Welwyn Tool has introduced its Leister Weldplast S4.0 plastics welding system, featuring a brushless motor driven pre-heated air blower, and a powerful drive system capable of producing an output of up to 4kg/h. A very useful development eliminates time-consuming set-up when re-configuring the welder for different materials. The user simply enters, via a digital display panel, the type of material to be welded and the system's inbuilt intelligence automatically regulates the temperature and speed setting compatible with that material. The tool can handle a variety of material thicknesses, from 6mm to 20mm, making it a useful assembly device for large storage tank construction or the butt-welding of large plastic pipes.Conventional extruders can cause damage when they are inadvertantly activated before the plastic inside is hot enough. A built-in cold start protection device ensures that the Weldplast S4.0 cannot be used until the optimum extrusion temperature is attained within the gun.