What are the reasons for the breakage of laser cutting adhesive waste?

In addition to printing, die-cutting technology is also very important for self-adhesive products. Die-cutting is a process that uses a knife or laser to cut the adhesive material into an ideal shape. Most die-cutting processes are half-cut self-adhesive materials, that is, only the surface of the self-adhesive material and the glue are cut without cutting the bottom paper. Most of the time, after the self-adhesive material is die-cut, the excess surface layer and glue will be discharged, leaving the required part. The following Laisei Laser tells you the common problems and solutions in the die-cutting process:

1. The label is carried up with the waste discharge edge

The label phenomenon produced by the waste discharge edge is usually called flying label. The main reasons for this phenomenon are as follows:

1. Continuous die cutting

Traditional die cutting tools cannot completely cut through the surface of the rubber material, and it is very easy for the label to be taken away by the edge of the waste. The edge discharge phenomenon of the label caused by die cutting is very regular, basically the label and the waste discharge edge are glued to the same position of the label. Multi-modal material feeding, the position of the die cutter is fixed. The main reason for this problem is that the die cutter is damaged and the die cutting pressure is uneven.

Die cutting is the most common problem in the die cutting process of patch materials, and it is also quite simple to solve. Just replace the damaged knife strip or adjust the die cutting pressure. It should be noted here that sometimes due to uneven pressure, the die cutting of some parts will be more severely worn than other parts. When using this die-cut label, although there is no obvious damage on the surface of the tool, it is easy to produce continuous die-cutting. The way to determine whether the tool wear is serious and causes continued cutting is to understand the die-cutting depth of the base paper. If there is a clear indentation on the base paper and the surface is continuous, you should consider replacing the die.

2. The release force between the surface of the self-adhesive material and the base paper is too small

The force between the surface of the adhesive and the base paper is called the release force. If the release force of the adhesive is too small, it is easy to produce the phenomenon that the labeling edge follows the row edge. Because the glue cutting process will inevitably occur during the die-cutting process, the waste edge will exert an upward force on the label during stretching. If the release force of the self-adhesive material is less than the tension of the waste edge on the label, it is very easy to cause the label to fly.

The flying mark phenomenon caused by the problem of demoulding force is mainly solved by the raw material manufacturer adjusting the demoulding force. If the printing manufacturer encounters this situation, it can increase the processing temperature or increase the angle of the waste residue, and if necessary, replace the material.

3. The marked area is too small or has a special shape

Labels with a small marked area or complex shapes (such as five-pointed star labels) are difficult to release automatically. If you encounter such problems, try to increase the discharge angle (the discharge angle can be changed to an iron plate or iron ruler to greatly increase the discharge angle). If necessary, manual removal is required.

4. Glue backflow makes die cutting continuous

For many hot melt adhesives or thickened adhesive self-adhesive materials, during the die cutting process, the glue is cut out by the cutter and flows back and sticks together, causing serious stringing of the glue strip and causing the edge to fall off during die cutting. In this regard, the method of appropriately lowering the temperature of the die cutting process can be adopted to reduce the backflow of glue. At the same time, the die cutting knife must be kept sharp so that the knife head can cut the glue quickly and reduce the backflow of glue. If the continuous die cutting method is used, the printing speed can also be appropriately increased to reduce the backflow of glue.

5. Processing temperature is too low

Many label printing companies produce and process labels at very low temperatures in winter, which causes frostbite on the glue of the self-adhesive material. This greatly reduces the release force of the glue and causes die-cutting flying. In this case, the temperature of the workshop needs to be increased. Generally speaking, the temperature of the self-adhesive processing workshop in winter cannot be lower than 15掳C.

6. Improper discharge method

Improper discharge method can also easily lead to die-cutting flying marks. The main manifestations are: the distance between the waste discharge station and the die-cutting station is too far, causing glue backflow. The diameter of the waste discharge roller is too large, causing the waste discharge angle to become smaller, causing flying marks. The solution to this problem is to adjust the distance from the waste discharge station to the die-cutting station and the diameter of the waste discharge roller.

2. Waste edge fracture

During the die-cutting process, the waste edge often breaks. If the waste edge breaks frequently during the processing, it will seriously affect the production efficiency. The reasons for the waste edge fracture during mold processing are as follows:

1. The waste edge is too thin or the horizontal and vertical discharge is not correct.

If the edge of the waste is too thin and cannot withstand the pulling force of the waste roller, it is easy to break. Generally speaking, the width of the waste edge of the self-adhesive label is preferably 3-5 mm. When the horizontal width and vertical width of the waste edge are unbalanced (for example, the horizontal width is narrower than the vertical width), the stress of the waste edge is unbalanced, which is also easy to cause the waste edge to break.

2. Label edge

If the label edge is at a right angle, the edge tension of the waste is concentrated, which is easy to cause the edge of the waste to break. On the contrary, if the label has a rounded corner, the edge tension is more dispersed, and it is not easy to break; if the edge is at a right angle, the problem of easy breakage of the paper scraps can be solved.

3. Special label shape

Some have special shapes, such as five-pointed star labels, trapezoidal labels, etc., and the waste discharge edge shape is irregular. When the waste discharge edge is pulled, the waste discharge edge tension is uneven, which is easy to cause the discharge edge to break. If you encounter this problem, you can add paper pads during the waste discharge process to balance the tension of the waste discharge roller. If necessary, you need to clean it manually.

4. Poor contact of the die cutter

If the interface of the die cutter has no waste edge, there will be small burrs or dents. If the waste discharge edge is thin or the waste discharge roller has too much tension, it is very easy to cause the waste discharge edge to break.

5. Waste paper roller diameter

Generally speaking, the waste roller has a small diameter, a large waste angle, and a large waste edge tension. On the contrary, the waste roller has a large diameter, a small waste edge angle, and a small waste edge amount. Therefore, for some waste edge fines, if the waste roller has a thin diameter, it is easy to break the waste edge. These problems can be solved by increasing the diameter of the waste roller.

6. Rubber material problems.

Some rubber strips have too strong release force or uneven silicon coating on the edge, which can cause the waste edge to break. Uneven coating on the silicon edge is easy to find. The release force of the material itself is too large. You can try to peel it off with your hands. If it is difficult to peel it off, it may be due to the excessive release force. If it is not obvious, you can change the material to determine whether the edge of the waste material is broken due to the release force problem.