Plastic gravure failure - blocking version

Blocking, poor ink transfer, and missing dots are the most common and inconspicuous faults in gravure printing. Therefore, various factors should be taken into account in handling, and targeted measures should be taken to deal with them.

Block version

In gravure printing, the phenomenon of blockage is generally manifested as: shallow dot plate version can not be transferred (such as human skin color); deep dot plate ink transfer volume is reduced, usually from 50% to 70% down to 20% to 30%.
cause:
1 During printing, the viscosity of the ink caused by the solvent evaporation increases, and it is impossible to enter the fine cells or the network cable, causing the ink to gradually dry and cause blocking.
2 During printing, the distance between the squeegee and the plate cylinder is too large or the angle is unreasonable; due to the large diameter of the plate cylinder or the depth of entering the ink tank, the hot air blown from the drying equipment affects the plate cylinder, which also causes blockage. Version. This situation is very common in domestic printing presses.
3 The engraving depth of the printing plate and the angle of the cell site are not suitable.
4 printing environment temperature is too high, so that solvent evaporation speed is too fast, resulting in blocking plate.
5 Added curing agent series of ink, with the increase in the machine time ink curing in the plate cavity, gradually reduce the depth of the plate and cause blockage.
6 Insufficient design of ink formulation, using a solvent that dries too fast.
solution:
1 Adjust the ink drying speed, according to the actual situation, use slow-drying solvents.
2 Adding a varnish to improve and increase the fluidity of the ink.
3 After printing, immediately clean the plate.
4 According to the actual printing situation, add the appropriate solvent in time, try to ensure the consistency of the ink printing viscosity.
5 Redesign the ink formulation to reduce the initial dryness of the ink and the dryness of the ink and increase the fluidity and transferability of the ink.
6 For blockage caused by curing agent, hardener should be added as little or as little as possible; if it is really necessary to add curing agent, always check whether there is any blockage and handle it in time.