Overview of the history of digital printing
The working principle of digital printing is basically the same as that of inkjet printers, and inkjet printing technology can be traced back to 1884. In 1960, inkjet printing technology entered the practical stage. In the 1990s, computer technology began to become popular, and in 1995, a drop-on-demand inkjet digital printing machine appeared. From 1999 to 2000, digital jet printing machines using piezoelectric nozzles were exhibited in many countries. At present, the development of digital printing technology is showing a trend where all heroes are emerging and a hundred flowers are blooming.
In recent years, my country's textile printing and dyeing industry has developed rapidly, and printing output has also increased simultaneously. At the same time, the clothing fashion cycle is getting shorter and shorter, patterns are changing faster and faster, production requirements are getting higher and higher, order quantities are getting smaller and smaller, and pattern piracy is rampant. Although printing companies have introduced printing CAD systems, laser imagesetters, flat screens, rotary screen inkjet, wax spray screen machines and other digital means to improve the processing process in traditional printing methods, the concept that printing and dyeing factories are polluting factories seems to be It has left a deep impression. At the same time, internationally, my country's exports of printing and dyeing products are increasingly hampered by "non-trade barriers" including the environment. As far as current technology is concerned, digital printing is the best way to solve many problems in the printing field.
Traditional printing is inseparable from the use of flat screens or rotary screens. However, the cost and time consumed in plate making cannot satisfy the modern printing trend of small batches and multiple varieties. Therefore, the development of Print-free, stress-free digital printing. The basic principle is the same as that of an inkjet printer.
Inkjet printing technology can be traced back to 1884. American C.H. Richard put water in a syringe and applied pressure to the needle to fly out droplets. If the direction of the droplets is controlled, it can be formed on the paper. image, called fog ink printing. At that time, due to problems with the needle and ink, the effect was very poor. It was not until 1960 that it officially entered the practical stage. Ten years ago, inkjet technology was used for barcode processing or product serial number printing, called inkjet printers.
Digital jet printing is a systematic project that involves cutting-edge technologies such as CAD technology, network communication technology, precision machining technology, and fine chemical technology. It is a fusion of information technology and traditional technologies such as machinery, textiles, and chemicals. product.
Since digital jet printing technology involves a lot of calculation and control, it can be said that without today's high-speed computers, digital jet printing technology would not be possible. For now, the development of digital jet printing technology is basically synchronized with the working capabilities of computers, and the development of computer technology still shows no signs of weakening. With the development of computer technology, it can be expected that digital jet printing technology will also have high speed in the future. develop. At the same time, the manufacturing technology of the nozzle also benefits from integrated circuit related technologies, such as etching, precision assembly, etc. The continuous emergence of modern high-frequency, multi-nozzle sprinklers proves this point.
Computer technology gradually became popular in the 1990s, and continuous digital jet printing machines appeared. By 1995, they had been widely used in textiles with rough patterns such as carpets and wall hangings. The Austrian company ZIMMER took the lead in exhibiting a digital jet printing prototype for carpets with a resolution of 9-18. It uses valve spray technology and does not use a common nozzle. Its production speed is very fast, up to 16/min. However, due to the large spray droplets and low resolution, it cannot be applied to clothing fabrics.
In 1995, the on-demand inkjet digital jet printing machine appeared. At that time, it mainly used thermal bubble nozzles with a resolution of 300dpi. Later, it gradually developed to 600dpi, mainly 4 colors, and could basically be applied to fabrics. .
Digital jet printing machines using piezoelectric nozzles were exhibited in many countries from 1999 to 2000, including the Netherlands, Japan, Switzerland, the United States, Italy and China's Honghua Company, with resolutions up to 360~ 720dpi, 6/h. Since the minimum inkjet volume of the piezoelectric nozzle is very small, the products produced have finer patterns and more uniform and natural colors. Therefore, they are very popular and their application areas are gradually expanding.
At present, various new digital jet printing machines have appeared one after another, mainly using piezoelectric nozzles; the maximum printing speed has developed from 1/h in 1990 and 6/h in 2000 to 0.80-150/h. h; The use of dyes has developed from 4 colors to 6-8 colors and 2X6-8 colors; the application process has become increasingly mature; the control software functions have gradually improved. It can be seen that the development of digital jet printing technology has basically evolved from continuous shooting to on-demand jetting, from thermal bubble nozzles to piezoelectric nozzles, and from 4 colors to 6-8 colors.
There is no doubt that the emergence and successful application of digital printing technology is undoubtedly a major technological revolution in the textile industry. It has milestone significance. The economic and social benefits brought by digital printing will be particularly important to the world. It has a profound impact on China, a major textile printing and dyeing country. Like previous industrial upgrades and changes, the emergence of new digital jet printing technology is both a challenge and an opportunity. Chinese textile companies must seize the opportunity in the upcoming changes.
