Technical Tips - Film CLEANING

This month Peter King discusses how to clean phototool films before using them in production. Peter is one of our Agfa product specialists based in in Hitchin office. For further information, you can email him at pete@photodata.com   " Unless your production processes are spotless, there is a chance that from time to time the photo-tool films that you use for fabrication may need cleaning - perhaps to take off substances that have become attached to the emulsion side, such as residues from tape or gum. Below is a good procedure to ensure minimum damage to the film emulsion whilst doing this..."

"Even though our photographic films have an excellent scratch resistance coating, all films are inherently very soft and can damage easily - especially the emulsion side of the film.

To clean the film, you first need to choose an appropriate cleaning fluid - we recommend Use Isopropyl Alcohol (91%) or Heptane. Never use water, which will soften the gelatin, making it vulnerable to scratching. It's important when using Isopropyl Alcohol, 91% or higher is preferred because 70% is too "wet"—there is too much water."

" Next, choose a clean lintless, soft, absorbent, non-scratching cotton pad, such as Webril™ Hand-Pads (or equivalent). Since cotton materials may leave fibers behind, a (more expensive) alternative is a 100% knitted polyester cleanroom photo wipe."

Cleaning Methods
1. Apply cleaner to cleaning wipe. Squirt an approved cleaning fluid onto wipe. Do not dip the wipe into the cleaner, it should not be oversaturated. An oversaturated wipe should be squeezed and air dried until suitably damp for the wiping operation.

2. Wipe film in a single top-to-bottom direction, working from one side of the film to the other. Note: Do not wipe the film in a "scrubbing" motion (circular or back-and-forth). A particle of dirt can be picked up and embedded in the wipe. This can cause severe scratching if wiping in a circular motion.

3. Turn and refold the wipe frequently to expose a fresh surface and to bury any particles that may have been picked up.

4. Change wipes often. A single wipe should be dampened only once and discarded after cleaning an area no larger than 10 times the size of the wipe.

" If you find that your production process cause regular damage to the film surface, you may want to consider a more durable material. Our photomask department can produce images with a chrome finish onto glass substrates - chrome is much more durable and can be cleaned with more abrasive and harsh chemicals - the chrome finish is very difficult to damage under normal conditions."

" If you would like further information, please contact me directly - pete@photodata.com"

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