Adhesive label materials are widely used in the printing industry, and their application methods have become increasingly mature. The quality of adhesive label materials is also continuously improving, of course, there are also some inferior counterfeit products. How to distinguish good from bad adhesive labels? The structure of adhesive label materials appears to be composed of three parts, namely the surface material, the adhesive, and the backing paper. However, from the perspective of manufacturing process and quality assurance, adhesive label materials are composed of seven parts:

1. Face material: The surface material is the material that receives the printed graphics on the front and the adhesive on the back, and is eventually applied to the object to be pasted. Generally, any material that can flexibly deform can be used as the fabric of the self-adhesive label material. The type of face material depends on the final application and printing processing technology. The face material must be able to adapt to printing and printing, have good ink absorption, and have enough strength to accept various processing. The surface gloss and color consistency, the uniformity of density of the face material determine the uniformity of ink absorption of the self-adhesive label material, and also determine the color difference of the same batch of label products.

2、Surface Coating: Used to change the surface properties of the substrate. For example, improving surface tension, changing color, increasing a protective layer, etc., making it better able to accept ink and easy to print, achieving the purpose of preventing dirt, increasing ink adhesion force, and preventing the detachment of printed graphics. Surface coating is mainly used for non-absorbent materials, such as aluminum foil, aluminum-coated paper, and various film materials. The coating strength of the substrate determines whether there will be a large amount of paper dust during printing, and it is also an important indicator of determining the quality of printing.

3. Coating the undercoat: It is the same as the surface coating, but it is applied to the back of the substrate. The main purpose of the undercoat is: (1) to protect the substrate and prevent the adhesive from penetrating. (2) to increase the opacity of the fabric. (3) to increase the bonding force between the adhesive and the substrate. (4) to prevent the plasticizer in the substrate from penetrating into the adhesive, affecting its adhesive performance, leading to a decrease in the bonding force of the label, causing the label to peel off.

4. Release Coating (Silicone Layer): This involves applying a silicone layer to the surface of the backing paper. The silicone coating makes the backing paper have a very low surface tension and a smooth surface. Its purpose is to prevent the adhesive from sticking to the backing paper.

5. Adhesive: Adhesive is the medium between the label material and the adhesive substrate, playing a role in connecting. It can be divided into permanent and removable based on its characteristics. There are various formulas of adhesive, suitable for different surface materials and different occasions. Adhesive is the most important component in the technology of pressure-sensitive label materials, and it is the key to the application technology of labels.

6. Backing Paper: The role of backing paper is to accept the release agent coating, protect the adhesive on the back of the face material, support the face material, and enable it to be die-cut, waste removal, and to be labeled on the labeling machine. Similarly to the face material, the uniformity and strength indicators of the backing paper not only affect the printing performance, but also are important indicators for determining the uniformity of die-cutting and the speed and paper edge breakage during waste removal.

7、Back Coating or Back Printing: Back Coating is a type of protective coating applied to the back of the substrate to prevent adhesion of waste material after rewinding. The uniformity of the adhesive and silicone coating and the correct coating amount directly affect the peeling force (release force) between the label and the substrate. The size of the peeling force also directly affects the waste removal during die-cutting and the machine speed. The peeling force also determines the label's output condition, that is, the application situation. In addition, the amount of adhesive coating will also affect the situation of adhesive penetration at the material end surface.