The factors affecting the quality of film printing include film materials, ink, equipment, process technology, etc. At the same time, a good print process is also related to the use of solvent, ambient temperature and humidity, temperature and intensity of hot air .

Humidity & Temperature Control

When the ambient humidity is too high, nylon film is easy to distort due to moisture absorption, resulting in color mismatch, flappy, poor ink adhesion and other problems, so it is best to be curing for 2-3 hours before printing, or the first color group cannot be printed on the plate roller after being put on the machine. For pre-drying, it is recommended to set the temperature between 40-45 ℃.

Wetting Tension Inspection of Film before Printing

In order to ensure the adhesion strength of the ink, it is best to test whether the wetting tension value of film surface can meet the requirements before printing.

The Choice of Printing Ink

Special polyurethane resin ink shall be selected for nylon film printing. When using polyurethane resin ink, alcohol dilution solvent shall be added less or no. Because the polyurethane resin itself is terminated by – OH that can react with isocyanate -NCO in the curing agent of polyurethane adhesive, reducing the amount of reaction between the curing agent and the main agent of adhesive, and affecting the subsequent lamination strength.

Others

In order to make sure product quality, the printed film should meet some specific quality standards as following, the printing surface should be clean without dirt, silk and lines. The printing ink color is uniform and the hue is correct. The printing content shall be clear and not deformed with good printing fastness and accurate registration (meeting a certain range of deviation). Meanwhile it should meet the requirements of corresponding laws and regulations.