Print wrinkle failure is a common fault phenomenon in the printing production process. The reasons for the analysis of wrinkle-up failures in printed products are due to various reasons, including the presence of water-containing anomalies in the paper, and the source of defects in the printed layout; there are reasons for the improper lining process and print pressure; The paper gripper is poorly adjusted or the mouthwash is too small. It is caused by improper paper knocking. Therefore, careful analysis of various wrinkling failure phenomena, and correct grasp of the printing operation and process technology are important measures to prevent the wrinkling of printed products from ensuring the printing quality of the product.
I. Analysis and preventive measures of several phenomena of printed wrinkling failures 1. Wrinkle failure of printed products caused by edge curling of paper We know that paper is sensitive to changes in ambient temperature. If the temperature of the printing environment is not normal, it is easy to cause the paper to undergo stretching and variability. If the moisture content of the paper is too low, the paper tends to be curled around, and wrinkling may easily occur during printing. If the moisture content of the paper is too low, it is also prone to static electricity and it is difficult to achieve normal printing. If the moisture content of the paper is too high, it is easy to make the paper too soft to cause embossing and wrinkling. Therefore, we should pay attention to strengthening the scientific management of paper at ordinary times. The temperature of the paper storeroom should be controlled between 18-22 and the indoor relative temperature should be between 60-70%. The bagged products entering the warehouse should be unpacked and flattened and stacked neatly afterwards. The pile of paper should be high and away from the wall to prevent the paper from absorbing moisture and deforming. In addition, the paper should also be heat-resistant, anti-folding and pressure-proof, which is not only the basic requirement for better prevention of paper warp and deformation, but also the necessary measure to prevent wrinkling of printed products.
1. Wrinkles in printing layout caused by wrinkling and badness of some printing layouts are good, but wrinkling failures still occur during printing. This is due to the reasons of the layout structure, such as the letterpress of printing the solid lines. The moment of contact between the Chinese and Indian sheets and the layout is prone to air resistance, which makes the partial sheets of the printed sheets convex and wrinkle. In addition, the underplating of the cleats plate is uneven and the bottom brackets are not solid enough to cause the printing pressure to be heavy, which may cause the wrinkling defects of the printed products. This should be achieved by adding a good version of the padding technology and reducing the line layout. Pressure to avoid printing wrinkle failure.
2. Wrinkling of printed products caused by unsuitable lining discomfort The lining is the medium for imprint transfer. When the inner and outer lining layers are too soft, the lining is easily stressed after the lining is pressed, and the lining bag is not tight enough. There is a crack in the surface pack liner, the repeated lining or lining of the liner surface, the unstuck of the pad sticker, and the fluttering, etc., are all likely to cause wrinkling of the printed product. Therefore, the printing process should pay attention to a good lining process technology to prevent the lining because of virtual loose pressure, uneven surface caused by printing products wrinkle failure.
3. Wrinkle of printed products caused by worn and loose parts of equipment When the critical parts of the machine are used, the parts added with the linkage roller are worn out and lose their precision, so that the machine is imprinted with traces of looseness. Slippage occurs. This is also the result of printing certain layouts and the source of the paper creping. To this end, peacetime should pay attention to strengthening the maintenance and repair of equipment, so that the key parts of the equipment to maintain good lubrication and high accuracy, to prevent the occurrence of axial or radial loose parts between the phenomenon of occurrence, reduce the occurrence of printing wrinkling Opportunity.
Second, a number of printing products wrinkles occur processing methods 1, the paper knock processing, improve the printability of paper for thin or lack of flatness due to deformation and stiffness of the paper, such as the printed copy of the mouth curled In an unfavorable situation, it is necessary to make a physical change in the paper by knocking the edge of the paper to improve the flatness and firmness of the edge of the seal. As for the phenomenon of curling in the paper surface, a horizontal knocking or vertical knocking may be adopted as appropriate, so that the printed sheet can obtain the flatness required for printing so as to eliminate the wrinkling of the printed product.
