Digital printing can replace the screen printing?
In recent years, the rapid development of digital printing, a great alternative to screen printing trend. What are the differences between these two printing processes, in the end how to understand and choose? The following is your detailed analysis of digital printing and silk screen printing of the technical characteristics and development prospects.
Printing refers to the use of dyes or coatings in the fabric surface to form graphic. Printing technology development so far, has formed a screen printing, rotary screen printing, roller printing, digital printing and other printing process co-exist with each other. A variety of printing process for different scope, process characteristics, there are differences in the use of printing equipment and supplies are not the same. Screen printing as a traditional classic printing process, its wide range of applications in the printing industry, the proportion is relatively high, while the rapid development of digital printing in recent years, many people think there will be alternative to screen printing trend. These two printing process in the end what are the differences? In this paper, the differences between digital printing and screen printing are analyzed.
Substantial differences in printing materials
Digital printing is divided into acidic digital printing, active digital printing, coating digital printing, thermal transfer printing and decentralized direct-injection digital printing five categories. Digital printing acid ink for wool, silk and other protein fibers and nylon fibers and other fabrics. Digital printing Reactive dye ink is mainly applied to cotton, hemp, viscose fiber and silk fabrics such as digital printing can be applied to cotton fabric, silk fabrics, wool fabrics and other natural fiber fabric digital printing. Digital printing ink coating for cotton fabrics, silk fabrics, chemical fiber and blended fabrics, knitted fabrics, sweaters, towels, blankets digital inkjet printing. Digital printing thermal transfer ink for polyester, non-woven fabrics, ceramics and other materials transfer printing. Digital printing direct spray distributed ink for polyester fabrics, such as decorative cloth, banner cloth, banners and other digital printing.
Traditional screen printing in the types of printing materials compared to digital printing and not much advantage. First, the size of the traditional printing the size of the printing there are limitations, large-scale industrial digital inkjet printing inkjet width of up to 3 to 4 meters, can be printed without interruption, the length is not limited, they can even form a whole production line; In some materials, the traditional water-based ink printing can not achieve better performance, can only use solvent-based ink to print, and digital printing on any material can use water-based ink for inkjet printing, thus avoiding the large-scale use Flammable and explosive non-environmentally friendly solvents.
Digital printing colors more vivid
Digital printing of the biggest advantages are mainly concentrated in the color and pattern of the fine degree. First of all, from the color, the digital printing ink is divided into dye-based ink and pigment-based ink, dyes, bright colors, better than pigments. Acidic digital printing, reactive digital printing, decentralized thermal transfer printing and distributed direct digital printing are used in dye-based ink. Paint digital printing, although using a pigment as a colorant, but they are using the nano-pigment paste. Specific ink, as long as the dedicated dedicated ICC curve, color display can achieve the ultimate. The traditional color screen printing, one hit the color according to four-color network, the second is to rely on prepress ink color to control, color display power as digital printing. In addition, digital printing, pigment ink is used in nano-pigment paste, dye ink in water-soluble dye, even if the sublimation-type sublimation transfer ink, pigment is nano-level.
The fine pattern of digital printing and inkjet print head characteristics, print speed. Inkjet print head of the smaller droplets, the higher the printing accuracy, which Epson micro piezoelectric print head of the droplet is minimal, although the industrial head of the ink droplet than it is large, but you can print 1440 dpi image accuracy. In addition, the same printer, the faster the print speed, the smaller the print accuracy. Screen printing first need for negative plate, plate-making process errors and the number of mesh mesh pattern has an impact on the fine. In theory, the smaller the aperture aperture as possible, but more use of ordinary printing 100 to 150 mesh screen, four-color mesh of the mesh is 200 mesh. The higher the mesh, the greater the chance of water-based ink blocking the network, which is a common problem. In addition, the time of printing on the printed version of the accuracy of the degree of fine print design great impact on the machine printing is relatively better, but more difficult to control the manual printing.
Clearly, the color and fine graphic is not the advantage of screen printing, the advantage lies in the special printing paste, such as gold, silver, pearl color, crack effect, bronzing flocking effect, suede foam effect and so on. In addition, the screen printing can be printed 3D stereo effect, which are difficult to achieve the current digital printing. In addition, digital printing to make white ink more difficult. The current white ink is mainly dependent on imported ink to maintain, but in the dark fabric printing, no white is not enough, which is the current domestic digital printing needs to break through the difficulties.
Digital printing soft touch screen printing color fastness
The main performance of printing products include surface, that is, feel (softness), back tack, resistance to rubbing fastness, color fastness to washing; environmental protection, that is, whether formaldehyde, azo, pH, carcinogenic Aromatic amines, phthalates and the like. GB / T 18401-2003 "national textile products basic safety technical specifications" on the above listed some of the items made clear.
Conventional screen printing, in addition to water and discharge, other types of printing a strong sense of coating, which is because the printing ink formulations as a binder resin content is high, the other under the relatively large amount of ink reasons. The digital printing is basically no sense of coating, printing light, soft, back to stick better. Even if the coating digital printing, because the formula in the resin content is minimal, the basic will not affect the feel. Acidic digital printing, reactive digital printing, decentralized thermal transfer printing and distributed direct-injection digital printing, these are uncoated, does not affect the original fabric feel.
