A frozen dumpling factory once shared a common frustration: “The production date looks fine when it leaves the packaging line, but after a few hours in the freezer, the code becomes blurry or completely disappears.” If you work in frozen food production, this situation may sound very familiar.
The main reason is condensation. Frozen food packages often move between environments with different temperatures—warm packaging rooms, cold storage areas, and freezer warehouses. When a cold package meets warmer air, moisture forms on the surface of the packaging film. For traditional inkjet printing, this thin layer of water can prevent the ink from bonding properly to the plastic film.
Another factor is the type of packaging material used in frozen food. Many frozen products use smooth plastic films such as PE, PET, or laminated materials to protect food quality. These surfaces are non-porous, which makes it harder for liquid ink to dry quickly. When the package is stacked, transported, or rubbed against other packages, the ink can easily smear or fade.
Operators in many factories notice the problem only after products have already reached cold storage. At that point, some date codes become unreadable, which can create compliance risks and extra rework.
To avoid these issues, many frozen food manufacturers are moving toward thermal transfer overprinting (TTO). Instead of spraying liquid ink, TTO uses heat to transfer solid ink from a ribbon onto the packaging film. The printed code becomes more resistant to moisture, friction, and low temperatures—helping ensure that production dates and batch numbers remain clear even after long periods in cold storage.
For frozen food packaging lines, reliable coding is not just about printing—it’s about making sure the information stays readable from the factory to the consumer’s freezer.
