Final treatment of machine processed photographic material - by spraying both sides with regenerating liquor after leaving bath to increase efficiency

摘要

In final treatment of machine-processed photographic material, the regeneration soln. for the final treatment bath is sprayed above the liq. level of the bath onto both sides of the photographic material leaving the bath. Pref. several processing units are combined to a countercurrent cascade and the overflow of the next tank is sprayed onto both sides of the material leaving the preceding tank, above the liq. level in the tank. The final bath is pref. a stabiliser bath or water. USE/ADVANTAGE - The technique is simple and can improve final treatment, reduce tha amt. of final treatment bath required and/or reduce the number of cascade stages. In an example 1000 m2 colour paper was developed for 180 s with 325 ml/m2 regeneration, bleach-fixed for 90 s with 325 ml/m2 regeneration and washed 4 times, each for 45 s with 1000 ml/m2 regeneration. Each washing tank had a vol. of ca. 97 1 and the tanks were not connected in a cascade. The bleach-fixing bath contained 50 g/l Fe-NH4-EDTA, 100 g/l (NH4)2S203 and 20 g/l Na sulphite. After processing 1000 m2 colour paper, the first washing tank contained 3.79 g/l Fe-NH4-EDTA and 7.31 g/l (NH4)2S203 and the second 0.27 g/l Fe-NH4-EDTA and 0.53 g/l (NH4)2S203. If fresh water was sprayed onto the material leaving the first washing tank, the second washing tank contained only 0.09 g/l Fe-NH4 -EDTA and 0.16 g/l (NH4)2S2O3. Hence washing was more efficient and the number of washing stages or the water consumption could be reduced.