Permeation of oxygen, water vapor, and limonene through printed and unprinted biaxially oriented polypropylene films

Oriented polypropylene (OPP) and coated OPP (acrylic/OPP/PVDC) films were printed with two commercially available inks to investigate the influence of inks on water vapor and oxygen transmission rates. The permeation of an aroma compound (d-limonene) through coated OPP film printed with these inks was also evaluated at 35 degrees C and 100% relative humidity. The water vapor transmission rate increased significantly through OPP film printed with nitrocellulose-based ink. The oxygen transmission rate was significantly lower through both OPP and coated OPP films printed with the nitrocellulose ink. The effect of inks on limonene permeation was minor compared to the marked increase in permeation measured when the PVDC side of the coated film was exposed to the aroma, compared to the acrylic side. Scanning electron micrographs of coated film cross sections revealed changes in film structure upon exposure to limonene vapors, which were most pronounced when the PVDC side was exposed to limonene.