Hot plate welding machine IR

infraredspotPLC-controlled

For welding by means of infrared technology short-wave (0,78-2 μm) as well as medium-wave (2-4 μm) infrared radiation of the spectrum can be used. This depends particularly on the radiation absorption capacity of the respective polymer material. The more precisely the radiator is adapted to the absorption capacity of the polymer material, the higher is the degree of efficiency, that means the conversion into warmth. Short waves are absorbed in deeper layers of the material, whereas medium waves heat it up more at the surface. Additives like carbon black lead to absorption of the largest part of energy at the surface. Since in most cases short-waves have a higher capacity (Watt/cm radiator length) and medium-wave metal-foil radiators are absorbed at the surface, the material surface can be impaired thermally. The parameters, capacity, radiation time and distance must be adjusted and optimized accordingly. The nearer the radiation source is positioned at the spot to be heated up and the better the ray is focussed, the faster the material will be heated up. Also the infrared process consists of two stages, in which the heating-up phase is separated from the actual welding process. There is no matching phase like it is in hot plate welding. In a first step the parts to be welded are moved at a certain distance to the radiator. The distance depends on the part geometry, the material and its absorption property as well as on the wave length of the radiator (short-wave radiators at larger distance than medium-wave radiators). The distance to medium-wave radiators is often in the range of 3 - 5 mm, in short-wave radiators it is rather between 10 – 20 mm.