What Should I Do If The Self-adhesive Label Overflows

What should I do if the self-adhesive label overflows? Keep these lessons in mind!

Recently, Label Jun has received a lot of readers in the background asking what to do if the self-adhesive label is overflowing? In fact, in previous articles, there have been many articles on how to solve the problem of glue overflow in the die-cutting process. If you have a problem with glue overflow during the die-cutting process, you can refer to the solutions listed in previous articles.

If there is glue overflow after die-cutting or you want to prevent glue overflow in advance, the following experience can be summarized for your reference:

01

The shape design of the label

Odd-shaped labels are more likely to cause glue overflow than square or rectangular labels. In the die-cutting process of special-shaped labels, due to the inconsistent distribution of the winding tension in the axial direction, the local tension will be excessive, resulting in local glue overflow of the label. In addition, square labels with a small area are also prone to local glue overflow due to greater pressure under the same pressure.

Therefore, it is suggested that the die-cutting and waste collection of special-shaped labels can be reversed; Die-cut waste edges of a certain width can be retained on both sides of special-shaped labels (such as round labels, etc.); Consideration can be given to wrapping foam or high-resilience sponge on the surface of the core tube when the finished label is rewinded.

02

Several basic judgment criteria for overflowing glue before printing

When the roll self-adhesive material is unwound on the printing press, if there is no drawing or slight drawing phenomenon between the upper and lower layers, the self-adhesive material can be judged to be qualified. Of course, you should also understand the temperature and humidity of the site environment. When the sheet-fed self-adhesive material is fed on the paper feeding table of the offset press, if there is drawing or adhesion between the upper and lower layers, it can be judged that the self-adhesive material is unqualified. Because the phenomenon of wire drawing between the upper and lower layers occurs when feeding paper on the paper conveying table, the self-adhesive material will deviate and cause inaccurate overprinting.

03

Glue overflow after printing die-cutting

If the end face of the white material is seriously adhered to, there will be obvious wire drawing phenomenon during printing and unwinding, and it is very likely that glue leakage will occur around the label after die-cutting. It should be pointed out that the overflow is also related to the displacement and shrinkage of the label on the liner. During the die-cutting process or when rewinding after die-cutting, the label movement will cause the label to overflow on one side, and the label shrinking will cause the label to overflow around the label.

04

Control of rewinding and unwinding tension

Due to the different processing materials, production processes, and printing presses used, it is unrealistic to give a "correct" tension data. The result of tension control is ultimately reflected in the tightness of the roll, and it should be the best practice to tighten the roll as loosely as possible if it is acceptable to the customer. When printing (including in-line die-cutting), the tension of rewinding and unwinding is controlled as small as possible without affecting the overprint accuracy and post-processing.

Regardless of the processing process, the winding tension should be smaller than the unwinding tension, and the tension ratio should not be too different. When judging whether the winding tension is appropriate, if you pick up the small roll cut into by die-cutting with both hands, at least you can use your thumb to push the end face up and down at will, indicating that the winding tension is appropriate; If the small roll cut into after die-cutting is like a "discus", then the winding tension must be too great.

05

Storage environment temperature and humidity

It is recommended to control the temperature of the label processing and storage environment in the range of 23±2 °C, and the relative humidity to be controlled in the range of 55% ±5%, because the high temperature and high humidity environment will increase the fluidity of the adhesive.

In short, there are many types of glue and surface materials used in self-adhesive labels, and the die-cutting properties of different glues and surface materials are also different, so it is recommended that printing companies should communicate with material suppliers in detail about the appropriate die-cutting process before producing self-adhesive labels to reduce the label surface pollution caused by die-cutting overflow, so as to meet the application needs of end customers.