Analysis of paper breakage in the most popular new

2022-10-23
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Analysis of paper breaking in newspaper printing

in newspaper printing, paper breaking is a headache. Whether it is manual threading or automatic threading, it is common to break the paper for more than 10 minutes. Frequent paper breaks make the operator miserable

the author had the honor to contact uniset and colorman of MAN Roland, and conducted some research. This paper gives some opinions on the reasons for paper breaking in the development space of China's plastic machinery dispensing structure upgrading extruder industry

1, edge crack, edge bruise

if it is found in time, deal with it immediately, and this fault is not a big problem

2. There is a problem with the paper roll itself

the paper quality is unqualified or stored improperly, and the center of gravity of the paper roll may shift, resulting in eccentricity. It is generally believed that the paper roll is unqualified if its eccentricity exceeds 5mm, and eccentricity is easy to cause 4. The forming temperature of polyphenylene oxide is 280 ℃ (3) 30 ° fracture

under normal conditions, the tension and braking force are balanced. When using eccentric paper roll, due to the change of paper roll radius r, the paper is subject to an oscillation with gradually decreasing oscillation period and amplitude. In each short period, the higher the startup speed is, the greater the internal stress of the paper is

3, the speed change is abnormal

4, the tension is too large

the paper has a tension limit. When increasing the tension, try to stay away from the limit tension. At high speed, a very small change will also produce a very large stress, resulting in paper breakage

5. When the paper feeding must be stopped immediately due to other reasons, the stacker breaks the paper tape

6. When the machine is turned on for a long time, ink dirt is deposited on the paper guide roller

for example, the tension of MAN Roland's colorman offset press is controlled by sections. When the machine is turned on for a long time, the deposition of ink scale increases the radius of each roller, thus increasing the tension

in addition, there are many paper guide rollers between the roller and the power roller, and the ink scale deposition on them will also increase the tension

when the tension is anchored to the limit value, the machine beater will break the paper protectively. ◎

source: printing technology

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