Characterisation of Eco-Innovative Polymer Composites Obtained by Processing Hard-to-Recycle Plastic Waste: Extrusion Parameters, Chemical Composition, and Mechanical Performance.

problem statementContaminated mixed plastic waste-bearing metallic, paper, cardboard and organic residues-remains largely excluded from mechanical recycling because conventional routes require a costly, water- and energy-intensive washing-drying pretreatment. Research gap: No published study combines a fully dry, washing-free valorisation route for such waste with certified mechanical characterisation and a quantified CO METHODOLOGY: This study presents DMP (Downcycled Mixed Plastic), a patented (OSIM, Romania) dry valorisation process based on continuous single-screw extrusion (D = 150 mm, L/D = 17.3), characterised through differential scanning calorimetry (DSC), certified mechanical/thermal testing at accredited Romanian laboratories, Weber-number dispersion analysis, and a process-parameter sensitivity study. KEY

findingsThe composite exhibits certified mechanical properties (tensile strength 9.22 MPa, elongation at break 112.8%, compressive strength 14.5 MPa); composition-property analysis across four batches shows that increasing the PP weight fraction from 20 to 28 wt% raises tensile strength by 8.3% while reducing elongation by 5.2%; a computed Weber number (We = 166.7 ≫ We_crit) is consistent with fine PP-phase dispersion within the PE matrix; the sensitivity study confirms statistically robust structure-property relationships (R SIGNIFICANCE: dry, washing-free processing is a technically promising pathway for valorising plastic waste streams currently considered non-recyclable, potentially reducing production cost by 60-70% relative to wet recycling, pending additional characterisation identified as priorities for future work.