| Abstract [eng] |
Plastic packaging consumption worldwide is continuously increasing, and flexible packaging accounts for a significant share of plastic waste. Due to the growing environmental impact and increasingly strict European Union requirements from 2030, which foresee a transition toward recyclable, reusable, or biodegradable packaging, there is a rising need to seek alternatives to traditional polyolefin-based films. However, the application of biodegradable materials is still limited by insufficiently studied performance properties and unclear competitiveness compared to conventional and recycled plastics. The object of the study is conventional, recycled, and biodegradable polymer films used or potentially usable in flexible food packaging production. The aim of the work is to evaluate the suitability of biodegradable films to replace conventional polyolefin-based flexible plastic packaging by analyzing their physical-mechanical and barrier properties, seal formation, and environmental impact. To achieve this goal, scientific literature and regulatory frameworks were analyzed, experimental testing of physical and mechanical properties of films was conducted, seal strength and packaging integrity were evaluated, and a life cycle assessment (LCA) was performed. Experimental and analytical methods were applied in the study. The mechanical properties of the films were determined according to EN ISO 527-3 and ASTM D882 standards, seal strength was evaluated according to ASTM F88/F88M methodology, and packaging integrity was tested using the ASTM F2338 vacuum decay method. LCA was carried out using the “OpenLCA” software in accordance with ISO 14040 and ISO 14044 standards, applying the ReCiPe Midpoint (H) impact assessment method. The environmental assessment was conducted for three different film groups: conventional polyethylene (LDPE), recycled polyethylene (rLDPE), and polylactide (PLA). For each material, alternative end-of-life scenarios were modeled (incineration, landfill disposal, mechanical recycling, or industrial composting), and the results were analyzed both by comparing different scenarios for the same material and by evaluating comparable waste management options across different materials. The conducted research revealed significant differences between the studied film groups. Conventional polyolefins exhibited the best physical-mechanical properties. The highest tensile strength was recorded for LDPE-120 film, while the highest elongation at break was observed for rLDPE-90 film. Biodegradable films demonstrated lower mechanical resistance, lower elongation at break, and a narrower sealing process window. Seal strength tests showed that the strongest seals were formed by LDPE-based films, whereas biodegradable films produced mechanically the weakest seals. Packaging integrity tests revealed that conventional films generally ensured stable hermeticity, while a portion of biodegradable packages exhibited significant leakage. Life cycle assessment results showed that closed-loop waste management solutions provide the greatest environmental benefits. The best results in the climate change category were observed in the PLA industrial composting scenario, while mechanical recycling of LDPE and rLDPE also generated significant environmental credits. In contrast, incineration and landfill disposal scenarios had the highest negative environmental impacts. It was found that PLA is an environmentally promising alternative from a sustainability perspective; however, its application is currently limited by insufficient mechanical properties and lower reliability of seals and packaging integrity. From a technical perspective, conventional LDPE, LLDPE, and PP films demonstrated the best performance, while from an environmental perspective PLA and recycled LDPE showed the greatest potential. To improve the sustainability of flexible packaging, it is recommended to further develop mono-material polyolefin packaging and the use of recycled feedstocks. In the case of biodegradable materials, it is necessary to further improve their mechanical and sealing properties and ensure efficient operation of composting infrastructure. |
