Label is a printed matter used to represent the relevant instructions of the product. Some are self-adhesive on the back, but there are also some printed matter without glue. The Label with glue is known as the "self-adhesive Label".
Self-adhesive label is a kind of material, also called self-adhesive material. It is a composite material made of paper, film or other special materials, coated with adhesive on the back, and coated with silicon protective paper as the base paper. Self-adhesive is a general term for materials with such properties.
The development history, current situation and application of self-adhesive
Self-adhesive label material is the 1930s by the American R- Stanton - Alley invention, Mr. Alley invented the first coater began to mechanized production of self-adhesive label. Because sticker labels, compared with traditional labels, do not need to brush glue or paste, and easy to preserve, can be used conveniently and quickly in many fields, soon, sticker labels spread to all over the world, and developed a number of categories!
From the late 1970 s, China began the non-drying label printing, equipment and technology from Japan, the first is a low-end market is given priority to, with the development of the society and the improvement of awareness, the non-drying label soon occupied a big chunk of the high market packaging, domestic private enterprises engaged in self-adhesive label printing thousands of home, Greatly promoted the development of the industry!
In market research, the market prospect is usually evaluated by the number of self-adhesive labels consumed per capita, and the data of relevant media are evaluated: The average annual consumption in the United States is 3~4 square meters, the average annual consumption in Europe is 3~4 square meters, the average annual consumption in Japan is 2~3 square meters, and the average annual consumption in China is 1~2 square meters, which also means that there is still a large room for development in China!
The market demand for high-grade labels is increasing day by day. All kinds of high-grade labels can be processed in China. Labels processed abroad before have gradually been converted to domestic production, which is one of the main reasons for the rapid development of domestic label printing.
Application of self-adhesive labels
As a packaging form to achieve appearance effects and specific functions, self-adhesive labels can be flexibly applied to all walks of life. At present, labels have excellent applications in the pharmaceutical industry, supermarket logistics industry, electronics industry, lubricating oil, tire industry, daily chemical, food, clothing and other industries!
Self-adhesive labels are generally divided into two types: one is paper self-adhesive labels, and the other is film self-adhesive labels.
1) paper adhesive labels
Mainly used in liquid washing products and popular personal care products; Thin film materials are mainly used in high - grade daily chemical products. At first, the market of popular personal care products and household liquid washing products account for a large proportion, so the corresponding paper materials are used more.
2) film adhesive labels
Commonly used PE, PP, PVC and some other synthetic materials, film materials mainly white, matt, transparent three kinds. Since the printability of thin film materials is not very good, it is generally treated with corona or increased coating on its surface to enhance its printability. In order to avoid deformation or tearing of some film materials in the process of printing and labeling, some materials are also subjected to directional treatment and stretched either in one direction or in two directions. For example, BOPP materials with bidirectional stretching are widely used.
Structure of self-adhesive labels
In a general sense, we call the structure of self-adhesive label "sandwich" structure: surface material, glue (adhesive), base paper, these three layers of structure is the basic structure, but also we can see with the naked eye.
Structure of self-adhesive labels
In fact, many materials may be divided into more detailed, for example, some film surface material and coating, easy to print, some materials and glue between the coating, easy to fully combine materials and glue and so on.
The production process of self-adhesive labels
To put it simply, the production process of self-adhesive label materials is completed by coating and composite processes. There are usually two types of equipment, namely split type and series type. According to different products, or different output requirements, choose different equipment.
In the whole production process, there are many details that need to be focused on, which will directly affect the subsequent use of materials, including:
1, the weight of the base paper coated with silicone oil (there are also special base paper manufacturers);
2, the weight of the glue;
3. Drying the glue;
4, coating process back to wet treatment;
5, coating uniformity;
This section describes the materials of self-adhesive labels
Due to the wide variety of self-adhesive label materials, this paper mainly chooses the materials widely used in the market to introduce!
(1) Surface material
1, paper surface material
Mirror coated paper, coated paper, matte paper, aluminum foil, thermal paper, thermal transfer paper and so on, these materials can be directly judged by the naked eye or simple writing;
2, film surface material
PP, PE, PET, synthetic paper, PVC, and special film materials developed by some companies (Avery Dennis Avery Dennison) such as Primax, Fasclear, GCX, MDO, etc. The film surface materials have a unique effect, can be white, or transparent or bright silver and subsilver treatment, etc. Embody the colorful appearance.
Note: The development of surface material types is still in progress, the rendering effect of surface material is closely combined with printing technology!
(2) Glue
A, according to the coating technology is divided into: latex, solvent glue, hot melt glue;
B, according to the chemical characteristics are divided into: acrylic acid (namely acrylic) class, rubber base class;
C, according to the characteristics of glue, it can be divided into permanent glue, removable (can be repeatedly pasted) glue
D, according to the perspective of consumer use is divided into: general type, strong viscous type, low temperature type, high temperature type, medical type, food type, etc.
The choice of glue is determined according to the application of the label. There is no universal glue. The definition of the quality of the glue is actually relative, that is, whether it meets the requirements of use is to determine the scheme.
(3) the base paper
1. Glazin backing paper
The most used base paper, mainly used in web printing and conventional automatic labeling field;
2, coated plastic base paper
Often used in the need for better flatness printing or manual labeling;
3. Transparent base paper (PET)
It is used more in two fields. First, it needs the surface material to have the effect of high transparency. Second, high-speed automatic labeling.
Note: Although the base paper will be "abandoned" after use, the base paper belongs to a very important part in the label structure. The glue flatness brought by the good base paper, or the labeling stiffness brought by the good base paper, or the smoothness of the standard brought by the good base paper, are the key factors in the use of the label!
Notes for the application of self-adhesive materials
1. Choose self-adhesive materials
Need to consider the following aspects, such as: posted surfaces situation (on the surface of things can change), posted material Be stick to surfaces shape, labeling, labeling environment, label size, final storage environment, small batch test label, confirm the final use effect (including selection of suitable to meet the requirements of printing material), etc
2. Several important concepts
A. Minimum labeling temperature: refers to the lowest labeling temperature that the label can withstand during labeling. If the temperature is lower than this, labeling is not suitable. (This is the value of a laboratory at the lowest temperature attached to the steel plate, but the surface energy of glass, PET, BOPP, PE, HDPE and other materials will change during the manufacturing process, so it needs to be tested separately.)
B. Operating temperature: refers to the temperature range that the label can withstand when it reaches a stable state after 24 hours of pasting above the lowest labeling temperature;
C, initial viscosity: the viscosity generated when the tag and the pasted are fully contacted by the force, and the initial viscosity of several digits;
D, Final stickiness: usually refers to the stickiness displayed when the label reaches a steady state after 24 hours of labeling.
Understanding these concepts will be very helpful in the actual selection of label materials, or the corresponding requirements for glue!
Post time: Aug-06-2022