The gravure products did not dry out, but it was caused by these seven reasons.

The gravure printing product does not dry out and is prone to back sticking, which has a great influence on the quality of the printed product. The following summarizes the seven reasons why the gravure products are not dried out, for your reference.

Gravure Since the ink layer is thick, the problem of poor drying is always present. The gravure printing feature is wet and wet. Although there is a long drying tunnel, the ink of the former color group does not dry out when the gravure is superimposed, but a film is formed on the surface of the ink layer to prevent the latter color. The ink of the group re-adheres the ink of the previous color when it is stacked.

Seven reasons why gravure products are not dry

1. The gravure mesh is deep, sometimes the depth reaches 60μm, the amount of ink is large, and drying will be difficult.

2. In order to ensure the transfer of high-gloss small dots, a slow drying agent must be added in the gravure printing process, which also affects the drying effect of the ink.

3. The comprehensive balance of the mixed solvent is not easy to grasp, resulting in a large amount of slow drying agent.

4, some printing process, the last color printed white ink, and then the winding, the distance between the drying and winding station is too short, drying is difficult. Moreover, the white ink base requires the ink to have a good hiding power and can only thicken the ink layer. In general, the amount of ink in the white ink is the largest of all colors.

5. When film printing, the temperature of the drying device should not be too high, and the drying tunnel should not be too long, otherwise the film will undergo tensile deformation, which will affect the overprinting precision and product length. The commonly used method is to use low temperature, high air volume, use the volatilization method in the drying process, and discard the evaporation.

6. The dependence of solvent volatilization on environmental conditions. When the atmospheric pressure is relatively low, it is difficult to effectively control the drying efficiency with a mechanical exhaust device.

7. There is a boundary layer between the ink layer on the surface of the printed matter and the atmosphere (the foreign counterpart is called “Boundarylayer”, and some people translate it as “mirror film”), which is a layer containing hot air and solvent vapor. The mixture has a higher temperature. When the ink is dried, under high temperature, the liquid solvent will evaporate and move to the boundary layer. If there is no solvent in the boundary layer, the solvent vapor can be easily transferred to the atmosphere. However, as the concentration of solvent vapor in the boundary layer increases, the evaporation rate of the solvent will decrease, and as the solvent vapor in the boundary layer tends to be saturated, the evaporation process will stop. The traditional gravure drying process does not pay attention to the existence of the boundary layer, ignoring the role of evaporation in drying. Although the industry has made some improvements to the curve of the gravure drying tunnel, reducing the wind resistance and increasing the air volume, but because of this layer Some non-volatile residual solvent in the ink will still be encapsulated in the presence of a boundary layer that does not follow the air flow.

Napkin Holders

Napkin Holders,Napkin Holder,Utensil Drainer,Metal Napkin Holder,Kitchen Napkin Holder,Paper Napkin Holder

Jiangmen Jianghai Jianshang Houseware Co.,LTD. , https://www.jm-jianshang.com