Whether in traditional water-based printing ink or printing ink, the resin as a binder, on the one hand used to increase the adhesion of the coating and fabric fastness, so that it is not easy to crack and washed off; the other hand, the resin can be wrapped with paint Particles, it is not easy to discoloration friction. Traditional water-based printing ink and paste in the resin content of 20% to 90%, usually 70% to 80%, while digital printing ink in the printing ink contains only 10% of the resin. Obviously, the theoretical analysis, digital printing color fastness to rubbing, wash-resistant color fastness will be worse than the traditional printing. In fact, the digital printing without a certain post-processing, the friction color fastness is indeed poor, especially the wet friction color fastness. Although the color fastness of digital printing in accordance with GB / T 3921-2008 "color fastness test for textiles color fastness to washing" test can sometimes pass, but compared with the traditional printing of washing fastness, there is still some distance . At present, in the color fastness to rubbing and washing fastness in digital printing needs to be further explored and breakthrough.
Digital printing equipment, high cost
There are three main types of printers used in digital printing. First, Epson desktop machine modified tablet, such as EPSON T50 modified flat-panel machine, these models are mainly used for small-format digital printing ink coating production, the purchase cost of these models relative to other models to be much cheaper. The second is to load Epson DX4 / DX5 / DX6 / DX7 series of inkjet print head printers, the most common DX5 and DX7, such as MIMAKI JV3-160, MUTOH 1604, MUTOH 1624, EPSONF 7080, EPSON S30680, Taiwan printer purchase cost of about 10 million. Currently, DX4 print head market price of each 4000 yuan, DX5 print head market price of each more than 7,000 yuan, DX7 print head market price of each 12,000 yuan. Third, industrial inkjet digital printing machine, on behalf of the machine Kyocera Kyocera industrial nozzle digital printing machine, Seiko SPT nozzle digital printing machine, Konica industrial print head digital printing machine, SPECTRA industrial print head digital printing machine, printer purchase cost is generally high. The brand of the print head in a single market price of more than 10,000 yuan, and a print head can only print a color. In other words, in order to print four colors, a machine would have to install four print head, so the cost is very high.
Therefore, the high cost of digital printing equipment, inkjet print head as a digital inkjet printer's main supplies, the price is extremely expensive. Digital printing ink market price is indeed much higher than the traditional printing material, but the output of 1 kg of ink printing area and 1 kg of ink printing area is unmatched. Therefore, in this regard the cost of comparison, will have to see is the type of ink used, the specific printing requirements and printing process and other factors.
In the traditional screen printing, hand-printed screen when the screen and the plastic scraping for the consumables, then more significant human costs. Traditional printing machinery, the import of Octopus printing machine and elliptical machine to be more expensive than domestic, but domestic models have become increasingly mature, but also to meet the production requirements. If it and ink-jet printing machine for comparison, the purchase cost and maintenance costs are much lower.
Screen printing to enhance environmental protection
Environmental protection, the traditional screen printing brings environmental pollution, mainly in the following aspects: in the production process of waste water and waste ink volume is quite large; in the printing production process more or less need to use some bad Of the solvent, and even plasticizers (thermosetting ink may not add environmentally friendly plasticizers), such as printing water, decontamination oil, white oil, etc .; printing workers in the practical work will inevitably come into contact with chemical solvents, Glue, toxic cross-linking agent (catalyst), chemical dust, etc., on the health of workers.
Digital printing production process will only be in the pre-treatment and post-treatment process of washing water to produce a certain amount of waste, the entire inkjet printing process rarely produce waste ink. The source of pollution is less than that of traditional printing, which has little impact on the environment and the health of the contact person.
In short, a wide range of digital printing materials, printing products, colorful, fine patterns, feel good, strong environmental protection, which are its typical characteristics. However, inkjet printing machine is expensive, supplies and maintenance costs, which is its shortcomings. Digital printing products in the fastness of washing and rubbing fastness is difficult to enhance; difficult to develop a stable white ink, resulting in black and dark fabrics can not be better printed; due to inkjet print head constraints, it is difficult to develop can Printing special effects of ink; printing sometimes to be pre-and post-processing, more complex than the traditional printing, which are the current digital printing the disadvantages.
The traditional screen printing in the printing industry in order to develop steadily in the current, we must grasp the following points: to enhance the environmental protection of printing inks, printing production in the control of environmental pollution; improve the existing special printing effect printing, and the development of new printing special effects , To lead the printing trend; keep up with the 3D boom, the development of a variety of 3D printing effect; printing products in maintaining the color fastness to washing and rubbing at the same time, conventional printing imitation of the development of digital no feel, light printing effect; Program, and continuously improve the printing efficiency of production capacity, it is best to develop printing assembly line platform; simplify printing equipment, reduce supplies input, improve the printing input-output ratio, and enhance the competitive advantage of digital printing.