With the continuous development of China's economy, consumers have increasingly high requirements for product packaging, and more and more thin film materials are used for self-adhesive label printing. At the same time, with the annual increase in the use of thin-film materials, the production batch of self-adhesive labels has gradually increased. Traditional relief printing has gradually been eliminated due to low production efficiency, and more and more enterprises are using flexographic printing for production. Due to the higher requirements for printing of thin film materials compared to paper materials, many problems often arise in the actual production process. In this article, the author will share with readers some common problems and solutions in the process of flexographic printing of thin film materials for reference. PART 01

Poor adhesion of ink

Due to the fact that thin film materials are not as absorbent as paper materials for ink, printing thin film materials often encounter phenomena such as weak ink adhesion and ink loss. The current standard in the industry is the tape test method, which uses 3M810 tape or 3M610 tape to adhere to the surface of the printed matter. After 30 seconds, remove the tape. If there is no ink or sporadic ink loss, the printed matter is basically qualified, while if a large area of deinking is unacceptable. There are three common reasons for ink loss in the printing of thin film materials.



01 Low material surface energy

There are many thin film materials with relatively low surface energy. Generally speaking, the surface energy of thin film materials must reach at least 38 dB before printing can be carried out. Is it possible to achieve 38 dB without ink loss? In my experience: No. Generally, only when the surface of a thin film material can reach more than 42 dB can the ink adhere firmly to the material surface, greatly reducing the risk of ink loss. However, thin film materials with a surface between 38 and 42 dB can be printed normally, but it cannot be guaranteed that the ink adheres firmly to the material surface. Therefore, the best method is to perform online corona treatment on thin film materials during printing. Generally, the surface energy of thin film materials subjected to online corona treatment can reach 42 dB or more.