Post Office Sponge

Alongside the many standard sponge, foam and rubber materials, Advanced Seals & Gaskets Ltd also specialise in supplying other unique materials such as “Post Office Sponge” or orange open cell natural sponge. Post office sponge is manufactured in blocks of various sizes and thicknesses up to 80mm, which vary depending on density which we can supply in full or convert into a range of finished products.  Using our state of the art on-site conversion facilities, we are able to split these blocks down into sheets in thicknesses starting at around 2mm, laminate them to achieve greater depths for use in fabrications or using one of our many splitters, presses, saw or log cutters, we can cut and supply products such as pads, gaskets, washers and strips, all supplied in plain or self-adhesive options.

Material Enquiry

For information on Post Office Sponge please complete the following quick enquiry or call us on +44(0)1384 252555.

    Key Characteristics of Using Post Office Sponge Rubber

    Colour: Orange
    Structure: Open cell (fine or medium)
    Density: 140 to 600 Kg/m3
    Temperature Range: -40ºC - +80ºC
    Tensile Strength:  0.23 N/mm2 - 1.2 N/mm2 approx (vary between densities)
    Elongation at Break:   455% - 817% (vary between densities)
    Resistances (Ozone/Acids/Alkalis/oils/fats/solvents): Not resistant
    Flammability:  Highly flammable

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

    Help and guidance

    If you would like to speak to a representative to discuss your specific application or requirements please call our sales office direct on 01384 469100, alternatively you can send an E-mail. Simply click on the link and forward us your details along with your question and we will contact you immediately.

    Samples - Technical Post Office Sponge

    Samples can be submitted for testing upon request.

    Call now for sample requests or further help.

    What is Post Office Sponge?

    Orange open cell is manufactured using high quality natural rubber, and available in a range of densities from 160kg/m3 to 600kg/m3  and with a choice of pore sizes creating very soft or very firm materials each suited to different applications. Orange open cell natural sponge is recognisable by its bright orange colouration and the visible cell structure which is designed to be absorbent to hold liquids within it (you may have seen this sponge in the post offices on which they would moisten stamps before the self adhesive backed ones were introduced!).

    Why use Post Office Sponge?

    As Post Office sponge is not resistant to oils, acids or alkalis, it is limited for use in certain industrial or automotive applications, however perfect for wet applications, labelling, packaging and even to create vacuum lifting seals.

    As with many other types of block foam, post office sponge can be split down and supplied as sheets, or further converted into a range of finished usable products including rollers, pads, washers and strips.  Post office sponge has been developed so that it can be produced in a choice of densities, pore sizes and firmness in order for it to be utilised in a wide range of applications.

    Benefits of Using Open Cell Natural Sponge Rubber

    There are various ways in which our customers utilize acoustic foam gaskets, these include sound absorption. Due to its excellent sound-dampening properties, acoustic foam gaskets are often used for fittings within marine applications, recording studios, acoustic/compressor or generator enclosures, etc.

    Many industries also utilize acoustic foam gaskets for insulation, vibration control and cushioning due to the material's exceptional fire resistance properties (Surface Spread of Flame Class 1 BS 476 part 7 and Building Regulations 1991 (fire safety) Class 0 BS 476 part 6&7).

    These include heating & ventilation, construction, automotive, and electrical equipment and appliance manufacturing.

    Other Grades of Sponge Materials Available

    • EPDM - medium, firm, semi-open cell, high temperature
    • Neoprene - FR, medium, firm
    • Silicone
    • Polyurethane

    The Advantages of Using Post Office Sponge

    Using post office open cell natural sponge offers numerous advantages, available in a choice of soft- feel or very firm materials with an open cell structure allowing the material to be used in wet applications for water absorption for example in within packaging applications where these components help protect goods from impact damage or liquid spillages,whilst allowing for the circulation of moisture and gas when the application requires it. As this material catches liquid and holds it - it’s perfect for applications which then re-use the retained moisture such as paint pads and rollers, or floats used for plastering and tiling, etc. Post office sponge is available in a range of thicknesses, all offering excellent compression recovery particularly when it’s used for repetitive loading and distortion applications such as packaging and vacuum lifting. Orange open cell natural rubber depending on density is available in sheet sizes of up to 2120 x 920mm and in thicknesses up to 80mm, all of which can be split down or laminated to achieve non-standard sized sheets and can also be further converted into perfectly fitting finished cut products such as washers, gaskets, strips, pads or discs.

    Have a Question About Post Office Sponge?

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