عملية غسيل الفلم بعد التثبيت .. كتاب أسس التصوير الضوئي

Film washing process after installation

After fixation, all traces of salts and acids that were used in the previous steps must be removed. The removal was done by washing with water in one of the two ways shown below:

1) If it is in a dark room, in preparation for washing in constantly running water, and this is better, leave the film in the basin and renew the water by placing a rubber hose up to it. From the tap to below the water level in the basin so that the water is continuously replenished regularly, and the water is drained from above, and the process lasts thirty minutes.

2) In the absence of running water, the washing process was carried out in a basin whose water was changed every five minutes, six times in a row.

Wetting Agent: Wetting Agent

When placing the film in a liquid, we often find that the liquid does not spread on the layer directly adjacent to it, which sometimes leads to the start of the appearance effect in some parts and not others, or that some air bubbles accumulate on the surface of the sensitive layer, preventing the effect of the appearance solution or other solutions used. Imaging directly in the sensitive layer. The damage appears clear when using rapid exposure solutions, and to avoid this, some drops of solutions prepared by photographic materials factories are sometimes added, and their function is to help the liquids spread in a consistent degree. On the surfaces that are in contact with it, and the film is also dipped in it after the last washing process following fixation, in order to help the droplets of water attached to the surface of the film fall off, and the film dries in one go.

Removing stains resulting from the appearing solution from the display basins:

It is very difficult to remove old stains from pool bleaching solutions
used. But by installing and using the following mixture, it can be removed easily:

60 grams of potassium bichromate


- 1000 cm water 100

- Sulfuric acid (conc) 60 cm concentrated sulfuric acid. After the stains are gone, wash with water.

This solution can be used until it appears to us that it is exhausted: Note:

(1) Sulfuric acid must be added to the water and not the other way around.

(2) Due to the large amount of sulfuric acid in the previous solution, it is recommended to touch it by hand