Color Printing Offset Printing Machine (II)

These preparatory printing units may not rotate with the host, but may also rotate in reverse. Due to the variety of paper paths, high demands are placed on the automatic paper-laying system of the equipment. Therefore, in addition to the traditional chain mechanism, a fully automatic paper-threading method using a chain and a guide pneumatic device is also applied. The automatic paper threading system can set 24 kinds of empty paper routes, not only can reliably achieve rapid wear of paper, but also can adapt to changes in the edition to meet the requirements of different kinds of newspapers.
The electrical part of UNISET press adopts Siemens's main control system and sub-control system designed and manufactured by MAN Roland. It is used to complete the basic control and display functions of the machine, such as remote tracking of water and ink with the host speed, remote control color printing. Register the system and display curves and data. The main control system and the sub-control system use INTERBUS connection to form a network. Both are digital adjustment methods, accurate and reliable. Console operation has manual, automatic double insurance. Security monitoring is also controlled by two computers (central control, color control). There are three levels of electrical fault display; the first failure is displayed on the console, the operator eliminates the fault according to the display content; the second fault is displayed in the electrical cabinet, and the maintenance electrician is excluded according to the display symbol; and the three communications faults are searched by the computer software. The downside of this machine is that the machine runs with excessive noise.
The manufacturing technology of the Goss-Fond Global 70 offset printing press is world-class. It uses thick, strong box-type panels and plate and rubber cylinders forged from solid stainless steel. Shares, run more smoothly and with less noise. The printing roller of Universal 70 machine adopts N-arrangement, which makes the web “S” type when it is imprinted on the printing roller to form the best printing status. The tension of the paper tape is stable, which is more conducive to ensuring the printing quality. Accurate instructors and computer-controlled water-supply devices without water, pulse-controlled water jet nozzles synchronized with the host, and remote control flap angle ensure accurate water flow, fast ink balance, and less wasted printing. Gaussian France Global 70 has advanced non-shaft driven paper feeding device. This device guarantees stable tension, balance of paper and accurate color overprinting before the web is fed into the printing unit. The machine also uses a DC motor drive, independent ring opening control and controllable bending moments. The degree of automation is the same as that of UNISET. It has a master console that can automatically track water and ink, remotely register, remotely adjust the ink, and automatically display faults. It is not as easy as UNISET to automatically wear paper.
Imported offset rotary presses also have a small roll of small rolls, that is, the print cylinder rotates only one page of a week, commonly known as a minicomputer. This type of machine has a higher degree of automation. The more advanced models are Gaussian Global 45, SSC MAGNUM, Heidelberg Mercury Harman, MAN Roland COROMAN, and Swedish sauna HU200. Because their technical characteristics are not higher than the medium-sized machine or mainframe, it will not be repeated here.
Third, the development trend of newspaper offset presses The rapid development of various high and new technology, newspaper offset printing press how to develop it? Or, what is its development trend? The recent developments of several international web offset rotary press manufacturers and their technological development directions can help us find the answer.
The digital lithography technology concept machine introduced by Gauss in 1997, or “Gaussian concept machine” for short, can explain the problem. The features of this machine are: high production efficiency and production flexibility, fast printing setup and preparation before printing, With low printing costs, hundreds to millions of prints in different batches can be printed economically. The machine's technological breakthrough and application are as follows:
First, use reusable copper-plated printing cylinders. The unprinted printing roller is composed of a roller body and a sleeve (made of glass fiber, the surface of which is covered with a nickel oxide semiconductor). Nickel oxide semiconductors are exposed to laser light and are negatively charged. The copper can be plated up to form a printed image area, ie a printing plate is formed, eliminating the need for conventional laser photolithography, printing, and printing.
Second, single-fluid lithography is used. The water and ink are directly mixed into a mixed ink in a high-speed stirrer on the printing press, and are evenly transferred to any position of the printing plate by the keyless ink fountain. Then, water and ink are deposited in the blank portion and the graphic portion, respectively. print. The excess milk is scraped into the circulatory system and no separate water supply is required. The technology is about to be applied to newly-marketed New Zealand presses.
Third, the cutting size is variable. The use of different thickness fiber sleeves for blanket cylinders and non-engraved copper printing cylinders enables different cutting sizes to be achieved, so that a variety of products can be printed on the same offset rotary press.
Fourth, the printing cylinder adopts seamless technology. This technology is a major breakthrough in improving production efficiency. It fundamentally overcomes the impact of vibration caused by printing plates and blanket cylinders on high-speed operation, and because the rollers are not connected. Sewing, greatly reducing the paper loss of the non-printing part, so as to achieve the purpose of indirect reduction of paper costs. Because the blanket cylinder and plate cylinder can be made more solid, this solves the problem of cylinder deformation and is conducive to improving the printing quality. The seamless technology has been used in thermoset offset printing machines and has become the standard design of the model. The first seamless offset rotary printing press was produced by Harris Corporation in Heidelberg, Germany, which was installed by the Donnelly Printing Company in 1993. The famous printing press manufacturers such as BA also successively launched. Stencil offset rotary press.
Fifth, the use of shaftless gearless transmission technology. Each print cylinder is driven independently, which fully guarantees the synchronous operation between the blanket cylinder and the plate cylinder. The shaftless transmission technology has been widely applied to existing universal web offset printing presses. This kind of global model without shaft transmission has not been used in our country.
The United States Gaussian recently declared that the "Gothic concept machine" is the offset rotary press of the 21st century. We will look at it for this purpose.