1. The concept of digital printing technology
Digital printing technology is a high-tech technology that has gradually formed with the continuous development of computer technology and integrates machinery, computer and electronic information technology. product, which first appeared in the mid-1990s. The emergence and continuous improvement of this technology has brought a new concept to the textile printing and dyeing industry. Its advanced production principles and methods have brought an unprecedented development opportunities.
In short, digital printing is to input the pattern into the computer in digital form, edit it through the computer printing color separation and tracing system (CAD), and then control the micro-piezoelectric inkjet nozzle by the computer. The special dye solution is sprayed directly onto the textile to form the desired pattern. The promotion and application of digital printing technology will have a major impact on the development of my country's textile industry in the 21st century, as follows:
(1) Promote the production methods and business models of enterprises
For a long time, Due to the limitations of traditional technology, the production of printed products must reach a certain scale and quantity in order for the enterprise to be profitable. With the development of the economy, market demands are becoming more and more diversified and personalized. The emergence of digital printing technology has solved this problem that has long plagued enterprises. In the past, a product took several days or even dozens of days from design to delivery. Now, after customers select patterns and fabrics, the finished product can be obtained in 1 to 2 hours, which can better meet consumers' personalized needs for clothing or decoration. Some people predict that in the 21st century, digital technology will be combined with network technology at the fastest speed to achieve a completely personalized, one-to-one tailor-made business model.
(2) It will meet people’s individual needs to the greatest extent and improve people’s quality of life.
For the majority of textile designers, it is an excellent tool to unleash their personal creativity, allowing them to fully demonstrate their creative talents and turn their most ideal works into realistic finished products. Digital printing is rich in color, using four colors plus spot colors, and can print 16.7 million colors. For the majority of consumers, everything from home decoration to clothing and travel supplies can be personalized according to personal preferences. In this sense, the emergence of a new technology will also drive a new market and stimulate a new round of consumer demand.
(3) Digital printing will directly promote the development of "green textiles" and "green manufacturing".
Since digital printing puts the dye solution directly into a special box and sprays it on the fabric on demand, there is no waste or waste water pollution. It eliminates the dye solution discharged from the printing machine flushing in the pulp mixing room. The printing process is pollution-free. Film is also eliminated. Consumption of materials such as wire mesh and silver tubes. It not only reduces the burden on enterprises, but also meets the requirements of environmental protection.
2. Characteristics of digital printing technology
The production process of digital printing is simply through various digital means such as: scanning, digital photos, images or computer production and processing. The digital pattern is input into the computer and processed by the computer color separation printing system. The special RIP software uses the printing system to directly print various special dyes (reactive, dispersed, acidic main coatings) onto various fabrics or other media. After further processing, various high-precision printing products are obtained on various textile fabrics. Compared with traditional printing and dyeing processes, it has the following advantages:
1. The production process of digital printing greatly shortens the original process route, speeds up order taking, and greatly reduces the cost of proofing.
Because the production process of digital printing gets rid of the color separation, drawing, and screen making processes in the production process of traditional printing, the production time is greatly shortened. Patterns can be accepted through various advanced means such as CDs and E-mails. Generally, the proofing time does not exceed one working day, while the traditional proofing cycle is generally about a week.
In addition, due to the simplification of the process, the cost of proofing is also greatly reduced. The shortening of the proofing cycle and the reduction of proofing costs will undoubtedly bring more market opportunities to enterprises under the current market competition rules where time is money and efficiency is life.
2． The principle of digital printing technology allows its products to break the limitations of color registration and flower return length in traditional production, and can achieve high-end printing effects on textile fabrics.
Because digital printing technology can use digital patterns, and use computers to measure, match, and print colors, the colors of digitally printed products can theoretically reach 16.7 million, breaking through the color registration of traditional textile printing and dyeing patterns. Limitations, especially in the printing of high-precision patterns such as color gradients and moire, digital printing has unparalleled advantages in technology. In addition, traditional printing patterns are often limited by the length of the "flower return", while the concept of "flower return" does not exist in the digital printing process, which greatly expands the space for textile pattern design and improves the quality of the product.
3. Digital printing production truly realizes a small-batch, quick-response production process, and the production batch is not subject to any restrictions.
Since the entire digital printing production process realizes computerized digital production, production flexibility is greatly improved. Some products can even be delivered on the same day and can be picked up immediately. In addition, due to the application of computer technology, printing a series of patterns with different tones of the same pattern, and the designer's continuous modification of patterns and colors during the production process have become a major technical advantage that distinguishes digital printing production from traditional printing production.
4. The high-precision printing process eliminates the need for water or color paste during the printing process.
The use of dyes during the jet printing process is "distributed on demand" by the computer, so that during the jet printing process, there is no waste of dyeing materials, no waste water is generated, and no waste water is generated during the computer-controlled jet printing process. Noise, so that no pollution is produced during the printing process, and a green production process is realized, thus enabling the production of textile printing to get rid of the high energy consumption, high pollution, and high noise production process in the past, and achieving a low energy consumption, pollution-free production process, giving The production of textile printing and dyeing brought about a technological revolution.