Offset press is a kind of lithographic press. the printed image and text are first printed on the rubber cylinder from the plate When printing, and then transferred to the paper by the rubber cylinder.
Offset press can be divided into sheet fed offset press and web offset press; According to the chromatic number of printing completed in one run, it can be divided into monochrome, two-color, four-color and multi-color presses; According to the maximum paper size, it can be divided into small offset press, six open press, four open press, split press and full sheet press. In addition, there is a double-sided press which can complete two-sided printing at the same time. Sheet fed offset press is a lithographic press, which is used to print high-grade commercial printing and packaging printing. It is the mainstream of modern paper printing.
The birth of offset press
In 1904, Kaspar Herman of Germany was trying to improve the lithography technology, trying to find a new way of production through countless experiments. However, American Mr. Ella Washington Rupert was accidentally involved in this research work. In a printing job, Ella Washington rube noticed that a piece of paper did not follow the normal route in the printing process. He tried to print patterns on both sides of the paper. The image was first transferred from the plate to the blanket of the impression cylinder, and then printed on the paper. Unexpected scenario: this indirect imprinting method produces higher printing quality products, and the elastic blanket surface transfers ink more evenly to the paper. The printing method developed by Caspar Herman and Ella Washington Rupert was born, which is the origin of offset printing. They respectively designed sheet fed offset printing equipment, but did not immediately commercialize. In 1912，the world’s first rotary offset printing equipment, came out, with a speed of 8000 sheets per hour.
The prototype of offset press
In 1911, gaobao and Manroland, who had decades of experience in the production of gravure and relief printing machines, developed their first offset press. Since then, they began to make more attempts in the printing field.
In the 1920s, Manroland, gaobao, Xiaosen and other companies have launched their own sheet fed, web offset printing equipment. And with the relevant companies, we have developed a variety of automatic printing equipment with paper delivery unit, refrigeration unit, folding and roller drying components.
In 1932, gaobao (radboyle company) launched the world’s first four-color sheet fed offset press Planeta deca, which made offset printing technology a big step forward.
The second world war destroyed many factories, and the development of offset printing technology was also affected, and stagnated for more than ten years.
In the 1940s, with the vigorous rise of American newspaper production and mass distribution, offset printing technology was further promoted. After 1945, offset printing made it possible for commercial advertisements to achieve high quality and high requirements.
Classification of offset press
The offset press can be divided into monochrome, two-color, four-color and multi-color presses according to the color number of printing completed in one run. According to the maximum paper width, the offset press can be divided into small offset press, six open, four open, split and full sheet press. In addition, there is a double-sided press which can complete two-sided printing at the same time in one run. According to the fountain system, it can be divided into alcohol machine (i.e. alcohol fountain offset press), water truck (i.e. water fountain offset press) and waterless offset press.