Gravure Common Faults and Solutions (Chinese)

Fault 2 causes:
(1) Ink dilution filter, viscosity drop;
(2) The contact angle between the squeegee and the printing plate is not good, and the knife edge warpage is caused by too much upward or excessive force of the top knife;
(3) The ratio of gold oil and metal powder blending is incorrect;
(4) The squeegee blade is too soft, the distance between the bead and the knife edge is too large during installation, and the blade protrudes too long;
(5) Excessive pressure on the impression cylinder, ink extrusion;
Solution:
(1) increase the viscosity of the ink, if there is no obvious improvement, the ink can be changed again;
(2) Adjust the contact angle of the squeegee down, and reduce the top knife force;
(3) Moderately reduce the amount of gold transfer oil;
(4) Use a flexible high hard blade, preferably made in Japan, to reduce the elongation distance between the blade and the bead;
(5) Reduce the pressure of the impression cylinder;
(6) If the phenomenon of smearing is not serious, the speed can be increased to eliminate it.
Failure three sticky reasons:
(1) The drying oven temperature is too high or too low;
(2) The cooling circulation system is faulty and the water flow rate is too small;
(3) improper temperature and humidity control in the workshop;
(4) The viscosity of the ink is too high and the drying speed is too slow;
(5) Improper pressure adjustment (heavy or light) of the impression cylinder.
Solution:
(1) The temperature of the drying oven should be determined according to the speed of the machine and the layout of the layout. Large area printing should be performed at a temperature of 60-80 degrees Celsius, and the screen should be printed at a temperature of 40-60 degrees Celsius.
(2) Increase the cooling roller water flow. Special attention should be paid to the paper guide roller being hot and easy to adhere to the substrate, and the temperature of the oven must be reduced in time;
(3) The temperature and humidity of the printing shop is controlled at 18-22 degrees Celsius;
(4) It is possible to increase the printing pressure and make the prints solid when you run the game (12). .
Failure four imprinted false, exposed bottom reason:
(1) Insufficient embossing force;
(2) Excessive dilution of the ink destroys the flowability and adhesion of the ink;
(3) Too much white ink in the ink;
(4) Blocked or printed version of the Internet site wear, off version;
(5) The original ink modulation is not appropriate.
Solution:
(1) increase the printing pressure;
(2) increase the ink viscosity;
(3) Add as little ink as possible in the ink (grain more easily damaged version), can be used to replace the ink;
(4) Wash the remaining ink in the hole with a brush to increase the transfer rate;
(5) According to the characteristics of the original ink group, reasonable deployment of ink.
Failure five outlets, incomplete text printing:
(1) The viscosity of the ink is too high, the ink layer on the printing plate is thick, and the positive and negative ions are difficult to transmit through the sheet. The electrostatic ink-absorption effect is reduced, and it is not easy to transfer the ink on the printing plate to the surface of the substrate;
(2) poor smoothness of paper, uneven fiber arrangement;
(3) There are inks on both sides of the electrostatic roller, so that it does not form insulation and causes current conduction leakage, affecting the adsorption force;
(4) The squeegee pressure is too large;
(5) The ink vaporizes too quickly and the transfer rate decreases;
(6) The printing plate absorbs too little ink in the ink tank.
Solution:
(1) properly reduce the viscosity of the ink;
(2) When paper is purchased, check the quality of the paper;
(3) Electrostatic roller 2mm deep on both sides, the width can be determined according to the long-term printing area to prevent sticking ink;
(4) The squeegee angle of contact is inclined;
(5) Add slow-drying solvent to improve ink transfer performance;
(6) Raise the squeegee holder, shorten the transfer time, and increase the amount of ink stored in the web;
(7) Raise the ink tank so that the printing plate absorbs ink sufficiently. (To be continued)