Circular economy of barrier packaging produced in co-injection molding technology

¹ Doctoral School, Bydgoszcz University of Science and Technology, Kaliskiego 7, 85-796 Bydgoszcz, Poland
² Department of Manufacturing Techniques, Faculty of Mechanical Engineering, Bydgoszcz University of Science and Technology, Kaliskiego 7, 85-796 Bydgoszcz, Poland

^* Corresponding author: piotr.wieczorek@pbs.edu.pl

Abstract

The paper presents the study of mechanical recycling of three-layer PP/EVOH/PP packaging containers made by the co-injection molding process. It is in alignment with European Circular Economy guidelines. The main objective was to evaluate the recyclability of these packages and their reuse as a secondary material. Thin wall packaging by special cutting and grinding methods were disintegrated, and recorded cutting force allowed the determination of energy per single cut. During these processes, delamination between PP and EVOH layers was observed. The recyclate r(PP/EVOH) was used to produce samples in the standard injection molding process. The similar samples were prepared from recycled virgin PP using the same technology. The paper presents the results of the mechanical properties of samples manufactured from recyclate r(PP/EVOH) and compares them with the properties of samples obtained from recycled polypropylene (rPP). It was observed, that the content EVOH in the PP matrix does not significantly affect the mechanical properties of r(PP/EVOH) samples. It was also found that r(PP/EVOH) blends are characterized by favorable apparent viscosity and MFI and can be a valuable raw material for reuse.