Application of Screen Printing in Stickers

Screen printing belongs to stencil printing, which is called four printing methods together with plain printing, embossing, and gravure printing. The principle of screen printing is: when the printing plate is printed, the ink is transferred to the printing material through the holes of the printing plate through a certain pressure to form an image or a text. In the field of label printing, screen printing is not a major printing process, but according to the recent development of international and domestic packaging markets, there has been a steady increase in screen printing.

The advantages of screen printing

The main features of screen printing compared with other printing methods are the following:

1, strong printability. The three printing methods of plain printing, embossing, and gravure printing can generally only be printed on flat substrates. And screen printing can not only print on the plane, but also on the surface of curved, spherical and concave and convex surface printing;

2, thick ink layer, strong three-dimensional, rich texture. The ink layer thickness of offset printing and embossing is generally 5 micrometers, the gravure printing is about 12 micrometers, the thickness of the ink layer of the flexographic printing is 10 micrometers, and the ink layer thickness of the screen printing far exceeds the thickness of the above ink layer, generally Up to about 30 microns. The screen printing ink layer is thick, the printing quality sense is rich, the three-dimensional sense is strong, this is other the printing method cannot compare. At the same time, screen printing can not only print in a single color, but also perform color registration and screen printing.

3, layout soft. The silk screen printing plate is soft and has a certain elasticity. It is not only suitable for printing on soft articles such as paper and cloth, but also suitable for printing on hard articles such as glass and ceramics.

4, screen printing can use a variety of types of ink. Namely: oil, water, synthetic resin emulsion, powder and other types of ink;

5, screen printing imprinting force is small. Due to the low pressure used during printing, it is also suitable for printing on fragile objects.

Self-adhesive label printing classification

At present, global sticker printing can be divided into the following major camps based on the different printing methods used:

1, based on flexo

North America, represented by the United States and Canada, is a typical example of the use of flexographic printing stickers. The equipment for the unit type printing unit, ink-based water-based ink, using circular pressure round die-cutting.

2, embossing and flexo half

This type of processing is mostly in Europe. The application of flexo printing is basically the same as that of the United States. Toppan printing also accounts for 50% of the total, and all of the letterpress printing uses UV ink. Most of the devices are stacked or satellite.

3, mainly by embossing

This approach is based in the Asia Pacific region. Most of the developing countries in the Asia Pacific region are still lagging behind in label printing. Even with the use of letterpress printing, only a minority of UV inks are used. Most of the label printing still uses resin ink, roll-to-roll printing, and sheet-fed printing. Coexistence; due to the higher proportion of artificial labeling, so the use of sheetfed offset adhesive labels is widely used; in the die-cutting mode is mainly flat die-cutting.

4, offset printing

Offset printing is the main method for printing paper stickers in China's label printing plants. Offset printing is characterized by fine graphics and rich layers, suitable for large-volume printing, and printing equipment can be used in one machine, which is suitable for the characteristics of the Chinese label market. However, sheet-fed offset printing is not suitable for printing films with no absorptive surface, because the film labels are mostly roll-to-roll and require volatile drying inks. Offset can print thicker plastic materials, such as in-mold labels, label hangtags, but the machine must be equipped with a UV curing device, which requires a small fee.

5, screen printing

Screen printing is the most adaptable printing method for substrates. At present, there are many screen printing companies that use inexpensive screen printing equipment to undertake self-adhesive labels and film label printing services. The screen printing label is characterized by strong ink and strong three-dimensional impression. It can use UV ink to print film products. In addition to a handful of rotary screen printing equipment capable of roll-to-roll label printing, most screen printing equipment is a semi-automatic screen printing machine, which can only print a single sheet, and the overlay accuracy is not high, and is not suitable for supporting the production line. Film label production equipment. Moreover, the post-press processing technology in the business transformation at the same time, should also pay attention to the corresponding changes in label processing, such as printing stickers, according to the application of the label after the processing of the adhesive into a single sheet Paper processing and web processing.

Application of Screen Printing in Stickers

Screen printing sticker labels are mainly used in the electronic machinery industry, and membrane switches are typical products of their technology. The advantage of silk screen printing is that the ink layer is thick, colorful, concave and convex, strong visual impact, suitable for restoring simple lines, color blocks, text and other patterns, and the general total printing color number does not exceed 4 colors, the disadvantage is the printing gradient The effect is not good, can not achieve beautiful multi-color printing effect.

The current label market is increasingly demanding for printing technology. The requirements for the printing of label products are as follows: They must be eye-catching, have a strong visual impact, have subtle details in local details, and have a three-dimensional surface finish; they can produce high added value and have better anti-counterfeiting effects. Obviously, a single printing method simply cannot meet these requirements for the printing of label products.

The combination printing method adapts to the needs of layout design for the development of the modern printing industry, and brings huge profits to the printing manufacturers, and therefore it is rapidly developed. In foreign countries, more than 10% of label products have been printed using combination printing. Such as transparent material label. Transparent material labels often need to be screen-printed with a background color, followed by trapping or letterpress logos and patterns. The printing effect of this method is different from general label printing, which can improve the grade of the product very well.

From the perspective of market trends, this type of printing will become more and more popular. The excellent coverage effect of screen printing not only makes it suitable for printing on transparent materials, but also can be used for printing gold ink, silver ink, and bakelite.

Silk and soft combination printing

The most widely used joint method is mainly screen printing and flexible printing. The rotary screen printing unit is printed with a flexographic printing press and has the following applications:

1, To enhance the attractiveness of the product, use penetrating effect design, such as the use of very heavy colors or luminous ink;

2. Labels used in more severe environments, such as battery labels, lube barrel labels, and paint cartridge labels;

3, need to emphasize the product name and logo of the product, such as drug labels, injections, etc.;

4. Certain elements need to be warned by law, including the blind;

5, need to obtain gold and silver and other metal effects;

6, need a more simple printing process, such as the use of screen printing a large area, only missed printed text instead of printing fine text on a blank substrate;

7, in some cigarette packs or cosmetic packaging requirements embossed, matte effect.

In flexo-screen printing, there are many factors that affect the quality of the printing. In addition to grasping the screen printing and flexographic printing techniques, we must pay attention to the characteristics of different printing methods, so that the two are truly advantageous. Complementary to form a good combination, such as printing materials and ink use issues, speed matching issues, standardization issues and problems with screen printing itself.

With the application of new materials and new processes, label printing technology will continue to improve, and combination printing will gradually become the mainstream method for label printing; combined printing can not only complement the advantages of multiple printing methods, but also create new ones. D. The future market is broad, and it is believed that flexo-silkprint combination printing will be the preferred method for future label combination printing.