During the printing, the paper passes through the feeder and the paper feed table, passes through the front gauge and the specified position, and is finally printed by the rolling of the blanket cylinder and the impression cylinder. In these links, improper adjustment of one part of the machine will affect the operation of the paper and cause printing failures. Therefore, the following machine parts must be adjusted.
1. Nozzle, mouthpiece, platen
Due to the uneven size of the paper blowing mouth, or the improper suction position of the suction nozzle, the paper cannot be separated to form double sheets or multiple sheets; the suction of the suction nozzle is too large, resulting in double sheets or multiple sheets, and the sheets are too short to form an empty sheet. Zhang.
Remedy: Adjust the amount of air and inspiratory volume through the two air valves on the air pump until it is suitable; adjust the position of the nozzle to the right.
2. Paper and paper rollers
Inconsistent transfer belts result in inconsistent rotation of each transport belt, which skews the paper. When the pressure roller is placed in an improper position or the rotation is inflexible, it causes the feed to skew, or the paper cannot be stretched naturally on the transfer table. The paper arches unevenly, and after the rolling, the printed products appear wrinkled.
Remedy: Adjust the axis of the conveyor belt under the control of the feeding table so that all the feeder belts are loosely connected. Check whether the axles are worn and the pressure is uniform. Fill the oil regularly.
3. Lateral pull
The paper is pulled by the front gauge and gauge to the side fence to complete positioning. When the tensile force of the side gauge is too large, the paper arches under the resistance of the side gimbal baffle. After the embossing, the printed product forms an inverted arc-shaped fold.
Remedy: Adjust the side gauge to normal.
4. Impression roller bite row
During printing, when the impression force of the impression cylinder is inconsistent, arching occurs at the mouth of the paper. After imprinting, the printed product forms a circular fold in the mouthpiece; or the paper corner is just half bitten by the impression cylinder and causes the paper edge to be subjected to excessive force. After the printing, a fold is formed at the edge of the paper.
Remedy: Check the teeth and the toothpaste, if there is wear, need to be replaced; adjust the teeth force to make it uniform; check the bite bite paper position is appropriate.
The relationship between printing quality and paper is very large. As a printing job, we must fully understand this point, continuously accumulate experience, and take corresponding countermeasures, so as to improve the quality of printed matter and reduce the scrap rate caused by paper factors.
Source "Printing World"