Self adhesive is divided into three parts: surface material, glue and substrate. What kind of self-adhesive we usually talk about generally refers to the distinction of surface materials. Commonly used self-adhesive is printed with ordinary coated paper, pet, PVC, PP and other paper or composite materials.
Paper is a common type of printing materials, and most of the applications of self-adhesive printing are printed with paper surface materials. It is mainly used for the printing of product outer box stickers, logistics stickers and storage stickers.
The printing of pet, PVC, PP and other materials is a high-grade material that requires strict printing. It is mainly used for packaging and self-adhesive printing of electronics, electrical appliances, machinery, motors and daily cosmetics.
Classification of adhesive materials
1. According to the characteristics of adhesive, it can be divided into permanent adhesive materials and removable adhesive materials;
2. According to the classification of adhesive coating technology, it can be divided into hot-melt adhesive materials, solvent adhesive materials and emulsion adhesive materials;
3. According to the classification of adhesive and chemical properties, it can be divided into rubber based and acrylic adhesive materials;
4. According to the characteristics of the base paper, it can be divided into three kinds of adhesive materials: opaque base paper, translucent base paper and transparent base paper;
5. According to the characteristics of surface materials, it is divided into paper adhesive materials, film adhesive materials and special adhesive materials.
Basic structure and function of adhesive materials
What is the basic structure and function of self-adhesive materials? The self-adhesive mainly consists of: surface coating, surface material, primer, adhesive, release coating, backing paper and back coating or back printing. The composition of the self-adhesive is described as follows:
1. Surface coating
Used to change the surface characteristics of the surface material. Such as improving surface tension, changing color, adding protective layer, etc., to make it better accept ink and easy to print, so as to prevent dirt, increase ink adhesion and prevent printing text from falling off. Surface coating is mainly used for non absorbent materials, such as aluminum foil, aluminum coated paper and various film materials.
2. Adhesive
The adhesive is the medium between the label material and the adhesive base material and plays a connecting role. According to its characteristics, it can be divided into permanent and removable. It has a variety of formulas, suitable for different surface materials and different occasions. Adhesive is the most important component of adhesive material technology, and is the key of label application technology.
3. Release coating (silicon coating)
That is, silicon oil layer is coated on the surface of the base paper, which can make the base paper become a very smooth surface with low surface tension and prevent the adhesive from adhering to the base paper.
4. Backing paper
The function of the backing paper is to receive the release agent coating, protect the adhesive on the back of the surface material, and support the surface material so that it can be die-cut, discharged and labeled on the labeling machine.
5. Surface material
That is, the surface material is the material that receives the printed text on the front side and the adhesive on the back side and is finally applied to the object to be pasted. Generally speaking, all flexible deformable materials can be used as the fabric of self-adhesive materials, such as commonly used paper, film, composite foil, various textiles, thin metal sheets and rubber. The type of surface material depends on the final application and printing process. The surface material shall be able to adapt to printing and printing, have good inking property, and have sufficient strength to accept various processing, such as die cutting, waste discharge, slitting, punching and labeling.
6. Back coating or back printing
Back coating is a protective coating on the back of the backing paper to prevent waste discharge. The adhesive around the rewound label is bonded to the backing paper. Another function is to manufacture multi-layer labels. The back printing function is to print the manufacturer's registered trademark or pattern on the back of the backing paper to promote and prevent counterfeiting.
7. Priming
Like the surface coating, it is only coated on the back of the surface material. The main purpose of coating the bottom layer is:
(1) Protect surface materials to prevent adhesive penetration;
(2) Increase the opacity of the fabric;
(3) Increase the adhesive 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, resulting in the reduction of the adhesive force of the label and the label falling off
