Problems to be Solved in Gravure Printing Machine Upgrade
The upgrading of the gravure printing machine must also solve the problems associated with the existing equipment, such as the mechanical transmission accuracy of the original gravure printing machine, the registration system, the tension control, and the upgrade and transformation of the electrical control system, and the new addition of waterborne varnish Dry, UV varnish curing functions.
1. The mechanical transmission accuracy of the original gravure printing machine
The original gravure printing machine has been used for a certain number of years after all. The main mechanical transmission gear box will have a large degree of wear and tear. Fuji Xerox will have a greater degree of wear and tear. Therefore, when the equipment is upgraded and reformed, the mechanical wear of the original equipment should be fully analyzed. After the upgrade, the accuracy of the entire production line will be affected (within ±0.15mm). If the gravure printing machine loses the accurate combination of registration accuracy with the increase of the color group, even if there are more color groups, no high quality products can be produced.
2. Register control system
The original register control is another key step in the upgrading of the gravure printing machine. It determines the grade of the gravure machine after the transformation. If the registration error between the modified gravure color groups reaches ±0.30 mm, or even more, such a gravure printing machine merely increases the number of color groups that can be printed at the same time, and may only serve the low-grade product making. However, this is not the real purpose of upgrading the gravure printing machine. For the upgrade register control system, the market is now a standard system, the key is to match with the gravure printing machine, if possible it is also necessary to increase the horizontal automatic register control, so that it can better solve the printing set Quasi-accuracy problem. Combination printing
3. Tension control system
The tension control system is upgraded to print on demand, mainly to solve Infeed and Outfeed control. Now the best solution is to use a servo motor to directly control the paper feed roller and paper exit roller to reach the entire unit. The gravure tension is stable. Of course, there are still many gravure presses that increase the accuracy of the tension control. The tension of each color group is also a separately controlled font. The newly added color group also needs such a control method.
The original tension control system of the gravure printer still has a great shortcoming in adapting to the change of the current paper tension, especially in the case of high-speed operation, this aspect is reflected more clearly. But you can see a new phenomenon, the newly purchased gravure printer is very adaptable to the range of paper tension changes. Packing material, paper that cannot be used due to paper tension change on the old gravure printing machine, newly purchased concave There is no problem using it on a printer. The main reasons are as follows: First, the new gravure printing press has greatly improved the tension control precision, and the tension control precision can reach 0.2N; secondly, the commonly used servo motor driven paper feed rollers; The unwinding machines of the printer are all zero-speed tying modes, and are equipped with a paper storage device, so that the paper tension is corrected to a certain degree, or the paper is pre-tensioned by the paper storage device, which is better Solve the problem of paper tension changes. However, because there are no retrofit cases in the upgrading of gravure printing machines, it is only a theoretical analysis.
4. Drying of waterborne varnish
The original gravure printing machine can only print solvent-based varnish, but with the improvement of the environmental protection requirements of the cigarette package, customers now basically require the use of water-based varnish. There are two special printing methods for water-based varnish drying, one is high-temperature short-range drying, the other is low-temperature long-distance drying. The old gravure printer can only choose the first drying method due to the limitation of the oven size, but it is prone to problems such as large paper deformation, poor drying effect, insufficient thickness of the waterborne gloss coating layer, and insufficient brightness of the waterborne varnish. The second drying method is now the design of the new air duct, fully considering the requirements of the water-based varnish on the drying tunnel, increasing the running distance of the paper in the oven, and increasing the air volume for drying hot air, so that it can be compared. Achieve a better drying effect at low temperatures, but also fundamentally solve the problem of paper deformation. Regional reports
5.UV Varnish Curing
Now, the amount of composite paper used on cigarette packs is increasing. Especially for laser composite paper, if the cigarette pack products printed on such substrates are subjected to water-based gloss coating, the anti-friction effect of the printing ink layer is very poor and must be used. UV varnish coating can meet the requirement, so it is necessary to add UV varnish curing function to the original gravure printing machine. The current ink supply, UV curing effect mainly depends on the following five important conditions: First, the printing speed; Second, whether the use of low temperature light source, low temperature light source to solve the problem of paper fire and paper deformation; Third, whether the power is adjustable, is Two-level, four-level and other multi-level power adjustment, or 40%-100% stepless power adjustment, can solve the problems of coating of various cigarette pack products and future UV ink curing; Fourth, UV curing units can only be A color group dedicated packaging trade, or in several color groups can be universal, if it is universal, you can increase the flexibility of UV curing unit position; Fifth, the UV lamp power should be strong enough, or easily cause UV Varnish Incomplete cure.
