The main reasons for the edge warping of self-adhesive labels are as
follows:
1. Adhesive adhesion is too weak: suitable adhesive materials should be
selected;
2. Insufficient pressure on the pressure roller of the labeling machine:
the reasons and solutions are as above;
3. Label surface material: When selecting a label surface material, one
should consider whether the labeled object is flat or curved, large or small
diameter, single surface or spherical, rigid body or compressible deformation.
These indicators are directly related to the selection of surface material. Soft
bottle bodies should be made of soft materials such as PE, PVC, unstretched PP,
and materials composed of PE and PP. Hard bottle bodies can consider using PET,
BOPP, or PS materials;
4. Improper selection of adhesive: When choosing a self-adhesive adhesive,
the first step is to determine whether the adhesive required for the produced
self-adhesive label is removable, whether it can be pasted once or reapplied,
and whether the product has special requirements for the chemical properties of
the adhesive for individual self-adhesive labels;
5. Poor control of lamination tension: After correctly laminating, the
label is peeled off from the backing paper and is flat without curling. After
labeling, the label can maintain good follow-up; After the label with too tight
film tension is peeled off from the backing paper, the label will curl up, which
can easily cause the label edge to peel off and curl up after labeling;
6. Unreasonable design of bottle body shape: A reasonable design should be
that the surface within the labeling range of the bottle body is flat (mainly in
the design of flat circular bottle bodies), but if the surface within the
labeling range is partially spherical, the labeling area will be larger when
using paper labels, and the lower end will be prone to wrinkles on both sides
after labeling,
Of course, the above phenomena are just a few common fault analyses that
occur when labeling self-adhesive labels. In practical work, there are still
many complex labeling faults that need to be explored and analyzed.
