Diazo Machines, Continued
Diazo machines fail to perform or become dangerous to operate without
regular maintenance. Daily maintenance consists of emptying residue bottles
every 8 hours, replenishing the ammonia supply, cleaning the outside of the
glass cylinder, and cleaning the feedboard, receiving tray, and print tray of
debris and paper scraps. Weekly maintenance is cleaning the inside of the
cylinder and wiping the lamp assembly. Lubricating all bearings using a No.
10 motor oil and cleaning the suction holes is done monthly. Remove, clean,
and dust all hoses annually.
In addition to precautions ascribed to electrically powered machinery, diazo-
type machines require the following specific safety precautions:
store ammonia in shatterproof bottles,
protect bottles in storage by securing them in place,
handle ammonia bottles carefully to prevent:
blindness and bums to personnel,
stripping finishes off of surfaces, and
never turn ammonia flow completely off while machine is running.
Diazo sensitive materials are papers, acetate, and lightweight cardstock
coated with diazo salts and azo dyestuff emulsion. This emulsion is sensitive
to light. Exposure to light through a transparent or translucent master
desensitizes areas not protected by the opaque image of the master. After
development in ammonia vapor, desensitized areas appear clear and protected
areas appear as the image. Paper comes in different weights and as standard
line, continuous tone, and sepia line stock. Drafting film comes as a blueline
or sepia image stock. Foils or acetates, used for transparencies, come in
normal intensity colors and pastels, black or color on color backgrounds, and
in a variety of densities, weights, and sizes. Cardweight stock is available
with a metallic shine. All diazo materials fade in time and exposure to
daylight accelerates fading. Because developed images retain residual
ammonia vapor fumes that permeate and deteriorate paper, do not store them
with other file images, particularly photographs.
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