Common quality anomalies and countermeasures in gravure printing: Unpleasant Odor (Solvent Residue)
In the drying machine, most of the organic solvents in the ink dry rapidly, but trace amounts of residual solvents may solidify and remain in the original film. The concentration of residual organic solvents in the printed matter directly determines the magnitude of the final product's odor. The abnormality can be determined by smelling with the nose. However, relying on the sense of smell is considered outdated with the progress of scientific technology. For items requiring low solvent residue, professional instruments can be used for measurement.
Causes of Anomalies:
Printing speed too fast.
Inherent properties of resins, additives, and adhesives in the ink.
Too low drying efficiency or insufficient drying methods.
Duct blockage.
Countermeasures:
Moderately reduce the printing speed.
Consult with the ink manufacturer to understand the situation of ink residual solvents and take preventive measures. The use of fast-drying solvents only accelerates solvent evaporation and has little effect on reducing solvent residue.
Use fast-drying solvents or low-temperature drying. Rapid drying may cause the ink surface to skin, affecting the evaporation of internal solvents. Slow drying is effective in reducing solvent residue.
Regularly clean the duct to ensure smooth exhaust.