In the process of die-cutting, bonding and packaging of color boxes, the explosion angle and crack problems often beset many packaging and printing enterprises. Let's take a look at some techniques experience by experienced technicians.
1) Improper pressure causes a burst
1.1 There is a foreign body in the indentation slot in the bottom plate, resulting in a sharp increase in pressure during die cutting. This is a common cause of burst and is also destructive in production. It will break the underwire and cause the product to be scrapped.
1.2 Running version, namely the die cutting or the base plate, makes the steel line fall outside the indentation slot. The reason for this reason is that the burst is mainly concentrated in the same direction, because the cutter or the indentation knife is not tightly coupled with the wood template, and it is deflected in the pressure condition.
1.3 The thickness of steel wire and the width of the groove width are not matched with the paper material. According to the requirements of die cutting process for different paper should choose different steel wire, and the blank of different thickness and different wiring groove width, if not match, could easily lead to dark lines.
2) The die-cutting version of the production process caused the burst
2.1 When making die cutting version, the steel wire is not handled properly or the steel wire is cut off with a burr. If the product has a surface treatment, such as a covering. In the die - cutting steel wire, some of the burrs can damage the tensile strength of the surface film. When the product is formed, the film can't bear the force, and it will burst.
2.2 The steel blade of the underwire has a blade and an interface. Tear occurs when the interface is not smooth at the die cutting.
2.3 When the position of the pressure line knife is improper, the pressure line will burst, and the pressure line knife will be distorted and damaged.
2.4 Whether the knife on the die is reasonable with the line. In particular, the paper thickness is not considered in the design, and the knife and line cannot be effectively avoided in the lap joint, and interferes during the forming process, which causes the stress concentration of the place to burst.
3) Material quality problem
3.1 The paper is too low and the paper is crisp. This phenomenon more in winter, because winter weather, dry and low relative humidity in the air, will directly affect the moisture content of paper board, after line pressing board have a fracture phenomenon, general base paper moisture content control in the ceiling (between 8% and 14%);
3.2 The paper coated material has a small gap in the bidirectional stretching polypropylene film, resulting in a decrease in tensile strength. Coated is a common way of paper surface treatment, its main material is BOPP film, if the BOPP film before die cutting damage will cause after die cutting bending BOPP film cannot stress lead to burst. Membrane burst occurs only in film layer, with the stress point will add burden and extend in the direction of the burst, not burst at the bottom of the paper, it shows that has nothing to do with paper, such as membrane unsolved paper has crack has nothing to do with the film, the paper has a problem.
3.3 Paper is wrong. In die cutting, if the indentation steel wire and paper fiber direction are perpendicular, the paper fiber will be damaged in the radial direction, the dark wire will be easy to bend, the shape is good, the Angle is small; If the indentation steel line is parallel to the direction of the paper fiber, the paper is not damaged on the transverse side, but the dark line is not easy to bend, forming a rounded Angle, and the Angle is large, which is large for the outer support of the paper and easily ruptured. Paper the direction of sheet-fed products die-cutting, only shape is not good, but not allow explosive line, but for the card framed card products have great influence, if processes is not good, not only the shape is not good, also easy to line, mainly wiring in a different position of parallel to grain line, and in the other direction is not.
3.4 The corrugated configuration is too high. The resistance and transverse ring compressive strength of the original paper are one of the influencing factors. It can also be easy to crack if you have a low paper folding.
3.5 The mold is used too long. The die-cutting version of the die cutting plate will loosen after long use of the die cutting plate, causing the cable knife to spring up in the die cutting process, resulting in the bursting of the paperboard. Due to the long time use of the rubber cushion, the rubber cushion causes the pressure line to burst.