During the labeling process, self-adhesive labels often face many challenges, such as wrinkles, skew or bulging. These seemingly small but influential problems may cause considerable economic losses to the company once they occur in batches during the production process. This article aims to explore these common problems in the labeling process of self-adhesive labels and try to provide practical solutions.
Label skew is a common problem in the labeling process. Occasional slight skew has little impact on the overall production. However, if label skew occurs frequently, it will cause considerable trouble to production. Usually, the problem of label skew is mainly caused by the following factors:
1. Insufficient stiffness of the label surface material
Stiffness refers to the physical property of whether the surface material of the label can maintain its original shape without curling or sagging after it is peeled off from the base paper. The thickness and hardness of the surface material of the self-adhesive material vary, and the stiffness is also different. If the label surface material is soft or thin, its stiffness is often poor. During the automatic labeling process, the surface material of such materials often sags or curls at the moment of peeling off the backing paper, which makes it impossible for the label to be accurately attached to the object, and finally causes the problem of skewed labeling.
Therefore, if you often encounter the problem of skewed labels during the labeling process, it is recommended to carefully observe the shape of the label surface material after peeling off the backing paper. If sagging or curling is found, you can try to adjust the labeling machine to solve this problem. Specifically, by reasonably adjusting the timing of the matching between the object and the label, ensure that the label can be accurately attached to the object at the moment of peeling off the backing paper, so as to significantly reduce the probability of skewed labeling.
2. Uneven pressure of the label roller
Automatic labeling machines are usually equipped with labeling devices, such as sponge rollers or bristle brushes, whose purpose is to smooth the label after labeling and make it more tightly attached to the object through appropriate pressure. However, if the pressure of the labeling device is improperly adjusted or the labeling roller is aged, it may lead to uneven pressure distribution, which in turn causes the label to be skewed due to uneven force. This skew usually shows regularity, and the problem may occur in batches, so it is easy to detect. For this problem, re-adjusting the pressure of the labeling device or replacing the aged and worn labeling roller can effectively solve it.
3. The label area is too large
During the operation of the automatic labeling machine, sometimes the label area is designed to be too large. This type of label usually uses soft surface materials, such as self-adhesive materials. Because the label area is too large, when it is lifted up by the automatic labeling machine and attached to the object, it often droops or curls, which leads to skewed labeling.
For the problem of too large label area, you can try to adjust the label design after obtaining customer permission, or use self-adhesive materials with higher stiffness to make labels, so as to reduce interference with the subsequent labeling production process.
2 Labeling wrinkles
Labeling wrinkles are a common problem in labeling operations. Sometimes wrinkles can be observed during labeling, while other times they only gradually appear after a period of time after labeling. This problem may be caused by a variety of factors, the main reasons of which include:
The shape of the object to be labeled
Self-adhesive labels are flat, so to achieve a good labeling effect, the object to be labeled must also be flat. However, in actual use, many bottles have a certain curvature, especially spherical bottles with a large curvature. When the label is attached, it is easy to wrinkle because it cannot be fully unfolded.
To solve this problem, first observe whether the wrinkles are mainly concentrated on the edge of the label (sometimes the wrinkles are regular, which is often caused by the label roller squeezing the part that cannot be fully unfolded to the same position during automatic labeling). Then, check the bottle to determine whether its curvature is too large. In this way, we can determine whether the wrinkles are caused by the unreasonable design of the shape of the object to be labeled. If so, the shape of the object to be labeled needs to be redesigned.
2. Uneven distribution of labeling pressure
The automatic labeling machine is equipped with a labeling device with adjustable pressure. However, some objects are soft, and if the pressure is set too high, it may cause deformation of the object, which may lead to wrinkles. Therefore, when adjusting the label pressure, it is necessary to ensure that it is controlled within an appropriate range. It should usually be adjusted to the point where the label can be easily attached.
3. Label water absorption problem
In rainy seasons, the humidity in the air tends to rise significantly. When the moisture content of the label is significantly lower than the humidity in the air, the label is prone to swelling due to water absorption, especially for paper labels. If labeling is performed at this time, the attached label may wrinkle due to water absorption and swelling.
To avoid this problem, it is recommended to remove the label from the package before labeling in the rainy season and leave it for 24 hours to ensure that the label reaches a balance with the moisture in the air before labeling.