Gravure printing ink common fault causes and exclusion

During the storage and use of gravure printing inks, they will precipitate, delaminate or fold out due to their low viscosity. Therefore, before printing or printing process, should be fully stirred, not only involving ink, printer ink, printers and printing materials and handling techniques, but also determines the quality of the printing and the added value. In addition to the listed faults, other faults and remedies can be dealt with by referring to the printing faults and handling of printed and woven bag inks.

First, ink precipitation, delamination and precipitation

the reason:

1, ink storage time is too long;
2, the ink viscosity is small or the solubility can not reach;
3, large and large particles;
4, the resin content is small or the mutual solubility of the solvent is poor;
5, color filler flocculation.

Method of exclusion:

1, fully stir the ink before use;
2, increase the ink viscosity (such as adding ink);
3, the amount of real solvents to increase 3-5%;
4, using a small proportion of the color, filler or add 1-5% wax;
5, add anti-flocculant (such as PK150);
6, for the use of good dispersion ink;
7, increase the proportion of resin in the ink or reduce the pigment, filler;
8. Add anti-precipitation agent or make the ink slightly thixotropic.

Second, poor printability

the reason:

1, not frost-resistant or excessive flocculation (or transfer is not on the roller);
2. The pigment has poor wettability or thickening;
3, too much thin material, especially the printing process has water infiltration;
4, using the wrong solvent;
Method of exclusion:
1. Put the ink in the workshop at about 20°C one day in advance or place it in warm and hot water;
2, fully stirred to restore the ink, on the contrary exchange ink;
3、Add appropriate amount of true solvent in ink fountain or use special diluent or mix each component solvent and then add it;
4. When ink is used for printing, ink fountains are added less frequently and thinner materials are added, and some original inks are added at the same time;
5, ink should not be adjusted too thin.

Third, the graphic network

Note: Generally, no ink or full version can be printed on the online bar;

the reason:

1, ink and plate roller discomfort;
2. The adaptability of the blade and the substrate is not good;
3, the ink viscosity is too high (especially the ink is too hard), and poor fluidity or dry too fast;
4, eccentric printing plate or aluminum plating is not good;
5, scraper too tight (too much ink scraping);
6. Insufficient printing pressure (20kg/cm2 for normal paper and 50kg/cm2 for rough paper).

Method of exclusion:

1, the use of normal corrosion and plated aluminum plate roller;
2, adjust the blade angle;
3, increase printing pressure as much as possible;
4, the use of good ink;
5, add slow-drying solvent (adjust the film dry speed time);
6, there are foam can add about 0.2% defoamer (excessive shrinkage will lead to ink film);
7, replace the smooth and smooth printing materials;

Fourth, staining and ghosting


the reason:
1, the ink softening point is too low (in the printing product roll or accumulation, especially in the hot season, the back of the ink)

2, the ink has a dye or has been deteriorating;
3, multiple ghosts due to the wear of the gear teeth of the printing machine affect the overlay accuracy, and substrate and other factors;

Method of exclusion:

1. Renew ink or add resin varnish to ink ink;
2, adding coupling agent or fixing agent (this refers to transparent ink staining);
3, ghosting is to re-exchange or cut the printing machine meshing parts or parts;
4. Replace the new material if the substrate is too loose;

(to be continued)