Plastic bag production. Extrusion of tubular film for the production of plastic bags. During extrusion, molten plastic is forced through a thin rectangular orifice (not seen here) to form the film (centre left). A current of air is passed through the film in order to expand it into a tubular film (at right). Later on in the process the tubular film is cut to size and heat sealed to make plastic bags. Photographed in the Ste SMS- Pouance factory at Maine-et-Loire, France.