The effect of an air-dielectric barrier discharge on the surface properties and peel strength of medical packaging materials

In this paper we report and discuss the effect of air dielectric barrier discharge (DBD) surface treatments on adhesion, using poly(ethylene)/poly(ethylene terephthalate) (PE/PET) film and non-woven PE (Tyvek(R)) medical packaging materials. The modification of the surface properties of the treated samples has been studied using X-ray photoelectron spectroscopy (XPS), contact angle and peel strength measurements. The influence of the surface treatment parameters, such as the energy deposited by the discharge, the inter-electrode gap and the treatment time, when related to the surface characteristics, allowed establishment of the relationship between such parameters and the properties of the DBD treated samples. Of the three process variables investigated the duration of the treatment has a statistically significant effect on the surface modification. It was found that very short air-DBD treatment (fractions of a second) markedly and uniformly modify the surface characteristics for both Tyvek(R) and PE/PET. The treated materials show remarkable stability with ageing time. Improved adhesion properties, with an increase in the peel strength and a greater adhesive transfer are also observed after DBD treatment. Finally, the surface properties investigated tend to reach a plateau following approximately 1 s of processing. (C) 2003 Elsevier B.V. All rights reserved.