What are the methods for laminating BOPP synthetic label paper?

The laminating method of BOPP synthetic label paper is mainly determined by the printing and processing method of its raw materials, generally divided into two categories: single sheet laminating and roll material laminating. The following are specific methods for laminating:

1、 Single sheet laminated paper

Single sheet paper laminating is mainly completed on laminating machines. According to the functions of laminating equipment and the characteristics of composite films, there are two laminating methods for single sheet paper adhesive labels:

Instant coating composite:

Apply adhesive on the surface of BOPP film roll and evaporate the solvent in the adhesive through a drying device.

On the composite workstation, a single sheet of paper is combined with a roll of film, and the two are pressed together by a hot roller to complete the laminating process.

Pre coated film composite:

Use a composite film pre coated with adhesive, which can be either hot melt adhesive or pressure-sensitive adhesive.

The laminating machine is equipped with a heated embossing cylinder. During laminating, the pre coated film comes into contact with a single sheet of paper. Under the action of the hot pressing cylinder, the adhesive melts and the film is bonded to the paper as a whole. If pressure-sensitive composite film is used, the heating switch can be turned off and only pressure composite can be used.

2、 Roll material coated with film

The roll material laminating is completed on the laminating station of the label machine or a dedicated laminating machine. Depending on the different forms of equipment, it can be divided into the following types:

Bottom paper composite film composite:

On the labeling machine, a specialized composite film with backing paper is used to film the film under the action of the composite device. This is a traditional laminating method, but in recent years it has been replaced by the process of bottomless paper composite film.

Paperless composite film composite:

On the label machine, the principle of laminating is basically the same as the process of laminating with backing paper composite film.

The bottomless paper film replaces the base paper by rewinding it based on the surface smoothness (surface tension) of its own material. After the adhesive is bonded to its surface, it can be peeled off without leaving any adhesive residue. The material used for the bottomless paper film is BOPP film with low surface tension.

Bottom less paper film laminating has low cost and is currently the most widely used laminating method.

Dry composite:

It is mainly used for laminating thin film materials on laminating machines or gravure printing machines.

Dry laminating of roll materials is suitable for large-scale label products, with good laminating quality and low cost. But after the roll label is laminated, it needs to undergo secondary processing such as die-cutting and waste disposal on the processing machine, such as the processing of battery labels and alcohol labels.

UV coating:

The latest technology abroad is mainly applied to rotary label machines with UV drying devices.

The process principle is that the surface of the laminated material is first printed with UV adhesive by a regular printing unit. After the adhesive is cured by a UV drying device, it becomes a pressure-sensitive adhesive. Then, the ordinary BOPP film (usually the composite surface has been corona treated) is laminated with the roll material at the laminating station to complete the laminating process.

UV coating has low cost, minimal tension changes in composite films, and does not require specialized films, making it suitable for high-speed production.

Overall, there are various methods for laminating BOPP synthetic label paper, and the choice of method depends on specific production needs, equipment conditions, and cost considerations. In practical operation, the laminating method should be flexibly selected according to the actual situation to ensure the printing quality and laminating effect of the label.