Plant for the production of plastic films to be then subjected to a stretching process and related method

A method for production of plastic film subjectable to a stretching process, said method being implemented in a plant that comprises in succession:

• a flat extrusion head of polyethylene-based plastic material,
• at least a first roller and a second roller, arranged to form a rolling press, and
• at least a third cooling/stabilizing roller,
• wherein said at least first roller and second roller are facing each other and collaborate with each other,
• wherein said flat extrusion head has a width dimension ranging from at least 1,000 mm up to 5,000 mm,
• said first roller of said rolling press has a diameter ranging from at least 200 mm to 800 mm,
• said second roller of said rolling press has a diameter ranging from at least 200 mm up to 800 mm,
• said at least third cooling/stabilizing roller has a diameter ranging from at least 400 mm up to 1,000 mm,
• wherein said at least first roller and second roller are made of ferrous material, with a conductive heat transfer coefficient of at least 15 W/(mK), said ferrous material being a construction steel with a chrome-plated and mirror-polished surface, having a roughness (Ra)<1 μm, copper coatings, or coatings having a conductive heat transfer coefficient of at least 15 W/(mK), and surface-roughness values of (Ra)<1 μm,
• wherein, at least one of said first roller and second roller comprises a coating of deformable and non-stick material;
• said method comprising:
• extruding at least 95% polyethylene-based plastic material from the flat extrusion head to form molten plastic material or melt exiting from the flat head passing said molten plastic material or melt exiting from the flat head into said at least first roller and second roller facing each other and collaborating with each other before being directed onto the at least a third cooling/stabilizing roller.