Reel paper paper commercial paper printing and matching problem processing
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Nowadays, computers have become an important tool for modern office, which has also led to the development of a large number of emerging industries. Computerized roll paper commercial paper printing is a new type of printing product with web paper as raw material, strict process requirements and high product quality requirements. It is widely used in the field of computer applications such as banking, transportation, post and telecommunications, aviation, etc. Bill printing companies serving the field have also risen rapidly. However, many domestic manufacturers have neglected the production management, resulting in unstable product quality, which ultimately affected the user's use efficiency and even caused the product to be scrapped. Therefore, it is necessary to correctly grasp the technical characteristics and quality requirements of commercial paper printing. This article only discusses the problem of page matching in the production process of computerized web paper.
For web-based commercial paper products for multi-unit computers, firstly, each single-printing is carried out, and punching, ridge-line, "Zigzag" folding and paper-receiving are carried out, and then the matching is carried out. In production, coding and matching is the last process and is done on the collating machine. In order to prevent the printed multi-notes from being misaligned in the matching page, it is necessary to press the multi-notes together through the embossing teeth on the collating machine. Because of the web printing, the expansion ratio of each layer of paper is not necessarily the same, so the change of each single length after printing will bring many problems to the matching, and even the matching cannot be completed.
Factors affecting paper length change
1. Tension
Tension is the stretching force of the paper feeding system on the paper during the printing process. Excessive tension during the printing process will lengthen the paper, and the tension will be removed after printing. The paper will be retracted, which will cause the sheet to appear for a long time and a short period of time. Matching page.
2. Paper moisture content
The difference in water content of the paper also causes a change in the length of the paper. The greater the moisture content of the paper, the more severe the shrinkage of the paper after printing.
3. Paper quantification
Under the same tension, the greater the amount of paper used for printing (the thicker the paper), the more severe the shrinkage of the paper after printing, but also the factor of the large moisture content of the thick paper. Under normal circumstances, the thick paper should be increased in tension.
Precautions
(1) In the printing process, a printing product should use paper of the same brand and the same thickness as much as possible, so that the tension can be kept constant during printing.
(2) In actual production, even if paper of the same brand and the same thickness is used, the water content of the paper is different, so be careful to distinguish it. It can be touched by hand. Generally, paper with a large water content will be cool and bun; paper of the same width and length will be heavier with a larger water content, so the tension should be appropriately reduced. But pay attention to the paper adaptability, you can put the paper in the production workshop for a period of time to adapt to the temperature and humidity of the workshop, so as to solve the problem of paper moisture content.
(3) When encountering multiple orders of different quantitative or different types of paper, it is necessary to pay attention to the adjustment of tension. First, when printing a joint, measure with a hole distance of more than 3m, and release 2 ~ 4mm than the standard length to compensate for paper shrinkage caused by water loss: Second, when printing two, also need to use The 3m hole distance gauge measures the paper hole pitch. If the paper is thicker, it can release 1~2mm more than the standard length. The paper has high water content and large shrinkage coefficient. In this way, all the joints are given different amounts of the paper according to the thickness of the paper, so that the paper can be kept substantially consistent when the sheets are combined.
Despite paying attention to the above problems, complicated jagged problems can occasionally be encountered in multi-joint printing, such as thermal paper with a basis weight of 180 g/m2 + double-adhesive paper with a basis weight of 70 g/m2 + a basis weight of 40 g/ The back of the m2 is coated with carbon dictionary paper + color page coated paper + thinner paper, sometimes even with 10 layers of different paper. In this case, do not rush to start, use a hole distance ruler to combine the thickness of the paper layer by layer. The water content is measured, and even 3m of each paper can be taken in front of the printing, ventilated and dried, the shrinkage coefficient is counted, and then different tensions are determined after comparison. After each printing, it must be wrapped with plastic film to prevent loss of water and water, resulting in difficulties in matching pages.
Remedy
If there is a problem with the matching page, the following measures can be taken to remedy:
(1) The longer one of the papers can be ventilated to dry and shorten.
(2) When the page is matched, a humidifier can be installed under the short one to increase the moisture of the paper and make the paper stretch.
(3) If the paper is shortened, you can increase the paper resistance in the middle of the paper passing process while using the humidifier. For example, add a sponge to the paper rod to increase the resistance and make the paper stretch.
If the above method is used, do not ventilate, and immediately put it in a box with plastic film and store it under pressure.
The printing of commercial papers has strict requirements on the temperature and humidity of the environment, especially the requirements for environmental humidity. Therefore, it is necessary to control as much as possible without drastic changes. At the same time, it should be wrapped with plastic film immediately after printing, but it can not be placed for too long. It should be matched as soon as possible to prevent the paper from shrinking and affecting the quality of the product due to changes in ambient temperature and humidity.