Many packed foodstuffs must not be allowed to oxidise and the water content must not change if the contents are to remain palatable. The penetration of oxygen and moisture also enable the growth of bacteria and mould, and eventually results in spoilage of the packed product.
By means of plasma polymerisation, plastics packaging that otherwise has only a minor barrier effect can be provided with a coating with superior barrier properties (frequently SiOx). The producer of the plastic cups will generally have the coating process carried out by an external company but does not have any possibility to evaluate its quality. Because of the transparency and low layer thickness of the coats (around 20 nm), the coatings cannot be checked visually.
Through this quick test, an SiOx coating was identified on all the supplied specimens. The adhesion measurements resulted in adequate values for the application.
The barrier improvements attained by the supplier's coatings are almost identical to those that can be obtained with the coatings developed at IKV.