Post Office Sponge Strip

Post Office Sponge Strip

Post Office Sponge Strip

Amongst the thousands of strips and tapes manufactured and supplied by Advanced Seals & Gaskets Ltd each day, a number of them are made using one of many unique and more specialist materials such as “Post Office Sponge '' or orange open cell natural sponge as it is also known. Post office sponge is manufactured in blocks of various sizes and thicknesses up to 80mm, which vary depending on density 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 which can be used to further cut and convert into strips from around 4mm in width and from a few centimeters long up to 50 meters in length (depending on thickness). By using customers' samples, drawings or given dimensions as a guide, we can produce made to measure post office sponge strips using one of our bandsaws, strippers, log cutters and even presses depending upon the size and quantity of strips required.  In-house production allows us to closely oversee the whole production process to ensure that we consistently produce high-quality, competitive prices strips. During the conversion process we can laminate layers of Post office sponge material to produce strips in greater non-standard thicknesses, supply them plain, laminated with a choice of self-adhesives foils or even other materials.

Product Enquiry

For information on Post Office Sponge Strip 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.

    What are Post Office Sponge Strips?

    Post Office Sponge Strips are pieces of material often cut to a specific width and length or supplied as continuous rolls/coils to be cut as and when needed by the end user.  Post Office Sponge strips are often purchased to be used in the same way as a gasket, whereby they are used to create a seal between uneven surfaces and fill irregularities or for anti vibration and acoustic insulations. The material used for these strips is manufactured using high-quality natural rubber, available in a range of densities from 160kg/m3 to 600kg/m3  and with a choice of pore sizes creating a selection of 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 Strips?

    Post Office Sponge strips are usually used in a similar way to other sponge gasket tapes and strips, whereby they are used to fill gaps, provide a solution to unwanted rattles, noise and vibrations. Open cell post office sponge strips can also be used as air, dust and to some extent moisture seals when under enough compression, the cells squash down enough to stop anything passing through.

    As this material is not resistant to oils, acids or alkalis, these strips are limited in how they can be used in certain industrial or automotive applications, however are 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  further converted into a range of finished usable products including strips.  Post office sponge has been developed so that it can be produced in a choice of densities, pore sizes and firmness allowing the strio to be utilised in a wide range of applications.

    Benefits of using Open Cell Natural Sponge Rubber

    • Good abrasion resistance
    • Soft and flexible to seal around uneven or complex shapes
    • open cell structures also allows for water absorption
    • Excellent recovery following repeated compression
    • Good tear resistance

    Other Grades of Sponge Materials Available

    • EPDM - medium, firm, semi-open cell, high temperature
    • Neoprene - FR, medium, firm
    • Silicone
    • Polyurethane
    • Open Cell Natural Industrial Sponge

    Advantages of Using Post Office Sponge Strips

    Using strips cut from post office open cell natural sponge offers users numerous advantages.  The material itself is available in a choice of soft- feel or very firm grades, 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 in the production of 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 and then converted into strips, coils or tapes coated in a choice of foils and adhesives.

    Have a Question About Post Office Sponge Strips?

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