GB1342572A - Manufacture of photographic film units - Google Patents

Abstract

1342572 Manufacturing film units POLAROID CORP 18 June 1971 [18 June 1970 20 April 1971] 28784/71 Heading G2A Photographic film units are made by a continuous process of adhering a sheet of photosensitive material across the frame opening 28 in a strip 40. The unit is of the type shown in Fig. 3, in which a photo-sensitive sheet 12 is laminated to an image-receiving sheet 14, the sheets being bound together along their edges by the edges of a sheet 18 having a rectangular opening 28 through which the photographic exposure is made, and having at one end pods 16 containing processing liquid which are ruptured to spread the liquid between the sheets, and an element 20 at the other end for trapping unused liquid. Initially the sheets 12 and 14 are laminated together by introducing a laminating liquid between them from a nozzle 50 and then pressing them together between rollers 46, 48. The strip 40, which may be some hundreds of feet long, has the openings 28, and notches 42 and 44, stamped out initially. Strip 40 and the laminated sheets 12, 14 are brought together at a guide station 52, the laminate having been severed by a knife 58. The length of the laminate sheet now lies across the width of strip 40. Heat sealing jaws 64 (only one shown) seal the leading edge portion of the laminate to strip 40. A further pair of jaws 66 (only one shown) seals the laminate to strip 40 in the region surrounding the opening 28. At the next stage the pods 16 and the element 20 are sealed at opposite ends of the laminate, and at the next station the leading and trailing end sections 30, 32 are folded over. The unit is now severed by a knife 74, and the detached unit passed to further stations at which the marginal sections 34 are folded over and sealed. A number of inspection and monitoring stations are provided so that action may be taken immediately if any step is defective.