How does Standard Washing use different solvents to clean flexographic labels?
Publish Time: 2024-11-05
In the Standard Washing process of flexographic labels, different solvents play a key role and achieve cleaning effects through multiple mechanisms.
First, for some organic solvents, such as ethanol, acetone, etc. They have good solubility and can dissolve the ink components on flexographic labels. These solvent molecules can penetrate between the ink and the label surface, destroying the viscosity and adhesion of the ink. Take ethanol as an example, it can interact with the resin, pigment and other components in the ink. For water-based inks, ethanol can react with the water-soluble resins therein to dissolve the ink from the label surface. Acetone has a strong solubility for some polymer inks. It can quickly decompose the polymer structure of the ink, turning the ink into small particles or dissolving it in the solvent, making it easier to remove.
Secondly, surfactant solvents also play an important role in cleaning. Surfactant molecules have hydrophilic and hydrophobic groups. During the washing process, the hydrophobic group combines with the oily components in the ink, and the hydrophilic group faces the aqueous solution. When stirred or rinsed in the washing liquid, the surfactant will wrap the ink to form an emulsion, allowing the ink to be stably dispersed in the solvent without reattaching to the label. This emulsification effect is very effective for removing oil stains on labels and some complex inks.
In addition, the use of some composite solvents can combine the advantages of multiple solvents. For example, mixing organic solvents and surfactant solutions can act on different components in the ink at the same time. Organic solvents first dissolve insoluble components such as resins in the ink, while surfactants deal with grease and other impurities in the ink. The two work together to clean flexographic printed labels more thoroughly, meet the requirements of Standard Washing, and ensure that the labels reach the ideal clean state during subsequent processing or reuse. At the same time, when selecting and using solvents, it is also necessary to consider the impact on the label material itself to avoid damaging the label.
