Dealing with the problem of printing and matching of commercial paper on roll paper

Nowadays, computers have become an important tool for modern office, which has also led to the development of a large number of emerging industries. Web commercial paper printing for computers is a new type of printing product that uses web as raw material, strict process requirements, and high product quality requirements. It is widely used in banking, transportation, post and telecommunications, aviation and other computer applications. Bill printing companies serving this field have also risen rapidly. However, many domestic manufacturers have neglected production management, resulting in unstable product quality, which ultimately affected the user's efficiency and even caused product scrapping. Therefore, it is necessary to correctly grasp the technical characteristics and quality requirements of commercial paper printing. This article only discusses the problem of collating in the production process of roll paper commercial paper for computers.

For the roll paper commercial paper products for multi-unit computers, each single unit must be printed first, and punched, ridged, and "Zigzag" folded paper should be collected, and then collated. In production, coding and collating is the last process, and it is completed on the collating machine. In order to prevent misprinted multi-couplings from being misaligned in the collating page, it is necessary to press the multi-couplings together through the embossing teeth on the collating machine. Because it is web printing, the expansion and contraction rate of each layer of multi-single sheets is not necessarily the same, so the change of the length of each single-segment after printing will cause many problems with collation, and even make collation impossible.

Influencing factors of paper length variation

1. Tension

Tension is the tensile force of the paper feeding system during the printing process. Excessive tension during the printing process will lengthen the paper. After printing, the tension will be removed, and the paper will inevitably shrink, which will cause the problem of the length and time of the collation. Collation.

2. Paper moisture content

Different paper moisture content will also cause changes in paper length. The greater the moisture content of the paper, the more severe the paper shrinkage after printing.

3. Paper weight

Under the same tension, the larger the amount of paper used for printing (the thicker the paper), the more serious the paper shrinkage after printing, but the factor of the large moisture content of the thick paper should also be considered. In general, the thick paper should increase the tension.

Precautions

(1) In the printing process, a printed product should use the same brand and the same thickness of paper as much as possible, so that the tension can be kept constant during printing.

(2) In actual production, even if the same brand and the same thickness of paper are used, the moisture content of the paper is different, so pay attention to distinguish it. It can be touched by hand. Generally, paper with a large water content is cold and astringent; paper with the same width and length will be heavier, so it is necessary to reduce the tension appropriately. But pay attention to the suitability of the paper, 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) Pay attention to the adjustment of tension when encountering multi-sheets with different quantitative or different varieties of paper. First, when printing one unit, measure with a hole gauge of more than 3m, and release 2 to 4mm from the standard length to make up for the paper shrinkage caused by water loss: second, when printing two units, it is also necessary to use The 3m hole distance ruler measures the paper hole distance. If the paper is thicker, it can release 1 to 2mm more than the standard length. The paper has a high water content and a large shrinkage coefficient. In this way, according to the thickness of the paper, all the joints are given different addition amounts on the hole distance, so that each jointed paper can be kept basically the same when collating.

Despite paying attention to the above problems, in the multi-single printing, you will also occasionally encounter complex collation problems, such as thermal paper with a basis weight of 180g / m2 + double offset paper with a basis weight of 70g / m2 + basis weight of 40g / The back side of m2 is coated with carbon dictionary paper + color page coated paper + thinner paper, and sometimes even encounters 10 layers of different paper collation. In this case, don't rush to do it, and use a hole gauge to combine the thickness of the paper layer by layer. The water content can be measured, and even 3m of each paper can be taken before printing, air-dried and dried, the shrinkage coefficient is counted, and after comparison, it is decided to apply different tension. After each joint printing, it should be wrapped tightly with plastic film to prevent the loss of waterproof points, causing difficulties in collating.

Remedy

If there is a problem with the collation, the following measures can be taken to remedy:

(1) A long piece of paper can be ventilated to dry to shorten it.

(2) When collating, you can add a humidifier under the short one to increase the moisture of the paper and make the paper stretch.

(3) If the paper is shortened greatly, you can use the humidifier and increase the paper resistance in the middle of the paper running process, such as adding a sponge to the paper passing rod to increase the resistance and make the paper stretch.

If the above method is adopted after collating, do not ventilate, immediately wrap it with plastic film and put it in the box, and store it under pressure.

The commercial paper printing has very strict requirements on the environmental temperature and humidity, especially the requirements on the environmental humidity is high, so it should be controlled as far as possible without sharp changes. At the same time, it should be wrapped with plastic film immediately after printing, but it should not be placed for too long. It should be paged as soon as possible to prevent the change of ambient temperature and humidity from causing the paper to expand and contract and affect the quality of the product.

1) Disposable Face Mask package: 50pcs/pack, 1pack/inner box, 40 inner boxs/ctn, 2000pcs/ctn.

2) Disposable Face Mask certificates: CE, FDA 

Disposable Mask

Disposable Face Mask,3Ply Disposable Face Mask,Ce Fda Masks,Earloop 3-Ply Surgical Face Mask

Homefelt Houseware co.,ltd , https://www.dghomefelt.com