Will water-based ink print BOPP film fade?
Date: Aug 21 2024 From: Star Color
Recently, someone asked if printing BOPP film with water-based ink would cause color fading, so I am writing this article to explain.
1、 Compatibility between water-based ink and BOPP film
Water based ink is widely used in the field of plastic film printing due to its environmentally friendly, non-toxic, non flammable, and non explosive properties. BOPP film, as a biaxially oriented polypropylene film, has a smooth and flat surface, making it suitable for high-quality printing. However, due to the poor absorption of ink by thin film materials, the adhesion strength of ink on the film becomes a key factor affecting the quality of printed materials.
2、 Analysis of color fading reasons
Ink formula: The formula of water-based ink directly affects its adhesion effect on BOPP film. If the resin, pigment and other components in the ink have poor compatibility with BOPP film, it may lead to poor adhesion of the ink.
Surface energy of BOPP film: The surface tension of BOPP film is relatively low. If it does not meet the minimum surface energy requirement for water-based ink adhesion (usually above 38 dynes, preferably above 42 dynes), the ink will be difficult to firmly adhere to the surface of the film.
Printing process: Parameters such as pressure, speed, and temperature during the printing process can also affect the adhesion effect of ink. If the printing process is improper, it may lead to poor ink adhesion or insufficient drying.
Ink drying problem: The drying speed of water-based ink is relatively fast, but if the drying is not sufficient or the curing is not thorough, the ink layer is prone to peeling off when subjected to external forces, leading to color fading.
Batch differences in materials: BOPP films from different batches may have performance differences in surface energy, thickness, smoothness, etc., which may result in different adhesion effects of ink on different batches of films. If the surface energy of a certain batch of film is low or there are other factors that are not conducive to ink adhesion, it may cause the printed matter to fade.
3、 Solution measures
Improve the surface energy of the film: Perform corona treatment on BOPP film before printing to increase its surface tension. This can increase the contact area and interaction force between the ink and the film, thereby improving the adhesion strength of the ink.
Optimize ink formula: Choose a water-based ink formula that is compatible with BOPP film. Zhongzhixing has water-based ink specifically designed for BOPP, ensuring full adhesion.
Improve printing process: Adjust printing pressure, speed, temperature and other parameters to ensure that ink can adhere evenly and fully to the surface of the film. Meanwhile, pay attention to controlling the humidity and temperature of the printing environment to avoid adverse effects on ink drying.
Strengthen drying and curing: Ensure that water-based ink is fully dried and cured during the printing process. This can be achieved by increasing the number of drying equipment, raising the drying temperature, or extending the drying time.
Material selection and testing: When choosing BOPP film, pay attention to selecting products with high surface energy and stable quality. At the same time, surface energy testing should be conducted on the film before printing to ensure that it meets the requirements for ink adhesion.
In summary, water-based ink printing BOPP film is not prone to color fading under normal circumstances, but it may also be affected by factors such as weak ink adhesion, low film surface energy, and insufficient ink drying, resulting in color fading. Therefore, corresponding measures need to be taken during the printing process to ensure the quality of printed materials.
As a professional manufacturer of water-based ink, Huizhou Zhongzhixing pays special attention to the performance and environmental characteristics of ink in its product design and research and development process. For BOPP (biaxially oriented polypropylene) film, due to its smooth surface and strong hydrophobicity, the ink requirements are very high during the printing process, especially the need for good adhesion to ensure that the printed pattern will not easily fall off.
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