Influence of structural feature of aluminum coatings on mechanical and water barrier properties of metallized PET films

Abstract This article focuses on description and evaluation of multilayer films, which are used for vacuum insulation panels (VIP). The materials investigated include a neat polyethylene terephthalate (PET) and PET films coated by chemical vapor deposition with different aluminum thicknesses. The aim of these investigations was to evaluate the influence of structural features on the physical properties of Al/PET systems. The morphological analyzes associated to water vapor permeability measurements showed that the metallized surface exhibited defects through which a small amount of water vapor can permeate. It is shown that the permeance varies linearly with the surface fraction occupied by pinholes which in turn changes linearly with the aluminum thickness. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010