The technology of covering a sealed film with a layer of hot polyethylene or polyethylene melt. The main advantage of this technology is the absence of an adhesive layer, which reduces the level of chemical migration from packaging to the product being packed. Also, this technological solution allows creating a lamination layer of smaller thickness compared to traditional technologies. This makes it possible to reduce the temperature of the weld, which in turn makes it possible to increase the productivity of the packaging line.
The polymer in a viscous condition enters the head through a side entrance, turning 90 °. Passing through the screw distributor, the melt enters directly into the forming channel and exits through the annular slot in the form of a circular cylindrical billet. Then the workpiece is inflated to the required diameter with compressed air. Thus, a film sleeve is formed. The sleeve is cooled by a uniform air flow from the blowing ring. Further, the film sleeve, passing through the folding device, is drawn out by pulling rolls and when folded, through a system of bypass rolls, enters the winding device, where the finished film is wound onto the core.