Printech Archive, October, 1998: Press rust

Press rust
Thu, 22 Oct 1998 10:28:06 EDT

This Ask PNEAC question was from:
Kathy Mulaney

Thanks for the reply to my question. I had not had a reply so thanks for
sending it on. In our operation the platemaking is done in a separate area of
the plant and not in the press room were we are having the problems. Could the
fumes from the ink be causing the same problem? I have also heard that water
treatment chemicals used in the humidifying process could cause this problem.
Since we do not dehumidify during the summer the water treatment chemicals
would only account for a portion of the problem.

Are there any suggestions on what we might change in this room to solve the

Kathy Mulaney

The following response to the question from Kathy Mulaney is provided by Fred

Since you did not indicate what kind of a press or what component of the
press, is rusting, my suggestions may or may not be of value.

a. If you have a water cooled CI drum or chilling roller prior to rewind, the
temperature of the drum or roller may cause condensation if there is a
temperature gap, cold vs warm. This, in turn, could cause rust.

Check temperature and maintain a temperature that will not allow moisture in
the pressroom to condense on the drum/roller surface. Temperature controls on
the water chiller should be checked to assure that they are maintaining
consistent temperature.

b. If you are running with water based inks and the impression rollers or drum
are steel or chrome, there is a possibility of rust occurring. This could
result from water used for cleaning, as well as from the inks. Cracks in the
chrome surface can allow water to seep through and rust the steel base. Poor
housekeeping, allowing water inks or cleaning solutions to remain wet on the
press surfaces can result in rusting.

(1) From a structural perspective, rollers and drums can be resurfaced with
new alloys that are impervious to water and the potential of rust. Contact
Bender in California for information about resurfacing CI drums, or your
roller supplier for rollers made with rustproof alloys.

(2) Housekeeping is imperative. Wipe up all spills. Dry press parts as

c. This one is far fetched, but you never know. If you use any 11
Trichloroethane, this will form Hydrochloric Acid on contact with heat (your
dryers) and the acid will cause oxidation of the metal. I don't think you use
this chlorinated solvent, but it is a possibility.

I expect to toss this question to one of the engineers who works with me and
will follow up. Would help if there was a better description of where the rust
is located on the press.



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