Standardized operation of the most popular offset

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Offset press: standardized operation of the whole machine

the standardized operation of the whole machine is a comprehensive embodiment of the six major routing standardized operations. Next, take the printing process of a print as an example to talk about the standardized operation of the whole machine

1. Preparation before starting up

check the machine before starting up, especially when operating the machine that has not been started for a long time or connecting other people's machines. The main inspection places are the joint between the drum and the drum, the notch of the drum, etc. if there are sundries, they should be removed in time. The holy dipper and the ink dipper roll are also a key point of inspection. First, check whether there are sundries in the middle. Second, check whether the ink dipper roll and the ink dipper blade are too tight. When idling the machine, open the ink dipper. In addition, check whether some important parts (such as paper feeding teeth, paper receiving chain, etc.) are loose. In addition, we should not forget the oil pointer, especially those equipment without oil pressure detection. Unsafe items on the cardboard, wallboards on both sides of the ink path, cover plates at the paper receiving part, foot pedals and other ultra-high temperature materials should be removed in time

after the above inspection, turn by hand. If the force is uneven within a week, check the relevant parts in detail, and then jog the machine. If there is any abnormality, stop the machine for inspection. After these works are completed, the machine can be started for operation

2. Start up and run

ring the bell before starting up, so that people around the machine can get ready for extraction. If there are many people, the ringing time should be longer. In order to ensure safety, you should also observe around. Before pressing the operation switch, the other hand should be placed on the emergency stop switch. If there is any abnormality, the emergency stop should be carried out (this judgment is usually based on the sound of the machine). Generally, the machine should be idled first when loading the plate, rubber blanket or cleaning the surface of the drum, so that there is enough lubricating oil on the surfaces of bearings, gears, cams, sprockets and so on

3. watering and inking

the amount of watering and inking depends on the specific print. Generally, the amount of watering and inking should be slightly larger than the actual needs (the required amount can be given through empirical estimation or approximate calculation). When filling water, pay attention not to pour water outside the water tank or bucket, so as to avoid water dripping on the machine and causing rust on the surface of machine parts. When applying ink, the ink should be placed as close as possible to the lowest part between the ink bucket blade and the ink bucket roller, which should not be everywhere on the whole ink bucket. Generally, watering and inking should be carried out when parking. Be sure to pay attention to safety when operating when starting up. In addition, the ink skin and impurities in the ink bucket should be removed when inking

4. The upper version and upper blanket

blanket should generally be installed in advance. Whether the rubber blanket is installed properly can be judged by flipping and listening to its sound. Use the middle part of your finger to play the rubber blanket. If the sound is crisp, it indicates that the rubber blanket is tight; The sound is dull, and this article is from Purdue University, indicating that the blanket is relatively loose. Both sides should be carefully checked

the printing plate should be installed in the pressed state, so that the printing plate can be close to the drum. For the equipment that does not bring the upper plate for pressing, you can put down the plate water roller. Before the last edition, the printing plate should be checked in detail, and the specific inspection method is described above

5. even water and ink

start the machine to make water and ink enter the water and ink path and mix evenly. If the ink quantity is insufficient, you can use the method of pressing ink bucket to make it ink quickly. After the water and ink are all beaten evenly, put the plate water roller against the printing plate, so that the printing plate surface is watered first, and then basically evenly (the watered condition can be observed through the surface reflection), and then put down the plate ink roller. At this time, the ideal condition of the printing plate surface should be that there is no reflection of water and no plate pasting. If there is reflection of water, indicating that the water is large, the water volume should be reduced; If there is a paste version, it indicates that the water is small, and the water volume should be increased. In short, water and ink should be in balance

6. For the regular line

the paper used at this time should be to find the regular paper. The usual way is to find some white paper in the waste printing sheet. Note that the rolled paper should be basically the same as the white paper to be printed (format, quantity, category) until the rules are aligned. If the rules are not correct, you can make the rules accurate by drawing plates, borrowing rollers, borrowing rules and other measures

there are two points to pay attention to when finding rules: ① when the version moves, the paper does not move, that is, when the version is pulled forward, the position of the text and text on the paper moves forward (in the same direction); ② When the paper moves (rules move), the version does not move, that is, when the paper moves forward, the graphics and text move to the back of the paper (in the opposite direction)

the accuracy of the rule refers to that the picture and text are parallel to the front mouth of the paper and the side mouth of the paper (pull the rule edge), and the whole picture and text can be printed on the surface of the paper, and the left and right are basically in the middle position

there are two ways to judge whether the rule line is parallel to the first four: first, fold the paper in half to make its rule line coincide, and see the difference between the front mouth of the paper; The second is to align the front of the paper to see the relevance of the rule line. After the beginners fold the paper, they can press the two sides of the paper together with the nails to control the construction leakage of the National Construction Department of the paper for more than 20 years

judge whether the picture and text are consistent with the front edge of the paper, which can be observed by the difference degree of the regular line. The usual practice is to rush a dozen papers with its mouth as the benchmark, and then twist them to one side to visually measure the difference. If there is basically no difference, it can be considered as qualified; If there are obvious differences, the reasons need to be analyzed in detail (this problem is mostly caused by improper regulation of rules)

the method of marking is mostly used to judge whether the side rules are accurate. According to the position of the image and text on the printing sheet from the edge of the paper, on the printing plate (pull the gauge edge), Use a scribe to draw two lines (1mm to the left) so that these two lines can be printed on the print sheet, and the first line on the edge is printed on the edge of the paper. If this line is not printed on each other, it means that the side gauge is not pulled in place, and the size of the error can be estimated through the second line. If you do not draw a line, you can also use the dot method, but this mark is not easy to observe. Note that: circle the ink after the line is drawn (that is, apply ink on the scribed line, and then wipe off the excess ink with an oilcloth). During normal printing, you should always check the regular line. If the rules are not correct, it will bring great difficulties to the follow-up work

for monochrome overprint, it can be completely carried out as described above. For multicolor overprint, a benchmark should be selected first from the regular lines of various colors to minimize the adjustment without causing other problems. After selecting the benchmark, pull other printing plates to make the rule line coincide with the rule line of the benchmark, and then make the rule meet the specified requirements by borrowing the previous rule. However, the more standardized approach is to first meet the requirements of monochrome overprint, and then make the regular lines of various color plates coincide through the overall circumferential and axial movement of the plate cylinder. This method is carried out in the actual process: take a color plate closest to the requirements of the monochrome rule line as the benchmark, pull the plate to make it meet the specified requirements, and then pull other color plates close to this rule line. If one of the rule lines is parallel to the reference rule line, the rule line can be overlapped by the overall movement of the drum. Double sided overprint should also be aligned according to this method, that is, take one side as the reference, and overprint the other side with the reference plane

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