1. Development level of web offset printing equipment
Some technologies of rotary offset printing and sheet-fed offset printing are common, such as ink supply technology, automatic Q version and cleaning, connection processing, online quality inspection of printed products, etc. The following is a summary of some unique technologies of commercial rotary offset printing .
â‘´ Shaftless transmission technology In the past 10 years, the shaftless transmission technology has become the basic transmission form of high-end printing machines, especially medium and high-end unit-type web printing machines (including tower printing presses), but its There are few applications on printing presses. At present, the unit-type web printing machine generally uses a servo motor in each color group, and the gear transmission is still used between each cylinder. Less servo motors are used on each drum.
⑵Seamless cylinder technology The gap on the web offset printing press not only affects the printing speed, print quality and the stability of the machine operation, but also can not be printed due to the gap, which will cause paper waste. . In recent years, at some domestic printing exhibitions, there have also been seamless? L-tube commercial web offset presses exhibited and started to be used in China. The combination of seamless cylinder technology, sleeve technology and shaftless transmission technology has created conditions for solving the variable printing size of web offset presses. Despite the higher price of seamless cylinders, the seamless variable-size web offset press should be one of the important directions of the development of web offset presses.
(3) Narrow slot technology The narrow slot technology is to change the gap of the cylinder of the web offset press from wide to narrow. The advantages of the narrow-slot rubber cylinder are that it can reduce the blank printing size, save paper, reduce machine vibration, and help improve the stability, speed and printing quality of the machine. At present, narrow-slot plate cylinders of 1 to 1.5 mm are being popularized, and narrow-slot rubber cylinders of about 6 mm have been introduced in China, but have not yet been produced.
â‘·Closed-loop color control Closed-loop color control system uses online CCD recording technology or Combo video / spectrophotometry system to measure optical density online. Each device can scan and measure the color mark while the machine is running, then read in the data, and send it to the ink console to compensate the ink film thickness. Companies that have used these systems have found that closed-loop color systems not only contribute to the stability and consistency of color quality, but also a way to collect static process control and ensure real-time data on print quality. Manufacturers, including Psrrett8 Graphic, Graphic Microsystems Inc, and QTI, have all introduced closed-loop color technology to the rotary printing market. Now closed-loop color control technology is more and more used in sheet-fed offset printing presses.
⑸Closed-loop heat radiation control This technology saves more fuel than traditional composite dry matter / oxide. And this technology is very close to a completely closed-loop radiation control system. Using a completely closed-loop radiation control system, during the hydrogenation process, the energy released by the ink solvent is sufficient to destroy the VOC and dry the web without additional fuel. The use of high-efficiency technology can also reduce pollution and reduce costs.
⑹ Electrostatic auxiliary drying Static electricity can remove the electrostatic energy barrier of the ink, while improving the drying effect, it can also reduce the demand for energy, so you can increase the effectiveness by adding static electricity to the drying agent. This means shorter drying time, higher drying efficiency for commercial rotary printing, and better drying results at lower temperatures and less air flow. The paper is damaged and the quality is improved. All of these are gradually improved technologies, and they are being applied to related new dryers.
⑺Folding web printing machine without needles, after multiple sets of printing, enter the triangular plate to fold, and after folding, enter the? L tube for cutting, one fold, two fold. In order to make the folding continue, the paper tape that has been folded in half is driven by the pin on the roller to cut and fold the next sheet of paper. The resulting pinholes not only waste paper, but also affect print quality.
â‘»Ink roller temperature adjustment system Because the speed of the web offset press is very high, the temperature of the ink roller and the printing plate will increase a lot due to friction and other factors during high-speed operation. If the temperature is too high, it will affect the printing quality. Generally, a closed pump circulation system is used to provide temperature adjustment water for the ink pump. The temperature of the water returned from the ink roller is controlled by the ink roller temperature control device. According to the printing speed of the printing press, the friction of the ink, the adjustment of the roller, and the quality of the heat dissipation conditions, the temperature of the water supply is adjusted to balance. The latest hybrid refrigeration device developed by Technotrans Company can combine the dampening liquid refrigeration system and the ink roller temperature adjustment system into one.
⑼Roll paper cut sheet is mainly realized by roll paper-sheet feeder. That is, the roll paper is continuously cut into a single sheet of paper, the cutting length can be adjusted steplessly according to the needs of the printing paper, and the cutting accuracy can generally reach ± ​​(0.2 ~ 0.5) mm. The width is the width of the roll paper. Cut the cut sheet paper directly into the sheet-fed offset press at a certain step, or install the roll-sheet feeder behind the original sheet-fed paper feeder, and install the roll-sheet The sheet feed conveyor is extended and directly connected to the original sheet feeder paper feeder. The two paper feed methods can be replaced. The roll paper-sheet feeder can store a large amount of paper, reduce the number of paper changes and downtime, and improve machine utilization. Roll paper is cheaper than sheet paper. Can reduce the cost of paper by 5% to 25%. If it is coated cardboard or film, using coiled material can obtain higher economic benefits, and at the same time completely solve the double or multi-sheet feeding failure.
Leather Chair,Leather Lounge Chair,Leather Desk Chair,Brown Office Chair
Feat Top International(China) CO.,LTD , https://www.lounge-seating.com