Patent Number: 
Section: claims

1. A device for treating a packaging material by UV radiation, the device comprising a source of said radiation, and a screen for protecting said source and which is interposed between the source and the material for treatment; wherein said screen comprises a film of a polymer resistant and permeable to said UV radiation, and a pair of substantially rigid grilles between which said film is supported. 2. A device as claimed in claim 1, wherein said polymer is fluorinated. 3. A device as claimed in claim 2, wherein said film is of a thickness ranging between 20 and 200 μm. 4. A device as claimed in claim 3, wherein the thickness of said film is selected between 40 μm or 100 μm. 5. A device as claimed in claim 1, wherein said polymer is completely fluorinated. 6. A device as claimed in claim 5, wherein said polymer is in the perfluoroalkoxy (PFA) class. 7. A device as claimed in claim 6, wherein said film is of a thickness ranging between 20 and 200 μm. 8. A device as claimed in claim 7, wherein the thickness of said film is selected between 40 μm or 100 μm. 9. A device as claimed in claim 5, wherein said film is a of a thickness ranging between 20 and 200 μm. 10. A device as claimed in claim 9, wherein thickness of said film is selected between 40 μm or 100 μm. 11. A device as claimed in claim 1, wherein said polymer is an MFA. 12. A device as claimed in claim 11, wherein film is of a thickness ranging between 20 and 200 μm. 13. A device as claimed in claim 12, wherein the thickness of said film is selected between 40 μm or 100 μm. 14. A device as claimed in claim 1, wherein said film is of a thickness ranging between 20 and 200 μm. 15. A device as claimed in claim 14, wherein the thickness of said film is selected between 40 μm or 100 μm.