What are the four key principles for successful TPU film printing?

TPU films are widely used for printing due to their excellent properties — abrasion resistance, flexibility, corrosion resistance, and aging resistance. However, many people face challenges when printing on TPU surfaces. To achieve optimal results, it’s essential to follow these four core principles:

1. Choose the right ink: Use polyurethane-based inks (PU or TPU ink) as they are chemically compatible with TPU materials, ensuring strong adhesion and durability.
2. Perform corona treatment: Treat the TPU film surface with corona discharge to increase its surface energy to above 38 dynes — ideally between 40 and 42 — for better ink adhesion.
3. Apply chemical surface treatment: Wipe or coat the surface with chemical solvents to further enhance printability. The effectiveness ranking of common solvents is: DMF > MEK > Toluene > Ethyl acetate > Thinner > Alcohol.
4. Choose the right surface texture: Matte or frosted TPU films provide better ink adhesion and higher color fastness compared to glossy surfaces due to their larger surface area.

By mastering these four principles, printing on TPU films becomes straightforward and worry-free.