Processing Machine, Photographic

a device used in the processing of exposed motion-picture and still photographic materials, including films, and paper. It performs all the processing, from developing the latent image to drying the photographic material.

A processing machine incorporates a film transport and drive mechanisms, tanks for solutions and water, a drying chamber, and auxiliary equipment, for example, systems for mixing and controlling the temperature of solutions and conditioning devices for the air used during the drying process. The film transport, driven by an electric motor, moves the photographic material inside the processing machine through all the processing stages. The rate of motion and the variable length of the course traveled determine the length of time the photographic material is immersed in a solution. Many processing machines have film transports designed to process photographic materials of two or three different sizes, for example, widths of 16, 35, and 70 mm. The film transport is partially or completely immersed in the tanks.

In many types of processing, the temperature of the tank solutions must be kept constant. For this purpose, a solution is usually pumped through a heat exchanger that is washed with water. The water is heated or cooled by means of automatic devices that maintain its temperature within a given range. As the photographic material is processed, the working solutions are depleted; that is, the concentration of active components is reduced. The solutions become saturated with reaction products, which impede the development process, and the solution volume is reduced. In order to compensate for changes in the composition and volume of the solutions, batchers are used to feed the necessary compensating additives into the solution.

In order to eliminate any defects that may occur on the image as a result of the irregular effect of a solution on the photosensitive layer, the tank solutions are agitated in a circular motion; this also reduces the processing time for the material. In another method, the solution is directed at the material in a strong jet from special nozzles; this is particularly effective during washing. In processes in which no strict monitoring of temperature and time is necessary, the tank solution is made to flow in a direction opposite to the direction of the photographic material.

The productivity of various types of processing machines ranges from 25 m/hr for small portable machines to 5,000 m/hr for machines used by enterprises engaged in film duplication.