We cannot ignore that label warping is a common problem encountered by users of self-adhesive labels, which can be divided into warping immediately after labeling and warping 24 hours after labeling. Warping immediately after labeling, also known as the so-called inability to stick, is generally related to the viscosity of the adhesive in the self-adhesive label, while the factors causing the warping 24 hours after labeling are more complicated. Common factors causing label warping include incorrect selection of self-adhesive materials, poor adhesive viscosity, poor cohesion, unreasonable process settings, and unreasonable customer use.
1.Small product labeling warping
Wrong labeling causes warping Bottles with a diameter of less than 30mm are usually called small bottles. If the selected label material itself has a large stiffness, it is easy to warp the label. Therefore, the self-adhesive used for small bottles generally uses a strong adhesive, and its adhesion on the bottle must be greater than the elasticity of the label surface material itself to resist bending, so that it can be achieved without warping after labeling.
There are many types of self-adhesive materials on the market, most of which are not recommended for small bottles, but some end users lack professional knowledge and mistakenly choose inappropriate label materials, which causes the label to warp after labeling. Usually, the warping of small bottles caused by the wrong selection of self-adhesive materials will start at the latest a few hours after labeling, and the degree of warping will increase over time.
In view of this, when accepting self-adhesive orders, label printing companies must carefully understand the customer’s labeling body. If they see that the customer is applying to small bottles, they must consult a professional self-adhesive material supplier to select a material that best suits the customer’s application to produce labels.
2.Poor adhesive adhesion causes labeling to lift up
Poor adhesive viscosity causes label warping. Some self-adhesive materials lose viscosity quickly after a period of production. In addition, the end user may not use the self-adhesive finished product immediately after production, so the label will warp when the label is affixed.
Label warping caused by this factor usually manifests itself as no problem with labels produced with new materials, but problems with labels produced with old materials, or problems with inventory labels, and there is a big difference in the viscosity of new and old label materials. Label warping caused by this factor usually starts within a few hours after labeling, and the longer it lasts, the more serious it is. If you encounter such a problem, you can complain to the raw material supplier and request replacement of qualified materials.
3.Improper use by customers causes the label to warp
Improper use by customers causes label warping. Some customers put the products in a cold storage with very low temperature immediately after labeling; some customers take the labeled objects out of the cold storage and label them when there is still condensed water on the surface; some customers also label on steel or iron plates placed in the open air, or label in a dusty environment. All of the above are unreasonable applications and are very likely to cause label warping.
4.Unreasonable process settings cause label warping
Unreasonable process settings cause labels to warp. Some labels that use the glazing process are overlapped on the object, that is, the label is wrapped around the object for a week without a gap in the middle, and the two sides overlap each other.
Since the varnish itself contains a certain amount of silicone oil, the label is easy to warp after being overlapped. Therefore, it is not recommended to use the glazing process for labels that use the overlapping process, and it is best to change to the laminating process.