{
  "spore": "profile",
  "id": "flax-fibre",
  "spore_version": "0.2",
  "family": "flax",
  "name": "Flax fibre (natural bast fibre)",
  "role": "Plant-based reinforcement fibre for composites",
  "category": "composites",
  "type": "glass-fiber-reinforced",
  "summary": "Flax fibre is the bast fibre from the stem of the flax plant (Linum usitatissimum L.), used to reinforce composites as a plant-based alternative to glass fibre. Elementary flax fibres reached 1500 to 1800 MPa in tension and around 1200 MPa in a loop compression test (Bos et al. 2002), although a review quotes a lower tensile figure of 976 MPa. Density, ageing and supply data were not found in the two sources read for this profile.",
  "best_for": "Plant-based reinforcement for composites, where the review says flax can substitute for glass fibres",
  "weakest_at": "Strength depends on the isolation and decortication process; no density, ageing or supply data found yet",
  "identity": {
    "formula": "Cellulose-based bast fibre from the flax stem (Linum usitatissimum L.); a natural fibre bundle, not one chemical compound, so no single formula",
    "designations": [],
    "source": "goudenhooft2019",
    "where": "Introduction and cell-wall layers section (cellulose-rich G-layer)"
  },
  "tags": {
    "environments": [],
    "stresses": [],
    "applications": []
  },
  "properties": [
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength of elementary flax fibres, range by isolation procedure",
      "value": 1500,
      "value_high": 1800,
      "bound": "range",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "elementary (single) flax fibres, decorticated and hand-isolated",
        "test": "tension",
        "range_basis": "depending on the isolation procedure"
      },
      "method": "Tensile tests by the authors (Bos et al. 2002), range as printed in the abstract",
      "status": "ground",
      "source": "bos2002",
      "where": "Abstract, tensile strength sentence",
      "source_detail": {
        "title": "Tensile and compressive properties of flax fibres for natural fibre reinforced composites",
        "id": "doi:10.1023/A:1014925621252 (J. Mater. Sci. 37(8), 1683-1692); authors H.L. Bos, M.J.A. van den Oever, O.C.J.J. Peters",
        "url": "https://research.wur.nl/en/publications/tensile-and-compressive-properties-of-flax-fibres-for-natural-fib/",
        "year": 2002,
        "kind": "paper"
      }
    },
    {
      "benchmark": "compressive_strength",
      "label": "Compressive strength of elementary flax fibres, loop test",
      "value": 1200,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "elementary flax fibres",
        "test": "loop test",
        "qualifier": "printed as around 1200 MPa"
      },
      "method": "Loop-test compression measurement by the authors (Bos et al. 2002); value as printed in the abstract",
      "status": "ground",
      "note": "The same abstract says standard decortication can lower the compressive strength severely, so this figure is for hand-isolated fibres.",
      "source": "bos2002",
      "where": "Abstract, compressive strength sentence",
      "source_detail": {
        "title": "Tensile and compressive properties of flax fibres for natural fibre reinforced composites",
        "id": "doi:10.1023/A:1014925621252 (J. Mater. Sci. 37(8), 1683-1692); authors H.L. Bos, M.J.A. van den Oever, O.C.J.J. Peters",
        "url": "https://research.wur.nl/en/publications/tensile-and-compressive-properties-of-flax-fibres-for-natural-fib/",
        "year": 2002,
        "kind": "paper"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Strength at break of flax fibre, as quoted in a review",
      "value": 976,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "form": "flax fibre (form and test not stated in the review)",
        "basis": "figure quoted from earlier work the review cites"
      },
      "method": "Quoted in an open-access review from earlier work; not measured by the review's authors",
      "status": "ground",
      "note": "Lower than the 1500 to 1800 MPa range measured by Bos et al. (2002). The review does not say which isolation or test gave 976 MPa, so the two are not directly comparable.",
      "source": "goudenhooft2019",
      "where": "Introduction, paragraph comparing flax fibres with glass fibres",
      "source_detail": {
        "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
        "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
        "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
        "year": 2019,
        "kind": "paper",
        "license": "open access, Frontiers in Plant Science"
      }
    },
    {
      "benchmark": "elastic_modulus",
      "label": "Average elastic modulus of flax fibre, as quoted in a review",
      "value": 52.4,
      "bound": "exact",
      "unit": "GPa",
      "scope": "material",
      "conditions": {
        "form": "flax fibre (form not stated in the review)",
        "basis": "figure quoted from earlier work the review cites"
      },
      "method": "Quoted in an open-access review from earlier work; not measured by the review's authors",
      "status": "ground",
      "source": "goudenhooft2019",
      "where": "Introduction, paragraph comparing flax fibres with glass fibres",
      "source_detail": {
        "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
        "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
        "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
        "year": 2019,
        "kind": "paper",
        "license": "open access, Frontiers in Plant Science"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Strain at break of flax fibre, as quoted in a review",
      "value": 2.15,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "flax fibre (form not stated in the review)",
        "basis": "figure quoted from earlier work the review cites"
      },
      "method": "Quoted in an open-access review from earlier work; not measured by the review's authors",
