By definition this paper defect occurs when the diameter of a web press paper roll is not uniform. The roll diameter will show different measurements depending on where the measurement is taken.
An out of round roll can have several causes. Here are a few:
1. The roll sustained a hard impact during the transportation process.2. It was stored for an extended period of time with weight on it.3. Excessive clamp truck pressure.4. Loosely wound roll from the paper mill.
Problems caused on an offset web printing press:
1. Roll stand will bounce.2. Web tension can fluctuate as the roll wobbles.3. Doubling in the printing units.4. Web breaks.
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| Out of round rolls often show waviness. |
The best way to prevent this type of paper defect is through proper storage and handling.
- Care must be taken when handling the rolls.
- Clamp pressure must be set according to specifications outlined by the paper company. Storage mush also be such that paper rolls are stored on their side.
On an offset web printing press, the remedy is to run the press slower. This will mitigate the effects as it wobbles.
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