Regarding the manufacturing process of semi-finished plastics like films or plates, foil stretching is used to regulate the thickness of the films or plates, to the required thickness.
At first the film is manufactured by extrusion of plastic granulates and additives such as plasticizers, stabilizers or colorants. Following the material is stretched on rollers under thermal action.
While stretching, the film thickness and therefore the weight, is adjusted in proportion to the surface to the required level. In this process the material is stretched at length, and optionally the width is maintained.
It is particularly important to keep the exact temperatures of several heating and cooling cycles.
Consequently, Elstein infrared heaters are installed in machines for film stretching due to the homogeneous radiation behavior and the control-precision.
Individual and modular arrangement possibilities of different heater sizes and the ability to control each heater in a heating panel, ensures precise temperature management. An unbalanced heating would lead to undesirable variations in film thickness and quality.
Another point is the absorption capacity of radiation energy of the plastic. Especially for transparent films, the heat effect of Elstein infrared heaters is reliable for decades, due to their long-wave radiation.
Particularly in the production of optical films are often production environments which are similar to cleanrooms. There are special requirements for the components used. Elstein infrared heaters can be used here; many have a cleanroom certificate of class I.