6. Pre-control of paper moisture
With the emergence of a large number of products such as full-screen halftone patterns and multi-color superimposed mesh patterns, the demand for halftone patterns is now increasing. When printing such cigarette pack products, Esko required the installation of electrostatic ink transfer devices on 3-4 color groups to achieve the fine mesh print pattern printing requirements. The printing screen adjustment is not the strong point of the gravure printing machine, especially considering that the first color group needs to use the electrostatic ink transfer device, so it is necessary to control the moisture of the paper. It is recommended that before entering the process color group, the infrared and hot air drying policies and regulations should be adopted, and the low-temperature and long-distance drying mode should be adopted to effectively control the moisture content of the paper and ensure the stable use of the electrostatic ink transfer device in the printing process.
Gravure Printing Machine Upgrade Notes
In order to ensure the smooth progress of the gravure printing machine's upgrade and transformation work and ensure the expected results, it is necessary to pay attention to the following issues.
1. Contradiction between upgrade and production
Under normal circumstances, the original gravure printing machine must also undertake certain production tasks. Taking into account the implementation cycle of upgrading and transformation and the existing technical risks, the impact of upgrading on the production must be taken into account in the preliminary planning. By ordering production in advance or transferring to other machines to produce Heidelberg [product news space], and converting to external processing and production, etc., to ease the pressure of production. At the same time, it can also ease the impact on production by adjusting the upgrade program. First, you can consider increasing the position of the color group. If you increase the activity outside the line, the impact on the original equipment is minimal. You can also consider adding the color group between the first color group and the uncoiler, so that only the unwinder is moved and the number of color groups increases. The way of passing the paper rack can also reduce the impact on the original equipment. Second, it is possible to consider the addition of color groups and the registration system and the control system upgrade to synchronize the publication dynamics. This can also reduce downtime, and can avoid new problems in the registration system and control system after adding color groups.
2. Impact on device layout and appearance
Because the equipment manufacturers can now use the non-shaft drive technology to add color groups, their basic idea is to not move the original equipment as much as possible, and it is more appropriate to increase the number of equipment outside the equipment. Nowadays, printing companies not only have to do a good job of supplying ink for products, but also have high requirements for production sites, which will affect the layout of equipment. Therefore, when formulating a plan, we must carefully consider the retrofit programs for those newly added color groups and equipment that are 90°. If this is implemented, the original layout report will be changed. Even the logistics of the machine platform needs to be readjusted. Moreover, it is not yet possible to predict the horizontal control of paper after turning 90°. The appearance mainly involves the addition of waterborne glazing ovens or UV curing ovens, or even an increased color group. Its appearance size and color should be consistent with the original equipment as far as possible so that the integrity of the entire production line can be maintained. Ink
3. Matching new features and original features
This is mainly because the operator is already familiar with the operation of the original equipment, and if the new function matches the original function, there is no need to train the newly added color group and function. For example, the embossing roller, printing plate, ink tank, squeegee, and register adjustment, etc., should be used as far as possible with the original function to support the use, do not specifically produce for the newly added color group, otherwise it is not only not easy to manage printing Education will also increase the difficulty of operators. At the same time, we should also take into account the problem of the separation pressure sequence of the color group, the opening and stopping sequence of the oven, etc., which have a great impact on the operation. It must be consistent with the original equipment. It is best to be able to make these color groups according to the original equipment. Order automatic control.
4. Acceptance standards for equipment modification
In order to ensure the smooth implementation of equipment transformation, in the development of detailed technical standards at the same time as variable data printing, it is also necessary to formulate the acceptance criteria for equipment transformation, not only locking down the expectation of various technical indicators for the transformation of equipment, but also enabling the implementation of equipment transformation. Conduct inspections. Several key factors that must be taken into account in the acceptance criteria are: register accuracy, speed, light oil printing effect, interchangeability of pressure rollers and printing plates, etc., some key indicators such as transformation progress, completion time, etc. In order to take these indicators into consideration, it is also necessary to consider how to perform assessment and layoffs on these indicators and reach consensus with the equipment reformer in advance so as to avoid contradictions due to inconsistencies between the two parties. Especially in the case of not upgrading the register system, how to reasonably formulate the accuracy requirements after the upgrade must be carefully considered.
It is the dream of many cigarette pack printing companies to upgrade the original gravure printing machine. However, in the face of some not-so-complete scheme labels and even immature technologies, many printing companies have chosen to purchase new equipment or suspend renovations. I hope that this article can give printing companies some inspirations to help them successfully complete the upgrading of the original gravure printing press, and better adapt to the current cigarette package printing process requirements.
