Magical point-line cutting method to improve cutting quality

In the traditional collision table, the tail of the printed sheet is usually a vertical line, but sometimes the printed sheet is irregularly jagged. It is also very accurate to observe the front and the back of the sheet. How can we cut the rules? Through careful observation and research on the cutting process, equipment used, and printing presses, we have found a rule that any printed matter that deviates from the vertical line (the vertical line formed by the combination of the tail lines after a collision) is skewed. Misplaced printed sheets, to be exact, printed sheets that are not at right angles are offset from the vertical line. How to solve and respond? We have reached the following conclusions from various aspects of the discussion and analysis:

(1) If you want to fundamentally solve the problem, you need to make the cut paper 90°.

(2) The solution to the cutting of finished printed sheets is the “dotted line cutting method”.

To explore this method, we must first understand the printer's paper feeding mechanism. The paper-feeding mechanism of the printing press conveys the paper from the feeder to the paper-feeding table, and then sends the paper to the front stopper through the belt drive, and then pulls the paper to the specified position through the side gauge. The paper sent to the paperboard must pass through two actions before it can be handed to the tusks. The first motion is longitudinal motion, which is the motion to come forward. The second motion is lateral motion, which is the movement of the pull gauge. Observed that if the paper sent to the front gauge is closer to the pull gauge, if it is less than 90°, the tip of the paper will be pulled out of the pull gauge; any paper larger than 90° (on the side of the pull tab) will have its tail side Beyond the rules. When the crux of the problem is found, there is a solution. The position of the printed paper is composed of dots and lines. The point is the point determined by the pull gauge bearing, and the line is the line formed by the front baffle. Through the understanding of the printing press, in order to cut out a more accurate finished product, we decided to reconstruct the collision table. Change the collision table into a dotted line structure.

Specific approach: Add a piece of width 100mm, thickness about 20mm on the original collision table, and the length of the board is higher than the height of the original side of the original collision board, and put it to the position of the pull gauge. Using this type of page-flipping method, the printed sheets are in place, and the printed sheets are also particularly suitable for cutting. However, the method of cutting did not change, or it did not meet the ideal requirements, so it added a cutting device. Specific approach: use the same specifications of the board fixed it on the pusher, through the measurement and practice, in the pusher from the side to help the 110 ~ 120mm (press the machine's pull gauge position) with double strands of 8 wire nest into horseshoe In the form of a card stuck to the board and one card stuck to the paper feeder, the thickness of each stack should be 70mm. This method is easy to handle, flexible, and does not affect the structure of the knife. As long as the overprinting is accurate, it can be beautifully cut, improving the reliability of high-quality products, reducing the loss rate caused by cutting and “bleeding”, as well as the cost loss caused by the offset printing and improving work efficiency. Through more than 10 years of application, the effect is very good.



Source: HC Network Printing Industry Channel