A film is made from polymer granules which are extruded and blown. Being co-extruded in three layers, the thickness of these films ranges from 50 to 150 microns. The blown film is allowed to cool naturally and slit into the required width to be rolled and stored for further processing. Essel Propack utilizes a variety of polymers during this process based on customer requirements to acquire a desired structure for the finished product.
Accurate temperature controls are essential in this process as a minor deviation could upset the process and in turn disturb the desired outcome. A heater melts the plastic granules from hopper, and this molten material is passed through the screw to the die and punch area, where temperature-controlled air is blown to form the film. The film is further treated for corona on one side and wound to the plastic core.