How to use the Doctor Blade correctly

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The Doctor Blade is a common tool for the printer. If it is not sure, it will affect the effect of the printing. The following I teach you a few tricks to use the Doctor Blade. I hope you can help you.

 

Add a few drops of oil for fine grinding

 

Before installing Doctor Blade, usually add a few drops of oil to the oil stone for rough grinding, then use 1000# water resistant cloth with a few drops of oil for fine grinding. Add a few drops of oil to lubricate, reduce friction, grinding effect is generally good, peers might as well try.

 

Most printing plants often encounter the phenomenon of  color or light or dense printing, especially when printing mesh adjustment printing, this is not only related to  transfer,  scraping knife and printing plate drum angle can not be ignored, most gravure printing machine can choose 45 °or 65 °angle. Small angle, dark color printing  layer, good gloss, but the effect of  scraping is poor, easy to scrape, picture and text fuzzy phenomenon. And the angle is too large, the shallow screen part may not be able to achieve  transfer, such as the shadow pattern of the main pattern printed out, but its shadow can not be printed out and so on. The solution is to adjust the blade position and raise the position of the tool holder, so that the  can be rotated as much as possible. Move to the substrate film.

 

Adjust the angle of the Doctor Blade

 

To adjust to the best angle, also consider the mesh depth,Doctor Blade position and printing speed and other factors. If the net is too deep, the angle should be larger.

 

Doctor Blade pressure will also have a very important impact on the quality of printing materials, the pressure can be adjusted according to the depth of mesh holes and graphic and text levels. If the plate roller is too long and corrodes the gravure, the pressure will be greater. Because of etch intaglio mesh depth, but the pattern edge is prone to burr and other phenomena. However, it is easy to scrape the  off the shallow mesh hole under too much pressure, causing the shallow screen part not to be printed out; and too much pressure will make the contact angle become smaller, it is difficult to wipe off the excess  in the layout, resulting in the  accumulation under the Doctor Blade, resulting in the knife line. In general, the contact angle of the  scraping system in good working condition is about 60 °.

 

Pay attention to grasping the strength of Doctor Blade

 

Doctor Blade pressure is too light, will produce towing and other problems. The solution is to blow at the blade edge of the Doctor Blade, that is, the interface between the Doctor Blade and the plate.

 

Doctor Blade used for a period of time will appear burr, cracks and other phenomena,  scraping knife can not work effectively, this time the need to sharpen or replace the new Doctor Blade. In practical work, sometimes the Doctor Blade ruptures, it can prolong its service life by grinding or adding pad, one can save the use cost of Doctor Blade, and the other can solve the corresponding quality trouble.