Hot air heater for welding plastic materials together and method of

Abstract

An air guiding arrangement for welding materials having plastic films includes a device to supply a uniform hot-air stream at any given air velocity. The air guiding arrangement has a nozzle which contains a swirl chamber functioning as a diffuser which tapers in the shape of a funnel. The nozzle is preceded by an adjustable air divider through which the amount of air to be supplied to the welding site is varied. The hot-air welding machine serves for a seam-shaped connection of plastic containing materials providing uniform heat distribution in the welding gap. In accordance with the inventive method, air is generated in a hot-air generator and delivered through an air divider in which only the quantity of air necessary for correct heating of a plastic material is permitted to flow further to a nozzle and wherein in the nozzle the air is directed through a plurality of radial openings through a swirl chamber which converges to an opening which is of a much larger area than all of the openings so that the hot air is permitted to swirl in the chamber between the sets of openings in which the air is guided so that it can be directed more precisely onto the welding materials and the air may be concentrated as desired over a welding strip.