Gravure product quality control

"I. The main factors affecting the quality of gravure printing products
1, ink performance changes on the ink requirements:

1 ink should have appropriate thixotropy and good fluidity; 2 should have good drying ability and adhesion; 3 must have sufficient cohesion to prevent centrifugal force imbalance at the high-speed operation of the copper plate; 5 must have suitable re-solubility, Due to the inability to completely transfer the ink in the dots to the material during printing, some parts remain in the dots. If there is no proper re-solubility, it can cause blocking.

2, changes in tension:

1If the tension is too small, the film will loosen, affecting the accuracy of overprinting; 2 If the tension is too large, the film will wrinkle, stretch and deform, adhesion, etc.; 3 thick film tension is larger than the thin film.

Second, the factors that affect the drying speed of gravure ink
1, the influence of the solvent;

(1) The role of solvent; 1 Dilution ink; 2 Dissolve and evenly ink; 3 Drive ink,
Determine the viscosity of the ink; 5 Improve the ink printability, such as anti-static and so on.

(2) The volatilization rate of the solvent should be measured by the boiling point. The lower the boiling point, the faster the volatilization rate. Conversely, the higher the boiling point, the slower the evaporation rate.

2, the impact of drying device:

Usually, OPP begins to soften at 88°C. Therefore, the oven temperature should not exceed 85°C. Generally, the oven temperature can completely dry the ink (45 to 60°C).
If the temperature is too high, the residual heat remaining in the film after printing will cause anti-adhesion, especially gold.

3. The influence of the printing plate level:

(l) The outlet is too deep: it is mainly caused by the deep etching of the printing plate. Measure; Add dilute agent, reduce ink color concentration, increase the scraping angle. Increase the pressure of the squeegee, thick ink layer,
It is difficult to dry the ink and remake the plate.

(2) The outlet is too shallow: the corrosion is too shallow. Remedy: Use dark ink to reduce the pressure of the squeegee. Reduce the squeegee's squeegee angle.

4. Influence of ambient temperature: The higher the temperature, the faster the drying.

Third, the technical measures for printing gravure printing products
1. The control of ink volume: The size of the ink volume should be determined according to the depth of the printing plate network. The deep ink used in the network line is large, and the network line has less ink.

2, color printing.

3, "sticky bottom." After printing, the ink layer of the printed product adheres to other contact surfaces, making it impossible to unwind.

(1) The remaining (residual) solvent is not completely volatilized, and the resulting ink softens anti-sticking. Solution: Store the product in a cool place and reduce the printing speed.

(2) The printing temperature is too high or the humidity is too high. Solution: Reduce the ambient temperature as much as possible and keep it dry.

(3) The winding tension is too large, or the ink area is too thick at the same position. Increased local tension.

(4) The printing area is too thick. Solution: The depth control of the network is 25~28μm.
Too deep will be sticky, and printing is difficult to control.