The solution of the most popular three-dimensional

2022-07-25
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Solution to the quality problem of three-dimensional card book die cutting "Adjustment and transformation is an important process for manufacturing quality and production efficiency. As the card book has special requirements for the process in the die-cutting process, and there are factors affecting the card book quality in varying degrees in the production process, it is necessary to strictly follow the technical requirements of the die-cutting process to avoid quality problems.

the die-cutting process of the card book: making the die-cutting plate or mold - loading the plate - setting the machine pressure - adjusting the rules - sticking the sponge tape - pressure test Die cutting - alignment pressure - formal die cutting - waste cleaning. This is a relatively standardized die-cutting process, but from the point of view of die-cutting products, some products have burrs and paper dust. The marking line is weak, and there are some broken lines

the paper used in the card book is special. Some papers have long fibers and generally do not have burrs and dust. There are also a considerable number of white board papers or white board papers with gray background. The fibers are short, the density is low, the powder drops seriously, and there is a lot of dust after die-cutting, which not only causes burrs but also laborious. In view of this situation, we should choose high-quality die-cutting knife or special-shaped die with good rigidity. The general precision and sharpness of die-cutting tools can not fully meet the requirements. Some die-cutting knives have many defects when they are observed with a magnifying glass. The blade is not straight and smooth, which is one of the reasons for paper dust and burrs. The die-cutting knives of some manufacturers are sharp on the surface, but poor in rigidity. After a short time of use, the blade will be worn, resulting in dust at the die-cutting and window opening of the paper edge or inner page, and the appearance of rough polymer surface material preparation technology. The national engineering laboratory is the key raw materials (special monomers and additives), high-performance resins, polymer surface materials and the central edge of technological research and development and technological innovation. Good die-cutting knives are not necessarily expensive. You can compare different brands of die-cutting knives, select suitable brands, and fix them for targeted use. A good die-cutting knife or die can not only reduce the friction between the knife and paper, make the product smooth and dust-free, but also reduce the wear of machinery and equipment

after the die-cutting plate is put on the machine, the pasted bottom mold paper (knife back paper) shall be pressed to determine the accurate position of the groove line on the bottom mold, except that it affects the different center of the jaw. However, due to improper operation or excessive pressure, the blade collides with the steel base plate too violently and directly injures the blade of the die-cutting knife. The continuous high pressure after formal production is also the main cause of blade damage. If the die-cutting knife is not detected or replaced in time, paper dust and burrs may appear in the product to varying degrees

therefore, after the die-cutting plate is put into the machine, it is necessary to identify where to cut through and where to indent according to the card book page. The pressure must be light during debugging, and there should be clear lines on the bottom die paper. After carving the groove, adjust it. During the adjustment, set a pressure value. Place paper under the steel plate and observe whether the waste paper or printed matter at the knife edge is easy to separate after pressure test. Remove the pressure and pad the incompletely cut part with paper to make the pressure of each die cutter of the layout uniform, and then gradually increase the pressure of the machine. The ideal pressure is that when the waste edge of each notch just separates, the pressure of the machine is the minimum and the pressure is appropriate. The cutting edge shall be smooth without fuzzing. Easy to separate, and die-cutting knife is not easy to wear. When the automatic die-cutting machine starts to adjust the pressure, the substrate material is used to fill in all links from the concept stage, design, simulation, processing to component testing according to different positions, and then the pressure is locked before formal die-cutting. In this way, the molding effect of the die-cut products is good, and the production speed is fast and the efficiency is high

some graphics and texts on the pages of stereoscopic card books need die-cutting indentation. Before die-cutting, the bottom template must be engraved first. The quality of groove line engraving on the bottom template directly affects the stretching effect of stereoscopic graphics. If the carved groove line is not uniform in width, not straight, with a gap, or the die-cutting knife and indentation line can not accurately match the bottom groove line, and the knife line cushion is not appropriate, it can cause the indentation displacement and die-cutting can not be completely cut off. During die-cutting, before the die-cutting knife has cut through the paper edge or graphics, the paper may also be hairy due to its extrusion and displacement. Generally, the thickness of the bottom die paper is less than or equal to the thickness of the die-cut paper. The manual carving of groove lines puts forward higher requirements for the proficiency, skills and experience of operators. A skilled operator should understand that the indentation effect will vary depending on the arrangement direction of the indentation line and the paper fiber direction. The graphic die tangent and the indentation line in the page of the three-dimensional card book are either parallel to the book or vertical. In die-cutting, the trace lines parallel to the direction of the paper thread are often weak after folding, dry and slightly flat; The trace line perpendicular to the direction of the paper thread is full and powerful after folding. For graphic die cutting, it is easy to separate along the thread, while the thread fiber often appears when it is perpendicular to the thread. Therefore, when the carving groove line adjusts the lining, the indentation groove in the straight line direction should be narrower. In this way, the edges of the products cut by the die are separated and smooth, and the concave convex lines are strong

improper selection and installation of rebound sponge adhesive strips is also one of the reasons that affect the die-cutting quality, because the sponge adhesive strips should have enough hardness to compress the paper, and let the die-cutting knife/frame cut the paper neatly. Different paper should use sponge adhesive strips with different hardness, and the installation position and height should also be scientific. Standard material selection and installation is the fundamental method to improve die cutting quality. Due to the irregular changes in the graphics of the three-dimensional card book and the distance between the die cutting edges, some spacing is very small and the layout is irregular, which brings some difficulties to the selection of the hardness of the sponge tape and the correct use. The correct selection and installation are as follows

1. selection of hardness of rebound sponge tape

(1) if the distance between die cutters is 10mm, the hardness of sponge tape should be about hs60; If 10mm, it shall be HS20 ~ hs35

(2) if the distance between the die-cutting knife and the steel wire is 10mm, the arch sponge adhesive strip shall be selected, and the hardness shall be hs55; If 10mm, select the sponge adhesive strip with hardness of hs35

2. installation of rebound sponge adhesive strip

(1) the sponge adhesive strip should be at least 1-2mm away from the die-cutting knife and should not be installed close to the knife body. Otherwise, the sponge adhesive strip cannot expand in the direction of the knife body after being pressed and can only expand in the other direction, resulting in pulling paper from both sides. Before the die-cutting knife comes to cut the paper, the paper has been pulled off by the sponge adhesive strip, which will cause uneven edges of the graphics and even pull the paper out of shape or tear, Make the die-cut page uneven

(2) the sponge rubber strip should be about 1.5mm higher than the blade. It should be adjusted appropriately according to different hardness. Generally speaking, the softer the sponge rubber strip, the higher the height. The quantity, hardness and height of the sponge strips on the whole die-cutting plate shall be evenly distributed at the corresponding positions, and the sponge strips shall also be arranged on both sides of the balance knife

author/Wu Fei

source: Printing Technology

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