Abstract: A polymeric anticorrosion film having a thermoplastic matrix made with a gradual transition from a nonporous to a porous structure formed by a system of closed and communicating pores filled with an inhibitor liquid with an increasing apparent density to a value equal to the thermoplastic density by 1/4-2/3 of the film thickness in the direction from one of its surfaces.

Abstract: An extruder head for making an anticorrosive tubular polymeric film has a body having an extrusion die, a hollow core mounted in the body and extending through the extrusion die, a molding passage terminating in an annular opening. Chambers are defined in the body of the core and die in the zone of the annular opening, the core chamber communicating with a passage for supplying a corrosion inhibitor, A pipe for supplying compressed air is provided in the interior of the core for blowing polymer melt into a tube. A scroll having a tangential nozzle for supplying compressed air is secured to one end of the pipe and is provided with a diaphragm in the form of a converting tube coaxial therewith and communicating with the chamber of the extrusion die. The other end of the pipe is made in the form of an opening-forming diverging tube.

Abstract: A process of producing a tubular polymeric anticorrosion film which includes extrusion of a mixture of a thermoplastic polymer with a corrosion inhibitor in a liquid phase or with a solution thereof in a plastifying agent employed in an amount exceeding the limit of compatibility with the polymer, blowing this melt into a tubular film upon cooling, application of a layer of an enamel or a varnish incompatible with the thermoplastic polymer onto the external surface of the formed tubular film before the line of crystallization, which layer has a difference of the solubility parameters in respect of said corrosion inhibitor or a solution thereof in a plastifying agent of not more than 8.