Gravure printing ink common fault causes and exclusion two

Fifth, printing paste

the reason:

1. Ink drying is too fast (small prints and high-profile parts of the print are not printed);
2. The printer is too slow or the plate is not good (usually a layer of ink with no anatomy can be seen when printing).

Method of exclusion:

1. Add slow-drying (solvent boiling at 120-150 °C to slow dry speed);
2, appropriate to increase the printing speed or re-plate.

Sixth, printing sticky

the reason:

1. Ink film is too slow (it tends to make the prints stick together);
2, the printing speed is too fast (usually lead to the back of the printed product is dirty);
3, hair dryer, especially bad after cooling or poor ventilation conditions in the workshop;

Method of exclusion:

1, slow down the printing speed;
2, increase hair;
3, add fast drying solvent;
4. Open doors and windows to adjust air convection;

Seven, bite when overprinting

the reason:

1. When overprinting, the second or third color ink sticks and pulls off the first or second color;
2. Improper dilution of additives;
3, the second color or the third color printing pressure is too large or too fast printing (inconsistent with the previous color);
4, after cold, hot hair bad;
5, poor adhesion fastness.

Method of exclusion:

1. Add the quick-drying solvent to the first color;
2, increase the amount of hot air;
3, the second color to reduce the pressure or ink adjusted thin and small viscosity;
4, slow down the printing machine speed;
5. Replace the ink with good adhesion or adjust the surface tension control device;

Eight, print pinhole

Note: It is often divided into chemical pinholes and mechanical pinholes;

the reason:

1, the current size of India is not consistent with the trachoma - that is, chemical pinholes, there are different blank spots, the reason is that the ink on the substrate poor lubrication or ink foam (small viscosity);
2. The latter is often printed on the same site with white spots of the same size after printing. Generally, the plate has damage or the surface is not smooth;

Method of exclusion:

1. Add defoamer or slow down the printing speed;
2, adding leveling agent;
3. Adjust the viscosity of the ink by adding about 10% of the ink.
4, boot airprint run-in for some time or re-plate;

Nine, poor adhesion fastness

the reason:

1, using the wrong ink or misuse of the solvent can not form hydrogen bonds;
2, ink resin ingredients;
3, poor surface treatment of plastic or surface tension is not controlled when printing (Note: This surface treatment refers to corona treatment of plastic film surface);
4, ink film is hard and brittle or ink is rough;
5, the viscosity is too high, especially ink ink film is too thick (ink film thickness or printing plate too deep);
6, printing pressure is too light.

Method of exclusion:

1. Replace ink or use thinner material correctly;
2, increase the proportion of resin or ink in the fountain to add the same properties of the resin gold transfer oil;
3. Reprocess plastic film (adjust tension control device to 38 dyne/cm2)
4, ink viscosity adjustment in 18-25 seconds / 25 °C, Tu - 4 cups;
5, replace the printing plate (version depth 25-35 microns);
6, increase the pressure;

(to be continued)