Filamento 3D con Pet reciclado.
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Date
2025
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
La impresión 3D ha experimentado un notable crecimiento en los últimos años; sin embargo, los elevados costos de los filamentos comerciales y la acumulación de residuos plásticos, especialmente de botellas de PET, plantean desafíos económicos y ambientales. En este contexto, el presente trabajo tuvo como objetivo diseñar, construir y validar un prototipo de máquina capaz de transformar botellas de PET recicladas en filamento para impresión 3D, contribuyendo a la valorización de residuos y a la economía circular.
La metodología contempló el diseño mecánico y la fabricación de los principales subsistemas corte de fibras, bloque calefactor, transmisión de potencia y bobinado junto con la selección de materiales de bajo costo y la integración de controles térmicos y de velocidad. Se realizaron pruebas de extrusión con fibras de diferentes espesores, impresión de probetas normalizadas y ensayos de tracción según la norma ASTM D638. Finalmente, se desarrolló una evaluación económica a partir de los costos de fabricación, estimación de la producción y comparación con alternativas comerciales.
Los resultados experimentales mostraron que el filamento de rPET presenta propiedades mecánicas inferiores al PLA: resistencia media de 20,9 MPa y módulo de 1,5 GPa frente a 60,2 MPa y 12 GPa del PLA. No obstante, el rPET evidenció mayor deformación antes de la fractura (18,2 % en promedio), lo que lo convierte en una alternativa viable en aplicaciones donde la flexibilidad y la sostenibilidad sean prioritarias. Estos hallazgos se alinean con estudios recientes que reportan valores similares para filamentos reciclados, confirmando que, aunque no se cumple íntegramente la hipótesis inicial de alcanzar propiedades comparables a las de filamentos comerciales, el material conserva potencial de uso en contextos específicos.
Se identificaron limitaciones críticas en el rPET relacionadas con su preparación previa (lavado, secado y control de humedad) y con la calidad interlaminar durante la impresión FDM, factores que condicionan tanto la homogeneidad del filamento como la repetibilidad de las piezas impresas. Estas limitaciones, descritas en la literatura, explican la dispersión observada en los resultados mecánicos y plantean la necesidad de optimizar los parámetros de procesamiento.
Desde el punto de vista económico, el prototipo fue fabricado con un costo total de $128.650 CLP, cifra inferior al valor de equipos comerciales de$190.000 CLP. El costo de producción del filamento reciclado se estimó en $35 CLP por metro, lo que representa un ahorro respecto a los $45 CLP por metro del filamento PETG comercial. Además, los indicadores financieros (VAN positivo y TIR cercana al 20 %) evidencian la viabilidad del sistema en escenarios de pequeña escala.
Se confirmó que el trabajo valida la factibilidad técnica y económica de producir filamento 3D a partir de botellas recicladas, aunque reconoce que el rPET no alcanza plenamente las propiedades mecánicas de filamentos comerciales como el PLA. La investigación resalta la importancia de mejorar las etapas de pretratamiento y sugiere como línea futura la incorporación de aditivos, mezclas poliméricas y una segunda máquina que permita unir los tramos extruidos para obtener filamentos continuos de calidad comercial. Estos avances permitirán fortalecer el aporte del rPET a la manufactura aditiva sostenible y a la economía circular.
