1. Glue: Glue is the medium between the label material and the bonding substrate, which serves as a link. According to its characteristics, it can be divided into two types: permanent and removable. It has a variety of formulas, suitable for different surface materials and different occasions. The adhesive is the most important component in the technology of self-adhesive materials and the key to label application technology.
2. Surface material: the surface material. Generally speaking, all flexible materials can be used as self-adhesive materials. The type of surface material depends on the final application and printing process.
The surface material must be able to:
(1). Suitable for printing and printing, with good inking properties
(2). There is enough strength to accept various processing
(3). The surface gloss and color consistency and density uniformity of the surface material determine the uniformity of ink absorption of the self-adhesive material and the color difference of the same batch of label printing.
3. Surface coating: used to change the surface characteristics of the surface material. Such as improving the surface tension, changing the color, adding a protective layer, etc., to make it better accept ink and easy to print, achieve the purpose of preventing dirt, increasing ink adhesion, and preventing printed graphics from falling off.
(1). Surface coating is mainly used for non-absorbent materials, such as aluminum foil, aluminized paper, and various film materials.
(2). The strength of the coating determines whether a large amount of paper powder will be produced during printing, which is an important indicator of printing quality.
4. Bottom coating: It is the same as the surface coating, but it is coated on the back of the surface material. The main purpose of coating the bottom layer is:
(1). Protect the surface material and prevent the penetration of adhesive
(2). Increase the opacity of the fabric;
(3). Increase the bonding force between the adhesive and the surface material;
(4). Prevent the plasticizer in the plastic surface material from penetrating into the adhesive, affecting its adhesive performance, causing the label’s adhesive force to decrease and the label to fall off.
5. Bottom paper: The function of the bottom paper is to accept the release agent coating, protect the adhesive on the back of the face material, and support the face material so that it can be die-cut, discharged, and labeled on the labeling machine. Like the face material, the thickness uniformity and strength of the backing paper are not only related to the printing performance, but also an important indicator that determines the uniformity of die-cutting, the speed of waste discharge, and the edge breakage of the paper.
The self-adhesive material requires that the bottom paper has good flatness, uniform thickness, consistent light transmittance, and the higher the density, the better so that the surface material can be completely die-cut.