The feedbelts move the master and diazo material around the revolving
print cylinder where they are exposed to the ultraviolet light. After
the machine has exposed them, the pickup assembly directs them toward
the developing section. After the pickup assembly has directed the
original and diazo material toward the developer section, a guide roller
directs them between a printer and tracing separator belt. The tracing
separator belt delivers the print and the original to two separator tank
assemblies where the original and print separate from each other. From
this point, the original leaves the machine and the print continues to
the developing section. However, if you want the print removed before
entering the developing section, you can accomplish this by simply
operating a lever.
(2) Developing section (figure 25). This section has a
perforated, stainless steel developing tank and ammonia feed system.
Using a gravity feed system, the tank is continuously supplied with
ammonia from the ammonia supply tank.
Next, the ammonia is directed to the evaporating drip trays suspended in
the developer tank. These trays have electric heaters attached to
speedup the formation of ammonia vapors. The ammonia vapors leave
through holes in the upper part of the developing tank and activates the
image on the diazo material.
Most machines have an automatic shutoff valve in the ammonia feed line
that protects the machine from flooding with ammonia when shutting off
the machine. This valve closes automatically when you shut off the
machine, and opens automatically when turning on the machine.
(3) Cooling and exhaust sections. The cooling and exhaust
sections prevent excessive amounts of heat and ammonia vapors from
reacting the area surrounding the machine. These systems use a motor
driven blower to remove fumes and hot air from the machine's enclosure
and vents them to the outside atmosphere. The blower creates a partial
vacuum in the machine's enclosure that causes air to flow into the
machine's enclosure continuously.
(4) Timer switch. A separate timer switch controls the blower.
This switch allows the blower to run after shutting off the machine to
ensure no ammonia vapors or heat build up in the machine enclosure while
the machine cools down.
d. Diazo Materials. You find diazo materials available in a
standard paper weight and a clear cellulose film.