1. Reason for the problem: "Burst line" refers to the phenomenon where the pressure on the die-cutting indentation exceeds the bearing limit of the paper fiber, causing the paper fiber to break or the department to break; Dark lines "refer to unnecessary indentation lines, which are generally caused by improper selection of die-cutting plates and indentation steel wires, improper adjustment of die-cutting pressure, poor paper quality, inconsistency between the fiber direction of the paper and the cutting direction of the die-cutting plate, and a decrease in flexibility due to low water content of the paper.
Solution: Choose a suitable die-cutting plate; Adjust the die-cutting pressure appropriately; Before die-cutting, place the printed materials to be die-cut in the workshop for a period of time; Improve the relative humidity of the workshop environment. A better method is to reduce the height of the indentation steel wire, which is usually 0.1-0.2mm. The details should be determined based on the weight of the paper. The height of the indentation steel wire should be reduced by 0.2mm for papers with a weight of 350g/m2 or above, and 0.1mm for papers with a weight of 350g/m2 or below.
2. Die cutting fuzzing and dusting
Reason for the problem: During die-cutting, there is often a phenomenon of uneven and fluffy cutting edges of die-cutting products, especially at some cutting edges closer to the indentation line. This is because during die-cutting and pressing, the adhesive strips and indentation steel wires on the die-cutting plate generate tension on the paper, which breaks the paper before it is fully cut through and causes burrs to appear.
Solution: First, choose different types of die-cutting knives based on the paper. Die cutting knives include straight grain knives and horizontal grain knives. The blades of the two types of patterns have different heights and heights, and the patterns formed by the blades are directly related to the quality of die cutting and the service life of the die cutting knife. In terms of avoiding die-cutting fuzzing, straight grain knives are better than horizontal grain knives; In terms of service life, short blades are better than high blades. When die-cutting laminated cardboard, a straight grain high blade should be used, and the blade should be ground. It is best not to use a one-time forming process of pressing concave and convex, otherwise too much pressure will have a significant impact on die-cutting; When processing ordinary cardboard, it is advisable to choose a short blade and determine the grain of the blade based on the quality of the paper fibers.
3. Low die-cutting accuracy
Reason for the problem: The reasons for the low precision of die-cutting include problems with the die-cutting version and printing materials. Handmade die-cutting plates have significant errors; The difference in homework environment between die-cutting indentation and printing process can cause paper deformation, resulting in inaccurate position of die-cutting indentation. Especially after polishing and laminating, the deformation of the paper is more severe, affecting die-cutting accuracy.
Solution: Choose to improve the advanced die-cutting plate making process and improve the accuracy of die-cutting plates. Try to ensure that the die-cutting indentation and printing process are carried out in a unified homework environment, or ensure the consistency of the homework environment (i.e. the same temperature, relative humidity, etc.); Die cutting pretreatment should be carried out on the glossy and coated paper to minimize the impact of paper deformation on die cutting accuracy.