The lamination of theself-adhesive labelis generally made of a transparent BOPP film on the paper self-adhesive material, which can achieve the purpose of protecting the pattern, waterproof, anti-corrosion, and increasing the three-dimensional effect of the label. Other types of films, such as PET and PVC, can also be used as composite films, but they are not widely used. Due to the high cost of paper roll material coating, it has been gradually replaced by UV coating process.
Self-adhesive labelsare divided into sheet-fed lamination and roll material lamination according to the printing and processing methods of raw materials. The sheets are laminated on the laminator. The roll material is compounded on the compound station of the label machine or on a special compound machine.
1. Leaflet self-adhesive lamination
According to the function of the laminating equipment and the characteristics of the composite film, there are two lamination methods for sheet-fed self-adhesive labels:
Ready-to-coat lamination – done on the laminating machine. The compounding process is as follows: firstly, coat the adhesive on the surface of the roll BOPP film, and volatilize the solvent in the adhesive through the drying device, and then combine the sheet paper with the roll film at the compounding station, and heat The two become one under the extrusion of the roller to complete the coating process.
2. Roll self-adhesive lamination
According to the different equipment, web lamination is carried out on the labeling machine, and the principle of lamination is basically the same as that of the bottomed paper composite film lamination process. The backing paper film is rewound by the surface smoothness (surface tension) of its own material to replace the backing paper. After the adhesive is bonded to the surface, it can be peeled off without leaving any glue traces. The material used for the linerless paper film is a low surface tension BOPP film. The cost of the bottomless paper film lamination is low, and it is the most widely used lamination material at present.
UV lamination process – a foreign process, mainly used in unit-type rotary labeling machines with UV drying devices. The principle of the process is: the surface of the film material is first printed with UV adhesive by the ordinary printing unit, and after the adhesive is cured by the UV drying device, it becomes a pressure-sensitive adhesive. Then the ordinary BOPP film (generally the composite surface has been corona treated) is composited with the roll material at the lamination station to complete the lamination process. The cost of UV coating is low, the tension of the composite film changes little, no special film is needed, and it is suitable for high-speed production. UV coating is a promising process, which has been applied in developed countries in Europe and America.
All kinds of self-adhesive labels can be applied to materials that ordinarypaper labelsare not capable of. It can be said that self-adhesive labels are a kind of labels. Compared with traditional printed matter printing, self-adhesive label printing has a great advantage. The difference is that self-adhesive labels are usually printed and processed on a label linkage machine, and multiple processes are completed at one time, such as graphic printing, die-cutting, waste discharge, cutting and rewinding, etc. It can be seen that self-adhesive labels have higher requirements for printing technology and printing equipment.