Analysis of common die cutting problems of self-adhesive labels

According to statistics, China in 2013 The consumption of labels is about 10 billion square meters, of which the consumption of self-adhesive labels accounts for 35%, and the annual output value reaches 30 billion yuan. The application of self-adhesive labels in various terminal fields is becoming more and more widespread. However, various problems that often occur in the actual processing of self-adhesive labels cannot be ignored, such as die-cutting problems. Next, the author will analyze and summarize the causes and solutions of the problem of the die-cutting of the self-adhesive label.

Die cutting target (flying standard)

The die-cutting mark is also called the die-cutting flying mark, which refers to the phenomenon that the self-adhesive label is brought along with the waste side during the die-cutting process. Once there are too many labels to be brought up, it will bring a large amount of replenishment work to the subsequent inspection process. At present, most of the label companies in China still adopt the method of manual replenishment, which greatly affects the production efficiency. At the same time, manual patching may cause the label position to be misaligned, affecting the end user's use. So, what are the reasons for the die-cutting?

Die cutting tool damage

In general, the die-cutting phenomenon caused by the die-cutting tool damage has a certain regularity. If you look closely, you will find that the sticker is not completely cut off, and there is a small section between the label and the waste edge (or One point) is still connected. When this phenomenon is encountered, the die cutting tool needs to be repaired, and the fault can be eliminated.

However, it should be pointed out that in addition to die-cutting tool damage, sometimes the die-cutting pressure is uneven, which may cause die-cutting. Therefore, when such problems occur, it is advisable to try to partially pad under the part that has not been completely cut. If there is still a continuous cut after the pressure is adjusted, it can be judged to be caused by the damage of the die cutting tool.

2. Adhesive layer drawing

Some adhesives used in self-adhesive labels are hot melt adhesives, which have strong initial adhesion and good fluidity. However, in the process of die cutting, hot melt adhesives are prone to drawing back. Since the adhesive is adhered between the label and the waste side, the label is easily taken down along with the waste when the die is cut.

In this regard, it may be necessary to carefully observe whether the waste side and the label have been completely cut off. If the two are completely cut off, it is necessary to observe whether there is adhesive drawing between the label and the waste side.

If there is a phenomenon of adhesive drawing, the backflow of the adhesive can be reduced by inserting a sea foam on the side of the die cutter and spraying a silicon auxiliaries on the blade. In addition, a solution that appropriately increases the die cutting speed can also be employed. Since the hot-melt adhesive label material is die-cut, the adhesive will quickly reflow, causing the waste edge to re-adhere to the edge of the label. When the die-cutting speed is accelerated, the time from cutting the material to discharging is shortened. So that the adhesive can not be returned, so as to reduce the occurrence of the labeling phenomenon.

3. The material peeling force is too small

The self-adhesive label material is a composite material composed of a face paper, an adhesive, and a backing paper. The force that normally peels the tissue from the surface of the backing paper is called the peeling force of the self-adhesive label material. If the peeling force of the self-adhesive label material is too small, the labeling phenomenon is likely to occur during the die cutting process.

In this regard, it is advisable to uncover the self-adhesive label material by hand to roughly feel the peeling force of the raw material. It is better to uncover the missing material and the non-marking material at the same time for comparison. If the peeling force of the missing material is significantly lower, it is very likely that the die-cutting is caused by the cause. Generally speaking, the phenomenon of the mark-off phenomenon caused by the small peeling force of the self-adhesive label material is irregular.

The best solution for label companies to solve this problem is to replace the raw materials with good peeling force. If it is too late to replace the materials, the method of using sea foam on the die cutter and the waste roller can be used to reduce the mark.

4. Label shape, size

Many labels belong to the special-shaped labels, such as triangles and pentagrams. When the labels are cut and discarded, it is easy to cause the label to fail to form a uniform pulling force due to the waste side. Therefore, for some special-shaped labels, it is not suitable to adopt the method of automatic waste disposal, and it is possible to use the manual waste disposal method to reduce the mark-off.

In addition, if the area of ​​the label is too small (such as the size of some electronic labels below 10mm × 10mm), it is easy to appear in the die cutting process. This is because the label area is too small, and the force of the waste edge when the die is cut is greater than the peeling force of the label itself and the bottom paper.

In this regard, it can be solved by adding a scraper at the waste-cutting position of the die-cut waste side. Since such labels are generally hand-labeled, materials with a large peel force can also be used to solve this problem.

5. Environmental temperature impact

Self-adhesive labels, especially hot melt adhesives, have a greater peeling force due to temperature. If the temperature in the processing workshop is too low, the fluidity of the adhesive will be affected, which may cause the peeling force of the self-adhesive label material to drop sharply, causing die-cutting.

In this regard, it is recommended to increase the processing and storage temperature of the self-adhesive label. When the temperature rises, the peeling force of the material will gradually return to normal. At this time, the die-cut label will be die-cut, and there will be no label deviation. .