New Techniques for New Products: Substitute Blanket Wash FAQ
|When you first use a substitute blanket wash, you may find that it looks, smells, and handles quite differently from your traditional wash. Do not let these differences stop you. With slight changes in the way you use your wash, you will find that the substitute can perform as well as your standard product. Printers should ask their suppliers what substitute blanket washes they offer and how to use them properly. Some of the more common questions raised by volunteer printers during the Design for the Environment (DfE) Lithographic Printing Partnership product trials, and their answers, are discussed below.|
Q.1: What can I do about the oily film left behind?
Q.2: What can I do about the longer drying time?
Q.3: How do I get the substitute wash to work as well as my traditional wash?
Q.4: How can I make the thicker substitute wash easier to use?
Q.5: Do the washes also work on ink rollers?
Q.6: What should I do if my substitute blanket wash has a strong or unusual odor?
Substitute blanket washes can leave an oily film on the blanket. Some believe that this film has little or no effect on the printed image, and disappears after three or four sheets are passed through the press.
- Experiment to see if the film is actually causing a problem.
- Use a firmly wrung water-soaked wipe instead of a dry wipe to remove the oil film from the blanket surface.
Q.2: What can I do about the longer drying time? [ top ]
By their nature, substitute blanket washes are low in VOCs and do not evaporate (or dry) very quickly. This is what keeps the wash from entering the air around the press and the outside environment.
- Dry the blanket with a clean dry wipe. Although this extra step requires more time and effort to clean the blanket, the money saved from less blanket wash evaporating, and the environmental and health benefits, will probably outweigh this disadvantage.
Q.3: How do I get the substitute wash to work as well as my traditional wash? [ top ]
A particular substitute blanket wash, when used the same way as standard washes, may seem less effective. However, a substitute blanket wash can perform as well as your standard product if you change the way you use it.
- Shop around and try different substitute products until you find the one that works best.
- Let the blanket wash set on the blanket for a short time after being applied.
- On two-color and multi-color presses, apply the blanket wash to all the blankets and then go back to wipe it off of each blanket in the same order.
- Wipe the blanket with a firmly wrung water-soaked wipe before you start cleaning. This will remove some of the excess ink as well as any paper lint.
Q.4: How can I make the thicker substitute wash easier to use? [ top ]
Some of the substitute blanket washes are thicker and more oily than traditional washes, and may not absorb as quickly into shop wipes.
- Give the wash enough time to soak into the wipe.
- Keep a supply of shop wipes and substitute wash mixed together in a covered container. Then use the wash-soaked wipes, squeezing or wringing as much wash as possible back into the container. This method may actually help you reduce the amount of wash you use.
Q.5: Do the washes also work on ink rollers? [ top ]
Many of the volunteer printers said they prefer to use the same wash on their blankets as they do on their rollers, ink trays, impression cylinders, and printing plates. Many, but not all, substitute washes can be used throughout offset presses.
- Check with the product supplier to be sure that the product can be used as a roller wash and is compatible with the other components of your press.
- Using substitute washes effectively on other parts of your press may require changes in your technique, as in blanket washing.
- Ask the supplier for information on the techniques best suited to each product.
Q.6: What should I do if my substitute blanket wash has a strong or unusual odor? [ top ]
Some of the substitute washes, especially the terpene-based washes made from citrus products, may have a different or strong smell. However, many press operators who have switched to a substitute product say that they prefer the smell of the substitute to the strong solvent smell of a traditional wash. Regardless of the wash you use, there are several steps that can be taken to reduce odor problems you may encounter.
- Increase the ventilation (around the press or the source of the odor).
- Use as little blanket wash as possible and avoid spills.
- Cover blanket wash and used wipe containers.
- If odor continues to be a problem, try different substitute products to find one that works best for you.