The adhesion of the ink film on the substrate is called the adhesion fastness of the ink. In plasticgravure printing, there are many factors that affect the adhesion fastness of ink on the surface ofthe substrate. Only by comprehensive analysis and evaluation of ink components, solvent properties, and substrate properties can the ink’s adhesion fastness be fundamentally improved.

The test of ink adhesion fastness is generally measured by scotch tape sticking and pulling. If the ink is transferred in a large area or completely after sticking and pulling, it means thatthe ink has poor adhesion on the printing film. Poor ink adhesion will cause a large area or all ofthe ink to transfer when the composite film is unrolled, resulting in low composite strengthand affecting the use of composite packaging bags.

The ratio of true solvent to false solvent in the ink solvent will also affect the ink adhesionfastness. Although the false solvent cannot actually dissolve the resin, its cooperation withthe true solvent can make the polarity of the mixed solvent system adjustable in a wide range,so as to adapt to the polarity of the ink resin itself and achieve the best solvency.

Resin molecules are stretched microscopically in a solvent system with suitable polarity, which isconducive to dispersion and wetting during the grinding process with pigments, and formsa uniform package state. However, if the proportion of the false solvent is out of balance,the stability of the resin system will deteriorate, the microscopic resin molecules will becomecurled, and even multiple resin molecules will be entangled and wrapped by the false solvent,which will not be well formed with the pigment particles during the dispersion process.Very good wetting will affect the uniformity of ink fixation and film formation on the surface of the substrate, and the adhesion will decrease.

It can be seen that in plastic gravure printing inks, there are many factors that affect theadhesion fastness of the ink on the surface of the substrate. Only by comprehensively consideringthe performance indicators of the ink can the ink have a fundamental impact on the adhesionfastness. While improving, it will not affect other properties of the ink.

Sunman Resins can improve quality of your ink. Such as: glossiness, adhesion, fast drying, yellow resistance, leveling, weather resistance and pigment wettability. So if you have any questions, contact us now.