In the past few decades, plain printing technology is a very important printing technology in the United States. Most prints in the United States today are still produced using the plain printing technology. According to estimates of the US Department of Commerce, the total value of commercial print produced in the United States is 74.8 billion U.S. dollars per year, of which the total value of printed matter produced using lithographic offset printing technology is 58.4 billion U.S. dollars, accounting for 75%. At present, sheet-fed offset printer manufacturers are designing and manufacturing new types of equipment to meet various needs in the printing press market. Large-scale typographic printers have become popular products. An important feature of the new type of typographical machine is its increased level of automation and direct imaging capabilities. A significant development trend of the new type of typographic machine is the use of color management technology. When we entered the 21st century, the above trends indicated the direction for the development of sheet-fed offset presses.
Automated printing as a production standard Recently, a survey published by the American Association of Printing and Publishing Technology Providers, titled “The Present Situation and Future of the US Press Market,†showed that most customers who purchased a new type of printing press had automated printing jobs. The function is in a very important position. At present, various important printer manufacturers are working hard to improve the performance of the printing press and regard the automatic printing operation as the basic production standard to meet the needs of our customers. The latest presses have the following features: automatic alignment control, automatic adjustment of roller pressure and side gauges, automatic and semi-automatic plate loading, automatic cleaning of blanket cylinders and impression cylinders, and fully integrated color control panels. This will allow printers to reduce commissioning time to 10-20 minutes. Sheet-fed offset presses have a short setup time and can print 15,000 sheets per hour. Therefore, the productivity of this type of printing press is very high.
An example of an innovative attempt at automatic printing press operations is the CPC 32 prepress interface device from Heidelberg. This device can automatically pre-adjust the ink key according to the data provided by the pre-press RIP. There is no need to scan the plate again. In addition, Heidelberg’s CP 2000 color touch screen display (running under windows NT) can dynamically adjust the press (including changing the alignment position and ink supply) during high-speed printing production. CP 2000 can store 250 job production data in its standard memory for repetitive production of jobs.
The degree of automation of small presses is also increasing. As monochrome copier type printers are being replaced by digital copy/printer machines, many printer manufacturers are striving to develop multi-color, highly automated, small-format printers. For example: According to Japan's Leung Ming company, the company's newly developed 3304 HA4-color A3 size press has only 6 minutes to prepare. This press has semi-automatic loading capabilities and is equipped with an offline computer-to-plate system that can produce plates. Another example is ABDick, which has long produced monochrome printers. The company has developed the Century 3500 2 printing units, A3 size presses with the characteristics of a large press. As with Leung Ming and ABDick, more small-press printer manufacturers will continue to increase the degree of automation of their products and increase the number of printing units.
The trend toward large-scale printing presses The manufacture of the single-sheet printing presses with the largest specifications ever has now made sheet-fed printers enter the traditional operating site of a web printer. This large format printer, which is primarily manufactured for the packaging industry in the printing industry, allows sheet-fed printers to achieve considerable economic benefits when producing large quantities of printed matter. The major printers with outstanding performance include the Rapida 162 8 printing units produced by KBA, 60-inch printing presses; the Speedmaster 102-10-p type 10 printing units produced by Heidelberg, 40-inch printing presses and Man Roland The company's 900-type 8 printing units, 56-inch printing presses. Each of the above printing machines is a double-sided printing machine that can perform double-sided color printing at a time. The Speedmaster 102-10-p type press produced by Heidelberg has an automatic print job function. The preparation time of the machine is very short, and double-sided printing can further save the production time. According to press manufacturers, these large sheetfed presses are currently selling well. Therefore, major printing press manufacturers may begin production of 8-10-color double-sided printing presses within the next one or two years.
Direct Imaging Presses Many printer manufacturers today are selling offset presses with direct imaging capabilities that allow direct imaging of the printing plate. OmniAdast introduced the 70SCDI first 4-joint direct-imaging press. The company is continuing to make technical improvements to the 70SCDI. Heidelberg has launched the Speedmaster DI 74 4-joint press after the DP-type dual-link presses, forming a complete range of fully automatic presses with direct printing capabilities. The plate imaging process can be performed directly on the roller of the Speedmaster DI 74 press, as well as the plate imaging process in the traditional way, which makes the workflow more flexible. Heidelberg also recently launched an improved product, the FastPay DI Plus, on the basis of Speedmaster DI. The printing plate imaging time of this type of printing press is about 4 minutes, which is twice as fast as the previous model.
