Printed Codes Keep Fading
Hi :-), our company plans to upgrade to Vertical form fill seal packing machine that is connected to an inkjet printer. We are now testing the print quality especially during freezing and storing stage. Our product is a marinated uncooked chicken cuts that we blast freeze after packing in LDPE bags. The problem is, the label printed on the packaging is easily erased after freezing. Has anyone experienced the same? What can we do to make sure the label stays on the packaging? Appreciate any suggestions to help us out. Thanks.
Have you contacted the printer manufacturer?
Maybe this explanation will help;
Surface Tension of the SubstrateThe same way an insect like the water strider can stand on water’s surface without falling in, surface tension plays a role in whether the ink will properly adhere to the plastic or just wipe away when touched.
To ensure ink adhesion to the plastic surface, it’s recommended that the surface tension of the ink should be at least 10 dynes lower than the surface free energy of the plastic sheet. This is because liquids don’t dampen planes with surface free energy lower than the surface tension of the liquid. Translation: if you’ve got a bad surface tension/surface free energy match up, the ink will sit atop the plastic, barely contacting the plastic itself. If you have a good ink/surface match, the ink will lay flatter against the plastic, allowing it to “wet” or “dampen” the plastic surface (and that’s what you want). According to Printing.org, for ideal inkjet printing you should select plastic sheets with free surface energies between 40-50 dynes. Always keep in mind, however, that this number varies for different printers and printing techniques.
Need to match the type of ink used to the material it is going on, the smoother the surface the more likely the issue. You may want to interface with the manufactuer of the inkjet to get their input based on the type, smoothness, thickness, etc. of the packaging itself.