3D printing has experienced significant growth in recent years; however, the high cost of commercial filaments and the accumulation of plastic waste, especially PET bottles, pose both economic and environmental challenges. In this context, the present work aimed to design, build, and validate a prototype machine capable of transforming recycled PET bottles into 3D printing filament, thus contributing to waste valorization and the circular economy. The methodology included the mechanical design and fabrication of the main subsystems —fiber cutting, heating block, power transmission, and winding— along with the selection of low-cost materials and the integration of thermal and speed control systems. Extrusion tests were performed with fibers of different thicknesses, followed by the printing of standardized specimens and tensile tests according to ASTM D638. Finally, an economic evaluation was carried out, considering manufacturing costs, production estimates, and comparison with commercial alternatives. Experimental results showed that rPET filament exhibits lower mechanical properties compared to PLA: an average tensile strength of 20.9 MPa and a modulus of 1.5 GPa, versus 60.2 MPa and 12 GPa for PLA. Nevertheless, rPET demonstrated a higher deformation before fracture (average of 18.2 %), making it a viable alternative for applications where flexibility and sustainability are prioritized. These findings are consistent with recent studies reporting similar values for recycled filaments, confirming that although the initial hypothesis of achieving properties comparable to commercial filaments was not fully met, the material retains potential for specific applications. Critical limitations of rPET were identified, mainly related to pre-processing stages (washing, drying, and moisture control) and interlayer quality during FDM printing, which affect both filament homogeneity and the repeatability of printed parts. These limitations, also reported in the literature, explain the variability observed in the mechanical results and highlight the need to optimize processing parameters. From an economic perspective, the prototype was built at a total cost of 128,650 CLP, which is lower than the value of commercial extruders (≈190,000 CLP). The production cost of recycled filament was estimated at 35 CLP per meter, representing savings compared to 45 CLP per meter for commercial PETG filament. Furthermore, financial indicators (positive NPV and IRR close to 20 %) demonstrate the viability of the system at a small-scale level. It was confirmed that this work validates the technical and economic feasibility of producing 3D printing filament from recycled PET bottles, although it acknowledges that rPET does not fully match the mechanical properties of commercial filaments such as PLA. The study emphasizes the importance of improving pre-treatment stages and suggests as future work the incorporation of additives, polymer blends, and the development of a second machine capable of joining extruded segments to obtain continuous filaments with commercial quality. These improvements will strengthen the contribution of rPET to sustainable additive manufacturing and the circular economy.
3D printing has experienced significant growth in recent years; however, the high cost of commercial filaments and the accumulation of plastic waste, especially PET bottles, pose both economic and environmental challenges. In this context, the present work aimed to design, build, and validate a prototype machine capable of transforming recycled PET bottles into 3D printing filament, thus contributing to waste valorization and the circular economy. The methodology included the mechanical design and fabrication of the main subsystems —fiber cutting, heating block, power transmission, and winding— along with the selection of low-cost materials and the integration of thermal and speed control systems. Extrusion tests were performed with fibers of different thicknesses, followed by the printing of standardized specimens and tensile tests according to ASTM D638. Finally, an economic evaluation was carried out, considering manufacturing costs, production estimates, and comparison with commercial alternatives. Experimental results showed that rPET filament exhibits lower mechanical properties compared to PLA: an average tensile strength of 20.9 MPa and a modulus of 1.5 GPa, versus 60.2 MPa and 12 GPa for PLA. Nevertheless, rPET demonstrated a higher deformation before fracture (average of 18.2 %), making it a viable alternative for applications where flexibility and sustainability are prioritized. These findings are consistent with recent studies reporting similar values for recycled filaments, confirming that although the initial hypothesis of achieving properties comparable to commercial filaments was not fully met, the material retains potential for specific applications. Critical limitations of rPET were identified, mainly related to pre-processing stages (washing, drying, and moisture control) and interlayer quality during FDM printing, which affect both filament homogeneity and the repeatability of printed parts. These limitations, also reported in the literature, explain the variability observed in the mechanical results and highlight the need to optimize processing parameters. From an economic perspective, the prototype was built at a total cost of 128,650 CLP, which is lower than the value of commercial extruders (≈190,000 CLP). The production cost of recycled filament was estimated at 35 CLP per meter, representing savings compared to 45 CLP per meter for commercial PETG filament. Furthermore, financial indicators (positive NPV and IRR close to 20 %) demonstrate the viability of the system at a small-scale level. It was confirmed that this work validates the technical and economic feasibility of producing 3D printing filament from recycled PET bottles, although it acknowledges that rPET does not fully match the mechanical properties of commercial filaments such as PLA. The study emphasizes the importance of improving pre-treatment stages and suggests as future work the incorporation of additives, polymer blends, and the development of a second machine capable of joining extruded segments to obtain continuous filaments with commercial quality. These improvements will strengthen the contribution of rPET to sustainable additive manufacturing and the circular economy.
Description
Tesis presentada para optar al título de Ingeniero/a Civil Mecánico/a.
Keywords
Impresión tridimensional, Desechos plásticos, Economía circular