GB1202931A - Method and apparatus for the viscous processing of photographic webs - Google Patents

Abstract

1,202,931. Photographic film processing. GEVAERT-AGFA N.V. June 27, 1968 [July 3, 1967], No.30626/67. Heading G2A. In apparatus for processing an exposed photographic web, the processing material is applied to the web as a thin viscous layer in an atmosphere of which the wet bulb temperature can be maintained at a substantially constant value, and the relative humidity is maintained equal to or lower than the relative humidity with which the processing composition is in equilibrium with the atmosphere in the processing zone. Fig. 1 shows the processing apparatus, in which exposed film is led from a magazine 18 into a feed chamber 11, a developing chamber 12, a fixing chamber 13, a rinsing chamber 14 and a drying chamber 15. In chamber 12, the developing material is applied to the film as it passes over a roller 28, from an extrusion hopper 32, to which it is pumped from a constant temperature supply Fig.3, (not shown). Air is constantly circulated through chamber via inlet opening 33 and outlet opening 34, from conditioning chamber or humidifier 50 Fig.2. Water or an aqueous solution of sodium chloride is pumped into the chamber through downwardly directed spray nozzles 56, and the excess collects in a sink 55 at the bottom of the chamber. From here it is pumped up again, heated by a heater 57 and re-circulated. Moisture losses are made up from a constant level tank 60 fed from a supply 62. A second electric heater 68 is provided within the chamber itself. Heater 57 is controlled by a thermostat 67 dipping into the liquid in sink 55, and heater 68 is controlled by a thermostat 78 near the applicator hopper 32. As air from outlet 34 passes back into the humidifier via conduit 53 and compressor 54, it is augmented by air aspirated through a small pipe 65, so as to establish a slight over-pressure in chamber 12. Some dimensions and practical operational data are given, and the functioning of the apparatus discussed with reference to a psychometric chart Fig. 5, (not shown).