Self-adhesive is a multi-layer composite structural material composed of a base paper, a glue and a face material. Due to its own characteristics, there are many factors that affect the processing or use effect during processing.
With the arrival of the rainy season, the air humidity continues to increase. Therefore, the self-adhesive is also prone to various problems during use. Let's share some of the precautions for the use of the rainy season.
First, the self-adhesive stickers bottle wrinkles
I have encountered such a case where a customer puts a sticker on a bottle. It was fine when I just posted it, but after 24 hours, the label on the bottle began to wrinkle. And as time goes on, the label wrinkles on the bottle become more and more serious. The customer uses a self-adhesive label made of copper paper, which has a hot stamping and glazing process in addition to printing. The customer feels quite strange, because this kind of label is not the first use, and no such phenomenon has been found in the past.
After analysis, I found out the real reason for the label folds. Since the rainy season was at the time, the customer's workshop was humid, and the self-adhesive labels were sealed with plastic bags before use. Therefore, the water content of the label itself is quite different from the water content of the customer's workshop. The label swells rapidly during the period of time after labeling, causing wrinkles.
There are several ways to solve this type of problem:
1. Open the outer packaging of the label before labeling and put it into the labeling workshop for a period of time (more than 48 hours recommended) so that the label can fully balance the humidity of the labeling environment. Thus, after labeling, the label will not cause expansion wrinkles due to excessive water absorption.
2, change the label processing technology, you can use the laminating process instead of the glazing process, which can effectively block the label to absorb the external moisture, thereby reducing the probability of wrinkles.
3. In the printing process, you can use the second rewetting method to increase the moisture of the label. For example, the humidifier can be used to humidify the bottom paper of the label during label processing and die cutting to ensure that the label is not too dry, thereby reducing the influence of external humidity changes on the label.
Second, the self-adhesive material printing, curling during die cutting
In the rainy season, it is quite common to have curls in the printing or die cutting process that affect the printing process. This type of problem is particularly prone to use in the use of film-based self-adhesive materials. Because the film-type self-adhesive material surface material is almost unaffected by external moisture, its bottom paper is often greatly affected by external water. I have seen such a case. Some customers complained that using a film-type self-adhesive material could not be used normally due to the material curl during the printing process.
After learning that it was also in the rainy season, the humidity of the customer's production workshop was large. The bottom paper of the self-adhesive material absorbs moisture and rapidly expands during processing, causing the material to curl heavily in the direction of the facing layer. Since the customer uses a tension-free delivery tray to take the paper, the material is almost unreceived after the material is curled.
This type of situation can be solved in the following ways:
1. Strengthen the temperature and humidity control of the workshop. We all know that the best temperature for printing is 20-25 degrees Celsius and the relative humidity is between 50-60%. Therefore, to make a good product, we still need the majority of enterprises to control the temperature and humidity of the workshop, so as to solve this problem fundamentally.
2. For enterprises that have no conditions for temperature and humidity control, this problem can be solved by locally adjusting the humidity. For example, a heating tube or a heat fan can be installed at the winding position of the device to reduce the local humidity to solve the problem.
3. If the humidity in the workshop is too large, consider placing the material in the workshop 24 hours before the printing is used to balance the material with the water in the workshop. This can improve the curling of the self-adhesive material due to excessive humidity to a certain extent.