Application of stacked discharge setups at atmospheric pressure for packaging sterilisation

Summary form only given, as follows. Environmental and economical needs for food or health care packaging require the development of new efficient low-temperature sterilisation techniques. We investigate the application of non-thermal, atmospheric pressure plasmas for sterilisation of thermolabile plastic packaging materials like polyethylene terephthalate (PET). The investigation resulted in UV radiation as one main inactivation pathway but also plasmachemical effects occur. In order to enhance the UV irradiance on the sample a new stacked setup combining planar UV emission (e.g. from excimer light sources) with dielectric barrier discharge (DBD) plasma has been built. Experimental results that show a significant increase of sterilisation efficiency for spores of bacillus subtilis compared with standard DBD setups are presented. Almost sterile packaging can be reached now within a few seconds with the described setup.