The relationship between ink and drying speed in printing

The commonly used auxiliary materials for the modulation of printing inks include: varnish, kerosene, detackifiers, dilutants, and the like. In the printing, the main use of varnish (ie, oil No. 6) to increase the ink flow. However, the thickness (viscosity) of varnish is closely related to the speed of drying. The thicker the varnish, the faster the ink dries under the same conditions. Because the ink drying speed is increased with the increase in the degree of thickening of the ink. According to the principle of dry oil drying, the thickening process of the ink is its drying process, that is, when the varnish (added to the ink) is used for printing, it has completed its drying process. Part of the reaction, and this part of the reaction is carried out at high temperatures. If oil or thin varnish is used to thicken to the same degree at room temperature, the time required will be greatly extended. Therefore, the drying speed of the thin varnish drying film is generally slower than that of the thick varnish.

The thin varnish is plastic, easy to flow and infiltrate. It is coated on paper or glass, has a long time in flowing state, and the drying speed is slow, which is the resistance of film curing. The thick oil is not the same, can be fixed firmly on the surface of the substrate, easier to film curing, so it does faster.

Therefore, in the transfer of ink, it is necessary to clarify the purpose of ink transfer before deciding what type of ink varnish to use.

(Shanxi Provincial Tax Printing Factory Du Yongping)