While talking about the self-adhesive label printing process, we must also understand the basic structure of the self-adhesive material as a printing material and the function of each part. The structure of the self-adhesive material is composed of three parts, namely surface material, adhesive and base paper, but from the perspective of manufacturing process and quality assurance, the self-adhesive material consists of seven parts:
1, surface coating
Used to change the surface characteristics of the facestock. Such as improving the surface tension, changing the color, adding a protective layer, etc., to better accept the ink and easy to print, to prevent dirt, increase the adhesion of the ink and prevent the printed graphics from falling off. Surface coating is mainly used for non-absorbent materials such as aluminum foil, aluminized paper and various film materials.
2, face material
That is, the surface material is a material that receives the printed image on the front side and the adhesive on the back side and is finally applied to the object to be pasted.
In general, all flexible materials can be used as self-adhesive materials, such as commonly used paper, film, composite foil, all kinds of textiles, thin metal sheets and rubber. The type of facestock depends on the final application and the printing process. The face material should be able to adapt to printing and printing, have good ink repellency, and have sufficient strength to accept various processing such as die cutting, waste discharge, slitting, punching and labeling.
3, the bottom layer
Like the surface coating, it is only applied to the back side of the face material. The main purpose of the primer layer is to:
(1) Protect the surface material from penetration of the adhesive.
(2) increase the opacity of the fabric;
(3) increase the adhesion between the adhesive and the face material;
(4) Prevent the plasticizer in the plastic surface material from penetrating into the adhesive, affecting the performance of the adhesive, resulting in a decrease in the adhesive force of the label and a peeling of the label.
4, the adhesive
The adhesive is the medium between the label material and the bonded substrate and acts as a bond. According to its characteristics, it can be divided into two types: permanent and removable. It is available in a variety of formulations for different facets and different occasions. Adhesives are the most important component in the technology of self-adhesive materials and are the key to label application technology.
5, release coating (silicon coating) is to apply a layer of silicone oil on the surface of the paper, the application of silicone oil can make the paper a very low surface tension, very smooth surface, the role is to prevent the adhesive bond on the bottom paper on.
6, the bottom paper
The role of the backing paper is to accept the release agent, protect the adhesive on the back side of the facestock, and support the facestock to enable die cutting, waste disposal, and labeling on the labeling machine.
7, back or back printing
The back coating is a protective coating on the back side of the backing paper to prevent waste, and the adhesive around the re-rolled label is bonded to the bottom paper. Another role is to make multi-layer labels. The back printing function is to print the manufacturer's registered trademark or pattern on the back of the backing paper for publicity and anti-counterfeiting.