The upgrading of the gravure printing machine must also solve the problems associated with the existing equipment, such as the mechanical transmission accuracy of the original gravure printing machine, the registration system, the tension control, and the upgrade and transformation of the electrical control system, and the new addition of waterborne varnish Dry, UV varnish curing functions.
1. The mechanical transmission accuracy of the original gravure printing machine
The original gravure printing machine has been used for a certain number of years after all. The main mechanical transmission gear box will have a large degree of wear and tear. Fuji Xerox will have a greater degree of wear and tear. Therefore, when the equipment is upgraded and reformed, the mechanical wear of the original equipment should be fully analyzed. After the upgrade, the accuracy of the entire production line will be affected (within ±0.15mm). If the gravure printing machine loses the accurate combination of registration accuracy with the increase of the color group, even if there are more color groups, no high quality products can be produced.
2. Register control system
The original register control is another key step in the upgrading of the gravure printing machine. It determines the grade of the gravure machine after the transformation. If the registration error between the modified gravure color groups reaches ±0.30 mm, or even more, such a gravure printing machine merely increases the number of color groups that can be printed at the same time, and may only serve the low-grade product making. However, this is not the real purpose of upgrading the gravure printing machine. For the upgrade register control system, the market is now a standard system, the key is to match with the gravure printing machine, if possible it is also necessary to increase the horizontal automatic register control, so that it can better solve the printing set Quasi-accuracy problem. Combination printing
3. Tension control system
The tension control system is upgraded to print on demand, mainly to solve Infeed and Outfeed control. Now the best solution is to use a servo motor to directly control the paper feed roller and paper exit roller to reach the entire unit. The gravure tension is stable. Of course, there are still many gravure presses that increase the accuracy of the tension control. The tension of each color group is also a separately controlled font. The newly added color group also needs such a control method.
The original tension control system of the gravure printer still has a great shortcoming in adapting to the change of the current paper tension, especially in the case of high-speed operation, this aspect is reflected more clearly. But you can see a new phenomenon, the newly purchased gravure printer is very adaptable to the range of paper tension changes. Packing material, paper that cannot be used due to paper tension change on the old gravure printing machine, newly purchased concave There is no problem using it on a printer. The main reasons are as follows: First, the new gravure printing press has greatly improved the tension control precision, and the tension control precision can reach 0.2N; secondly, the commonly used servo motor driven paper feed rollers; The unwinding machines of the printer are all zero-speed tying modes, and are equipped with a paper storage device, so that the paper tension is corrected to a certain degree, or the paper is pre-tensioned by the paper storage device, which is better Solve the problem of paper tension changes. However, because there are no retrofit cases in the upgrading of gravure printing machines, it is only a theoretical analysis.
4. Drying of waterborne varnish
The original gravure printing machine can only print solvent-based varnish, but with the improvement of the environmental protection requirements of the cigarette package, customers now basically require the use of water-based varnish. There are two special printing methods for water-based varnish drying, one is high-temperature short-range drying, the other is low-temperature long-distance drying. The old gravure printer can only choose the first drying method due to the limitation of the oven size, but it is prone to problems such as large paper deformation, poor drying effect, insufficient thickness of the waterborne gloss coating layer, and insufficient brightness of the waterborne varnish. The second drying method is now the design of the new air duct, fully considering the requirements of the water-based varnish on the drying tunnel, increasing the running distance of the paper in the oven, and increasing the air volume for drying hot air, so that it can be compared. Achieve a better drying effect at low temperatures, but also fundamentally solve the problem of paper deformation. Regional reports
5.UV Varnish Curing
Now, the amount of composite paper used on cigarette packs is increasing. Especially for laser composite paper, if the cigarette pack products printed on such substrates are subjected to water-based gloss coating, the anti-friction effect of the printing ink layer is very poor and must be used. UV varnish coating can meet the requirement, so it is necessary to add UV varnish curing function to the original gravure printing machine. The current ink supply, UV curing effect mainly depends on the following five important conditions: First, the printing speed; Second, whether the use of low temperature light source, low temperature light source to solve the problem of paper fire and paper deformation; Third, whether the power is adjustable, is Two-level, four-level and other multi-level power adjustment, or 40%-100% stepless power adjustment, can solve the problems of coating of various cigarette pack products and future UV ink curing; Fourth, UV curing units can only be A color group dedicated packaging trade, or in several color groups can be universal, if it is universal, you can increase the flexibility of UV curing unit position; Fifth, the UV lamp power should be strong enough, or easily cause UV Varnish Incomplete cure.