2. Adjust the printing pressure to eliminate the wrinkling defects caused by uncomfortable printing pressure. For flexible papers that are prone to wrinkling of printed products, the printing should be as far as possible to meet the requirements for the ink volume of the layout in order to prevent the lack of ink on the layout. The misuse of printing pressure caused the printed sheets to wrinkle. In addition, the adjustment of the printing pressure should be achieved through the underpad as much as possible, and the underpad must be cushioned with the pad balance. To avoid large-area shimming on the outer liner, and even repeatedly outlining the inner liner, this is also an effective method to prevent wrinkling of the printed product. .
3. Adjust the pressure of the roller gripper and the position of the crepe paper to eliminate the wrinkle-up failure of printed products caused by mishandling of printed sheets.
When the pressure of the roller is not uniform, or the positional discomfort of the paper makes the corners of the paper not aligned with the teeth, and the defective condition of the paper is too small, it is easy to make the paper in the rolling process. The unevenness causes the printed product to wrinkle. In this regard, the pressure of the teeth and the position of the printed sheet in the row of teeth should be adjusted so that the paper polygon enters the bite position and the amount of the mouth opening is appropriately increased, so that the teeth are tightly pressed against the paper edge to avoid embossing and slippage. The occurrence of the shift was eliminated to eliminate the wrinkle failure of the printed product.
4, adjust the machine brush device, so that the print service flat close to the drum, eliminate the printing sheet fall caused by the printing press automatic printing press to ensure the quality of printing, in the drum press line part of the line with a row of flat paper brush mechanism, When printing soft and thin paper, if the brush overtightens the printed sheet on the surface of the roller, the wrinkling of the printed product is likely to occur. Should loosen the hair brush properly, it can eliminate the wrinkling problem of printing products.
In short, as long as we carefully sum up experience in practice, we carefully analyze and study various wrinkling phenomena of the printed products, and take various preventive measures to implement, from the source of the fault, to technical and technological control. , You can minimize or avoid various features of the printing product wrinkle failure, to ensure product printing quality. (Kang Qilai) ("China Packaging News and Printing Weekly")
I. Analysis and preventive measures of several phenomena of printed wrinkling failures 1. Wrinkle failure of printed products caused by edge curling of paper We know that paper is sensitive to changes in ambient temperature. If the temperature of the printing environment is not normal, it is easy to cause the paper to undergo stretching and variability. If the moisture content of the paper is too low, the paper tends to be curled around, and wrinkling may easily occur during printing. If the moisture content of the paper is too low, it is also prone to static electricity and it is difficult to achieve normal printing. If the moisture content of the paper is too high, it is easy to make the paper too soft to cause embossing and wrinkling. Therefore, we should pay attention to strengthening the scientific management of paper at ordinary times. The temperature of the paper storeroom should be controlled between 18-22 and the indoor relative temperature should be between 60-70%. The bagged products entering the warehouse should be unpacked and flattened and stacked neatly afterwards. The pile of paper should be high and away from the wall to prevent the paper from absorbing moisture and deforming. In addition, the paper should also be heat-resistant, anti-folding and pressure-proof, which is not only the basic requirement for better prevention of paper warp and deformation, but also the necessary measure to prevent wrinkling of printed products.
1. Wrinkles in printing layout caused by wrinkling and badness of some printing layouts are good, but wrinkling failures still occur during printing. This is due to the reasons of the layout structure, such as the letterpress of printing the solid lines. The moment of contact between the Chinese and Indian sheets and the layout is prone to air resistance, which makes the partial sheets of the printed sheets convex and wrinkle. In addition, the underplating of the cleats plate is uneven and the bottom brackets are not solid enough to cause the printing pressure to be heavy, which may cause the wrinkling defects of the printed products. This should be achieved by adding a good version of the padding technology and reducing the line layout. Pressure to avoid printing wrinkle failure.
