| Teknor Apex Vinyl Division, USA, a leading manufacturer of custom and standard compounds based on polyvinyl chloride, has recently announced that new technology involving Fireguard� low-smoke/zero-halogen compounds will enable installers of cable in municipal, public utility, and similar projects to save time and costs by using semi-flexible plastic conduit while eliminating concerns about excessive smoke generation in fires. Under a pending patent jointly applied by Teknor Apex and cabling system supplier Arnco Corp., USA, Arnco has used a speciality formulated Fireguard LSZH� compound to develop Fibre-Guard� LSZH� conduit, a coilable product that contains no halogen either in the base polymer or in flame-retardant additives. The first application of the new conduit is in a 8km long project beneath the city of Chicago. �Semi-flexible plastic conduit comes in continuous coils that can be fed through the city substructure with minimal disruption of surrounding components, In addition, continuous conduit permits the use of new fibre optic cable blowing techniques, which are precluded by the enormous number of joints required in any sizable installation of metal conduit�, commented Mr Robert Washburn, Arnco�s vice-president of R&D.;
The Chicago project involved running cables through the stations and tunnels leading into the city centre on one route of the Chicago Transit Authority (CTA) railway system. CTA requirements call for use of low-smoke/zero-halogen coiled conduits in order to increase the visibility of exit areas in the event of a fire and to reduce the toxic effects and corrosion caused by acid gases emitted as combustion byproducts.
Teknor Apex�s Fireguard� compounds meet the most stringent low-flame, low-smoke requirements for wire and cable insulation and jacketing. While most Fireguard products are PVC-based, Fireguard LSZH compounds are polyolefin-based, completely halogen-free formulations. They were originally developed for insulation and jacketing of copper and fibre optic cables for communications and data transmission. �While Fireguard LSZH compounds have been used successfully in the USA, our main goal in developing them was to support companies that manufacture in or distribute to Europe, where smoke-toxicity restrictions are particularly stringent,� commented Mr Donald G. Ouellette, industry manager for Teknor Apex. �To transfer this technology to applications in conduit, we adapted the Fireguard LSZH formulation for use in the process of extruding tubing�.
Photo: New semi-flexible Fibre-Guard� LSZH� conduit installed next to conventional metal conduit in a section of the Chicago Transit Authority�s railway tunnel |
