NOVELTY - Multi-layer structure comprises: a film (F1) of polyvinylidene fluoride (PVDF) joined with a layer e.g. of polyethylene terephthalate (PET); a film (F2) of PVDF with PET coupled with a film having PVDF; optionally a layer (I) of PVDF, polymethyl methacrylate (PMMA) and an UV absorber; a layer (II) of PVDF, PMMA, a mineral filler and polyalkylene glycol; optionally a layer (III) of PVDF, PMMA, a mineral filler and a polylakylene glycol; and an adhesive layer is laid out between the PET/PEN layer and the PVDF (F1) and/or (F2) films, where the adhesive layer is optional if (II) is present.    USE - The multi-layer structure is useful to protect a photovoltaic module having F1 film laid out on the module and to protect a substrate like the photovoltaic module, a technical textile (e.g. PVC, a glass fabric or glass mat, aramid fabric, a Kevlar (RTM: Para-aramid fibers)) and a metal (claimed).    ADVANTAGE - The film has a very good adherence to the substrate to be protected, thermal resistance, flexibility and mechanical resistance, particularly break resistance.    DETAILED DESCRIPTION - Multi-layer structure comprises: a film (F1) containing polyvinylidene fluoride (PVDF) joined with a layer of polyethylene terephthalate (PET) or polyethylene naphathalate (PEN); a film (F2) containing PVDF with PET or PEN coupled with a film containing PVDF; optionally a layer of composition (I) having PVDF at 5-40 parts, polymethyl methacrylate (PMMA) at 60-95 and a UV absorber at 0-5 parts; a layer of composition (II) having PVDF at 50-100 parts, PMMA at 0-50 parts, mineral filler at 0-30 parts and polyalkylene glycol at 0-3 parts; optionally a layer of composition (III) having PVDF at 80-100 parts, PMMA at 0-20 parts, a mineral filler at 0-30 parts and a polylakylene glycol at 0-3 parts; and an adhesive layer is laid out between the sheet of PET or PEN and the F1 and/or F2 films, where the adhesive layer is optional if (II) is present. INDEPENDENT CLAIMS are included for: (1) a protected photovoltaic module surfaces, a technical textile made out of PVC, a glass fabric or glass mat, aramid fabric, a Kevlar (RTM: Para-aramid fibers) fabric and protected metal surfaces protected by the multi-layer structure; and (2) a process of preparing the multi-layer structure comprising co-extruding the various PVDF layers, an adjacent polyolefin layer (E) to (I) or (III), and optionally another polyolefin layer extruded in PVDF layers or (E) on the side opposed to the layer extruded in E, and cooling co-extrudate, recovering and separating polyolefin layer and the multi-layer structure.