A: that is, it eliminates the excess ink on the surface of the gravure roller. If the adjustment is correct, after scraping knife scraping should leave only the net point in ink (ie graphic), and the version of the drum surface (non graphic) excess ink should be shaved, which will effectively image area be fully transferred to the substrate.

B: "scraping" means: in the course of moving objects, through the role of external force to break it. In the scraping process, continuous operation of the drive roller to rotate with the ink, and the ink scraping knife pressure is the force, the transfer from the ink pot to roll on Ink Graphics and non visual parts of fracture, which will roll on the graphic part of the effective transfer.

C: the working principle of the scraping knife: when the gravure press is driven by the motor at a high speed, the squeegee also swings accordingly. This placement is what we call (stroke)! The gravure machine made by different manufacturers has different structure of the swing mechanism of the scraping knife. The scraper swing is driven by a special micro motor, and the scraper swing is driven by the drive gear. No matter what form of swing structure, it has to achieve a goal: scraping the excess ink, while reducing the squeegee blade and plate friction, in order to extend the life of the squeegee and printing plate.

A: scraping knife without elasticity, cannot promptly return to in situ, the ink can not be timely wetting mesh, but also leave a knife, put produced in the roll will have a long time drag ink phenomenon, the product color and roll wear greatly influence.

B: scraper thickness is usually chosen from 0.12 to 0.16mm. The blade is too thick no flexibility, such as too soft will not scrape clean ink, with a strobe light can be seen in the roll with a layer of fog, will not only affect the color overprint fluctuations, will transfer to print, print and color caused by adverse changes will be.

C: if the blade is too thin, it is easy to leave marks on the blade plate, under the effect of frictional force, blade wear, blade will appear weak, the blade can not effectively scrape ink, good printing effect will not present a complete text location. Once too soft, we usually choose to increase the pressure, but this approach is not a good place to be, at this time the blade began to curl, only to a large area in the printing full version of white, with knife too thin will often appear longitudinal streak, it is also referred to as the jump problem.

The hardness of the squeegee also affects the quality of the printed matter. The scraper is iron, and copper drum gravure is chrome plated surface, because of the hardness of copper is 90 ~ 230HV, the hardness of chromium is 800 ~ 1000HV, so the best choice for hardness of 500 ~ 600HV scraping knife, so as not to hurt the printing plate, and is not easy to leave marks, but also can scrape excess ink layout.

The edge of the scraper should be arc shaped, so that it can protect the printing plate. Because the surface of the printing plate is arc shaped, if the blade is also arc-shaped, it is not easy to damage the printing plate, but also easy to wipe the ink, to ensure that the layout of the non graphic office clean, not stagnant ink. If the tool tip is flat, because the flat blade is very sharp, it is easy to damage the printing plate and affect the ink scraping effect, thus affecting the printing quality.

Before installing the scraping knife, whether to grind the old blade before use, general use 500-600 mesh water sand paper grinding, grinding, put the knife back to about 25 degrees oblique mouth with sandpaper, then the blade grinding, grinding blade angle 30 degrees is appropriate. We usually add a few drops of oil in whetstone for coarse grinding, and then use the same 1000# waterproof abrasive cloth and add a few drops of oil in fine grinding, fine grinding to the attention back and forth faster, add a few drops of oil lubrication, reduce friction, grinding effect is generally good, this is it from the practice experience. Sharpening must focus attention, sharpening efforts should be uniform, attention should be paid to safety, in order to prevent injuries to the hand. In this section, we recommend an experienced operator.

The quality of the printing of the gravure depends to a great extent on the correct sharpening of the squeegee. If the ink knife to 25-30 degrees angle, the blade is relatively strong, but the elasticity is poor, the blade scraping the plate cylinder surface ink effect is not good, so that the printing part of the brightness of the phenomenon of uneven thickness. If grinding the blade is too thin, the following into 18 degrees, although the blade is a good way to put the ink from the surface of the cylinder scraping, but easy to fall from the ink or paper scraping knife on the "hard particles" damage, sometimes wear plate cylinder, a small crescent appears on the blade scars. The crescent blade, will leave a very fine line in print, which is straight line and paper into a perspective. Therefore, the scraping edge depends on the printing products, ink, printing materials and printing machine speed, and the grinding angle changes from 30 degrees to 18 degrees. After grinding, with a nail cap gently cross, to test the quality of sharpening, whether there is a gap, whether smooth! Before sharpening, be sure to clean. The scraper can not have ink dirt.

Use the 0.25-0.35mm thick pad blade to carry the pad knife, and generally pad the blade out of the turret about 15-20mm, while the blade extends out about 3-5mm of the blade. The tightening bolts on the tool carrier should start from the middle and then be tightened separately on both sides so that the blade is uniformly stressed so that the blade does not produce wave shape and is advantageous for production. The length of the blade is 5mm longer than the plate and the pad is shorter than the blade. The installation requirements for the squeegee are shown in the illustration.

The installation of the scraping knife

Most of the printing factories often encounter printing ink or light or dark phenomenon, special printing halftone printing, in addition to this and ink transfer related, scraping knife and a printing plate roller angle can not be ignored, most of the gravure printing machine can choose 45 degrees to 60 degrees. The angle is small, the printing ink layer color is deep, the gloss is good, but the scraping effect is bad, and it is easy to appear scraping and blurred. And the angle is too large, shallow mesh parts may not be able to achieve ink transfer, such as with a shadow pattern, the main pattern printed out, and its shadow can not print out and so on. The solution is to adjust the position of the scraper and adjust the position of the tool holder, so as to transfer the ink to the substrate!

The installation of the scraping knife Most of the printing factories often encounter printing ink or light or dark phenomenon, special printing halftone printing, in addition to this and ink transfer related, scraping knife and a printing plate roller angle can not be ignored, most of the gravure printing machine can choose 45 degrees to 60 degrees. The angle is small, the printing ink layer color is deep, the gloss is good, but the scraping effect is bad, and it is easy to appear scraping and blurred. And the angle is too large, shallow mesh parts may not be able to achieve ink transfer, such as with a shadow pattern, the main pattern printed out, and its shadow can not print out and so on. The solution is to adjust the position of the scraper and adjust the position of the tool holder, so as to transfer the ink to the substrate!

　　The squeegee pressure is too light and will cause bristle and other troubles. The solution is to blow the blade at the edge of the blade, that is, the blade and the plate surface, and blow it with a special hair dryer.

After scraping the knife for a period of time there will be burrs, cracks and other phenomena, scraping the ink knife can not work effectively, then you need to sharpen or replace the new scraping knife. In actual work, sometimes the scraper breaks down, and the service life can be prolonged by grinding or adding padding. The utility model saves the scraper cost and solves the corresponding quality failure. Ink scraper can be used on both sides, such as the full version of the white version can use the knife to production, but to oil stone after use.