Self-adhesive also called self-adhesive labeling materials, generally used self-adhesive labels are composed of four parts: (1) surface material (2) adhesive (3) backing paper (4) printing ink on the surface of the first layer of paper, film or special materials for the main fabrics, while the back is coated with adhesive, coated silicone protective paper for the backing of a composite material.
As a result of a variety of coating technology, resulting in the formation of self-adhesive materials have different grades, the direction of development is by the traditional roller coating, scraper coating to the direction of high-pressure cast coating development to maximize the uniformity of the coated sensibility, to avoid bubbles and pinholes, to ensure the quality of the coated, and the cast coated cloth coating in the domestic technology is still not yet mature, the domestic main use of the traditional roll-type coating.
1) Glue: common self-adhesive glue, divided into three kinds: hot melt adhesive, water-soluble adhesive (usually called water glue), oil glue characteristics.
Glue is the medium between the labeling material and the bonding substrate, play a role in linking. According to its characteristics can be divided into permanent and removable two kinds. It has a variety of formulations, suitable for different surface materials and different occasions. Adhesive is the most important component of self-adhesive material technology, is the key to labeling application technology.
Self-adhesive labels are the same thickness of the glue coated on the same substrate above, the viscosity of the size is like this: oil glue > water glue > hot melt adhesive, the price is also like this. Need to pay attention to the place is self-adhesive labels are most suitable for the surface clean, dry, no oil and dust labeling substrate. Any labeling, need to keep the surface of the labeled object dry, no oil and dust, so as to achieve the best labeling effect.
2) Surface material: that is, the surface material. Generally speaking, all can be flexible material can be used as self-adhesive material fabric, the type of surface material depends on the final application and printing process. The surface material should mainly be able to:
(2-1). Adapt to printing and printing, with good inking properties
(2-2). Be strong enough to withstand a variety of processing
(2-3). Surface gloss and color consistency of the surface material, density uniformity, which determines the uniformity of self-adhesive material ink absorption and the same batch of label prints of the color difference.
3) Surface coating: used to change the surface characteristics of the surface material. Such as improving surface tension, change the color, increase the protective layer, etc., so that it is better to accept the ink and easy to print, to prevent soiling, increase the adhesion of ink and prevent the printing of graphics off the purpose.
(3-1). Surface coating is mainly used for non-absorbent materials such as aluminum foil, aluminized paper and various film materials.
(3-2). The strength of the coating determines whether or not a large amount of paper powder will be produced during printing, and is an important indicator for determining printing quality.
4) Primer: It is the same as the surface coating, but coated on the back of the surface material, and the main purpose of the primer is:
(4-1). Protect the surface material, prevent the adhesive penetration
(4-2). Increase the opacity of the fabric; and
(4-3). Increase the adhesion between the adhesive and the surface material; (4-4).
(4-4). Prevent plasticizers in the plastic surface material to penetrate into the adhesive, affecting the performance of the adhesive, resulting in reduced adhesion of the label, the label falls off.
5）Backing paper: the role of the backing paper is to accept the release agent coating, to protect the adhesive on the back of the face of the material, to support the face of the material, so that it can be die-cutting, waste and labeling machine in the labeling. The same as the face material, the uniformity of the thickness of the base paper and the strength of the instructions are not only related to the printing performance, or to determine the uniformity of the die-cutting and the speed of the waste and the paper edge of the important indicators of the fracture.
Self-adhesive materials require good flatness of the base paper, thickness uniformity, uniformity of transmittance, the greater the density, the better, so as to facilitate the face of the complete die-cutting.
