Top 4 skills for rotogravure printing press operator
a)Doctor blade hardness and flexible.
Blade hardness will affect printing quality. Blade is iron material, and gravure cylinder is chrome-plated copper, since copper has a hardness of 200 ~ 300HV, chromium hardness of 700 ~ 900HV, it is best to choose blade hardness of 450 ~ 600HV, so that does not hurt the printing plate , but not easy to leave marks, you can also scrape excess ink layout.
b) Doctor blade installation position.
blade to be placed in proper height, blade mounted to adjust according to the printing speed, fast printing speed, a little far away from the impression points, near it if slow.
c)Blade installation angle.
Generally, the installation of the blade contact angle 55 °~ 65 ° is suitable.
2.Pressing rubber roller
a) the hardness of the rubber roller material affect the amount of ink, less inking for harder rubber roller, more inking for softer ones.
b) big pressure on rubber roller, big amount of inking. pressure is small, small amount of ink.
c) Printed pattern deep, it require high hardness embossing rubber roller; printed pattern shallow, rubber roller adopt soft material.
d) High printing speed, high hardness rubber roller is needed; printing speed is slow, soft rubber embossing rollers are ok.
3.Ink transfer system
a) to Keep consistency of the ink viscosity, timing measurements and add solvent.
b) Keep proper blending proportion of used and new ink. use co-solvent to prevent ink composition disorders, to avoid ink separate out.
c) use ink pump and stirring bar for ink circulation, and ink tray do not need big one, proper size for ink tank.
It is one key part for drying oven to improve printing speed,good quality drying oven is necessary for high quality printing. Ink was dried by heated wind blowing, not high temperature heated baked.
a) if temperature is too high, the ink surface will have conjunctiva, resulting in fake dry phenomenon.
b) low boiling solvents of ink volatilize premature, high-boiling solvent was left over, this will slow down the drying speed. It requires heated wind in drying oven , temperature about in 40 ~ 50 ℃. The wind can not blow directly on the film, the heating can not be grilled directly on the film surface. To have good ventilation for drying oven.