Outdoor telecommunication infrastructures such as fiber optic boxes and electric enclosures often face many harsh environmental conditions. In environments where corrosive coastal air, flooding, and high humidity are common, telecom equipment is more prone to fungal attack. Fungus growth can severely deteriorate the conventional environmental seals such as foam and sponge gaskets, resulting in unprotected interior telecom components.
Therefore, sealing for outdoor telecommunication components is very crucial and is not as simple as keeping water out during a laboratory test. The seal has to exhibit excellent resistance to fungus while meeting other application requirements.
Fungal and microbial
Fungal and microbial attack of elastomer products can be an issue in humid or tropical environments. Materials need to be tested to ASTM G 21-96, “Resistance to Synthetic Polymeric Materials to Fungi,” to ensure suitability for use in many of the world’s extreme environmental conditions.
In addition to fungal attack, telecommunication equipment must also be protected from flame generated from either internal or external conditions due to its electrical components inside. In the event of a fire, the seal for telecommunication equipment must be able to self extinguish after the ignition source has been removed and must not create flaming drops or particles.
A good material to select would be one with a UL94 V-0 rating, a plastic flammability standard, to ensure regulatory compliance as well as safety for both the equipment and the surrounding areas. The V-0 standard is the most stringent UL flammability rating offered for elastomer products.
To pass the V-0 testing requirement, a seal has to stop burning within 10 seconds on a vertical specimen after the source is removed; drips of particles are allowed as long as they are not inflamed. In addition, the total afterflame time for the seal has to be less than or equal to 50 seconds.
UL 94, released by Underwriters Laboratories of the USA, is the standard for safety of flammability of plastic materials for parts in devices and appliances testing. From the least flame retardant to the most flame retardant, there are six classifications. Please visit UL’s official website for the general descriptions of each classification and its testing requirement.
One solution offered by Parker’s TechSeal Division is their S7395 material, which meets or exceeds all of the requirements for this harsh application.
It’s available in many standard low-closure force profiles including hollow O, hollow D, and many other custom engineered configurations. To learn more about this anti-fungal material, please contact TechSeal’s team of Application Engineers at (864) 573-7332 or Live Chat with our application engineers on our website