Improvement skills of the connection and cutting o

2022-08-22
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At present, the competition in the cigarette market is quite fierce, and many cigarette enterprises have unique die-cutting sizes. Therefore, printing enterprises have increased their choices in this regard, increasing production varieties and improving the level of cigarette decoration as the main means of equipment investment and strengthening technological transformation to ensure that gravure printing function can adapt to multi stimulus consumption. Although the varieties have increased, the total varieties and small batch production requirements. At present, the general gravure machine manufacturers are unable to go up, resulting in a reduction in the number of single varieties. In this case, only one or two sizes are provided, which simply cannot meet the production demand of multiple varieties of gravure printing machines with line die cutting and slitting. If you order from the original manufacturer, plus the decoration size and large sheet size supporting system suitable for the packaging machine of each cigarette enterprise, the price is very expensive. There are some differences in the general small printing specifications, and each variety needs to be used. A single enterprise will not be able to bear it

factors that should be considered in the design of gravure press

1. Designing a new transmission system is a thorough and complex work, and all relevant factors should be considered to ensure that the new transmission system meets the production needs. Different prints have different sizes. First of all, it should be classified according to the type and maximum size of packaging machinery. Those with small difference in maximum size can be classified in the same grade; The difference between the maximum size and the minimum size of products of the same grade can be controlled at about 20mm according to the different production enterprises. In this way, it will not cause paper waste, but also increase the applicability of the new design system. After the size of the product is determined, because the large sheet of paper that is cut out is usually die-cut on the platform die-cutting machine, in order to ensure that the large sheet size is suitable for the needs of product die-cutting, the size of its mouth, waste edge and excessive color should be added to the size of the original product. After fully considering the maximum size and other factors, the comprehensive size of the new product is finally determined and its original large size is compared. At the same time, we should also consider the future production capacity and determine whether to use the original large slitting size for processing. If the potential of the future market is particularly large, we should fully consider the utilization rate of paper and reduce paper consumption

2. The difference between the new size and the original size. After the new size is determined, compare the new size with the original size to see how much the difference is. If the difference between the two is less than 2mm, there is no need to carry out technical transformation of the equipment, only need to make local adjustments to the equipment. It can directly make printing plate equipment, and can also cut out the required size according to the overprint mark

3. If the difference between the two is 2mm-5mm, the transformation of the transmission system (i.e. the change of gear parameters) can be omitted, and the design requirements can be achieved by designing and processing a new paper feeding roller

4. If the difference between the two is more than 5mm, it is necessary to design another transmission system and paper feeding roller. If the data provided by the gravure machine manufacturer has a gear and size correlation table, it can be used as a basis in the design process to compare the printing size and slitting size respectively. The new large sheet size needs to be within the range of both at the same time to be used normally

the relationship between printing and slitting

1. In the production process of printing and slitting on gravure press, the linear speed is the same, but the rotation speed of printing plate and slitting cylinder is different. Therefore, it is necessary to consider the transmission relationship between the two and understand whether the speed ratio is 1:1, 1:2 or 3:2, which is closely related to the design of the whole transmission system. In the design process, one of them (generally the printing speed) can be determined as the main transmission ratio and the cutting speed

2. The circumference range of the printing plate cylinder. Each gravure press is applicable to a different range of plate cylinder circumference

design step 1) determine the new large sheet size, and at the same time, consider the product color transition, color interval, die-cutting waste edge and die-cutting double blades. At least 2mm shall be added for color transition; The color interval, die cutting waste edge and die cutting double knives should ensure a machining allowance of more than 5mm to meet the requirements of die cutting processing. According to the layout drawing, determine the final large size. At this time, try to round this size according to the upper limit. The main purpose is to facilitate the production of printing plates and die-cutting plates in the future. Comparing the new large size with the original large size, the gap is relatively large, more than 5mm. Considering that the future market demand is more important than the microcomputer controlled steel wire rope special experimental machine, which is used for the tensile and destructive experiments of various steel wire ropes, bolts, anchor chains, riggings, shackles and other test pieces, it is necessary to design the data display and cutting system of the new large size

2) design the system layout. After determining the new large sheet size, start to analyze the transmission system of the gravure press to determine which parts need to be changed and the parameters of which parts need to be changed. For this reason, the gravure press can be divided into three parts: uncoiling part, printing part and slitting part. The uncoiling part is a driven part in the transmission system from raw materials to equipment suppliers, and its control is based on the paper demand, so the transmission system of this part does not need to be changed. The printing part is the core of gravure press. Due to the different diameter of the printing plate cylinder, the linear speed of the printing plate cylinder is different under the same rotating speed, and the demand for paper by the time of determining the unqualified position of this batch of joints is also different. Moreover, the tension of the printing part is controlled by the relative paper feeding amount and paper output amount of the paper feeding roller and paper output roller of the printing part. It can be seen that when the size of the large sheet changes, the linear speed of the paper feeding roller and the paper outlet roller needs to be changed, that is, the transmission parameters need to be changed. The slitting part is the key to the design of slitting size. Therefore, the transmission parameters of the paper feeding roller need to be changed. The design of the transmission system of the slitting part is the focus of the large slitting

3) the change of the linear speed of the paper feeding roller in the slitting part should not change the parameters of the original gear as far as possible, and the diameter of the paper feeding roller should be changed to realize the change of its linear speed. If the linear speed changes greatly, you can consider changing the gear parameters and changing the diameter to achieve the required linear speed

4) map the original gear. After determining which gears need to be redesigned, the original gears in this part need to be mapped. This is the key to ensure the correct meshing and slitting accuracy of the new gear on the equipment. Generally, it is necessary to measure the diameter of the tooth tip circle, the full height of the tooth, the spiral angle, the width and the size of the installation structure. Among these parameters, the helix angle is difficult to measure, and it would be better if it could be measured at the gear manufacturer

5) design new gears. According to the measured parameters of the original gear and the requirements of the new transmission system, the newly designed parameters such as modulus, number of teeth, helix angle, addendum height coefficient, pressure angle, width and installation structure size are finally determined through reverse calculation and calculation. After these parameters are determined, the installation structure dimensions are designed according to the installation requirements. Finally, the machining drawings of gears are drawn and the basic parameters of gears are listed

author/(Quan Dong)

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