Nowadays, the Asian packaging market has developed rapidly, especially in China's packaging industry. With the continuous emergence and application of new materials and technologies, screen printing has a unique advantage in today's packaging and printing and is playing a huge role in providing an unprecedented variety of packaging products with unique shapes and special effects for the commodity market. The vast stage.
First, the application of screen printing on the packaging
The high flexibility of screen printing can print on the surface of various packaging products to achieve a variety of special effects. Therefore, screen printing technology is very popular in the packaging industry and is mainly applied in the following aspects:
Application on plastic packaging. Screen printing plastic film can be used for the packaging of food, clothing and other products, as well as the printing of plastic packaging containers.
Application on paper packaging. As the screen printing pattern has a thick ink layer and a strong three-dimensional effect, it can greatly improve the quality of packaging, and it is increasingly used in carton packaging for cigarettes, wine, cosmetics, nutritional products, and high-end footwear.
Application on metal packaging. Metal packaging mainly includes various beverage cans, food cans, and sundries. The screen printing inks used require strong adhesion, high hardness, good stretchability, and good abrasion resistance.
Application on glass packaging. Glass packaging is mainly a variety of glass bottles, used for a variety of liquid packaging, such as beverages, mineral water and a variety of beer, liquor, wine and so on.
Application on ceramic packaging. The direct method of ceramic screen printing is to print images directly onto ceramic embryos with a screen plate, and then glaze and burn to make porcelain. The indirect method is to transfer the screen-printed flower paper to the ceramic ware. Because the decal paper is printed finely, it is widely used in the ceramic packaging, such as some high-level packaging of wine.
Second, roller screen become the preferred choice for high-grade packaging screen printing
With the development of high-quality, high-efficiency and diversified packaging net screen printing, roller screen printing has become a high-tech printing and screen printing technology with a high level of technology. Its printed products have thick ink layers, bright colors, and high density. With good force, fine lines, and seamless pattern connection, it can use large-grained printing inks to increase the three-dimensional image and the clarity of printed images. It has been widely used in many high-end carton packaging and label printing fields.
The roller screen printing system is composed of a plurality of independent monochrome printing units, suitable for various width 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. The 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, suitable for Printing products with a large number or often repeated printing is the preferred model for packaging screen printing, and it is also a type of machine widely used in the domestic packaging printing industry.
Third, the renewal of screen material improves the quality and efficiency of packaging production
Wire mesh is the skeleton of the production of screen, is the basic support for photosensitive adhesive or photosensitive film, screen printing companies spend the largest area, mainly including the price of wire mesh and screen installation, recycling costs. The new screen material is the primary guarantee for creating high-quality printing products, saving costs and improving efficiency.
Disposable wire mesh system. By using a one-time screen system, labor intensity of laborers can be reduced and screen printing can be replaced quickly. Wire mesh can be pre-stretched with highly reproducible, stable equipment to ensure consistent mesh tension for every mesh.
Pre-coated wire mesh. Photoresponsive pre-coated screen can directly expose and develop the screen, which not only greatly reduces the steps of coating and drying the screen before exposure, but also pre-coating the screen coating can accurately control the thickness of the photosensitive adhesive and accurately control the ink. Layer thickness for better print quality stability.
Non-woven mesh material. This new type of wire mesh includes two kinds of punched and corroded materials. The non-woven wire mesh overcomes the trouble of applying photo-sensitive tape at the intersection of traditional wire and weft. The non-woven mesh material is made of 100% nickel by electroforming. The unique hexagonal structure can achieve excellent stability and ideal over-ink performance, allowing the mesh to be varied in width and width. Randomly stretched in printing, suitable for high-speed screen printing, with high calibration accuracy, high resistance to printing force and so on.
Fourth, a new screen printing ink for high-end packaging box to provide new results
With the introduction of various functional inks, especially the continuous development of UV ink production technology, the new screen printing process has been favored in the packaging and decoration field because of its unique advantages. At present, the most widely used are imitation metal etching, ice texture, refractive and other screen printing process, the printing of cigarettes, wine, gift packaging box, colorful, elegant and luxurious, can be called top grade, deeply loved by consumers, market outlets Look good.
Imitation metal etching screen printing process. It is the use of screen printing methods to print imitation metal etching inks on substrates with metallic luster such as gold and silver cards, to obtain a unique visual effect of smooth metal treated by corrosion, engraving or frosting.
Ice screen printing process. It is printed on the gold and silver card paper ice printing ink, after the UV curing the surface of the printed material will show a crystal clear, dense "ice" pattern, shining under the light, like the winter ice on the glass window .
Refractive screen printing process. The refractive screen printing technology that has emerged in recent years is a new star in the packaging screen printing family. Screen printing can easily print ultra-fine concave and convex lines on the mirror gold and silver card paper. After the light irradiation, it will produce a colorful refraction effect, so that the box is more noble and gorgeous.
Luminous printing. The ink used is a light-storing ink containing a luminous material, and is suitable for packaging and printing of high-end products such as high-grade cigarettes, wines, medicines and cosmetics.
Crystal glue printing. The use of crystal glue on the gold, silver paper silk screen printing with a three-dimensional effect of crystal glue droplets, now on the market the new UV curing crystal glue film, wear resistance, light better.
