Non-Destructive Recovery of Fibers from Natural Fiber-Reinforced Composites by Enzymatic Hydrolysis to Packaging Value Chain

High Resolution Image Download MS PowerPoint Slide Natural fiber-reinforced composites are widely employed on an industrial scale, especially in the field of automotive sector; however, managing post-use composites in line with circular economy principles remains a significant concern. This work intends to provide a demand-driven circular economy (CE) solution that allows for the effective reuse of post-use composite materials and end-of-life (EoL) components by converting them into new high-value goods. The shredded wood and polyethylene terephthalate (PET) fibers from natural fiber composites (NFC) from the automotive industry were washed with surfactants and then hydrolyzed using enzymes. The reaction was monitored by Fourier transform infrared (FTIR) spectroscopy, optical microscopy, scanning electron microscopy (SEM), high-performance liquid chromatography (HPLC), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). These characterizations confirm the degradation of PET into bis(2-hydroxyethyl) terephthalate (BHET), mono(2-hydroxyethyl) terephthalate (MHET), ethylene glycol (EG), and a high yield of terephthalic acid (TPA). HPLC study confirmed the progressive enzymatic depolymerization of PET into its characteristic hydrolysis products, including BHET, MHET, ethylene glycol (EG), and terephthalic acid (TPA), with the highest conversion rates observed during the early reaction phase. Then, the recovered fibers are washed and converted into pulp for reuse. This study involves optimizing various ratios of recovered fibers mixed with waste cardboard fibers and transforming these blended fibers into molded components for use in the packaging sector.