Set rollers as light as possible!

Setting rollers with too much pressure is a common mistake, and an expensive one. Pressmen sometimes think that the pressure is what moves the ink and water. It’s not. It’s the shearing forces generated by the different speeds of rollers with different diameters. More pressure does not help, and it can actually impair the quality of the printing and lead to extra downtime and operating costs.

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Set rollers as light as possible!

For even a small increase in the stripe, the pressure on the roller increases by several hundred percent. The pressure puts extra strain on journals, bearings, shafts, and housings, and it causes heat buildup that breaks down the rubber on the rollers. Rollers under high pressure require more energy to move, and thus the electric bill to run the press is significantly higher. Too much pressure can cause ink dams and uneven ink distribution; the heat buildup in the rollers changes the properties of the ink as well. All of these problems come from setting rollers with too much pressure, and all can be solved by setting as light as possible. Running with too much pressure is like trying to drive a car with the brake on.
A printing shop we know tried an experiment. They ran a 2-color press for two months at their typical settings: with lots of pressure and wide stripes. They measured the amount of electricity, ink and fountain solution consumed. Then they reduced the pressure settings by 50% and ran for two more months. The result, a 59% savings in electricity, 27% savings in ink, and 15% savings in fountain solution. And, the quality of the printing was better.
Set rollers as light as possible!
Always back rollers off before inserting new ones because new rollers may be slightly fatter than the old rollers. Set the new ones by coming forward until making contact with any surface, never by backing off.
Set rollers as light as possible!
For even a small increase in the stripe, the pressure on the roller increases by several hundred percent. So don’t guess: Use a stripe gauge for accurate pressure settings. By the way, it is not true that larger roller diameters should be set with wider stripes.

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