Effect of Doctor Blade on printing quality

The sharpness, pressure and contact position of Doctor Blade affect the printing quality. According to the actual needs, reasonable adjustment of these factors can solve many problems in printing.

 

1. the sharpness of the Doctor Blade, the sharpness of the knife depends on whether the knife is new, the blade angle of the knife, the model of the sand paper (oil stone). The sharpness of the knife should be effectively scraped out the and do not produce the knife wire. Too sharp blade is often easy to produce the trace of the knife and wear the plate at the same time.

 

2. The distance between the scraping knife and the printing plate, and the decrease of the distance between the Doctor Bladeand the printing plate are helpful to improve the transfer rate of, but it is easy to produce dirty plate. Otherwise, the dirty plate can be effectively solved and some small line marks can be avoided, but the transfer rate of will be reduced.

 

3. The smoothness of the Doctor Blade, the leveling and warping of the blade mainly depend on the method of installation, but it may also be related to the foreign body sticking to the liner in the groove of the tool holder or the blade. When the flatness of the knife is poor, the edge of the printing surface will appear some water bead marks, or from time to time some discontinuous line marks.

 

4. The pressure, which affects the pressure of Doctor Blade, is the size of cylinder pressure, the difference of hard and soft blade, the angle of cross between the blade and printing plate, the bigger the slope, the greater the pressure. Too much pressure will reduce the transfer rate of, for the printing plate, blade wear is larger; too small pressure prone to dirty or Doctor Bladeline.

 

5. The movement of the wiper blade and the movement of the wiper blade play an important role in reducing the Doctor Bladeline, improving the utilization ratio of the Doctor Blade, and reducing the wear of the plate. If the scraping knife movement is not normal, should find ways to improve. Line marks appear in printing, one is to cause plate injury, the other is the blade is not sharp. But another reason is that foreign bodies stick behind the blade. The solution is to move the wiper up and down in order to get rid of the adhesives.