Supplementary Files
Keywords
Fused Deposition Modelling (FDM)
Polylactic Acid (PLA)
Thermoplastic Polyurethane (TPU)
Layered Composites
How to Cite
Abstract
This study investigates the tensile performance of layered PLA–TPU composites produced by multi-material additive manufacturing (MMAM) via fused deposition modelling (FDM). Although PLA–TPU is a widely used rigid–flexible polymer pair, tensile performance is often limited by weak interfacial bonding and limited evidence on how layer thickness, material ratio, and stacking sequence influence load transfer and fracture. A screening study of 30 layered specimens quantified the effects of layer thickness (0.1 and 0.2 mm), material ratio (33:67, 50:50, and 67:33 PLA:TPU), and stack order on apparent stiffness, ultimate tensile strength (UTS), elongation, and post-fracture failure features. PLA-rich configurations achieved high strength (up to 33.5 MPa) with semi-ductile failure behaviour, whereas TPU-rich configurations showed large elongations (up to 298%) but lower strength (12–14 MPa). Across the configurations tested, a 67/33 PLA/TPU laminate provided the best balance of strength and ductility, reaching an average UTS of 33.5 MPa with 7.7% elongation, consistent with improved interlayer load transfer despite the intrinsic surface-energy disparity between PLA and TPU. Overall, the results demonstrate that MMAM by FDM can combine dissimilar thermoplastics within a single build to achieve an adaptive mechanical response, while interfacial optimisation remains the primary constraint for further performance gains.
References
Abidaryan, S., Akoundi, B., & Hajami, F. (2022). Additive manufacturing and investigation of shape memory properties of polylactic acid/thermoplastic polyurethane blend. Journal of Elastomers and Plastics. https://doi.org/10.1177/00952443221147028
Ahad, N. A. (2020). A Recent blend of thermoplastic polyurethane (TPU). IOP Conference Series: Materials Science and Engineering, 957(1), 012045. https://doi.org/10.1088/1757-899X/957/1/012045
Allum, J., Moetazedian, A., Gleadall, A., & Silberschmidt, V. V. (2020). Interlayer bonding has bulk-material strength in extrusion additive manufacturing: New understanding of anisotropy. Additive Manufacturing, 34, 101297. https://doi.org/10.1016/j.addma.2020.101297
Arruda, E. M., & Boyce, M. C. (1993). A three-dimensional constitutive model for the large stretch behavior of rubber elastic materials. Journal of the Mechanics and Physics of Solids, 41(2), 389–412. https://doi.org/10.1016/0022-5096(93)90013-6
ASTM D638. (2022). Standard Test Method for Tensile Properties of Plastics. In ASTM Standards. ASTM International. https://doi.org/10.1520/D0638-14
Brancewicz-Steinmetz, E., Sawicki, J., & Byczkowska, P. (2021). The influence of 3d printing parameters on adhesion between polylactic acid (Pla) and thermoplastic polyurethane (tpu). Materials, 14(21). https://doi.org/10.3390/ma14216464
Brancewicz-Steinmetz, E., Vergara, R. D. V., Buzalski, V. H., & Sawicki, J. (2022). Study of the adhesion between TPU and PLA in multi-material 3D printing. Journal of Achievements in Materials and Manufacturing Engineering, 115(2), 49–56. https://doi.org/10.5604/01.3001.0016.2672
Cao, A., Wan, D., Gao, C., & Elverum, C. W. (2024). A novel method of fabricating designable polylactic acid (PLA)/thermoplastic polyurethane (TPU) composite filaments and structures by material extrusion additive manufacturing. Journal of Manufacturing Processes, 118, 432–447. https://doi.org/10.1016/j.jmapro.2024.03.015
Darnal, A., Shahid, Z., Deshpande, H., Kim, J., & Muliana, A. (2023). Tuning mechanical properties of 3D printed composites with PLA:TPU programmable filaments. Composite Structures, 318, 117075. https://doi.org/10.1016/j.compstruct.2023.117075
Elmrabet, N., & Siegkas, P. (2020). Dimensional considerations on the mechanical properties of 3D printed polymer parts. Polymer Testing, 90, 106656. https://doi.org/10.1016/j.polymertesting.2020.106656
Feng, F., & Ye, L. (2011). Morphologies and mechanical properties of polylactide/thermoplastic polyurethane elastomer blends. Journal of Applied Polymer Science, 119(5), 2778–2783. https://doi.org/10.1002/app.32863
García-Collado, A., Blanco, J. M., Gupta, M. K., & Dorado-Vicente, R. (2022). Advances in polymers based Multi-Material Additive-Manufacturing Techniques: State-of-art review on properties and applications. In Additive Manufacturing (Vol. 50, p. 102577). Elsevier. https://doi.org/10.1016/j.addma.2021.102577
