Cause analysis and treatment of the most popular p

2022-10-19
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Cause analysis and treatment of paper wrinkling

if paper wrinkles in printing, it will inevitably affect the printing quality. Correctly analyzing and accurately judging the cause of wrinkling, and timely solving and eliminating the wrinkling fault is a problem worthy of attention for field operators and managers. This article talks about one of them on related issues

in order to identify the cause of paper wrinkling in the actual printing process, comparative methods can be used for analysis and judgment. The method is: replace the trailing tip of the unprinted paper (obviously, the paper quality used for comparison should be normal) with its mouth for printing. If the wrinkled part of the paper is fixed, it can be basically determined that it is caused by the improper adjustment of the components of the printing machine; If the wrinkled part of the paper changes, it can be determined that it is caused by the deformation of the paper itself

I. improper adjustment of printing machine components

1 If wrinkling occurs in the teeth position of the imprint cylinder, the shape of the wrinkles extends from the mouth to the trailing tip, which can be considered to be due to the insufficient force of individual teeth of the imprint cylinder. Check this situation carefully and readjust the gripping force of the embossing drum at the wrinkled part

2. If the positioning rules in the left and right directions of the paper, that is, the routine position is not appropriate, it will also cause the paper to wrinkle. Wrinkling caused by this reason usually universal tensile testing machine enterprises should enhance their awareness of innovation. At the edge of the paper, the wrinkle shape is skewed from top to bottom, from inside to outside. In this regard, the wrinkle fault can be eliminated after the position of the regular gauge is adjusted

3. When the wrinkle is between the two teeth near the mouth, it is generally caused by the uneven tooth pads of the paper delivery teeth. Therefore, it is necessary to adjust the paper delivery tooth pad so that each tooth pad on the tooth row is in the same straight line, and the gripping force of each tooth should be consistent and uniform

4. The teeth of the embossing drum and we should come together to understand the characteristics of the lower strand testing machine and the precautions for the protection of the equipment: the small opening teeth of the paper delivery teeth will also produce paper wrinkling, which is close to the mouth, and the shape of the wrinkles is horizontal or circular arc. Obviously, in order to eliminate this kind of wrinkling, we must check and adjust the size of the teeth of the imprint cylinder and the opening teeth, so as to achieve the appropriate size

second, the wrinkling caused by the deformation of the paper itself

we know that paper is very sensitive to the temperature and humidity of the air, and the moisture content in the paper always changes with the temperature in the air. Such a change will generally produce the following two situations

1. At the edge of the lotus leaf, because the air is wet, the paper absorbs moisture, and the paper will absorb moisture and stretch to the periphery, while the middle part remains the same size or changes only a little. In this way, the wrinkle appears in a straight line at the drag off point. The method of elimination is to put the paper in a drying room with appropriate temperature for dehumidification treatment. If the wrinkles are slight, they can also be dealt with directly by knocking paper

2. Tight edge, this is because the paper dehumidifies faster in a dry air environment, and dehumidification is often around the paper. The moisture content of the surrounding parts of the paper changes faster than, which leads to a tight state. The wrinkled part of this tight edge is not very fixed. The way to deal with it is to hang the paper again, and take effective measures in time. Sometimes you can also sprinkle water around the paper to make the edge of the paper absorb water and the edge of the paper even and flat

source: Shanghai Ruishi Printing Co., Ltd

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