Automatic Processing

Automatic Processing

RADIOGRAPHIC IMAGING SCIENCES

AUTOMATIC FILM PROCESSING

• Makes use of automated machine for chemical
• processing of the films.
• In automatic processing machines, the exposed film is
• fed at one end and it passes successively through
• developer, fixer, washing and drying sections.
• The machines make use of roller system for the
• transport of film.
• The film comes out through the other end of the
• processor, processed, dry and ready for viewing.
• The Systems of An Automatic Processor
• The film feed section
• The transport system
• Temperature control system
• Recirculation system
• Replenishment system
• Dryer system
• Electrical systems
• 1.The film feed section
• When no films are being processed, an automatic
• processor is normally in what is known as a stand-by
• condition, with certain system functions such as the roller
• drive inactive.
• As a film is fed to the processor, so the cycle of events
• listed below is initiated:
• (l) Drive motor energized (to turn the rollers).
• (2) Safelight above feed tray extinguished.
• (3) Developer and fixer replenisher pumped into
• tanks.
• (4) Drier heater energized.
• (5) Wash water now rate boosted.
• (6) Film signal delay timer activated (audible signal
• which will sound 1-3 s after the trailing edge of the
• film has passed the entry rollers, to let the operator
• know that the next film can be fed to the processor). 2.The Transport System
• The film to be processed is placed on the input tray and
• gently advanced until taken up by the entry rollers. It is
• then automatically transported via a system of rollers
• and/or guide plates in and out of developer, fixer, wash
• and drying sections of the processor in turn, to be
• delivered finally to the output tray, dry and ready for
• viewing
• NB: Squuege rollers; which are sited between the tanks, help
• to remove solution from the emulsion as the film leaves one
• tank and enters another.3.The Temperature Control System
• 4.The Recirculation System
• Is a system which ensures that the developer solution is
• continuously on the move to enable adequate agitation.
• Adequate agitation of solution is important in achieving
• satisfactory mixing of the chemical solution and thereby
• obtaining correctly processed films.
• While the actual movement of the rollers does provide
• some movement of the solution, the principal contributor
• is the recirculation system.5.The Replenishment System
• The purpose of replenishment;
• (I) To maintain consistent developer and fixer solution
• activity.
• (2) To maintain a constant volume of developer and fixer
• solution
• In automatic processors there is little carry-over of
• chemical solution from one tank to the next because of
• the effectiveness of the squeegee rollers sited between
• solutions.• Thus, the principal reason for replenishment in an
• automatic processor is point (1) above.
• How replenishment takes place
• Each time a film is fed into the processor, the entry roller
• detection system triggers off the replenishment pumps,
• and replenisher solutions are pumped to the developer
• and fixer tanks in the processor.
• The fresh solutions are rapidly and thoroughly mixed with
• 'old' chemistry, partly due to the action of the rotating
• rollers but in particular due to the recirculation activity.
• Excess developer and fixer solution overflow to drain and
• silver recovery system, respectively. Thus, both solution
• activity and solution level are maintained.
• Factors which affect the replenishment rate.
• (1) Area of film processed.
• (2) The type of emulsion.
• (3) The type of image.
• (4) Aerial oxidation.
• (5) Orientation of film.6.The Dryer System
• In order to facilitate rapid film drying, squeegee rollers
• situated between the wash and drier sections first
• remove excess water from the emulsion surface.
• After, the film is transported through the drier section
• (typical temperature range for automatic processors is
• 40-65°C) where the film is commonly dried in one of two
• ways.
• Two ways a film can be dried
• Hot air drying
• Dust-free hot air is blown onto the surface of the film.
• ii. Infrared drying
• contains a range of electrically heated elements
• arranged so as to radiate heat onto both film surfaces

as it passes through the heater section.

Image Communication

• The end product of automatic processing is a radiograph.
• A radiograph can be taken to a radiologist or doctor for
• viewing and diagnosis.
• A radiograph can be best viewed with the help of a
• lightbox.
• Advantages of Automatic Processing over Manual

Processing