Dielectric materials, such as belt carcass materials, are by definition poor conductors of electricity. When such materials are separated after contact with either a conducting material or another insulating material, a static electric charge can be produced by the capacitance effect which can lead to sparking or crackling. When these electric potentials discharge they can cause the following problems:
The British Standard BS2050 (1978) and DIN 22104 are the recognized specifications which cover the test procedures and accepted levels for rubber and polyurethane timing belts relating to antistatic properties. The maximum surface resistance for BS2050 is 5x106 x l / (8*b) Ohms and for DIN EN is 3 x 109 Ohms.
TransDev has developed a post manufacturing electrically conductive black coating which complies with the above specifications and is available on all polychloroprene type rubber timing belts and currently on 3 different polyurethane belt substrates (All Breco/Brecoflex & Synchroflex belts). Certification is available for all belt types. Other substrates may be suitable but please contact our technical department first.
The antistatic timing belt is, therefore, a specific and new solution for all those who operate in hazardous industrial fields where static build-up would present potentially disastrous circumstances (chemical, mining, oil and electronics). Elimination of RFI also makes for easier FCC and CE certification.
It is obvious that during the working life of the drive that the eventual reduction of conductivity means that the testing of the belt's resistance in a planned maintenance schedule is important. TransDev is also able to supply you with a belt surface conductivity tester.
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