The working principle of the laminating machine is to first paste the adhesive on the plastic thin paper film through the roller coating device, and heat it by the hot pressing roller barrel to soften the film, and then make the printed matter separated from the primer and the film be pressed together. The working principle of the type laminating machine, that is, the coating film is a process of using the instant coating laminating machine to immediately stick the film with the glue to carry out the paper-plastic composite. It is mainly produced by a film-coating factory or a processing workshop. According to the need, the roll plastic film is bonded to the mixture and then dried (slightly) compounded. After compression, the paper film is adhered together to form a film product. That is, there are two types of coating equipment: automatic and semi-automatic. The basic working principle is the same; the main process flow is unwinding → gluing separation → drying → compounding → slitting → complete stacking. Working principle of pre-coated laminating machine Pre-coated laminating machine is a special equipment for compounding printed matter with pre-coated plastic film. The main structure consists of film unwinding, automatic input of printed matter, hot pressing compound, and automatic rewinding. Part of the composition, mixed with instant coating laminating machine, does not require adhesive bonding, dry part, so compact structure, small size, low cost, easy operation, start-up with use, large production size, high efficiency. The combination of the pre-coated film and the paper printed matter only needs to be hot pressed. It is suitable for all kinds of laminating machines, laminating machines and plastic sealing machines with hot pressing function. The bridge type compound laminating machine of the glue-coated wet composite process does not need to be replaced, and can be completely coated with pre-coated film.