Is the adhesion of water-based ink printed PET insufficient?
Date: Jul 31 2024 From: Star Color
When
water-based ink is used to print PET film, if there is insufficient adhesion, it may be caused by various factors. The following is a detailed analysis of possible causes and corresponding solutions:
Cause analysisInsufficient surface tension of PET film:
The surface tension of PET film needs to reach a certain level in order for water-based ink to adhere well. If the surface tension is too low, the adhesion of the ink will be affected.
Poor adaptability between ink and PET film:
The formula, viscosity, and other characteristics of ink may not match the surface properties of PET film, resulting in poor adhesion.
Printing process issues:
During the printing process, if the scraper is damaged, the installation angle is improper, or the printing speed, pressure, and other parameter settings are not reasonable, it may affect the adhesion effect of the ink.
Insufficient ink drying:
If the ink is not completely dried on PET film, it will also affect its adhesion.
Impurities or precipitates in ink:
If there are impurities or precipitates in the ink, it may affect its uniformity and adhesion.
Surface contamination of printing materials:
If there are pollutants such as oil stains and dust on the surface of PET film, it can also affect the adhesion of ink.
solutionImprove the surface tension of PET film:
Perform corona treatment: Treat the surface of PET film with a corona processor to increase its surface tension and achieve the level required for water-based ink adhesion. Usually, the surface energy after corona treatment should reach 38 dynes or more.
Primer coating: Apply a layer of high adhesion primer on the surface of PET film as a transition layer between ink and PET film to enhance adhesion.
Choose the appropriate ink:
Ensure that the formula and viscosity of the ink match the surface characteristics of the PET film. Consider using water-based ink specifically designed for PET film.
Check whether the ink is expired or ineffective, and avoid using unqualified ink.
Optimize printing process:
Check and replace the damaged scraper, adjust the installation angle of the scraper to ensure even ink scraping.
Adjust parameters such as printing speed, pressure, and temperature to achieve the best printing effect.
Ensure the normal operation of printing equipment and avoid any malfunctions that may affect printing quality.
Ensure that the ink is fully dried:
Improve the temperature and humidity control of the printing environment to accelerate the drying speed of ink.
If necessary, increase the drying equipment or adjust its power to ensure that the ink is completely dried on the PET film.
Remove impurities and sediment from ink:
Before using water-based ink, stir evenly and filter out excess impurities and sediment.
If the viscosity of the ink is too high, water and ethanol can be added in moderation to reduce the viscosity, but attention should be paid to the proportion and stirring uniformity.
Clean the surface of the printing material:
Thoroughly clean the surface of PET film before printing to remove contaminants such as oil and dust.
Ensure that the surface of the printing material is clean, dry, and free of defects such as scratches.
Huizhou Starcolor specializes in producing water-based ink for PET plastic film, and is willing to help you solve printing difficulties. Welcome to consult: eva@starcolor-ink.com
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