Use of orange juice processing waste to produce films using blown film extrusion for food packaging

Orange peel (OP) is a by-product from citrus juicing that is wasted. Conversion of this waste into plastic filler can help reduce environmental problems. OP has been incorporated into plastics to form biocomposites using compression molding, injection molding, and casting. However, blown film extrusion, the most common manufacturing process for plastic films has not been investigated yet. The aims of this study were: (1) to produce linear low density polyethylene (LLDPE)/OP films using blown film extrusion, (2) to determine the maximum OP amount that can be used to replace plastic through blown film production, and (3) to assess the effect of OP amount on film morphology and properties. LLDPE/OP masterbatch pellets were produced and combined with neat LLDPE using specific processing parameters determined to produce blown LLDPE/OP composite films differing in OP content (5, 10, 11.5, and 12.5%). The morphology, thickness, and mechanical, barrier, optical and thermal properties of the blown composite films and neat films were compared. The results show that LLDPE/OP films containing up to 11.5% OP can be produced through blown film extrusion. These films have similar (p > 0.05) water barrier, crystallinity, and melting temperature, but lower tensile strength and elongation at break than neat LLDPE films. OP loading enhanced the UV and visible light blocking capacity of the films. This study revealed that blown LLDPE/OP films are suitable for food packaging.