Before Czech engineer Jiri Zajdlík founded Duflex, a company specializing in repair of plastic and rubber products, he studied fire and electric resistance in materials used for air ducts in mining operations. Air ducts are used in underground mines, tunnels, collectors or galleries to reduce explosion hazards from methane gas or dust build-up in confined spaces. Duflex, based in Baška in the Czech Republic, specializes in manufacturing flexible air ducts of all lengths and diameters from industrial fabrics welded with hot air. The company’s high-pressure air ducts withstand pressure tests of up to 2.32 pounds per square inch (psi), and safety specifications demand a welding seam width of 40 millimeters (approximately two inches).
As a young entrepreneur, Zajdlík purchased two universal VARIANT hot-air welding machines from Leister Technologies AG, a Swiss firm that designs plastic welding equipment. Twenty years later, Duflex continues using that Leister VARIANT equipment—and has purchased the newest Leister model, VARIANT T1, for its ease of handling, auto-start feature, lighter weight and digital display of welding temperature, speed and pressure. If the power in the plant fluctuates, the VARIANT T1 warns the operator and shuts off the tool. The VARIANT T1 also cools down and switches off when the weld nozzle is not in the welding position, a safety feature appreciated by Duflex employees. “We use the VARIANT T1 for the production of our entire product range, for a wide range of materials such as PVC, polypropylene or polyethylene,” says Duflex production manager Petr Rihosek.