{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T07:06:22Z","timestamp":1789542382121,"version":"build-2803163510"},"reference-count":30,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2025,9,25]],"date-time":"2025-09-25T00:00:00Z","timestamp":1758758400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"German Federal Ministry for Economic Affairs and Energy (BMWE)","award":["19400 N"],"award-info":[{"award-number":["19400 N"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This study presents a comparative investigation of the mechanical performance of epoxy-based composites reinforced with \u00b145\u00b0 multiaxial non-crimp fabrics (NCFs) made from natural flax fibers and conventional glass fibers. Flax fibers, despite their attractive sustainability profile and favorable specific mechanical properties, are typically processed into twisted yarns for textile reinforcement, which compromises fiber alignment and reduces composite performance. A novel yarn-free flax NCF was developed using false twist stabilization of aligned slivers to eliminate the negative effects of yarn twist. Composite laminates were manufactured via vacuum-assisted resin infusion (VARI) under identical processing conditions for both flax- and glass-based reinforcements and tested for tensile, compressive, and flexural behavior. The results show that, although glass fiber composites exhibit superior absolute strength and stiffness, flax-based NCF composites offer competitive specific properties and benefit significantly from improved fiber alignment compared to yarn-based variants. This work provides a systematic comparison under standardized conditions and confirms the mechanical feasibility of flax NCFs for semi-structural lightweight applications.<\/jats:p>","DOI":"10.3390\/ma18194469","type":"journal-article","created":{"date-parts":[[2025,9,25]],"date-time":"2025-09-25T12:05:13Z","timestamp":1758801913000},"page":"4469","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Comparative Study on the Mechanical Behavior of Flax and Glass Fiber Multiaxial Fabric-Reinforced Epoxy Composites"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-3502-6816","authenticated-orcid":false,"given":"Carsten","family":"Uthemann","sequence":"first","affiliation":[{"name":"Institut f\u00fcr Textiltechnik (ITA) of RWTH Aachen University, 52074 Aachen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2480-8333","authenticated-orcid":false,"given":"Thomas","family":"Gries","sequence":"additional","affiliation":[{"name":"Institut f\u00fcr Textiltechnik (ITA) of RWTH Aachen University, 52074 Aachen, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,9,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Rajak, D.K., Pagar, D.D., Menezes, P.L., and Linul, E. (2019). Fiber-Reinforced Polymer Composites: Manufacturing, Properties, and Applications. Polymers, 11.","DOI":"10.3390\/polym11101667"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1329","DOI":"10.1016\/j.compositesa.2010.06.001","article-title":"A review of bast fibres and their composites. Part 1\u2014Fibres as reinforcements","volume":"41","author":"Summerscales","year":"2010","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/j.compositesa.2015.08.038","article-title":"A review of recent developments in natural fibre composites and their mechanical performance","volume":"83","author":"Pickering","year":"2016","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1016\/j.compositesb.2012.07.004","article-title":"Green composites: A review of adequate materials for automotive applications","volume":"44","author":"Koronis","year":"2013","journal-title":"Compos. Part B Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1419","DOI":"10.1016\/j.compositesa.2011.11.019","article-title":"Critical review of recent publications on use of natural composites in infrastructure","volume":"43","author":"Dittenber","year":"2012","journal-title":"Compos. Part A Appl. Sci. Manuf."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"101271","DOI":"10.1016\/j.rineng.2023.101271","article-title":"A comprehensive review of natural fibers and their composites: An eco-friendly alternative to conventional materials","volume":"19","author":"Elfaleh","year":"2023","journal-title":"Results Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1177\/0021998319863156","article-title":"Fibre architecture modification to improve the tensile properties of flax-reinforced composites","volume":"54","author":"Rayyaan","year":"2019","journal-title":"J. Compos. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1007\/s10443-006-9010-2","article-title":"Development of Flax Fibre based Textile Reinforcements for Composite Applications","volume":"13","author":"Goutianos","year":"2006","journal-title":"Appl. Compos. Mater."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Aisyah, H.A., Paridah, M.T., Sapuan, S.M., Ilyas, R.A., Khalina, A., Nurazzi, N.M., Lee, S.H., and Lee, C.H. (2021). A Comprehensive Review on Advanced Sustainable Woven Natural Fibre Polymer Composites. Polymers, 13.","DOI":"10.3390\/polym13030471"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"6083","DOI":"10.1007\/s10853-013-7458-7","article-title":"Developing plant fibre composites for structural applications by optimising composite parameters: A critical review","volume":"48","author":"Shah","year":"2013","journal-title":"J. Mater. Sci."