In order to operate safely, it is vital that equipment that runs in explosive environments does not generate sparks or arcs. Electro static discharge results in sparks, for this reason plastics that are used in these environments have to be electrically conductive, so that it is impossible for electro static charges to build up. Industry standards refer to ATEX norms: the resistivity of the parts must be <109 Ohm/sq for ESD control, no spark generation, no explosion.
The Wittenburg Group is a leading supplier of conductive compounds based on a wide range of plastics, from polyolefins up to PEEK (PP, TPE, PA, POM, PBT, PPS… ). Most conductive materials are black, because many conductive additives are carbon based. There are conductive applications however, where coloured material is required.
Case in point: the WIKA Universal Process Transmitter (UPT) to measure pressure, volume and tank height even in extreme conditions. Apart from conductivity (ATEX and electro-magnetic compatibility), WIKA needed this material to meet an exacting property profile: low flammability, good impact resistance, high dimensional stability to ensure fluid/dust tightness, UV resistance and coloured in the signature blue colour. Christine Van Bellingen, market development manager for conductive materials at Witcom-Wittenburg Group, comments: “Together with WIKA, we developed a solution that fitted the extensive property profile. Our R&D department, together with our colour lab were able to tweak the formulation to get the colour within the WIKA specification.”
The compound is based on a PC/PBT blend which has been modified to reach a UL94 V0 rating. Christine Van Bellingen adds: ”This product exemplifies what Wittenburg Group excels at. Each property individually is not too difficult to achieve, but getting the combination of all requirements is really challenging.”
The Wittenburg Group is a leading supplier of speciality engineering plastics compounds. For more information on our products, please contact firstname.lastname@example.org