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 p rinted with two commercially available inks to investigate the influence of inks on water vapor and oxygen transmission rates. The permeation of an ar oma compound (d-limonene) through coated OPP film printed with these inks w as also evaluated at 35 degreesC and 100% relative humidity. The water vapo r transmission rate increased significantly through OPP him printed with ni trocellulose-based ink. The oxygen transmission rate was significantly lowe r through both OPP and coated OPP films printed with the nitrocellulose ink . The effect of inks on limonene permeation was minor compared to the marke d increase in permeation measured when the PVDC side of the coated film was exposed to the aroma, compared to the acrylic side. Scanning electron micr ographs of coated film cross sections revealed changes in film structure up on exposure to limonene vapors, which were most pronounced when the PVDC si de was exposed to limonene.