The coming of summer also means the arrival of high temperature and high humidity environment, which has a more obvious impact on plastic packaging printing enterprises. High temperature will promote the organic solvent in the ink to accelerate volatilization, and high humidity will change the ink viscosity, thus affecting the printing quality. So how can you avoid it? Let's see how professional manufacturers do it.
Rubber roll
In the process of flexible packaging production, equipment, film blowing (salivation) printing, composite, bag making and other processes, the most obvious change is the rubber roller: the soft rubber roller in the summer is particularly hard in the winter.
In order to cope with the changes brought about by temperature, Giant packaging timely adjustment of production methods. In summer, when the rubber roller is soft, the elasticity is better, and the pressure in production can also be slightly reduced, and the glue and ink transfer rate will increase. On the contrary, in the winter when the rubber roller is particularly hard, our pressure should be appropriately increased a little, serious need to consider whether the rubber roller will slip, while the transfer rate of glue and ink will be reduced, these microscopic changes we need to deal with and solve in advance in process design and actual production.
Materials
The materials we use, such as film, glue, ink and solvent, are basically chemical substances, and in general, the surface activity of the material has a positive correlation with temperature: The higher the temperature, the better the activity of the material, the better the activity of the material, the higher the affinity, the better the surface activity of the material, the higher the temperature is higher than the glue and ink, the better the infiltration of the material, and at the same time, the affinity of the material for glue and ink also increases. Therefore, the performance of the composite process is particularly obvious, the same material, machine speed, the probability of fast foaming in the summer is very low.
The change in weather temperature will cause the temperature of glue and ink itself to change, that is, the viscosity of the same glue and ink will change because of the change in temperature, so giant packaging in the summer production process, not only pay attention to the change in the viscosity of glue and ink, but also pay attention to the impact of temperature. In order to ensure quality, Giant packaging will use a viscosity controller, and the change of viscosity is strictly controlled in accordance with SOP.
The high temperature of the glue ink itself is very volatile solvent, so our temperature has a great impact on the volatilization efficiency of the solvent, producing dry plates in summer, producing dry in winter, in addition to the activity changes of the material, and the heat required for solvent volatilization is also closely related.
Solvent residue
Practice has shown that when the ambient humidity increases, the ink drying speed will slow down. Under normal circumstances, if the ambient temperature is 20 ° C, when the humidity rises from 65% to 75%, the drying speed of the ink before and after can be 1 to 2 times. The solvent of the glue ink itself is very volatile at high temperature.
In addition, most flexible packaging companies in the summer gravure production will use a large number of slow drying solvents, such as benzene-free ketone inks in the proportion of slow drying solvent butyl ester.
Especially for the low-speed gravure printing machine, to ensure the printing effect of the printed product, especially in the shallow network area, a large amount of butyl ester must be added, but the drying efficiency of the low-speed gravure printing machine is low, which will lead to excessive solvent residues.
For the high-speed gravure printing machine, because the machine speed is faster, there is no need to add too much slow drying solvent to adjust the ink drying speed, at this time the ink viscosity is low, the ink layer is thin after transfer, we cooperate with the larger air volume and the appropriate drying temperature to achieve a good drying effect.
In view of the phenomenon of excessive solvent residues in printed products that may be caused by high temperature and high humidity environment, Giant packaging uses gas chromatograph to do real-time monitoring work in order to prevent problems before they occur.
