The reason for the low accuracy is the problem of the die-cut version and the problem from the printed matter. The hand-made die-cutting plate has a large error; the difference between the die-cutting indentation and the printing operating environment will cause the paper to deform, resulting in the inaccurate position of the die-cutting indentation, especially the varnished and coated paper deforms more seriously and affects Die cutting accuracy.
Solution: Choose an advanced plate-making method to improve the accuracy of the die-cutting plate: try to ensure that the die-cutting indentation and printing are performed in the same working environment or the identity of the working environment (ie, have the same temperature, humidity, etc.); The printed sheets of light and film should be pre-processed by die cutting to minimize the impact of paper deformation on the accuracy of die cutting.
2. Die-cutting indentation produces burst and dark lines
"Burst line" means that the die cutting indentation pressure is too large, exceeding the cardboard fiber's bearing limit, causing the cardboard fiber to break or partially break; "dark line" refers to the indentation line that should not be there. Generally, it is caused by improper selection of die-cutting plate and indentation steel wire, improper adjustment of die-cutting pressure, poor paper quality, paper fiber direction inconsistent with die-cutting plate cutting knife direction or low moisture content of the paper, resulting in a decrease in paper flexibility of.
Solution: Choose the appropriate die-cutting plate; properly adjust the pressure of the die-cutting machine; put the paper to be die-cut in the workshop for a period of time before die-cutting; increase the humidity of the workshop environment.
In addition, there is a special case that when die cutting a small box of cigarette packs, because the distance between the indentation lines in many positions is very close, if the height of the indentation steel line is configured as normal, the tensile force on the paper during molding If it is too large, it will also cause a thread burst. Therefore, you should try to minimize the pulling force on the paper. There are two methods: one is to reduce the height of the indentation steel wire; the second is to reduce the thickness of the bottom mold strip of the indentation. The two cannot be used at the same time, otherwise it will not have a good indentation effect. A better method is to reduce the height of the indented steel wire, which is usually 0.1 to 0.2 mm. According to the thickness of the paper, determine the specific reduction. The paper with a certain amount above 350g / m2 should be reduced by 0.2mm, and the paper below 350g / m2 should be reduced by 0.1mm.
3. Positioning of the indentation line. Not full
The indentation of the indentation steel wire under the action of the die-cutting pressure will cause the indentation line to run; insufficient die-cutting pressure will cause the indentation to be not full. Replacing the die cutting plate and increasing the die cutting pressure respectively can improve this problem.
4. Die cutting fluff and dust
During die cutting, the phenomenon that the edge of the die-cut product is not smooth and fluffy often occurs, especially some of the edges closer to the indentation line are more serious. This is because when the die cutting and pressing, the rubber strip and the indentation steel wire on the die cutting plate produce a pulling force on the paper, and the burr occurs when the paper is not completely cut through the generated pulling force.
To solve this problem, we must first choose different types of die cutters according to the paper. Die-cutting knives include straight-edged knives and horizontal-edged knives, and the blades of the two lines are also divided into high and short. The pattern formed by the blade is different from the height, which is directly related to the quality of die cutting of different types of paper and the service life of the die cutting knife. In terms of avoiding paper wool, straight-edged knives are better than horizontal-edged knives; in terms of service life, short-edged knives are better than high-edged knives. When die-cutting film-laminated paperboard, straight-line high-fronted blades should be used, and the blades are required to be ground. It is best not to use a one-time forming process of pressing and bumping, otherwise too much pressure will cause a large impact on die cutting. When processing ordinary cardboard, it is better to choose short-edged blades, and determine the texture of the blades according to the paper fiber quality. When die-cutting paper with poor fiber or thicker, straight grain knife is used, and when the fiber quality is better, horizontal grain knife can be used to increase the service life of the knife.
It is also possible to affix a 60 ° arched rubber strip to the die cutter closer to the indentation steel line to reduce the tensile force of the indentation steel wire near the die cutter on the paper during die cutting and pressing. For example, when die-cutting paper with a fixed weight of 300g / m2, 0.4mmx 1.3mm indentation line and 23.4mm high indentation steel line are usually used. If this fault occurs, 0.4mmx1.2mm indentation line can be used instead. 23.3mm high pointed creasing steel wire. In this way, the pulling force on the paper during die cutting and pressing is reduced, and the fluff problem can be basically solved.
5. Die cutting "pasted version"
Die-cut "pasted plate" means that the paper sticks to the die-cut plate. The reasons for this kind of failure are: the density of the sponge rubber sticking around the die cutter is too low or the hardness is too low, and the resilience is not enough; the edge of the die cutter is not sharp, the paper is too thick, causing the clamp knife or sticking the knife during die cutting. According to the distribution of die-cutting knives, it is reasonable to choose sponge strips with different hardness or replace the die-cutting knives.
6. Die cutting "bulk version"
Die-cut loose plate is mainly related to plate-making process and sponge rubber strip. If the shapes of the live parts are complicated or there are many arranged live parts, and the connecting points on the die-cutting plate are small and few, it is easy to cause the loose version during die-cutting. In this regard, it is necessary to increase the number of connecting points appropriately. In addition, when making a die-cut plate, try to keep the length of the printed product in the same direction as the paper feeding direction. The stripping sponge strip attached to the die-cutting plate has a low hardness and is too soft to allow the paper to be smoothly separated from the die-cutting knife or the indentation steel wire, which will also cause loose printing. The solution is to use high-quality sponge rubber strips with high hardness and good elasticity.
Clean Paste Stains
The stain is a simple and powerful cleaning agent specially designed for deep cleaning of the ink roller, which has no elasticity and no damage to itself; removes ink stains, mirrors, and restores the elasticity of the ink roller (and blanket); Removes deep gel and smog; non-wearing
No residue on the surface of metal or rubber; colloidal, convenient and practical.
Clean paste Product parameters
Place of Origin: Shanghai, China
Weight: 330g / support
Storage conditions: put in the exercise, in the shade
Clean paste Instructions
For the ink roller: first wash off the wet ink, apply a proper amount of the spray paste on the drive roller, run at low speed for 5-10 minutes, then wash it off with car wash water, repeat steps if necessary.
For skin-like cloth: hand-apply the stain on the blanket and let it absorb it. It can be placed for one night, then thoroughly cleaned, then avoid the plate.
Clean paste Features
1. Clear ink stains, mirrors, and restore the elasticity of the ink roller (rubber)
2. Effectively clear deep gel and smog; no residue on metal surface
3. The colloid is convenient and practical. Deep cleaning improves ink delivery performance.
4. Reduce downtime and make it more economical.
5. Containing benzene, it does not damage human health, is not flammable, and is safe to use.
Clean Paste
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Shanghai Chenjie Printing Material Co., LTD , https://www.shprintbar.com