semi open Cell EPDM sponge, sometimes also called semi closed cell sponge or semi-open cell foam. This material is manufactured in block form, which we can split down into sheets or join together and then split to produce continuous lengths or rolls of materials in thicknesses starting at just 1.5mm from which semi open cell EPDM sponge washers can be cut.

Semi open cell EPDM sponge washers are manufactured on-site using drawings or measurements provided by our customers, with whom we work closely to ensure the final product is to their exact specification.  Depending upon the size and quantity of semi open cell EPDM sponge washers required, one of many presses or CNC machines can be used to manufacture the final product - from one-off samples to multiple thousand batches runs, we have a machine designed to quickly and accurately produce perfectly formed semi open cell EPDM sponge washers every time.   

On-site conversion facilities mean we can stock and supply rolls and sheets ready for despatch or use them to further convert into multiple usable finished parts including semi open cell EPDM sponge washers - all supplied plain or laminated with a choice of one of our many self-adhesives or foils.

What are Semi Open Cell EPDM Sponge Washers?

Semi-Open Cell EPDM is an extremely soft and flexible grade of EPDM sponge rubber, still manufactured from the chemical components Ethylene Propylene Diene Monomer, but using a different manufacturing process to create the mixture of open and closed cells throughout the material. 

The cell structure of Semi-Open Cell EPDM is created in the manufacturing process by physically "bursting" the closed-cell structure in order to create a product that is softer and therefore easier to compress than the more traditional medium or firm grade EPDM sponge rubber, making them great for producing sealing products such as gaskets and semi open cell EPDM sponge washers. 

Semi open cell EPDM sponge washers are a flat ring with an outer diameter (OD) and inner diameter (ID) measurement, cut from a sheet of material which is placed between two surfaces creating a level surface, acting as a spacer, seal or between nuts and bolts to spread the pressure when tightened. 

Product Enquiry

For information on Semi Open Cell EPDM Sponge Washers please complete the following quick enquiry or call us on +44(0)1384 252555.






    Product Specification & Key Characteristics

    • Colour: Black
    • Cell Structure: a combination of open and closed cells
    • Temperature Range: -40 ˚C and 100˚C
    • Density: 70 - 130 kg/m3
    • Fire-resistant: (FMVSS302 - FIAT 50433)
    • Resistances: Ozone, UV, high and low temperatures, electricity

    Full technical data can be supplied upon request,
    or downloaded from our online portal.

    Why use Semi Open Cell EPDM Sponge Washers?

    Semi open cell EPDM sponge washers offer similar flexibility and compressibility to an open-cell foam, but under compression, they have excellent sealing capabilities more like a closed cell sponge.

    Semi open cell EPDM sponge washers are durable and offer the excellent ozone and weathering resistance of a standard EPDM, but with a slower and better recovery following compression which is suited to sealing applications. 

    Semi-Open cell EPDM sponge can be taken as complete sheet or roll form, or as pre-cut parts such as semi open cell EPDM sponge washers, all suitable for use as a solution to indoor and outdoor sealing applications, providing protection against air, dust and moisture.

    Benefits of using Semi Open Cell EPDM Sponge

    • Resistance to ozone and UV light
    • Soft and compressible 
    • Combination of open and closed cells
    • Excellent acoustic performance
    • Good compression set
    • Seals against air, dust & moisture
    • Converted onsite into a range of thicknesses and products such as semi open cell EPDM sponge washers

    The Advantages of using Semi Open Cell EPDM Sponge Rubber Washers

    The super-soft nature of Semi-Open Cell EPDM creates washers with excellent sealing capabilities once compressed.

    Due to low compression load, the foam can compensate for dimensional deviations in substrates and can, therefore, be applied to both rough, smooth and low energy surfaces.  The material offers resistance to Ozone and UV, has a wide working temperature range of  -40 ˚C and 100˚C and can be used for sealing against water, dust and air. 

    Being such a soft and conformable material, Semi-Open Cell EPDM can be converted into a range of products including sponge rubber washers to be used as vibration and acoustic solutions, within HVAC systems, within the automotive industry and as glazing seals, to name a few.

    Grades of EPDM Sponge Available

    ASG stock a variety of other grades and densities of EPDM sponge which can call be used to manufacture gaskets each suited to individual applications. These include firm grade, high temperature and semi-open cell varieties:

    Medium Density EPDM is available in black or white colour options. EPDM sponge is a strong, synthetic material that has a closed-cell structure making it an ideal material for internal and external sealing applications where minimal compression is required for the material to work as an effective seal.  Medium-density EPDM sponge has a density of 90 – 140kg/m3, an operating temperature range of -20°c to +85°c and is flammability tested to  FMVSS 302.

    High-Temperature EPDM Foam is closed cell and highly flexible even at low temperatures, with an amazing temperature range of -50°c to +128°c.  High-Temperature EPDM foam has many excellent mechanical characteristics including thermal and insulation properties, making this material ideal for many industries and applications including HVAC, Refrigeration, Pipeline, Automotive, White goods and Building & construction, etc.

    Firm Grade EPDM Foam is a more resilient material that will not compress as much as the standard grades under load, also this material benefits from increased tear strength and suits some of the more demanding applications such as Automotive, White Goods, Marine, Defence, Building and Construction, etc

    For further information, you can view our online specification sheets or speak to a member of our sales team.

    Have a Question about Semi Open Cell EPDM Sponge Washers?

    Please contact us using the form below or by calling us on +44(0)1384 252555.