Offset Printing Partial UV Coating Effect/Spot LED UV Varnish (1)

Partial UV Coating Effect/Spot LED UV Varnish/ UV coating classification

-----Screen printing partial glazing

Screen printing has the characteristics of high ink transferability, thick ink layer and strong three-dimensional effect. The screen for glazing should generally be 200～300 mesh screen (for partial frosting and partial colorful glazing effect, the number of meshes is lower), and the tension of the stretched screen is 20-25N/cm. Because the equipment investment is not large. Many books and magazines and packaging factories prefer screen printing when increasing spot uv glazing business. Some professional printing and glazing companies improve glazing accuracy and production efficiency. Fully automatic cylinder screen printers are already in use. The production speed can reach 3000 sheets/hour. However, the screen printing partial coating basically adopts the offline production mode. The online rotary screen printing unit is less used.

Partial glazing of flexographic printing

The characteristic of flexographic printing is the ability to form a thicker coating with a simpler process. Therefore, it is very popular in UV glazing. The partial glazing of flexographic printing is divided into ordinary flexographic printing glazing and special flexographic printing glazing, and some simple pictures and texts are still using engraved flexographic printing plates. The partial glazing of flexographic printing is suitable for off-line glazing and can also realize online glazing. The flexographic printing and glazing method, with anilox roller and cavity doctor blade, can accurately control the amount of varnish, and the glazing quality is stable.

Gravure printing partial glazing

Gravure printing also has advantages in spot uv glazing due to the thicker printing ink layer and the high printing endurance of the gravure cylinder. In particular, the appearance of the sheet-fed gravure printing machine has contributed to the development of gravure sspot uv glazing. However, due to its high plate-making cost, it is mainly used for long-version glazing business.

Other printing partial glazing methods

Before UV varnish, no one would use offset printing for glazing because its printing ink layer was too thin. However, UV varnish has the advantages of thicker film, higher gloss, and high overprint accuracy. It also has some applications in partial /spot UV glazing, but it is mainly used for online glazing.

In terms of printing production methods, spot UV coating machines can also be divided into offline coating and online coating. Off-line glazing refers to printing. The glazing is performed on special equipment and requires the use of a special glazing machine or a calender. During off-line glazing, since the printed matter can be sufficiently dried, higher gloss can be obtained than on-line glazing. In addition, the flexibility of off-line coating production is great. The equipment investment is small. On-line glazing means that printing and glazing are completed on one production line, that is, glazing and UV curing devices are added to the printing machine. Make the printed matter directly glaze after printing.

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