DBD Non-Thermal Plasma Used on Surface Treatment of Polymeric Film for Food Packaging

The benefits of polymeric food packaging are widely recognized, but improper sterilization and disinfection of the inner surface of the polymer in contact with food can pose a major risk to food safety. On the other hand, the next generation of food packaging should be suitable for the incorporation of electronic labels and smart labels, in order to improve food traceability. The non-thermal plasma (NTP) has emerged as a technology capable of increasing the surface energy of polymers, improving adhesion and printability and has been successfully applied for surface decontamination of both food products and food packaging. This work was performed using a barrier discharge (DBD) reactor in air at atmospheric pressure to treat polyethylene terephthalate, biaxially oriented polypropylene and low-density polyethylene flat substrates for 0.3 s, 0.6 s, 1 s and 3 s. Two methods were used to obtain information on the surface of the samples used, namely by measurement of water contact angle with a goniometer by the sessile method and by determining the surface tension with Arcotest (commercial test using set of fluids with defined surface tension). The DBD treatment effect is highlighted through smaller values of water contact angles and better surface tension.