Post-press Experience Exchange: Analysis of Paperboard Die-cut Indentation (2)

When the layout of the vertical or horizontal layout of the layout, should use the longitudinal silk paper to print, in order to better ensure the accuracy of die-cutting.
The error in the production process of the die cutter makes it impossible to achieve the ideal position of die-cutting indentation. Die cutting knife production methods are mainly manual plate making and laser plate making. The precision of laser plate making is relatively high, and the design and cutting are done by computers and machinery. It is suitable for making middle and high-grade packaging die-cutting; the manual plate-making method has a higher level of technology for the plate-making person, and the plate-making precision is affected by the technical level and experience of the plate-making person. The influence of factors is suitable for short and medium version packaging with low precision requirements. To get good die-cutting accuracy, we must choose advanced plate-making methods.

Cardboard mouthwash is not the same, resulting in inaccurate die-cutting positions. Die-cutting machine itself will produce precision error, die-cutting machine without error does not exist, to improve die-cutting machine indentation accuracy, we must praise the high-precision die-cutting machine. If the paperboard mouthwash size error is large, it may be that the post-positioning (also referred to as secondary positioning) of the die-cutting machine is too small, which may be solved by adjusting the positioning and increasing the post-positioning toggle distance.

The position of the die-cutting indentation and the unaligned position of the printing position is not accurate. The die-cut version can be re-adjusted according to the requirements of the product, and the positive-printing and die-cutting indentation positions can be corrected; the positioning rules on the paper-feeding-side can also be adjusted. Or front positioning rules to correct, so that the die-cutting indentation line and printing position register.

Unlike the printed work environment, die-cut indentations can cause the cardboard fibers to deform or stretch, resulting in inaccurate die-cut indentations. It is necessary to ensure that the die-cut indentation is printed in the same working environment or to ensure the identity of the working environment (ie, the same temperature, humidity, etc.).

Indentation line is not clear with dark lines, burst phenomenon

The dark line refers to the indentation that should not appear in die cutting. Burst refers to the fact that the cardboard is broken due to the die-cut indentation pressure. The main causes of this type of failure are: copper pad thickness calculation is not accurate, pad paper is too low or too high; copper wire is not suitable; die press pressure adjustment is not appropriate, too large or too small; paper is too bad Paper has low moisture content, brittleness, and low toughness. We can take corresponding measures, such as recalculating and adjusting the thickness of copper paper; checking whether the copper wire is suitable; adjusting the pressure of the die-cutting machine appropriately; adjusting the conditions of die-cutting and indentation according to the condition of the molded paperboard.

Excessive die-cut pressure causes the indentation line to burst. How the die-cutting pressure is controlled has a great influence on product quality. If the pressure is not uniform, in order to completely cut off the scrap, if blindly adopting an overall increase in pressure to achieve the goal, it is easy to make the pressure at the indentation line too heavy and burst. At this point, the pressure should be reduced so that the waste edge is just separated. In order to ensure uniform die-cutting pressure, avoid mixing new and old steel knives and steel wires. The pressure of steel knives and steel wires must be uniform and adaptable. When padding plates, care must be taken to fully take care of them. Indentation line burst.

The paper is too dry causing the indentation line to burst. If you use paper that is relatively brittle in production, and the moisture content is low, it is easy to cause the indentation line to burst. Before the die-cutting, the paper is wetted, and the back surface of the paper can be filled with water to increase the water content of the paper, so that the paper can be flexibly put on the die-cutting machine. If a burst occurs when the box is folded after die-cutting, wipe the water at the crease to relieve the bursting condition. It is necessary to always pay attention to the strict control of temperature and humidity.

The indentation line bursts due to partial bowing of the die-cut plate or embossed plate. If the edge of the die-cut version is not square and there is a hypotenuse, the sturdy die-cut version is prone to bowing. The sturdiness of the die-cut version and the local deformation and bowing of the iron plate on the imprinting plate can cause bursting of the indentation line. To make the edge of the die cut plate meet the requirements of right angles and square roots, it will not cause the occurrence of layout bowing after fastening, and effectively prevent the indentation line from bursting.

Poor machine causes the indentation line to burst. Some important parts of the machine due to long-term use of the wear caused by excessive clearance caused by vibration and other undesirable phenomena, resulting in mechanical instability of the machine presses, so that when the die-cutting pressure is light and heavy, can also cause the indentation line burst phenomenon.