Digital Printing and Lithographic Offset

With the changes in the market, printers have finally found a space where digital printing and lithographic offset technology coexist.

In the past decade, the debate between digital printing and lithographic offset printing has continued. Now when the passions of the two printing technologies collide, most people's attention changes. The printers are no longer staring at the process. Digital printing and offset printing have been used as a combination to work together to increase the competitiveness in the market, and no longer rely on their own strengths and weaknesses alone.

Jon Brunken, the creator of Creo's product management department, who is now a Kodak company, said: "To be honest, we didn't expect that the competitive relationship between digital printing and lithographic offset would take such a long time. Successful companies It has been seen that digital printing and offset printing are two complementary technologies. In many cases, both can jointly provide customers with complete market solutions."

It is worth mentioning that digital printing and lithographic offset printing are complementary technologies, but it has also caused many vendors, printers and printing customers to confuse the scope of digital printing. For some people, all the concepts of digital printing are about documents. If digital documents pass through all the rollers they print, then this completes digital printing; for others, all the concepts of digital printing are about ink. The use of toner in printing instead of traditional ink, then became digital printing. Finally, there is another view that if the printer can print data files that can be changed on every page, then this is digital printing.

According to Howard Howie Fenton, senior consultant for digital technology at the American Offset Printing Association (NAPL), the definition of digital printing based on ink may be the most common method. No matter how you view or define digital printing, it is an objective reality. According to the American Printing Industry Association / Graphic Arts Foundation (PIA/GATF), digital printing is considered to be the fastest growing segment in the printing industry.

Technical partner

Laurie Haryman, owner of Queen City Imaging, New York, said: “By benefiting from the satisfaction of digital printing to customers and other good word of mouth, our business conditions have improved rapidly.” She bought the company in 1998, which was a small copy center at the time. In 2000, she wanted to increase her business and reduce costs, so she had printed two Ryobi color digital offset presses. Since then, she has integrated digital presses such as the Océ 3165 and the Canon 6000 into the company's operations along with the finishing equipment. She recently purchased the Océ VarioPrint 2090 with a patent for offset offset printing. Quinn Image uses offset printing for color cover printing, and then prints the variable data through the Océ VarioPrint 2090 digital press.

Dillon Mooney, PIA/GATF's technical advisor, has been in contact with many integrated printing processes. He said: "Color printing on the offset press, and then printing on the digital press. This is a good way for the printer to integrate the two technologies." Mooney warned that the use of ink and The moisture content of printed sheets may cause some problems. Digital printers that use toners use heat to melt the toner and then transfer it onto paper. If no laser security ink was used in the previous lithographic offset process, the ink on the printed sheet will melt during the digital printing process. Another problem is the moisture content of the paper. The high temperature of the digital printing process can dry the paper and curl the paper at the same time, jamming the paper during printing, printing and folding. If the situation continues to occur in print production, it will be very bad. If the press operator transfers the paper printed by the digital printer to the offset printing press, there is also a problem of humidity. Very dry paper absorbs moisture and deforms during printing on the offset press. Mooney added: "This is not simply a matter of simply printing a sheet of paper from one device to another and printing it on another device. You must be very careful about your raw materials."

Not only did the printers successfully solve these problems themselves, digital printer vendors were also trying to avoid these problems entirely. Bruce Ganger, senior sales director at Océ North America, points out that offset digital offset printing is designed to replace high-temperature melting with low-temperature melting. In addition, Océ has also developed a single-component toner including a developer. Due to the inclusion of the developer, the primary cause of inconsistent print quality due to deterioration of the developer is also eliminated. Low-temperature melting, single-component inks and shorter, simpler printing together ensure the stability of the printing. CopyPress technology also allows printers to print on more substrates. This low-temperature melting capability allows the press to print heavy, light, coated, and glossy papers at a constant speed.

Technology Alliance

The combination of short-run, low-cost digital output devices and high-quality lithographic offset technology – direct-imaging (DI) presses, offers the greatest advantage of both technologies. Presstek, as a pioneer in the industry, launched a DI solution in 1990 to provide jobs for the production of digital printing between small batch production and traditional offset large-volume printing. Presstek technology is still the core technology of most DI press equipment.

Digital printing machines use toner printing, so it is very close to the effect of laser printing, and DI printing press is the process of high-speed automated waterless offset printing using ink. Like traditional offset printing, DI printing requires plates and inks. But unlike traditional offset printing, the plate is already installed on the press before imaging. This reduces job preparation time, and automated operations also reduce many errors.

John Schuck, the global vice president of Kodak Poly Optical Digital Printing, stated: “The new generation of DI printers provides offset quality in an efficient and profitable manner. The DI printer is the best choice for controlling the short-run color printing market. ”

Reprinted from: International Printing