SiOx layer as functional barrier for PET bottles towards potential contaminants from post-consumer recycled poly(ethylene terephthalate)

Frank Welle (1) , Roland Franz

1 Fraunhofer IVV - Fraunhofer Institute for Process Engineering and Packaging

Within this study the barrier effect of a silicon oxide (SiOx) coating on the inner surface of PET bottles was investigated due to their ability to reduce the migration of post-consumer compounds from the PET bottle wall into the food simulants 3% acetic acid and 10% ethanol. The barrier effect was examined by artificially introduced model substances (surrogates) into the PET bottle wall in a worst case scenario. Test bottles with three different spiking levels up to about 1000 ppm per surrogate were blown and coated on the inner surface. The SiOx coated bottles and the non-coated reference bottles were filled with food simulants. From the specific migration of the surrogates with different bottles wall concentrations the maximum concentrations of the surrogates in the bottle wall corresponding to the migration of 10 µg l﷓1 were determined. The obtained experimental data demonstrate that the SiOx coating layer is an efficient barrier towards post-consumer compounds. The maximum bottle wall concentrations of the surrogates corresponding to the migration of 10 µg l﷓1 are in the range of 200 ppm (toluene) and about 900 ppm (benzophenone). Consequently, the investigated SiOx coating would allow to use conventionally recycled post-consumer PET flakes without a super-clean recycling process for packaging aqueous and low alcoholic foodstuffs under cold-fill conditions and prevent the food from migration of unwanted contaminants from post-consumer PET.

Mots clés: Life Sciences

Frank Welle, Roland Franz. SiOx layer as functional barrier for PET bottles towards potential contaminants from post-consumer recycled poly(ethylene terephthalate). Food Additives and Contaminants, 2008, 25 (06), pp.788-794. ⟨10.1080/02652030701704755⟩. ⟨hal-00577436⟩