Application and Solution of Narrow Rotary Printing of Labels (I)

Narrow web printing technology has benefited from the label market's annual speed increase of more than 30% and the ever-changing changes in the labeling and packaging market. It has become a wonderful work in printing industry in recent years.

The so-called narrow-width web presses generally refer to rotary printing machines with a web width of 20 inches (508 mm) or less, of which flexographic printing presses are the main ones. Rotary offset presses, rotary screen printing, rotary gravure printing, and rotary special processing are also included. Equipment, such as: hot stamping, cold stamping, laminating, transfer, die cutting, slitting and rewinding, super glazing, etc. Therefore, the combination of multiple processes becomes a distinctive feature of narrow-width rotary machines. Because of the different tension requirements and pressure requirements between different processes, the control of tension and printing pressure becomes the key to achieving multi-process combination printing.

I. Technical status and application

At present, with the development of technology, many equipment suppliers can provide combined equipment for flexographic printing + rotary screen printing units, but not all combinations of processes are realized on a single production line. Narrow-width rotary printing has very obvious technical features: a variety of processing methods, flexibility, diversity, high quality, high efficiency, and cost savings, which indicates that narrow-width rotation technology has the superior characteristics of various processes, at the same time, The relatively high overall cost of medium- and wide-width equipment is avoided. Therefore, it is particularly suitable for the needs of the following markets.

1, the label market

The narrow-width rotation equipment and process are suitable for label printing fields including clothing hang tags, cosmetics labels, toiletries labels, wine labels, and cigarette labels.

In the label printing market, with the increasing number of varieties and the increasingly complex process, the process requirements are also more stringent. The requirements for the printing of narrow-width rotary labels, such as adhesive labels and film labels, have their own emphasis.

(1) Stickers

For common adhesive labels, flexographic printing is mainly used, and wire bonding is combined with die cutting and slitting; for those with special requirements, screen printing devices may also be added for special effects printing. . For sticker products, in fact, more issues need to be considered in terms of production efficiency. Therefore, high-speed flexographic printing equipment has become the first choice. In addition, for ordinary stickers, you can also choose special processing units such as Super glazing to achieve a UV effect such as a mirror effect, increase the added value of the product.

(2) Film labels

For thin-film labels, it is necessary to consider how to eliminate film deformation and static electricity in the equipment configuration. There are two main causes of deformation, one is tensile deformation and the other is thermal deformation. To solve the problem of film deformation, we must first choose a material with good quality and good uniformity. Secondly, in the equipment configuration, the best choice is to use a cold UV curing method, which not only has a fast curing speed, but also does not theoretically cause deformation of the material. In addition, we must consider whether the device has a device to distribute tension, such as the main power of the drive roller or roller device.

In recent years, the most popular product in the label market is the in-mold label, which is a special film label that can be integrated with the bottle during the container molding process. Very good security performance. Although the added value of this kind of product is very high, it is difficult for manufacturers to realize high added value in actual production. The reason is that in addition to the requirements for printing equipment and film materials, such labels need to solve two outstanding technologies. Challenges: First, eliminate static electricity, and second, high-speed die-cutting.

The generation of static electricity is caused by the in-mold label material, and the solution is to use static elimination devices to control. Recently, some ink suppliers have provided a static-free ink, such as the UV-removal ink provided by Anoye for in-mold labels. It can effectively prevent the generation of static electricity and ensure good printing performance.

Die cutting speed and precision are another difficulty encountered in the process of in-mold label printing. Because the in-mold label generates a large amount of static electricity in the production process, and the stiffness of the film itself is low during die-cutting, it is easy to produce flying. phenomenon. Therefore, in the optional equipment needs to be equipped with a professional suction conveying device or in-mold label receiving device.

In addition. The application of cold stamping and screen printing units will also greatly increase the added value of in-mold label products.

2, the packaging market

Narrow web printing equipment is also suitable for a variety of packaging markets, including food packaging, cigarette packaging, beverage packaging, and the like.

3, special lottery market

In the field of security ticket printing, narrow-width rotary printing equipment also has a lot to do, such as the application of scratch-type lottery printing.

(to be continued)