2. Wrinkling of printed products caused by unsuitable lining discomfort The lining is the medium for imprint transfer. When the inner and outer lining layers are too soft, the lining is easily stressed after the lining is pressed, and the lining bag is not tight enough. There is a crack in the surface pack liner, the repeated lining or lining of the liner surface, the unstuck of the pad sticker, and the fluttering, etc., are all likely to cause wrinkling of the printed product. Therefore, the printing process should pay attention to a good lining process technology to prevent the lining because of virtual loose pressure, uneven surface caused by printing products wrinkle failure.
3. Wrinkle of printed products caused by worn and loose parts of equipment When the critical parts of the machine are used, the parts added with the linkage roller are worn out and lose their precision, so that the machine is imprinted with traces of looseness. Slippage occurs. This is also the result of printing certain layouts and the source of the paper creping. To this end, peacetime should pay attention to strengthening the maintenance and repair of equipment, so that the key parts of the equipment to maintain good lubrication and high accuracy, to prevent the occurrence of axial or radial loose parts between the phenomenon of occurrence, reduce the occurrence of printing wrinkling Opportunity.
Second, a number of printing products wrinkles occur processing methods 1, the paper knock processing, improve the printability of paper for thin or lack of flatness due to deformation and stiffness of the paper, such as the printed copy of the mouth curled In an unfavorable situation, it is necessary to make a physical change in the paper by knocking the edge of the paper to improve the flatness and firmness of the edge of the seal. As for the phenomenon of curling in the paper surface, a horizontal knocking or vertical knocking may be adopted as appropriate, so that the printed sheet can obtain the flatness required for printing so as to eliminate the wrinkling of the printed product.
2. Adjust the printing pressure to eliminate the wrinkling defects caused by uncomfortable printing pressure. For flexible papers that are prone to wrinkling of printed products, the printing should be as far as possible to meet the requirements for the ink volume of the layout in order to prevent the lack of ink on the layout. The misuse of printing pressure caused the printed sheets to wrinkle. In addition, the adjustment of the printing pressure should be achieved through the underpad as much as possible, and the underpad must be cushioned with the pad balance. To avoid large-area shimming on the outer liner, and even repeatedly outlining the inner liner, this is also an effective method to prevent wrinkling of the printed product. .
3. Adjust the pressure of the roller gripper and the position of the crepe paper to eliminate the wrinkle-up failure of printed products caused by mishandling of printed sheets.
When the pressure of the roller is not uniform, or the positional discomfort of the paper makes the corners of the paper not aligned with the teeth, and the defective condition of the paper is too small, it is easy to make the paper in the rolling process. The unevenness causes the printed product to wrinkle. In this regard, the pressure of the teeth and the position of the printed sheet in the row of teeth should be adjusted so that the paper polygon enters the bite position and the amount of the mouth opening is appropriately increased, so that the teeth are tightly pressed against the paper edge to avoid embossing and slippage. The occurrence of the shift was eliminated to eliminate the wrinkle failure of the printed product.
4, adjust the machine brush device, so that the print service flat close to the drum, eliminate the printing sheet fall caused by the printing press automatic printing press to ensure the quality of printing, in the drum press line part of the line with a row of flat paper brush mechanism, When printing soft and thin paper, if the brush overtightens the printed sheet on the surface of the roller, the wrinkling of the printed product is likely to occur. Should loosen the hair brush properly, it can eliminate the wrinkling problem of printing products.
In short, as long as we carefully sum up experience in practice, we carefully analyze and study various wrinkling phenomena of the printed products, and take various preventive measures to implement, from the source of the fault, to technical and technological control. , You can minimize or avoid various features of the printing product wrinkle failure, to ensure product printing quality. (Kang Qilai) ("China Packaging News and Printing Weekly")
Packing Tape,Hot Melt Tape Printing Adhesive Tape Co., Ltd. , http://www.nspackingtape.com