Printing methods classified according to the structure of the plate surface
Digital printing is a comprehensive printing technology developed on the basis of IT printing technology, which uses digital electronic text as the carrier and transmits it to digital printing equipment through the network to achieve direct printing. The most important feature of the printing production process is that there is no plate and variable information, covering a variety of technical fields such as printing, electronics, computers, networks, and communications.
The specific feature is that digital printing is an all-digital information transmission, eliminating the need for film and printing plates in the mechanism version. The information of digital prints is 100% variable. Digital printing is the process of using a digital printing system to convert digital information directly into printed matter. Digital originals can be digital files processed by the digital prepress system, or they can be sourced from the Internet and digital media. Digital printing can realize the output of printed matter anytime, anywhere, remotely, without time and space limitations. According to the imaging mechanism, digital printing is divided into electrostatic imaging, inkjet imaging, electrocondensation imaging, thermal transfer imaging, magnetic recording imaging, etc. In the market, electrostatic imaging and inkjet imaging are the mainstream digital printing machines.
Digital printing does not need the complicated process of traditional offset printing, and only needs to be sent to the printing machine by the computer to produce the finished product, so it fills the unattainable functions of traditional printing in the field of urgent printing, variable printing and on-demand printing, and can truly meet the ever-changing needs of rapid printing, and the development space is very large.
The printing plate of stencil printing has poor print resistance, slow printing speed, and poor reproducibility when reproducing color. Therefore, it is generally used for printing on the surface of non-flat molded items.
The main products of stencil printing are cotton, silk fabrics, printed circuit boards, commercial advertising, packaging and decoration materials, etc.
1. Digital printing
Digital printing is a new printing method that prints invisible computer digital files directly on paper, which is different from the cumbersome process of traditional printing. It is characterized by a single print, no plate making, immediate preferability, instant error correction, variable printing, on-demand printing.
Gravure printing plate-making is difficult, plate-making cycle is long, and the cost is high, but with the popularization and application of electronic engraving plate-making machine, gravure plays a greater role in packaging printing.
The main products of gravure printing are securities, banknotes, exquisite albums, cigarette boxes, paper products, plastic products, packaging and decoration materials, etc., these products have strong ink color, tone and color reproducibility.
2. Engraving printing
Stencil printing is a printing method that uses transcription plates, hollow plates, screen plates and other plates, and most of them use direct printing processes.
When printing, the ink is piled up on one side of the printing plate, and then scraped or rolled while moving with a scraper or pressure roller, so that the ink leaks through the holes or mesh of the printing plate to the surface of the substrate. Stencil printing can be done manually or by machine. Punch printing machines are divided into two types: flat and curved, and can print on a variety of substrates such as flat, curved, thick, thin, rough, and smooth.
In China, the history of stencil printing is older than that of engraving printing, and the Sui Dynasty has used this method to print and dye the clothes and costumes in the court. In the late 40s of the 20th century, plate-making with photosensitive materials began to be used, making it possible to print stencils with precise images.
3. Gravure printing
Gravure printing is a printing method that uses manual or mechanical engraving gravure, photogravure, electronic engraving gravure and other printing plates, which is a direct printing process.
Gravure printing first appeared in Europe in the 15th century, with manual carving of concave graphics on the metal plate, printing with ink, the ink on the layout is removed, leaving only the ink of the concave part, under the action of greater pressure, the ink is transferred to the surface of the substrate. Due to the different depths of the concave part of the printing plate and the difference in the size of the dots, the ink filled in the concave part is more or less, so that the ink layer transferred to the substrate is thick and thin, the color is dark where the ink layer is thick, the color is light where the ink is thin, and the shade level on the original manuscript has been reproduced on the printed matter. The printing machine used in gravure printing is mainly a circular pressurized rotary printing machine, flat
Gravure presses and gravure presses are rarely used.
4. Lithography originated from lithographic printing, when printing, first supply water to the printing surface, and then supply ink to the printing plate, under the action of printing pressure, the ink on the printing plate graphic is transferred to the substrate, which is a direct printing process. Therefore, in addition to the ink supply device, there is also a water supply device on the printing machine.
In the printing process, oil and water must be balanced in order to print a good product, and the balance of oil and water involves a series of factors, including the influence of air temperature and humidity. Therefore, the quality of lithography depends largely on operational skills and printing knowledge. Lithography has a large format and fast printing speed. Many lithographic printing machines are equipped with automatic ink conveying and automatic register systems, and some printing machines are also equipped with automatic plate loading and unloading devices, which have good printing quality and high printing efficiency. Lithography products include newspapers, periodicals and magazines, books, exquisite albums, USA commercials, wall calendars, posters, etc.
Lithography is a printing method that uses PS plate (pre-coated photosensitive plate), flat gravure plate, multi-layer metal plate, lithograph, Koro plate (glass as the base) and other printing plates, and uses the principle of incompatibility between oil and water to print.
5. Letterpress printingThe principle of letterpress printing is relatively simple. In letterpress printing, the ink feeding device of the printing machine first distributes the ink evenly, and then transfers the ink to the printing plate through the ink roller. Since the graphic portion of the letterpress is much higher than the non-graphic portion of the plate, the ink on the ink roller is transferred only to the graphic portion of the plate, while the non-graphic portion is left without ink. The paper feeding mechanism of the printing machine conveys the paper to the printing part of the printing machine, and under the joint action of the printing plate device and the embossing device, the ink of the graphic part of the printing plate is transferred to the substrate, so as to complete the printing of a printed matter. Letterpress prints are letterpress prints where the back of the paper has a slight imprint convexity, the lines or dots are neatly edged, and the ink appears pale in the center of the stroke. The edges of the raised imprint are under heavy pressure, resulting in a slight bump in the imprint.
Letterpress printing products mainly include newspapers, periodicals and magazines, etc., and now a large number of photosensitive resin letterpress and photosensitive resin flexographic letterpress printing trademarks and packaging and decoration materials have been used.
Letterpress printing is a printing method that uses movable type plates, lead plates, copper-zinc plates, photosensitive resin plates, rubber letterpresses, flexographic plates, etc., which are made of lead alloys. Generally, the direct printing process is used.
Letterpress printing is a printing method with a long history. Before the 70s of the 20th century, letterpress printing mainly used the combination of lead movable type and photographic letterpress (copper-zinc plate) to form letterpress, which was used for book and table printing. However, letterpress printing is not suitable for printing large-format products, mainly because lead movable type and paper-type lead plates are made of lead alloy, which not only increases labor intensity, but also causes environmental pollution. After the 80s of the 20th century, laser phototypesetting and photosensitive resin letterpress gradually replaced the lead typeplate, the new letterpress process not only eliminated the harm of lead pollution, but also improved the quality, plus this process can use the original letterpress printing equipment, so convex
Printing has been developed in a new way.