Computer To Plate (CTP) is one of the major trends in the development of printing technology in the first decade of the 21st century. It refers to the process of directly outputting digital pages onto printing plates through computers. CTP Computer to plate is composed of three parts: accurate and complex optical system, circuit system and mechanical system. The three parts are relatively independent, strictly coordinated and unified. This technology not only eliminates the need for traditional plate making processes such as laser phototypesetting and manual assembly and printing of soft films, but also saves equipment and materials required for intermediate processes. It avoids the drawbacks of dot loss, deformation, and expansion, reduces color and layer loss, and shortens the ink color adjustment and registration adjustment time and ink balance time during the printing process, greatly improving product quality and work efficiency. Since Autoligic developed the first computer direct plate making equipment in 1989, major equipment companies and printing manufacturers around the world have closely cooperated to accelerate the development pace of this technology research and gradually reached a mature and industrialized application level. Heidelberg, a world-famous printing equipment provider, and Pressek jointly developed the computer to plate on press technology and launched GTO-DI in 1991, becoming the first equipment in the world to make plates on a printing machine. At the DRUPA95 printing exhibition, the display of CTP system and direct plate making materials became the hottest technological highlights, indicating that the research on computer direct plate making technology has matured and entered the market.
CTP plate, also known as Computer To Plate, is a digital plate that can be directly made by a computer. Compared with the plate making process CTF of traditional PS plate, CTP plate has the advantage of short process flow, which can greatly improve the printing quality and shorten the production cycle, thus saving Labor burden. CTP plates can be divided into thermal sensitive, photosensitive, and silver salt based on their photosensitive principle.
The hot-rolled plate base mainly produced using the hot-rolled process. CTP plates produced using hot-rolled plates have inherent advantages over cast rolled plates due to their sufficient guarantee of tissue uniformity, as well as better control of surface quality and dimensional tolerances. In contrast, CTP plates produced using cast rolled plate substrates are prone to internal microstructure and surface defects due to production process conditions. During the production process of CTP plates (such as electrolysis, oxidation, coating, etc.), defects may occur, resulting in unstable quality. However, producing CTP plates based on cast rolled plates can reduce production costs, improve product cost-effectiveness, and enhance product market competitiveness.
At present, CTP plates are still produced using hot-rolled plates, and the technology for producing CTP plates using cast rolled plates is not yet mature. If CTP plates can be produced using cast rolled plates, it can fill the domestic and even international gap. How to use casting and rolling plate base and improve the electrolysis, oxidation, and coating processes to produce high-quality CTP plates has become a challenge for technology professionals