In the PRINT exhibition held in 1997, Karat (a joint venture between Saturn and KBA) first exhibited a 74 Karat printer equipped with an automatic keyless ink supply. It is said that this type of ink supply device utilizes an anilox roller to adjust the ink supply, so that unskilled operators can be employed. The 74 Karat presses are also equipped with color management devices that allow the press to match many ICC color files.
Japan's Screen's recently produced TruePress 4-color press can directly image Mitsubishi-made polyester plates on board. The plate's useful life is estimated at 25,000 sheets and can use traditional lithographic inks.
Color Management and Lithographic Offset Presses with direct imaging capabilities are best suited for the ICC standards and color management workflows in the printing industry. For example, a 74 Karat printer can print the same number of printed sheets of the ICC file standard after entering the appropriate program. For another example, the proofs printed with SWOP inks can be used for print production after color matching processing: offset printing documents based on Euro can be used for the next printing production after color matching. In addition, 74 Karat printers can be used with many proofing devices using appropriate ICC files. As color management technology is further utilized in traditional offset printing production, new control devices such as the CPC 24 developed by Heidelberg will play a significant role in the dynamic management of printing presses. CPC 24 relies on a sheet-fed scanner/colorimeter to analyze the entire print sheet without the use of various color patches. In this way, the CIE L*a*b* values ​​measured from the printed image part can be compared with the required CIE L*a*b* values. Then the corresponding adjustments are made so that the CMYK value matches the required CIE L*a*b* value. With the use of colorimeters and ICC files (rather than densitometers) in digital prepress processing, traditional color-code control methods are likely to be eliminated.
The use of color management techniques in the operation of sheetfed presses will have a profound effect on flat sheet production. In the traditional work plan for proofing by comparing proofs, the proofs are regarded as standards, and a highly skilled press operator adjusts the thickness of the ink layer on the printing press to obtain the same print quality. With the ColorSync color management workflow, the lithographic press automatically adjusts and calibrates the relevant data based on pre-defined color profiles.
Fewer and fewer users use the proofs-based workflow, which will ultimately result in the elimination of analog proofing solutions. Digital proofing, due to the use of calibrated precision presses, enables stable quality proofing within a moderate tolerance range, thus paving the way for the promotion and application of computer-to-plate technology.
The Potential Role of CIP3 Technology The CIP3 technology (integration of prepress, printing and postpress operations) will sooner or later have an impact on the sheetfed printing market. The CIP3 technology is characterized by the input of the job parameters into the digital prepress file through the CIP3 print production format (PPF), which integrates prepress, print and postpress operations. For example, the prepress processing job preparation document will contain data on the size of the sheet, the ink supply, the folding imposition, and the finishing process. As the job is passed in the CIP3 workflow, the machine device compatible with the PPF job format will be automatically adjusted according to the data stored in the PPF job file. Many manufacturers of prepress processing equipment, printing equipment and postpress equipment have agreed to adopt the PPF standard. However, a recent survey published by the Association of Printing and Publishing Technology Providers in the United States showed that customers who purchased new printing presses rarely considered whether the printing press had CIP3 technology capabilities. Most customers plan to completely replace all production equipment. Therefore, it will take some time for the CIP3 technology equipment to have an impact. However, in the next 10 years, the automatic printing process using the CIP3 standard will surely be popularized and applied.
Looking to the future From the current trends, sheet-fed offset printing technology is moving in different directions, targeting printers with different production scales and product markets. One of the main development directions is to increase the degree of automation and shorten the preparation time for the tuning. Automatic printers are easy to operate and require low operational skills. In fact, the latest offset presses with direct imaging capabilities have minimized training requirements for press operation. As employers continue to face the problem of shortage of skilled workers, the printing machine has a promising future from a human resources perspective. More and more color management technologies will be used in digital prepress operations. We will also see more and more printing companies make proofs based on the characteristics of the press, rather than rigidly trying to let the press meet the technical specifications of the proofs. There is no doubt that in the next five years, lithographic printing presses will not compete with digital presses in the short-run color printing market (especially for variable printing). However, in the use of various substrates, coating materials, and spot colors in the field, lithographic presses have greater flexibility than digital presses.
In general, lithographic offset printing machines will continue to be the most economical graphic transfer equipment for the printing industry after we enter the 21st century.