Patent GB-582436-A (GB)
Title: Method of transferring photographic emulsion layers from one support to another and apparatus suitable therefor
IPC: G03C7/22
Filed: 1944-05-30
Abstract: 582,436. Colour photography. KODAK, Ltd. May 30, 1944, No. 10382. Convention date, May 27, 1943. [Class 98 (ii)] In stripping a photographic emulsion layer from one perforated film strip and transferring it to a second perforated film strip of like composition, both of which film strips were, when manufactured, of equal perforation pitch but have subsequently been subjected to different conditions of storage or use which have caused their perforation pitch to become slightly unequal, the stripping and transfer are performed when any inequality in perforation pitch of the two films has been diminished by passing each film through a cabinet in which the temperature and. humidity of the atmosphere are maintained constant during the passage of the whole length of each film therethrough, in order to ensure that the.perforations in the emulsion layer to be transferred shall register as accurately as possible with the perforations in the second film strip. As shown in Fig. 1, rolls of unsensitized film F and exposed multilayer stripping film F<1> are mounted coaxially at 10 outside the humidifying chamber 11, the films F and F<1> being spliced to leaders threaded through the entire apparatus. The film F<1> may be as described in Specification 574,137, and the film F is provided with a subbing layer. Air is circulated in chamber 11 by conduits 42 connected to an air conditioning system. The film F<1> passes into chamber 11 to the driven sprockets 20 on shafts 21 and is spirally wound round idle rollers on shafts 21 and the floating rollers 24. It then passes over a driven sprocket 25, is given a half turn to bring the emulsion side into correct position, passes over the floating roll 26 to form a feed loop and then over guide rollers 27 out of chamber 11 into the water tank 28. The film F passes over rollers at one end of shafts 21, is driven through the chamber 11 by the sprockets 32 on the shafts 33, is spirally wound round idle rollers on shafts 33 and floating rollers 35, passes round the floating roller 36 to form a feed loop, over guide rollers 37 and into tank 28. The frame member 62 in tank 28 carries brackets 130 supporting rollers 27 and 37 and brackets 131 to which is pivoted an arm 120 carrying a scrubber roller 29 having a surface layer of chamois or viscose sponge. The arm 120 may be fixed in adjusted position by the slot and bolt connection 128. The member 62 also carries brackets supporting rollers 64, the rollers 29 and 64 being in a compartment 66 having slots for the passage of film. The member 62 is supported by posts 140 constituting guides for adjustable brackets, one carrying a sprocket 80, gate assembly 81, and accompanying gate members and the other rollers 31, 40. A bracket on member 62 also carries rollers 30, 39. As shown in Fig. 6, the teeth of the idler sprocket 80 extend through slots 83 in the member 84. The floating member 86 is resiliently pressed towards member 84 by the spring 88. The teeth 125 on one flange are narrower than the teeth 126 on the other flange in order to register the films. The plate 84 acts as a stripper plate and is undercut at 85 to prevent scratching. A roller 96, Fig. 1, is spring-pressed against presser roller 95, and above these rollers is a second gate assembly including a sprocket 100. The third gate assembly includes a sprocket 41. The shaft of sprocket 41 is chain-driven and carries a pulley connected by a belt of a pulley on the shaft of sprocket 100, which is friction driven from the shaft. A weighted brake band is applied to a sleeve on the shaft of sprocket 80 to provide a tension on the films between sprockets 80 and 41. The film F passes to gate 81 from roller 40 and the film F<1> from roller 31, a stream of water being directed between the films as they approach gate 81. After registering at the gate 81, the films pass to presser rollers 95, 96, where they are pressed together and surplus water removed. At sprocket 100, the films are re-registered. When the films reach sprocket 41 they are bonded together. One or other of the films may be stretched before bonding by adjustment of the bracket carrying the rollers 31 and 40. The tank 28 may contain water or aqueous ethyl alcohol. The bonded films pass between squeegees removing surplus liquid on leaving tank 28 and then pass over roller 43 and are spirally wound round rollers 44 in the drying chamber 45. The support F with the first colour component layer is stripped off by rollers 46 and is spirally wound round rollers 47 and floating rollers 49 and is fed by sprockets 50-to a take-up roll 10<1>. The multilayer film from stripping rollers 46 is given a half-turn, passes round rollers 51, 52, is spirally wound round rollers 53 and floating rollers 55, and is driven by sprockets 56 to a coaxial take-up roll 10<1>. Stripping of the second emulsion layer is performed similarly, except,that the roller 29 is adjusted to press harder against rollers 64 or is driven faster or both. Additional wiper rollers covered with mohair may contact the support sides of films F and F<1> and additional water jets may be provided on each side of the films. A jet may be directed against roller 29 and the emulsion side of film F<1>. If there is considerable difference in the dimensions of films F and F<1>, they may be conditioned in different chambers. The films are preferably made from the same batch of cellulosic composition. Specifications 574,164, 582,438 and 582,439 also are referred to.