First , the reason analysis
1. Effect of paper properties on die-cutting
PET film is very suitable for the development and application of general high-end brands due to its high surface gloss and flatness, strong folding-resistance, and good packaging. However, PET film has a strong toughness and tear resistance, making this product In the post-processing die-cutting process, quality problems such as constant die cutting and fuzzing are easily generated. The usual solution is to increase the die-cutting pressure during the actual processing operation, which in turn has a certain impact on the service life of the die cutter and thus cannot achieve the purpose of the cure. In contrast, the use of OPP film composite material is thinner than PET film, poor toughness, fluffing phenomenon in die cutting is much less. If you change to vacuum aluminum-plated transfer silver cardboard, you can fundamentally solve this problem. Therefore, we can determine that PET film paper is the objective cause of die-cutting.
2. Effect of die cutting operation on die-cutting
The implementation of correct and standardized equipment operation steps is an effective means to alleviate the above problems. Although paper is the objective cause of die-cutting, the operator's level of operation is also a major cause of instability. For example, improper operation or excessive pressure will cause the blade and the steel base plate to collide too much and directly hit the cutting edge of the die cutter. Continuous pressure and frequent plate changes after formal production are also subjective causes of blade damage. If they are not discovered or are not replaced in time, they may cause paper dust and burrs to appear to varying degrees. This imposes higher requirements on the operator's proficiency, skills, and experience. So a skilled operator must not only understand the indentation effect, but also the mechanical pressure needed for different paper materials.
3. The effect of die-cutting plate material on die-cutting fleece The choice of die-cutting plate material and safety
Loading is an effective way to improve the quality of die-cutting and reduce the number of cuts. First, a high quality die cutter should be used. In the general high-grade die-cutting blade front, using a magnifying glass to observe, will also find a lot of flaws, the blade is not straight, not smooth. Some die cutters look very sharp on the surface, but they are poor in rigidity. The blades will be worn out in a short time and cause fluffing on the edges of the paper, resulting in burrs. In addition, some die-cutting fuzzing is caused by improper installation of die cutters and sponge strips. The sponge strip should have sufficient hardness to compress the paper and allow the die cutter to cut the paper smoothly. Different papers use sponges of different hardness, and the placement and height of the sponges are also emphasized, otherwise they cannot achieve their intended effects. Therefore, the selection, matching and setting of process parameters on these materials have a direct impact on the die cutting effect.
Through the analysis and summary of the above three aspects, we can see that if you want to fundamentally solve the problem of die-cutting, only the paper is changed to aluminum-plated paper, which can meet the "green environmental protection" and "clean production" of the tobacco factory. Claim. However, the performance of aluminum-coated paper is not as good as the surface gloss, flatness, folding endurance, and packaging of the PET film. It will inevitably affect the printability and the packaging effect of the machine, which is reflected in the brightness and resistance of the ink. Folding, abrasion resistance and many other aspects. Therefore, at present, only from the standard operation, adjustment of process routes, use appropriate die-cutting materials to improve it, reduce or reduce the occurrence of the problem.
Second, solve the plan
1. Operation specification
According to the particularity of paper-cutting and fluffing, we have drafted the following standard operating procedures for your reference and implementation.
1 Loading plate: When a new knife plate is first tested on the machine, the pressure during the debugging process must be light. After the plate is printed, the product is pressure tested. The pressure during the debugging process can be clearly marked on the paper. .
2 pressure test die cutting: Under the steel pad at the bottom of a large area of pad pressure, the paper should be thinner than the thickness of 90 g/m2 coated paper thickness is appropriate, after the test pressure to observe whether the knife at the mouth is easy to separate. The ideal pressure is that the edges of each incision are just separated. At this time, the pressure of the machine is the minimum and the pressure is the most suitable. The die cutting edge is smooth, lint-free and easy to separate, and the die cutter is not easy to wear. When the die-cutting machine starts to adjust the pressure, it should be adjusted to about 20% first, and then according to different positions, a partial pad is used to balance the pressure, and then the pressure is locked to formally die-cut.
3 adjust the pressure: do not cut through the place to do a partial pad of paper processing, so that the layout of the die cutter pressure uniform, and then gradually increase the pressure of the machine.
4 Formal die cutting: The pressure is locked, the speed is controlled at 4 500 pieces/hour, and the pressure is about 42 tons. In the process of die-cutting, the overall blade will become blunt, and individual blades will be chipped or the olecranon will fall off. At this time, the operator will be required to change the blade. The tool change also needs to consider that the blade of the new blade will usually be higher than the blade of the old blade. This not only has good die cutting effect, but also has high production speed and high production efficiency.
2. Die cutting material
The selection and installation of die cutters and sponge strips is also one of the reasons that affect die-cutting quality. Different paper cutters and sponge strips should be used for different papers. The reason for the paper-cutting and fluffing is that the paper is pulled by the mechanical pulling force after the die cutter is dulled. Therefore, the sponge strip and the die-cutting knife with strong hardness can be used. The sponge strip can clamp the paper and reduce the pulling force of the mark on the paper.
When choosing a high-quality die cutter, you should pay attention to selecting the peak or dwarf cutter according to the thickness of the die-cut material, and pay attention to the horizontal or vertical ruler of the cutter. The knife with horizontal stripes is more effective and durable for die-cutting paper, with higher stability and precision, and it is not easy to crack after bending. Therefore, manufacturers of long-term die-cut cigarette cases can use dwarf cross-cut die-cutting knives because the stiffness of the blade peaks of the dwarf peak cutters is higher than the peak, so the pressure is more stable and the durability is more lasting.
3. Process adjustment
In order to reduce the impact of frame lines and marks on die-cutting quality, the effect of die-cutting should be further improved. The processing technology can be adjusted from the original pressing frame, indentation, and die-cutting process to the first pressing frame, then indentation, die cutting, and preparation of special steel template (without pressure frame). Sponge strips are all 60° solid sponge strips, and special planes can also be assigned to special editions responsible for die cutting of severe fuzzing products. That is, after checking the condition of the equipment, a high-precision, pressure-stable die-cutting equipment is specified to die-cut the product. This will not only reduce the number of plate changes, and reduce the problem of fluffing due to the damage caused by the die cutting knife due to plate change debugging, but also lays the foundation for the stability of batch product quality. In addition, it is possible to select excellent pilots with rich experience and skills from the position of the die-cutting machine commander. This will not only enable operators to build up more experience on a relatively single brand, but also help them find problems and obtain timely results. To solve, but also to provide technical support for improving product quality. The so-called special edition is to replace the wood stencil with the above steel stencil. Because the steel stencil does not have a base film, the force deformation of the paper in the die cutting process is much smaller, so the situation of paper fluffing will also be reduced.
In addition, with the improvement of the plate making process, the flat-die die cutting machine can follow the roll-to-roll die-cutting process in the die-cutting mode. First, the indentation and then the die-cutting, so that the constraints on the paper in the die-cutting process will be less. The paper is completely die-cut in the flat state. Theoretically, there will be no traction force on the paper caused by the indentation line, and the paper cannot be torn off.
Through the implementation of the above improvement scheme, the paper cutting and raising status will be effectively controlled and improved. With the acceleration of the country’s progress in the promotion of environmental protection paper, the improvement of die-cutting materials in the plate-making factory, the continuous improvement of die-cutting techniques and equipment, and the failure to clean the paper after the cigarette bag has been cut, and the common problems of fluffing will be overcome.
