The reason for the sticker "flying mark"
In addition to the need for printing in the production process, the die-cutting process is also very important. The so-called die cutting is a process of cutting a self-adhesive material into a desired shape by using a die plate. Most die-cutting processes are semi-cut through the self-adhesive material, that is, only the surface layer and glue of the self-adhesive material are cut through without cutting the bottom paper. In most cases, when the self-adhesive material is die-cut, the undesired surface layer and glue are discharged and the desired part is left. Let's talk about the common problems and solutions in the die-cutting process:
First, the label is taken along with the waste side
The phenomenon that the label is taken along with the waste side is commonly called the "flying standard". There are several reasons for this phenomenon:
1, die-cutting
When the die cutter is not completely cut through the surface layer of the self-adhesive material, it is easy to cause the label to be taken up by the waste side. The phenomenon that the label is continuously removed by the die cutting is very regular. Basically, the label sticks to the waste side at the same position of the label. In the case of multimode die cutting, the position of the problematic die is fixed. This problem is mainly caused by the breakage of the die cutter and the uneven die-cutting pressure.
Die-cutting is the most prone problem in the die-cutting process of self-adhesive materials. It is also relatively easy to solve. It can be solved simply by replacing the damaged blade or adjusting the die-cutting pressure. It is important to note here that sometimes some parts of the die cutter will wear more than other parts due to uneven pressure. When using this tool to die-cut labels, although the tool surface is not obviously damaged, it is easy to die-cut. Constant phenomenon. The method of judging whether the die cutting is caused by the local wear of the tool is to look at the die-cutting depth of the bottom paper. If there is already a significant indentation on the backing paper and the surface layer is still intermittent, it should be considered as a mold. The cutter replaces the blade.
2. The release force of the surface layer of the self-adhesive material and the bottom paper is too small
The force of the surface layer of the self-adhesive material combined with the bottom paper is called the release force. If the release force of the self-adhesive material is too small, the label may be brought up with the waste side. Because in the process of die-cutting, there is inevitably a phenomenon of glue drawing, and at the same time, the waste side will have an upward force on the label during the process of being pulled up, if the release force of the self-adhesive material is less than the row The pulling force on the label of the waste edge is prone to the phenomenon of “flying mark”.
Generally, the die-cutting "flying standard" phenomenon caused by the problem of the release force is mainly solved by the raw material manufacturer adjusting the self-adhesive release force. If the printing plant encounters such a situation, it can solve the problem by increasing the processing temperature or increasing the angle of discharge. If necessary, the material needs to be replaced.
3, the label area is too small or special shape
Labels with too small or complex shapes (such as pentagrams) are not easy to dispose of. If you encounter this problem, you can try to increase the angle of discharge to solve the problem (you can use iron or iron rule instead of row) The waste roller greatly increases the angle of waste discharge). Manual waste is required when necessary.
4, the glue backflow causes die-cutting
For many hot melt adhesives or thick glued adhesive materials, the glue is very easy to reflow and re-bond together after being cut by the cutter during the die-cutting process, resulting in a very serious glue drawing phenomenon and causing the label during the die-cutting process. The phenomenon of being taken up by the waste side. In the case of such a problem, it is possible to reduce the backflow of the glue by appropriately reducing the temperature of the die cutting process. At the same time, the sharpness of the die-cutting tool must be maintained so that the tool can be cut through the glue layer in an instant to reduce the backflow of the glue. If it is a die-cutting process, it is also possible to reduce the backflow of the glue by appropriately increasing the printing speed.
5, processing temperature is too low
In the winter, many label printing companies have low production and processing temperatures, which cause the glue of the adhesive material to be frostbitten. The release force of the self-adhesive material is greatly reduced, resulting in die-cutting "flying". In this case, the temperature of the workshop needs to be increased. Under normal circumstances, the temperature of the self-adhesive processing workshop in winter should not be lower than 15 °C.
6, the waste discharge method is unreasonable
Unreasonable ways of discharging waste are also likely to cause die-cutting "flying standards". The main performance is that the waste disposal station is too far away from the die-cutting station, causing the “flying standard” caused by the backflow of the glue, and the diameter of the waste-discharging roller is too large, resulting in a small “distribution”. This type of problem can be solved by adjusting the distance between the waste station and the die cutting station and the diameter of the waste roller.
Second, the waste edge break
The waste edge breakage is also a problem often encountered in the die-cutting process. If the waste-breaking phenomenon often occurs during the process, the production efficiency will be seriously affected. The reasons for the breakage of the waste edge during the die cutting process are as follows:
1. The proportion of the waste side is too thin or the horizontal side of the waste side is out of balance.
If the waste side is too thin to withstand the pulling force of the waste roller, it is prone to breakage. Under normal circumstances, it is recommended that the width of the waste label is between 3-5mm. At the same time, if the width and narrowness of the horizontal and vertical sides of the waste side of the label are out of balance (for example, the width and width are narrow and narrow), the waste side cannot be balanced and the force is easily broken.
2, the edge angle of the label
If the edge of the label is at right angles, it will easily lead to the breakage of the waste edge, because the tensile force of the waste edge is relatively concentrated. On the contrary, if the edge of the label is rounded, the tensile force of the waste edge is relatively scattered, so it is not easy to break; For the right-angled label, the film can be used to solve the problem that the waste side is easily broken.
3, the label shape is special
Some shaped labels have special shapes, such as five-pointed star labels, trapezoidal labels, etc., resulting in irregular shape of the waste edge. In the process of discharging waste, the uneven pulling force of the waste side is also easy to cause the waste edge to break. In the case of such a problem, the paper with a small force can be padded in the process of discharging waste to balance the pulling force of the waste roller, and if necessary, manual waste is required.
4, die cutter interface is bad
If the interface of the die cutter is bad, it will cause small burrs or gaps at the edge of the waste side. If the waste side is thin or the pulling force of the waste roller is large, it will easily lead to the breakage of the waste edge.
5, the diameter of the waste roller
Generally speaking, when the diameter of the waste discharge roller is small, the waste wrap angle is relatively large, and the pulling force on the waste side is relatively large. On the contrary, if the diameter of the waste discharge roller is large, the waste wrap angle is small, and the relay force on the waste side is relatively small. Therefore, for some labels with thin waste edges, it is easy to break the waste side if the diameter of the waste roller is finer. This type of problem can be solved by increasing the diameter of the waste roller.
6, the problem of self-adhesive materials
Some self-adhesive materials may have excessive release force or uneven edge-coated silicon. The phenomenon of uneven silicon coating on the edge is easier to find, and if the material itself is too strong, you can try to uncover the self-adhesive surface by hand. If it feels very difficult to remove, it is likely that the release force is too large. If the feeling is not obvious, you can change the material to determine whether the waste edge is broken due to the problem of the release force.
