1. Offset presses can be divided into monochrome, two-color, four-color and multi-color presses according to the number of printing colors completed by one paper feed,
2. Offset presses can be divided into small, six-open, four-open, folio and full-sheet presses according to the maximum paper format, and
3. Double-sided printers that can print on both sides at the same time by one paper feed.
4. according to the dampening system, it can be divided into alcohol machine (that is, alcohol dampening offset press, water wheel (that is, water dampening offset press) and waterless offset press.
offset printing press is a kind of lithographic printing machine. When printing, the printed graphics and texts are printed from the printing plate to the blanket cylinder, and then transferred to the paper by the blanket cylinder. Offset press can be divided into sheet-fed offset press and web offset press according to different paper feeding methods; According to the number of printing colors completed by one paper feeding, it can be divided into monochrome, two-color, four-color and multi-color printing machines; According to the maximum paper format, it can be divided into small offset presses, six-open, four-open, folio and full-sheet paper presses, and there is also a double-sided printer that can print on both sides at the same time. Sheet-fed offset press is a lithographic printing machine, which is used to print high-grade commercial printed matter and packaging printed matter, and is the mainstream of modern paper printing.
Prototype
In p>1911, Gaobao and Roland, who had decades of experience in letterpress printing and gravure printing, developed their first offset presses, and since then they have made more attempts in the printing field.
in the 192s, Roland, Gaobao, Komori and other companies all introduced their own sheet-fed and web-fed offset printing equipment. And cooperate with related companies to develop various automatic printing equipment with paper transfer unit, refrigeration unit, folding and drum drying components.
In p>1932, Gaobao (Radboyle Company) introduced the world's first four-color sheet-fed offset press-Planeta-Deca, which made offset printing technology take a big step forward.
World War II destroyed many factories, and the development of offset printing technology was also affected, which was stagnant for more than ten years.
in the 194s, with the booming production and mass distribution of American newspapers, the progress of offset printing technology was further promoted. After 1945, offset printing made it possible for commercial advertisements to achieve high quality and high requirements. In contrast, it is expensive and time-consuming to produce four-color continuous tone images with relief printing technology. With the increasing demand for image and printing quality, offset printing technology has made a new breakthrough.