Crystalline gloss printing. The transparent ink layer on the printed surface of the printed product contains a crystalline flash material, which can produce a colorful and sparkling special decorative effect when the incident angle of sunlight or light changes.
Mirror ink printing. Metallic screen printing ink, made of plastic resin mixed with special metal toner, printed on the back of the transparent plastic sheet, can get metallic mirror printing effect, just like hot stamping effect.
5. The digitalization process of screen printing and prepress plates is speeding up
Modern printing technology has entered the digital age, and the continuous maturation of digital printing technology has brought about tremendous changes in screen-making technology. At present, computer-printed plate-making films, photo-taking output films, and inkjet output films are being widely promoted. With the continuous enhancement of the economic strength of the screen printing industry, it is believed that screen printing CTP will become the mainstream of screen printing plate making technology. The computer-to-plate system broke the traditional screen-making mode, completely abandoning the film bottom plate, using the computer screen digital processing technology design required screen printing graphics and text symbols, and in accordance with the screen printing plate requirements for color separation, network management After professional processing and storage in the computer, and then through the digital conversion output, drive a dedicated inkjet equipment, the image will be sprayed onto the screen stencil coated with emulsion, after direct exposure, development (washing) to get the wire Screen printing plates used for screen printing. There is also a method of direct image plate-making, which uses a computer-scanning laser imaging method on a special metal alloy film. This method can eliminate the screen and photosensitive adhesive and does not require a complicated stretching process. No distortion, high level of alignment, and high printing accuracy are the directions for future development.
Sixth, combination printing makes packaging screen printing process colorful
Due to the strong visual impact of packaging, especially some high-end packaging products are seeking unique artistic effects, in order to be unique in the market, so the combination of printing has become one of the popular trends in the packaging field. As we all know, the main advantages of offset printing, gravure printing and flexo printing are the exquisite graphics, rich levels of reproduction, and good dot reproducibility, which are suitable for the printing of fine meshes and fine images. The screen printing is characterized by a thick ink layer, bright colors, high saturation, and a strong three-dimensional impression of printed products, and can achieve a variety of anti-counterfeiting functions and special effects. The appearance of the combination of screen printing and other printing methods has determined that screen printing has an unmissable position in the field of packaging and printing. It has gradually become one of the major printing processes in the field of packaging and printing, greatly improving the quality and grade of products. Product sales also have a certain role in promoting. In actual production, more and more companies have begun to adopt a combination of multiple printing processes to achieve the desired special effects, such as offset printing, screen printing, flexo printing, and screen printing. In particular, the rotary screen printing unit with extremely high printing precision combined with the application of the flexographic printing press makes the printed products icing on the cake. This method can obtain gold, silver and other metal effects and embossing and matte effects on the substrates.
Seventh, screen printing in the field of packaging and printing in the future improvement and development
The printing speed is slower. Although the printing speed of screen printing equipment has been greatly improved at present, it is still relatively slow compared to other printing processes. If the production volume is too large, the production may be restricted and the ink drying time may be affected. The thick ink screen printing feature brings great difficulties to drying and takes a long time; printed products cannot be piled up immediately, and many drying racks and large work places are required.
Accuracy and stability need to be further improved. From the point of view of production control and quality, the accuracy and quality stability of screen printing are inferior to those of offset printing and gravure printing. In particular, the accuracy of domestic screen printing machines still has certain problems, which may easily result in inconsistent product quality during production. Not only between batch products, but even the same batch of products is difficult to ensure the consistency of hue, specifications, etc.
higher cost. At present, the cost of screen printing is still relatively high. This mainly includes two factors: First, the ink thickness of screen printing is relatively large, and the use of ink is relatively large, which of course increases the cost; second, the production efficiency of screen printing is relatively Say it is lower, the same process effect, screen printing will take more time, this will also increase the cost of production.
Multi-color overprinting is more difficult. The current screen printing equipment is basically monochrome printing. If you want to achieve a variety of effects on the same product or perform multi-color overprinting, there will often be inaccurate color registration and cause a lot of waste products, not only a waste of time and resources, but also affect The delivery date is even the next order.
The market needs multicolor automatic screen printers. In order to increase production efficiency and overprint accuracy, it is hoped that fully automatic screen printers will be able to develop in the direction of multicolorization, and will be popularized and popularized, so that domestic packaging and printing users can fully enjoy the advantages brought by multicolor automatic technologies.
Ink should develop toward environmental protection. In general, China's production of screen printing ink is relatively complete, and some of the quality is very good, it should be said that rapid development. The problem is that the proportion of solvent-based ink solvents accounts for 60%. When drying, the solvents must be evaporated in the air, so the pollution is serious. With the rising popularity of environmental protection, the government has also successively introduced a series of related policies to formulate relevant standards. The environmental protection requirements of customers for packaging products will be higher and higher. Therefore, the development of environmental protection inks will be increased in the future.
Screen printing materials need to increase development efforts. China's screen printing industry is currently in a relatively backward state from equipment to materials, from platemaking process to printing and post-press processing, and has not formed scale and modernization. In particular, the use of high-quality, high-precision inks and special-purpose inks, four-color screening inks and UV inks are almost entirely imported. Therefore, the screen printing industry must actively absorb modern science and technology, so that screen printing technology re-grow
