the invention relates to a method of producing a film comprising at least one layer of a thermoplastic fluoro - polymer and at least one layer of another polymer . the inventive method consists in using extrusion blow molding to coextrude a fluoro - polymer and polymer which adhere to one another ; with a layer of another thermoplastic polymer such that it forms a layer which is adjacent to the fluoropolymer / polymer layer according to the invention , the thermoplastic polymer is incompatible with the fluoro - polymer and polymer and has adequate extrudate behavior to support the layers of fluoro - polymer and / or polymer . once the coextrudate has been cooled , by separating the layer of , at least the film is recovered , said film comprising at least one layer of a polymer selected from among thermoplastic fluoro - polymers and polymers .