Process flow of stamping anti-counterfeiting label with self-adhesive

Self-adhesive label material, which is called self-adhesive label material, is a kind of composite material with paper, film or special material as the fabric, adhesive on the back and silicon protective paper as the base paper. Nowadays, the demand for non-sticker labels in our country is growing at a rate of over 20% every year. The size of the sticker label market is about 450-500 million square meters per year. Therefore, the use of non-drying glue is becoming more and more widespread, widely used in commercial label printing and screen printing. Among them, bronzing technology is the most important technology of non-adhesive printing.



Generally speaking, self-adhesive includes a variety of bronzing processes: cold bronzing, round bronzing, flat bronzing and other processes. According to the processing method of trademark printing press, its bronzing methods are divided into sheet paper bronzing and web paper bronzing. Single sheet paper gilding process is the same as traditional gilding process, which is processed on special gilding machine. Roll paper stamping is accomplished on label linkage and is the most widely used processing method. At present, there are several ways of bronzing drum materials:



Cold stamping on rotary machine

This is a new gold stamping process. Instead of using heated metal plate, it uses printing adhesives to transfer metal foil and realize gold stamping. The process flow is as follows: first, UV pressure-sensitive adhesive is printed on the position where the stamping is needed, then the adhesive is dried by the UV drying device, and then the special metal foil is combined with the pressure-sensitive adhesive, and then the metal foil is peeled off, so the part of the metal foil that needs to be transferred to the surface of the printed matter is transferred to achieve cold stamping. Cold stamping process has the advantages of low cost, energy saving and high production efficiency. It can make use of existing equipment and components without adding additional devices. It is a new process with great development prospects.



Round pressing and gilding on rotary machine

The hot stamping plate used for round stamping is in the shape of a cylinder. When stamping, it contacts with the stamping cylinder to realize the hot stamping. Round stamping is suitable for continuous paper feeding wheel transformation label machine, but it has certain requirements for paper feeding speed, that is to say, it has an impact on printing speed. But compared with flat stamping, it greatly improves the efficiency. Because of the high manufacturing cost of round pressing and gilding roll, it is only suitable for long-plate live gilding.



Flat stamping on label machine

In relief label printing machine, whether flat or round flattening equipment, because of the intermittent feeding of web paper, all stamping uses flat flattening. Generally, the stamping station is an independent unit, and some models share a unit for stamping and die cutting, which is used separately.



Multi-station flat stamping

Some models have two-station stamping units, such as SMHC-45-MWL label machine in Shiki, Japan. One unit is close to the printing plate to complete horizontal stamping, and the other unit is an independent unit to complete vertical stamping. The machine can be used for two-color bronzing at the same time.



Flat pressing and stamping on processing machine



The machine is specially designed for processing printed drum labels and labels that do not need printing. Hot stamping is a function of a processing machine. Flat pressing and square method is commonly used in the stamping device on the processing machine. Its working principle is the same as that of the label machine.



According to the order of non-adhesive stamping, it can also be divided into first stamping process and then stamping process, in which first stamping refers to stamping on the label machine before printing, and then stamping refers to printing first, and then stamping. The drying of ink is the key to hot stamping and then hot stamping. Different inks are used, and different stamping and post-stamping processes are needed for label printing.



1. First bronzing process

When using ordinary ink to print labels on the label machine before installing the intermittent paper feeding and stamping parts, the first stamping process is adopted. Because the ink used is oxidative polymerization drying type, it takes a certain time to completely dry the ink after printing, so the stamping pattern must avoid the ink. The best way to avoid ink is to pre-press the roll material before printing.



The first stamping process requires that the printing pattern and the stamping pattern are separated (juxtaposed), because the surface of electrolytic aluminium is smooth, non-inking, and can not be printed. Gold stamping can prevent ink from rubbing dirty and ensure the quality of label printing.



2. Post-bronzing process

The post-stamping process is applied to the stamping parts installed on the label machine of the back door, and UV ink is used for printing. The drum material is printed first, and the ink is dried instantaneously by UV drying device. Then the material surface or the ink surface is bronzed after the ink is dried. Because the ink has been dried, the hot stamping pattern and the printing pattern can be juxtaposed or overlapped, and the ink rubbing phenomenon will not occur.