Carton die-cutting processing details that die-cutting machine leaders must understand
1. Paper Many people think that it is not difficult to obtain good processing results through die-cutting, and the internal details of the paper are often ignored. Each type of paper has different fiber structure, deformation resistance and surface coating quality. Therefore, when we select paper for carton, first of all, we must ensure that it has good folding resistance, and it is required to Under the circumstances, it is not prone to burst line phenomenon, and when bending, the surface coating will not produce serious cracks; secondly, the thickness of the same paper per unit area must be stable and consistent, and the thickness error between the papers should be maintained Within ±5μm, otherwise it is easy to cause problems such as impenetrable die cutting and low production efficiency, especially for some recycled paper; in addition, the degree of deformation of the paper also has a direct impact on the die-cutting quality of the carton. The deformation of the paper will lead to inaccurate die-cutting sets, resulting in a lot of waste. Conditional packaging and printing companies can use incoming paper inspection to group these details into the category of carton quality monitoring. 2. Die cutting knife Die-cutting knives can be divided into four types according to the form: low-end knife, single-sided low-end knife, high-end knife, and single-side high-end knife. The four types of die cutting knives are suitable for different types of materials. The short blade is mainly used for processing ordinary cardboard, the single-sided short blade is mainly used for processing fiber materials, and the high blade is mainly used for processing corrugated cardboard, leather and plastic. , Single-sided high-end knife is mainly used for processing EVA and sponge. Improper selection of die-cutting knife will not only cause poor die-cutting of cartons, such as burrs and dust on the edge of die-cutting, but also make it necessary to repeatedly replace die-cutting knives during processing, reducing production efficiency. Generally, the height of the die cutter used for carton die cutting is 23.8mm and the thickness is 0.71mm. If die-cutting processing special jobs, you need to choose the type of die-cutting knife targeted. At present, the carton die cutter brands widely used in the industry mainly include Sweden’s SANDVIK, Austria’s BOHLER, Japan’s TSUKATANI and Taiwan’s SANLI. For jobs with high quality requirements, large production batches, and repeated printing, it is recommended to use imported die cutters with excellent performance; for jobs with low quality requirements, small production batches, and mainly used for proofing, you can choose lower cost Domestic die cutter. 3. Sponge tape According to different hardness, sponge rubber strips are generally divided into low, medium and high grades. The application of each grade of sponge rubber strips is different. For example, the sponge rubber strips with hardness of 30～45 Shore hardness are suitable for the basis of 300g/m2 The following lightweight papers, sponge strips with hardness of 45-60 Shore hardness are suitable for corrugated cardboard and white cardboard with a basis weight higher than 300g/m2, and sponge strips with hardness of 60-75 Shore hardness are mainly used for easy Fuzzy die cutting edge. You also need to pay attention to some details when installing the sponge rubber strip. For example, the sponge rubber strip should not be close to the knife body of the die cutter. This is because the sponge rubber strip will be compressed during the die cutting process. When its curved surface hits the die cutter body, It will generate an outward pulling force on the die cutter, resulting in a jagged edge of the paper die. Therefore, a gap of 2 to 3 mm should be left between the sponge rubber strip and the die cutter blade. 4. Indentation die A suitable indentation die is also very important. When choosing an indentation die, you should mainly pay attention to its dimensional accuracy, backing paper hardness and pasting fastness. At present, CITO indentation die is widely used in the market. In addition, for different thicknesses of paper, the size specifications of the selected creasing die are also different, as shown in Table 1. 5. Fine operation Before die-cutting a batch of new jobs, the operator needs to clean the bottom plate of the die-cutting machine first, because the surface of the bottom plate may have impurities such as adhesives remaining in the previous process. In addition, the operator needs to adjust the die-cutting pressure gradually from small to large. If the die-cutting pressure is increased at one time, the die-cutting knife and the bottom plate will be damaged, and the die-cutting machine will be damaged in severe cases. For the same batch of jobs, different operators will get different die-cutting effects. Therefore, in daily production, operators need to implement standardized operating specifications, and at the same time maintain good communication between various departments and exchange experience with each other.