Roller screen printing - the preferred choice for high-end packaging printing

In recent years, the screen printing industry has flourished at an extremely fast pace. The quality of printed products has become a key factor in competition. For many screen printer manufacturers, upgrading and adding new high-quality screen printing equipment are imminent. Although flat and curved screen printers are used more often than roller screen printers, with the development of high-quality, high-efficiency, and diversified packaging printing, roller screen printing will become the current economy and technology. High-content packaging screen printing technology.

First, roller screen printing principle

The roller screen printing system is composed of a plurality of independent monochrome printing units, suitable for various widths of printing, and can achieve synchronized integrated intelligent control of the production line. The key technologies in roller screen printing are screen cylinders and printing systems. The printing system uses a rubber squeegee to squeeze the ink so that it penetrates the substrate through the mesh of the drum nickel mesh. The substrate is fixed by an impression cylinder, and the screen, substrate and impression cylinder move at the same speed. A "frictionless" system. As shown in Figure 1.

Using a roller screen printing plate, the photoresist is coated on the screen, the plate-making film is sealed and exposed, the exposed portion is washed away, the mesh is left, the printing image is formed on the printing plate, and then the roller is mounted. During printing, the squeegee abuts the screen plate in the plate cylinder, and the screen plate rotates relative to it to play the role of squeegee. The ink passes through the mesh and forms an image on the substrate. The pressure on the substrate can be adjusted by the impression cylinder behind the substrate. The thickness of the ink layer can be adjusted by selecting the mesh number of the screen and the pressure of the blade.

Second, roller screen printing has become the first choice for high-end packaging and printing

1. Characteristics of roller screen printing

(1) Roller screen printing uses a nickel metal round screen plate, built-in squeegee and automatic ink supply system. The squeegee transfers the printing ink from the circular screen plate to the substrate supported by the platen roller. surface. The entire printing process from paper feeding, ink supply, color registration to UV drying, etc. are all automatically controlled by the computer, the operation is very simple.

(2) The roller screen printing circular screen printing plate uses 100% nickel non-woven material and is electroformed. The mesh is hexagonal and the entire mesh is even and thin to ensure the stability and precision of the imprinting. This type of plate is suitable for large-format rotary printing, with a maximum speed of 125 m/min. The screen can be reused 15 times.

(3) Roller screen printers are modular and can be installed in the middle or back of the original color set of a commercial paper printing line. The entire production line's symbol printing, printing oil, printing ink and other processes in one go, strong confidentiality.

(4) The use of roller screen printing press printing ink, a printing, ink layer thickness and coating uniformity are in line with the requirements for complete coverage of the confidential information of the winning invoice.

(5) The printing pressure of the cylinder printing is small, and there is no problem that the silver powder covering the ink is squeezed into the optical oil isolation layer. No matter how long the product is stored, there is no problem of scratching.

(6) The printing ink layer of roller printing has thick texture, strong texture, and good hiding power. It can also produce metal texture, tactile printing (such as Braille) and so on. Equipped with hot air drying device, suitable for handling water-based inks and solvent-based inks.

(7) Roller screen printing can not only meet the requirements of special effects such as printing frosting and ice flower, but also hot stamping holographic anti-counterfeit logo embossing and die-cutting molding. It is easy to realize high-speed automatic printing paper box and has been widely used in many high-grade Carton packaging and label printing.

2. Characteristics of roller screen printing machine

(1) The roller screen printer is very easy to operate.

(2) The printing speed of the roller screen printing machine can generally reach 4,000 pieces per hour. In terms of printing speed, roller screen printers are relatively easy to support and combine with offset presses. If roller screen printers use more advanced positioning methods, high-speed screen printing positioning after offset printing is guaranteed. In this regard, the plane network is guaranteed. Printers can not match it. Therefore, roller screen printing machine can achieve the perfect combination of printing speed and printing accuracy.

(3) The roller screen printing machine can be combined with the paper feeding machine to form an automatic production line. Therefore, the roller screen printing machine can realize screen printing and automatic high-speed printing, which has been greatly favored by the industry.