6. Pre-control of paper moisture
With the emergence of a large number of products such as full-screen halftone patterns and multi-color superimposed mesh patterns, the demand for halftone patterns is now increasing. When printing such cigarette pack products, Esko required the installation of electrostatic ink transfer devices on 3-4 color groups to achieve the fine mesh print pattern printing requirements. The printing screen adjustment is not the strong point of the gravure printing machine, especially considering that the first color group needs to use the electrostatic ink transfer device, so it is necessary to control the moisture of the paper. It is recommended that before entering the process color group, the infrared and hot air drying policies and regulations should be adopted, and the low-temperature and long-distance drying mode should be adopted to effectively control the moisture content of the paper and ensure the stable use of the electrostatic ink transfer device in the printing process.
Gravure Printing Machine Upgrade Notes
In order to ensure the smooth progress of the gravure printing machine's upgrade and transformation work and ensure the expected results, it is necessary to pay attention to the following issues.
1. Contradiction between upgrade and production
Under normal circumstances, the original gravure printing machine must also undertake certain production tasks. Taking into account the implementation cycle of upgrading and transformation and the existing technical risks, the impact of upgrading on the production must be taken into account in the preliminary planning. By ordering production in advance or transferring to other machines to produce Heidelberg [product news space], and converting to external processing and production, etc., to ease the pressure of production. At the same time, it can also ease the impact on production by adjusting the upgrade program. First, you can consider increasing the position of the color group. If you increase the activity outside the line, the impact on the original equipment is minimal. You can also consider adding the color group between the first color group and the uncoiler, so that only the unwinder is moved and the number of color groups increases. The way of passing the paper rack can also reduce the impact on the original equipment. Second, it is possible to consider the addition of color groups and the registration system and the control system upgrade to synchronize the publication dynamics. This can also reduce downtime, and can avoid new problems in the registration system and control system after adding color groups.
2. Impact on device layout and appearance
Because the equipment manufacturers can now use the non-shaft drive technology to add color groups, their basic idea is to not move the original equipment as much as possible, and it is more appropriate to increase the number of equipment outside the equipment. Nowadays, printing companies not only have to do a good job of supplying ink for products, but also have high requirements for production sites, which will affect the layout of equipment. Therefore, when formulating a plan, we must carefully consider the retrofit programs for those newly added color groups and equipment that are 90°. If this is implemented, the original layout report will be changed. Even the logistics of the machine platform needs to be readjusted. Moreover, it is not yet possible to predict the horizontal control of paper after turning 90°. The appearance mainly involves the addition of waterborne glazing ovens or UV curing ovens, or even an increased color group. Its appearance size and color should be consistent with the original equipment as far as possible so that the integrity of the entire production line can be maintained. Ink
3. Matching new features and original features
This is mainly because the operator is already familiar with the operation of the original equipment, and if the new function matches the original function, there is no need to train the newly added color group and function. For example, the embossing roller, printing plate, ink tank, squeegee, and register adjustment, etc., should be used as far as possible with the original function to support the use, do not specifically produce for the newly added color group, otherwise it is not only not easy to manage printing Education will also increase the difficulty of operators. At the same time, we should also take into account the problem of the separation pressure sequence of the color group, the opening and stopping sequence of the oven, etc., which have a great impact on the operation. It must be consistent with the original equipment. It is best to be able to make these color groups according to the original equipment. Order automatic control.
4. Acceptance standards for equipment modification
In order to ensure the smooth implementation of equipment transformation, in the development of detailed technical standards at the same time as variable data printing, it is also necessary to formulate the acceptance criteria for equipment transformation, not only locking down the expectation of various technical indicators for the transformation of equipment, but also enabling the implementation of equipment transformation. Conduct inspections. Several key factors that must be taken into account in the acceptance criteria are: register accuracy, speed, light oil printing effect, interchangeability of pressure rollers and printing plates, etc., some key indicators such as transformation progress, completion time, etc. In order to take these indicators into consideration, it is also necessary to consider how to perform assessment and layoffs on these indicators and reach consensus with the equipment reformer in advance so as to avoid contradictions due to inconsistencies between the two parties. Especially in the case of not upgrading the register system, how to reasonably formulate the accuracy requirements after the upgrade must be carefully considered.
It is the dream of many cigarette pack printing companies to upgrade the original gravure printing machine. However, in the face of some not-so-complete scheme labels and even immature technologies, many printing companies have chosen to purchase new equipment or suspend renovations. I hope that this article can give printing companies some inspirations to help them successfully complete the upgrading of the original gravure printing press, and better adapt to the current cigarette package printing process requirements.
Aluminium Die-casting Grill Pan
Aluminium Die-Casting Grill Pan,Diecast Double Sided Grill Pan,Aluminium Oval Grill Pan
HOMEARTS INDUSTRIAL CO.,LTD , http://www.kitchenworks.cc