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Suriani, M.J., Rapi, H.Z., Ilyas, R.A., Petr\u016f, M., and Sapuan, S.M. (2021). Delamination and manufacturing defects in natural fiber-reinforced hybrid composite: A review. Polymers, 13.","DOI":"10.3390\/polym13081323"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"1906","DOI":"10.1007\/s11668-024-01979-7","article-title":"Influence of Fibre Architectures on the Mechanical Properties and Damage Failures of Composite Laminates","volume":"24","author":"Dalfi","year":"2024","journal-title":"J. Fail. Anal. Prev."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"111037","DOI":"10.1016\/j.compstruct.2019.111037","article-title":"Comparative design of E-glass and flax structures based on reliability","volume":"225","author":"Blanchard","year":"2019","journal-title":"Compos. Struct."},{"key":"ref_14","unstructured":"Uthemann, C. (2024). Flax Non-Crimp Fabrics with Improved Fibre Orientation for Sustainable Lightweight Composite Structures. [Ph.D. Dissertation, RWTH Aachen University]."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"2552","DOI":"10.1161\/STROKEAHA.108.528091","article-title":"Effect of aging on elastin functionality in human cerebral arteries","volume":"40","author":"Fonck","year":"2009","journal-title":"Stroke"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"P\u00fcsp\u00f6ki, Z., Storath, M., Sage, D., and Unser, M. (2016). Transforms and Operators for Directional Bioimage Analysis: A Survey, Springer.","DOI":"10.1007\/978-3-319-28549-8_3"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1038\/nmeth.2089","article-title":"NIH Image to ImageJ: 25 years of image analysis","volume":"9","author":"Schneider","year":"2012","journal-title":"Nat. Methods"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1007\/s10237-011-0325-z","article-title":"Experimental investigation of collagen waviness and orientation in the arterial adventitia using confocal laser scanning microscopy","volume":"11","author":"Rezakhaniha","year":"2012","journal-title":"Biomech. Model. Mechanobiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"23","DOI":"10.4028\/www.scientific.net\/AMM.884.23","article-title":"Fibre Orientation Distribution Assessment of Dynamically Sheet Formed Hemp Fibre Mats by Image Analysis","volume":"884","author":"Sunny","year":"2018","journal-title":"Appl. Mech. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2747","DOI":"10.1177\/0021998320962555","article-title":"Fiber Orientation Quantification Utilizing X-ray Micro-Computed Tomography","volume":"55","author":"Sietins","year":"2021","journal-title":"J. Compos. Mater."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Huling, J., G\u00f6tz, A., Grabow, N., and Illner, S. (2022). GIFT: An ImageJ macro for automated fiber diameter quantification. PLoS ONE, 17.","DOI":"10.1371\/journal.pone.0275528"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"9661","DOI":"10.1039\/C7RA12693J","article-title":"Coherency Image Analysis to Quantify Collagen Architecture: Implications in Scar Assessment","volume":"8","author":"Clemons","year":"2018","journal-title":"RSC Adv."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Marcotti, S., de Freitas, D.B., Trouphton, L.D., Kenny, F.N., Shaw, T.J., Stramer, B.M., and Oakes, P.W. (2021). A Workflow for Rapid Unbiased Quantification of Fibrillar Feature Alignment in Biological Images. Front. Comput. Sci., 3.","DOI":"10.3389\/fcomp.2021.745831"},{"key":"ref_24","unstructured":"(1997). Plastics\u2014Determination of Tensile Properties\u2014Part 4: Test Conditions for Isotropic and Orthotropic Fibre-Reinforced Plastic Composites (Standard No. DIN EN ISO 527-4)."},{"key":"ref_25","unstructured":"(2000). Fibre-Reinforced Plastic Composites\u2014Determination of Compressive Properties in the In-Plane Direction (Standard No. DIN EN ISO 14126)."},{"key":"ref_26","unstructured":"(1995). Fibre-Reinforced Plastic Composites\u2014Determination of Flexural Properties (Standard No. DIN EN ISO 14125)."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Ueki, Y., Lilholt, H., and Madsen, B. (2020). Experimental evaluation of stiffness predictions of multiaxial flax fibre composites by classical laminate theory. PLoS ONE, 15.","DOI":"10.1371\/journal.pone.0234701"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1016\/j.compositesb.2013.08.014","article-title":"Flax Fibre and Its Composites\u2014A Review","volume":"56","author":"Yan","year":"2014","journal-title":"Compos. Part B Eng."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1683","DOI":"10.1023\/A:1014925621252","article-title":"Tensile and compressive properties of flax fibres for natural fibre reinforced composites","volume":"37","author":"Bos","year":"2002","journal-title":"J. Mater. Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"5171","DOI":"10.3390\/ma6115171","article-title":"Recent Development of Flax Fibres and Their Reinforced Composites Based on Different Polymeric Matrices","volume":"6","author":"Zhu","year":"2013","journal-title":"Materials"}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/19\/4469\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T18:49:33Z","timestamp":1760035773000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/18\/19\/4469"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,9,25]]},"references-count":30,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2025,10]]}},"alternative-id":["ma18194469"],"URL":"https:\/\/doi.org\/10.3390\/ma18194469","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,9,25]]}}}