Exhaust system if not smooth, the solvent can not be removed in a timely manner. An excessively high concentration of solvent in the oven will hinder further volatilization of the solvent and affect the drying effect of the print.
2. The effect of ink on drying
(1) The drying effect of aqueous ink is closely related to the pH of the ink. Under the same conditions, when the pH is too low, the drying speed of the ink is accelerated; when the pH is too high, the ink drying speed is slow, and the back of the printed product is likely to appear dirty.
(2) The volatilization rate of the mixed solvent in the solvent type ink directly determines the drying performance of the ink, and the different components in the mixed solvent have different volatilization rates. By mixing different types and different proportions of solvents, the solvent evaporation rate of the ink can be conveniently adjusted, thereby improving the drying performance.
3. Effect of printing speed on drying
Different printing speeds have different requirements on the performance of the drying system. In the case where the speed requirement is relatively high, the heating distance and drying efficiency of the drying oven have relatively high requirements. If the supporting drying system can not fully evaporate the solvent, it is very easy to cause the residual solvent to exceed the standard.
4. Effect of printing plate on drying
For gravure, the depth of the printing plate has a great influence on the drying speed. For example, the depth is 33μm and the 18μm mesh. In the former printing, the drying time of the ink is more than twice that of the latter.
5. Influence of environmental conditions
Generally printed in a temperature environment below 20°C, the natural drying of the ink is weakened. Printing in an environment above 30°C tends to accelerate the natural drying of the ink.
The effect of high air humidity on the drying: First, the moisture in the air enters the ink, resulting in the deterioration of the comprehensive volatility of the solvent; second, the presence of large amounts of moisture in the air will inhibit the volatilization of the solvent.