Permeation of Methylethylketone, Oxygen and Water Vapor through PET Films Coated with SiOx: Effect of Temperature and Coating Speed

Abstract

The permeation parameters of commercial poly(ethylene terephthalate) (PET) films, PET films coated with SiOx and SiOx-coated PET films laminated onto low density polyethylene (LDPE) film were determined for methylethylketone (MEK) at 25°C, 35°C and 45°C using the permeation cell/gas chromatography method. Permeation of O2 and water vapor were also determined to monitor overall changes in the barrier properties of the experimental films. Results showed that the SiOx coating increased the film barrier to MEK by 7-8 times at 25°C. The barrier to oxygen and water vapor increased by 40 and 7-8 times respectively after coating at the same temperature. Increase in temperature by 10°C resulted in a ten fold increase in permeation rate of MEK and a two fold increase in oxygen and water vapor permeation rate. Permeation values showed slight variation indicating the need for further development and standardization of the SiOx web coating process. The web coating speed did not seem to influence the barrier properties of the films. Permeation coefficient, diffusion coefficient, solubility coefficient and activation energy values for permeation were calculated for all samples.