Development of Filagri: A Locally Fabricated Additive Manufacturing Filament Harnessing Agricultural Byproducts

Additive manufacturing (AM), particularly Fused Deposition Modeling (FDM), is widely used forrapid prototyping and small-batch production but remains costly in developing countries due toreliance on imported feedstock. This study developed and evaluated FilAgri, a locally fabricatedAM filament incorporating Philippine agricultural byproducts—specifically rice husk ash (RHA)and coconut coir—into a polylactic acid (PLA) matrix. Composite filaments with 0%, 10%, and20% filler loadings were compounded, extruded into 1.75 mm filaments, printed into standardizedspecimens, and evaluated for mechanical, thermal, printability, cost, and environmentalperformance. Mechanical tests following ASTM standards showed that RHA enhanced stiffnessand thermal stability of PLA with minor reductions in tensile strength, while coir improved impactresistance at moderate loadings. Differential Scanning Calorimetry (DSC) and ThermogravimetricAnalysis (TGA) revealed that glass transition and melting temperatures remained essentiallyunchanged, indicating good thermal compatibility. All printable formulations achieved acceptabledimensional accuracy and print success rates on a standard FDM printer. Cost analysis indicated a16–22% reduction in material cost per kilogram compared to neat PLA, with approximately 0.20 kgof agricultural waste valorized per kilogram of filament. Among the tested formulations, RHA20% emerged as the optimal blend for structural applications due to its high modulus and greatestcost reduction, while Coir-10% offered improved impact resistance and good printability fortougher prototypes. These findings demonstrate the technical feasibility and cost-effectiveness ofusing locally available agricultural byproducts to produce sustainable composite filaments foradditive manufacturing in the Philippines, aligning with Sustainable Development Goal 12(Responsible Consumption and Production) and supporting innovation and climate actionobjectives.