Multifunctional laminated polyethylene films with calcium carbonate and essential oil additives for food packaging applications

Multifunctional polymer film development has attracted increasing interest for food packaging applications by integrating barrier, mechanical, and antimicrobial functions into a single structure. This study developed multilayer polyethylene films by combining a calcium carbonate-filled polyethylene film and a polyethylene film containing a blend of clove and rosemary essential oils, using a polyurethane adhesive layer to assemble the multilayer structure. Two calcium carbonate sources, commercial calcium carbonate and eggshell-derived calcium carbonate, were evaluated. The polyethylene films, based on a blend of high-density polyethylene and low-density polyethylene, were produced by twin-screw extrusion followed by blown film extrusion, while the essential oils (2.0 wt%) were incorporated during a subsequent single-screw extrusion step. The films were characterized in terms of morphology, chemical structure, surface properties, thermal behavior, mechanical performance, oxygen permeability, and antimicrobial activity. The multilayer structure exhibited good interfacial integrity while maintaining the thermal stability of the polyethylene matrix. Compared with neat polyethylene, films containing 0.5 wt% commercial calcium carbonate showed a 27% increase in tensile strength and a 23% increase in Young’s modulus, whereas films containing 0.5 wt% eggshell-derived calcium carbonate exhibited a 26% reduction in oxygen permeability.These improvements were further correlated with changes in crystallinity, as revealed by differential scanning calorimetry analysis. The essential oil blend imparted antimicrobial activity, achieving a 96.85% reduction against Salmonella enterica serovar Typhimurium . These results demonstrate the potential of the proposed multilayer polyethylene system for active food packaging applications.