Development of a sustainable bayonet sheath from recycled plastic bottle filament

This study explores the feasibility of converting post-consumer polyethylene terephthalate (PET) beverage bottles into functional filament for additive manufacturing, with a specific focus on producing bayonet sheaths for Indonesian military applications. The primary objective is to determine whether recycled PET can serve as a viable alternative to conventional filaments in terms of mechanical performance and practical applicability. The research employed an experimental approach, processing PET waste into filament via the Fused Filament Fabrication (FFF) method. The material was evaluated for tensile and flexural properties in accordance with ASTM D638 and ASTM D790 standards. Two commercially available filaments, polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS), were used as benchmarks for comparison. PET specimens underwent controlled tensile and bending tests to assess strength, elongation, and deformation behavior. Results showed that recycled PET demonstrated comparable, and in certain metrics superior, performance relative to the benchmark materials, particularly in hardness and load resistance. Although minor inconsistencies were observed, likely to be due to extrusion or printing variations, these did not significantly affect functional performance. A bayonet sheath produced from recycled PET filament met both structural and practical requirements, confirming its suitability for protective gear. This study concludes that recycled PET not only fulfills mechanical requirements for military applications but also contributes to environmental sustainability by reducing plastic waste and supporting circular economy initiatives. The findings highlight the potential for recycled PET to be adopted in broader manufacturing sectors requiring durable, cost-effective, and eco-friendly materials. Further research is recommended to optimize processing techniques, enhance surface characteristics, and evaluate long-term performance under varying operational and environmental conditions to fully validate its industrial viability.