(4) roller screen printing machine also has deficiencies. For a drum screen printer, only one paper thickness is the most reasonable. However, for flat screen printers, with the change in the thickness of the paper, the net pitch can be adjusted accordingly, and the thickness of the printed paper does not have any effect on the printing accuracy of the flat screen printer.

Although roller screen printers have their shortcomings, their advantages far outweigh the disadvantages. Roller screen printing machine structure is stable and durable, the screen can be used repeatedly, overprinting is accurate, and the speed is fast. It has a simple and convenient job conversion control system. The downtime of the replacement work is very short, and the equipment can achieve higher output. The number of products that are printed in large quantities or often repeatedly printed is the preferred model for packaging screen printing, and it is also a model widely used in the domestic packaging printing industry.

3. Roller screen printing used in high-grade packaging

(1) Roll Invoice Printing

With the continuous development of the information industry and the continuous improvement of the quality of the national economy, bills will have more room for development. In particular, the state tax reform and the accompanying ticket reforms have brought new business opportunities to commercial paper printing. At present, many regions print scraping music on roll-up invoices and carry out prize-winning activities. Because roller screen printing products have the advantages of strong covering power, good coverage effect, on-line printing, good security performance, simple operation, and easy maintenance, the roller screen printing technology has been widely used in the printing of scraper invoices.

The new version of the invoice sets a scratch password area and a redemption area on the invoice face. After the confidential invoice number and the password are unified, the invoice will be used safely and normally. In order to ensure the reliability, confidentiality, and security of printed invoices and award-winning prize zone information, the printing of new invoices has adopted new printing techniques and anti-counterfeiting technologies. Specifically: 1 Print the invoice number and password of the new invoice with the high-precision digital ink-jet printing equipment of Sai Angel or Canada's "Creation" 300 dpi, and the prize area information of the prize-winning invoice; 2 Print the invoice password with the embossing method and The information area of ​​the prize area, the oil covering the ink layer, and the back side of the invoice password and prize information area are blackened; 3 Finally, the ink layer covering the invoice password and prize area information is covered with roller screen printing.

In the future, with the economic development, the field of commercial paper applications will continue to expand rapidly, and will be increasingly used by all walks of life. The society will also impose higher requirements on the printing technology of bills, and printing of bills will also be adopted. Many high-tech technologies. The application of roller screen printing to ticket printing will enable the development and prosperity of commercial paper printing.

(2) Carton Packaging

People are increasingly demanding packaging. As a result, the technology and equipment that are created in the packaging field are also being updated rapidly. Screen printing has the characteristics of thick ink layer, rich graphic layers, strong three-dimensional effect, and wide range of printing materials, etc. The application of high-grade tobacco and alcohol, food packaging cartons has gradually increased. The use of UV screen printing inks to print frosted, refraction, ice, wrinkles and other effects on cigarette packs will greatly stimulate consumers' desire to purchase. However, due to the flat screen printing method with low printing speed, slow ink curing speed, difficult to control printing quality, and large consumption of printing materials, it is unable to meet the needs of cigarette cartons for scale and mass production. The high-speed rotary screen printing production line has high printing speed, high productivity, stable quality and low consumption, and is suitable for high-speed automatic and large-scale mass production of exquisite folding cartons.

(3) Label Printing

With the economic development, the requirements for label printing have become higher and higher, and higher requirements have been put on printing equipment. This requires high-productivity machine designs and investments to target specific businesses and effective combinations of business development to meet the ever-increasing demands of the market. Due to the high precision of the roller screen printing equipment, multiple types of screen printing, color gradients, and the like that are difficult to achieve in plane screen printing are realized in the label printing. Therefore, roller printing has been favored in the field of label printing.

in conclusion

China's screen printing technology started late. At present, there are many plane and curved screen printing equipments. In the case of low printing speed, only general precision products can be printed. However, this has been unable to meet the needs of the industry. Increasing the speed and accuracy of screen printing has become the key to screen printing. The application of roller screen printing machine will not only improve the quality of screen printing products, enhance the company's competitiveness in the screen printing industry, but also create the conditions for the combination of screen printing and offset printing, will enable China's printing industry to further advance one step .

Reprinted from: Screen printing Author: Wang Color Printing