How to do a good job in offset printing

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How to do a good job of "three diligence" in offset printing

1. Checking the printing sheets frequently refers to constantly checking the product quality in the printing process. In the process of offset lithography printing, there may be various situations that may affect the product quality, resulting in a large number of defective or even waste products. Therefore, in the printing operation, qinyingchuang strives to bring about a revolution in the display industry. It is essential to check the printing sheet

frequently check the printing sheets, including the following contents: check whether the overprint is accurate, check the ink color, check the quality of points, and check whether there are dirty spots, white spots, pasted plates and embossed plates

2. Frequently stirring ink bucket

frequently stirring ink bucket means that the ink in the ink bucket is stirred at intervals during the printing process. Mixing the ink bucket frequently can ensure continuous ink dropping, which is the premise to ensure uniform ink color before and after printing

ink is a kind of plastic fluid, which has thixotropic property that the fluidity changes gradually with the action of external force. That is, when the temperature of the ink is kept at a certain level, the static ink is stirred with a certain external force, and the ink becomes thinner and softer gradually, and the rheological property becomes better; When the external force stops stirring, the ink gradually thickens and hardens, and the fluidity becomes poor. If the ink bucket is not stirred for a long time, the ink fluidity will become poor, which will lead to poor inking performance of the ink in the ink bucket, resulting in ink blocking or no inking. It is difficult for the ink roller to transfer and even the ink, and the amount of printing plate ink is insufficient. It is difficult to break the middle of the ink, so that the remaining ink layer can protect the plate and cause the plate to drop

an ink mixer can be installed in the ink bucket to stir the ink at a uniform speed to increase the fluidity of the ink. In addition, the mechanical impurities of the hydraulic oil are mineral oil during transportation. You can also use the ink knife to stir the ink in the ink bucket

3. Check the page moisture frequently

check the page moisture frequently refers to constantly checking the size of the page moisture during the printing process

in the process of printing, it is an important prerequisite to correctly master and control the moisture of the page to achieve the balance of water and ink in the printing process, and correctly identify the moisture of the page. Production 4. Identification method according to the size of moisture in the layout during the falling process of broach:

① visual inspection method. In daily production, visual inspection is generally carried out based on the operator's experience. The method is to use the floodlight to slant the layout, and judge the size of the layout moisture according to the intensity of the reflected light of the layout; The thicker the water film, the stronger the brightness of the experimental temperature with too high reflection, and the thinner the water film, the weaker the brightness of the reflection

② judge according to the printing product fault phenomenon. In case of paste and dirty version, pay attention to whether the moisture content of the layout is too small; For example, if the printing product appears Matt, embossed version, curl, uneven paper delivery and other phenomena, the page moisture may be too large

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