How to optimize the surface treatment of pet thermal release film to enhance ink adhesion?
Publish Time: 2024-12-05
In many industrial applications, pet thermal release film often needs to have good ink adhesion to meet the process requirements of printing, marking, etc. Optimizing its surface treatment to enhance ink adhesion is a key task.
First of all, corona treatment is a common and effective surface treatment method. By applying high-frequency and high-voltage corona discharge on the surface of pet thermal release film, the molecular structure of the film surface changes and the surface energy increases. Corona treatment can destroy the inert chemical bonds on the surface of the film and produce more polar groups, such as hydroxyl and carboxyl groups. These polar groups are highly active and can form chemical bonds or hydrogen bonds with resins, pigments and other components in the ink, thereby significantly enhancing the adhesion of the ink on the film surface. In actual operation, it is necessary to accurately control the voltage, frequency, treatment time of corona treatment, and the distance between the electrode and the film surface. For example, appropriately increasing the voltage and extending the treatment time can increase the increase in surface energy, but too high a voltage or too long a time may have adverse effects on other properties of the film, such as increasing the surface roughness of the film or decreasing the mechanical strength, so optimization tests are needed to determine the best parameter combination.
Secondly, plasma treatment is also a surface treatment technology with great potential. Plasma is composed of ions, electrons, free radicals and neutral particles, and has extremely high energy. When the pet thermal release film is exposed to a plasma environment, the active particles in the plasma react physically and chemically with the film surface. The physical effect includes etching, which can make the film surface rough and increase the contact area between the ink and the film; the chemical reaction is similar to corona treatment, introducing polar groups. Plasma treatment has the advantages of good treatment uniformity and little damage to the film. It can be carried out at a lower temperature and is suitable for temperature-sensitive pet thermal release films. Different plasma gases, such as oxygen, nitrogen, argon, etc., will have different effects on the treatment effect. For example, oxygen plasma treatment can introduce more oxygen-containing polar groups, which is conducive to ink adhesion, while nitrogen plasma treatment may form nitrogen-containing functional groups on the film surface, which has a better effect on the adhesion of certain special inks.
In addition, coating the surface with a special primer or adhesion promoter is also a feasible method. These primers or promoters usually contain active functional groups that can form good chemical bonds with the pet thermal release film surface and ink. When coating, make sure that the primer or accelerator is evenly covered on the film surface and control the coating thickness. Too thick a coating may affect the release performance of the release film, while too thin a coating may not fully enhance the ink adhesion. By optimizing the formula of the primer or accelerator and finely controlling the coating process, the ink adhesion of the pet thermal release film can be effectively improved to meet the diverse industrial production needs.
