Tests on polypropylene rigid packaging with an EVOH barrier suggest that the material is compatible with modern recycling processes, said RecyClass (www.recyclass.eu
), a cross-industry initiative developed by Plastics Recyclers Europe (PRE, Brussels / Belgium; www.plasticsrecyclers.eu
RecyClass commissioned independent laboratory Institut für Kunststofftechnologie und -recycling (IKTR, Weißandt-Gölzau / Germany; www.iktr-online.de
) to conduct the analysis in accordance with its Recyclability evaluation protocol for PP containers (see Plasteurope.com of 24.06.2020
). Testing was performed on a PP bottle consisting of 6% EVOH with 3% of PP-grafted maleic anhydride tie layers (by weight), as well as on PP sheet with the same levels of EVOH and PP-grafted maleic anhydride.
The results show that concentrations of up to 6% of EVOH (with respect to overall packaging weight) tied with PP grafted maleic anhydride will not have a negative impact on the PP rigids and, therefore, is fully compatible with the respective stream, RecyClass said. Additionally, the same structure with concentrations higher than 6% of EVOH were found to have limited recycling compatibility. Both conclusions are applicable to all types of PP rigid packaging, including tubes, pots and trays, and the recycled material coming from this packaging can be used in high-end applications including bottles and sheets, it added.
RecyClass recommends to compatibilise the EVOH-barrier layer with a minimal amount of tie layer, following a ratio below two of EVOH versus tie layer. It said the findings are in line with the previous testing done on EVOH in HDPE containers (see Plasteurope.com of 14.11.2019
). Similar test done on LDPE film using PP components, however, showed an adverse effect on the recycled material (see Plasteurope.com of 24.06.2021