Hamidi, M. N., Abdullah, J., Mahmud, A. S., Hassan, M. H., & Zainoddin, A. Y. (2025). Influence of thermoplastic polyurethane (TPU) and printing parameters on the thermal and mechanical performance of polylactic acid (PLA) / thermoplastic polyurethane (TPU) polymer. Polymer Testing, 143, 108697. https://doi.org/10.1016/j.polymertesting.2025.108697
Hasanov, S., Alkunte, S., Rajeshirke, M., Gupta, A., Huseynov, O., Fidan, I., Alifui-Segbaya, F., & Rennie, A. (2022). Review on additive manufacturing of multi-material parts: Progress and challenges. In Journal of Manufacturing and Materials Processing (Vol. 6, Issue 1, p. 4). Multidisciplinary Digital Publishing Institute. https://doi.org/10.3390/jmmp6010004
Mi, H. Y., Salick, M. R., Jing, X., Jacques, B. R., Crone, W. C., Peng, X. F., & Turng, L. S. (2013). Characterization of thermoplastic polyurethane/polylactic acid (TPU/PLA) tissue engineering scaffolds fabricated by microcellular injection molding. Materials Science and Engineering C, 33(8), 4767–4776. https://doi.org/10.1016/j.msec.2013.07.037
Nasution, A., Herianto, Rifai, A. P., & Atsani, S. I. (2025). Tensile performance of multi-material sandwich structures fabricated by multi-nozzle fused deposition modeling using PLA, ABS, and HIPS. Results in Engineering, 27, 106210. https://doi.org/10.1016/J.RINENG.2025.106210
Naveed, N., Anwar, M. N., Armstrong, M., Ahmad, F., Irfan Ul Haq, M., & Ridley, G. (2025). Enhancing Sustainability and Functionality with Recycled Materials in Multi-Material Additive Manufacturing. Sustainability (Switzerland), 17(13). https://doi.org/10.3390/su17136105
Nazir, A., Gokcekaya, O., Md Masum Billah, K., Ertugrul, O., Jiang, J., Sun, J., & Hussain, S. (2023). Multi-material additive manufacturing: A systematic review of design, properties, applications, challenges, and 3D printing of materials and cellular metamaterials. In Materials and Design (Vol. 226, p. 111661). Elsevier. https://doi.org/10.1016/j.matdes.2023.111661
Nofar, M., Mohammadi, M., & Carreau, P. J. (2020). Effect of TPU hard segment content on the rheological and mechanical properties of PLA/TPU blends. Journal of Applied Polymer Science, 137(45), 49387. https://doi.org/10.1002/app.49387
Omer, M. A. E., Shaban, I. A., Mourad, A. H., & Hegab, H. (2025). Advances in interlayer bonding in fused deposition modelling: a comprehensive review. In Virtual and Physical Prototyping (Vol. 20, Issue 1, p. 2522951). Taylor and Francis Ltd. https://doi.org/10.1080/17452759.2025.2522951
Plotzke, J. J., Torgerson, N. R., Seaberg, S. D., & McClain, M. S. (2024). Mechanical Properties of 3D-Printed Multi-Material Polymeric Composites. AIAA SciTech Forum and Exposition, 2024. https://doi.org/10.2514/6.2024-1225
Qi, H. J., & Boyce, M. C. (2005). Stress-strain behavior of thermoplastic polyurethanes. Mechanics of Materials, 37(8), 817–839. https://doi.org/10.1016/j.mechmat.2004.08.001
Rahmatabadi, D., Ghasemi, I., Baniassadi, M., Abrinia, K., & Baghani, M. (2022). 3D printing of PLA-TPU with different component ratios: Fracture toughness, mechanical properties, and morphology. Journal of Materials Research and Technology, 21, 3970–3981. https://doi.org/10.1016/j.jmrt.2022.11.024
Ranakoti, L., Gangil, B., Mishra, S. K., Singh, T., Sharma, S., Ilyas, R. A., & El-Khatib, S. (2022). Critical Review on Polylactic Acid: Properties, Structure, Processing, Biocomposites, and Nanocomposites. Materials, 15(12), 4312. https://doi.org/10.3390/MA15124312
Shi, X., Chen, B., Tuo, X., Gong, Y., & Guo, J. (2021). Study on performance characteristics of fused deposition modeling 3D-printed composites by blending and lamination. Journal of Applied Polymer Science, 138(9), 32495. https://doi.org/10.1002/app.49926
Tamburrino, F., Graziosi, S., & Bordegoni, M. (2019). The influence of slicing parameters on the multi-material adhesion mechanisms of FDM printed parts: an exploratory study. Virtual and Physical Prototyping, 14(4), 316–332. https://doi.org/10.1080/17452759.2019.1607758
Wang, F., Ji, Y., Chen, C., Zhang, G., & Chen, Z. (2022). Tensile properties of 3D printed structures of polylactide with thermoplastic polyurethane. Journal of Polymer Research, 29(8). https://doi.org/10.1007/s10965-022-03172-6
Wili?ska, K., Kozu?, M., & Pezowicz, C. (2025). Elastic Properties of Thermoplastic Polyurethane Fabricated Using Multi Jet Fusion Additive Technology. Polymers, 17(10). https://doi.org/10.3390/polym17101363
Yin, J., Lu, C., Fu, J., Huang, Y., & Zheng, Y. (2018). Interfacial bonding during multi-material fused deposition modeling (FDM) process due to inter-molecular diffusion. Materials and Design, 150, 104–112. https://doi.org/10.1016/j.matdes.2018.04.029
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Copyright (c) 2025 Array