Analysis of stripes and bars of the hottest prints

2022-08-09
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Analysis of print streaks (bars)

4. The characteristics of streaks caused by the wear of roller bearings with worn bearings are that there are several wide streaks at the bite, and a few are equidistant streaks. Due to the long-term use of roller wheel bearings, the gap between roller journal and bearings is too large, which makes the sleeve loose in normal operation. After the bite is pressed, the clearance value is large, and the "streaks" are caused by vibration during high-speed operation. In addition, a similar situation occurs when the cylinder journal is seriously worn and ellipses appear. After being worn by the testing machine, the tested material or grease needs to be taken out manually and then weighed for one step

the temperature fluctuation should not be greater than 2 ℃/h; Method: if it is confirmed that the bearing is seriously worn, it must be replaced with a new bearing

5

the gear caused by gear vibration is embedded with dirt such as paper wool and ink skin. The machine is improperly maintained due to long-term use. Some dirt such as paper wool and dried ink skin will be embedded between the gears, which will become small hard blocks after being rolled by the gears, resulting in vibration and striation of the drum gear during operation

solution: strengthen the cleaning and maintenance of the machine, thoroughly remove dirt, and ensure the smooth operation of the gear

6 the pressure between the printing plate and the ink roller caused by the pressure of the ink roller is too heavy, the printing plate pad is too thick or the pressure of the ink roller is not adjusted properly, so that the pressure between the printing plate and the ink roller is too large, causing the ink roller to jump and slip, resulting in streaks

solution: reasonably adjust the printing plate liner to make it suitable for the pressure of water, ink roller and rubber roller

7

(1) the ink roller pressure is improperly adjusted, and the part causing the "streak" is generally close to the bite, and its position changes up and down

(2) the outer circle of the ink roller is uneven, and the roll core is not straight, and the position causing the "streak" is generally at the bite

(3) the ink roller gear is worn or the accuracy is not enough, causing "streaks" whose pitch is equal to the pitch of the ink gear

solutions: (1) adjust the pressure between ink rollers; (2) Remove the ink roller for grinding or replace the ink roller with a flat roll core: (3) if the gear is seriously worn, replace it with a new one

8 the thinness of

ink caused by improper ink allocation will not only produce greasy and paste, but also have low cohesion, which will affect the transfer of ink. However, the ink roller is often restricted by the high cost of silver (the current market price of silver is about 4million yuan/ton), and ink pigment particles are gradually accumulated on the printing plate and blanket, which increases the surface friction and pressure and causes streaks

solution: properly add No. 0 ink blending oil to the ink cow to improve the viscosity and transfer performance of the ink

9 the paper with rough surface caused by the printability of the paper has poor strength, which is easy to remove powder and hair, and accumulates on the printing plate, ink roller and blanket, causing the increase of friction and pressure and causing streaks

overcoming method: when encountering paper printing with poor surface strength, the blanket should be washed frequently, and the adhesive remover or no. 6 inking oil should be properly added to the ink to reduce the de dusting and hair loss

(to be continued)

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