      "status": "ground",
      "source": "goudenhooft2019",
      "where": "Introduction, paragraph comparing flax fibres with glass fibres",
      "source_detail": {
        "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
        "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
        "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
        "year": 2019,
        "kind": "paper",
        "license": "open access, Frontiers in Plant Science"
      }
    },
    {
      "benchmark": "fibre_diameter",
      "label": "Average diameter of flax fibre",
      "value": 20,
      "bound": "exact",
      "unit": "μm",
      "scope": "material",
      "conditions": {
        "form": "flax fibre",
        "basis": "average diameter for a fibre length of 25 mm, as quoted in the review"
      },
      "method": "Quoted in an open-access review from earlier work (van Dam and Gorshkova); not measured by the review's authors",
      "status": "ground",
      "source": "goudenhooft2019",
      "where": "Introduction, paragraph on flax fibre applications",
      "source_detail": {
        "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
        "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
        "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
        "year": 2019,
        "kind": "paper",
        "license": "open access, Frontiers in Plant Science"
      }
    },
    {
      "benchmark": "fibre_cell_wall_thickness",
      "label": "Cell-wall thickness of flax fibre, lower bound",
      "value": 10,
      "bound": "lower",
      "unit": "μm",
      "scope": "material",
      "conditions": {
        "form": "flax fibre cell wall",
        "qualifier": "printed as more than 10 μm"
      },
      "method": "Stated in an open-access review; the review does not name a measurement method for this figure",
      "status": "ground",
      "source": "goudenhooft2019",
      "where": "Cell wall thickening section",
      "source_detail": {
        "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
        "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
        "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
        "year": 2019,
        "kind": "paper",
        "license": "open access, Frontiers in Plant Science"
      }
    },
    {
      "benchmark": "cellulose_content",
      "label": "Cellulose content of the G-layer in flax fibre cell walls",
      "value": 90,
      "bound": "upper",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "layer": "G-layer, the fibre-specific cell-wall layer (not the whole fibre)",
        "qualifier": "printed as up to 90%"
      },
      "method": "Stated in an open-access review; the review does not name a measurement method for this figure",
      "status": "ground",
      "source": "goudenhooft2019",
      "where": "Cell wall layers section (G-layer description)",
      "source_detail": {
        "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
        "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
        "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
        "year": 2019,
        "kind": "paper",
        "license": "open access, Frontiers in Plant Science"
      }
    },
    {
      "benchmark": "microfibril_angle",
      "label": "Cellulose microfibril angle in the G-layer",
      "value": 8,
      "value_high": 10,
      "bound": "range",
      "unit": "°",
      "scope": "material",
      "conditions": {
        "layer": "G-layer, the fibre-specific cell-wall layer",
        "note": "microfibrils almost parallel to the fibre axis"
      },
      "method": "Stated in an open-access review; the review does not name a measurement method for this figure",
      "status": "ground",
      "source": "goudenhooft2019",
      "where": "Cell wall layers section (G-layer description)",
      "source_detail": {
        "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
        "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
        "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
        "year": 2019,
        "kind": "paper",
        "license": "open access, Frontiers in Plant Science"
      }
    }
  ],
  "corrosion": [],
  "risks": {
    "hazards": [
      {
        "text": "The review says plant fibres have a 'low hazard manufacturing process for human health' compared with glass fibres, citing earlier work. No safety data sheet or PubChem hazard record for flax fibre was read in this run, so this is the only hazard statement held.",
        "ghs": [],
        "source": "goudenhooft2019",
        "where": "Introduction, paragraph comparing plant fibres with glass fibres"
      }
    ],
    "failure_risks": [
      {
        "mode": "Kink bands from the standard decortication process",
        "trigger": "Standard decortication process, as described by Bos et al. 2002",
        "consequence": "Kink bands form in the fibres and contain cracks bridged by microfibrils; the abstract says decortication can lower compressive strength severely.",
        "severity": "high",
        "source": "bos2002",
        "where": "Abstract, compressive strength and kink band sentences"
      }
    ],
    "side_effects": [],
    "handling": [],
    "mitigations": []
  },
  "uses": [
    {
      "application": "structures",
      "device": "Flax fibre composite reinforcement (technical fibres or short fibres in a polymer matrix)",
      "example": "The review states that flax fibres are used as reinforcement in composite materials, either as technical fibre bundles or as short fibres impregnated with a polymer matrix.",
      "source": "goudenhooft2019",
      "where": "Introduction, paragraph on composite reinforcement"
    }
  ],
  "supply": [],
  "media": [],
  "documents": [
    {
      "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties (open access review)",
      "type": "paper",
      "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
      "year": 2019
    },
    {
      "title": "Tensile and compressive properties of flax fibres for natural fibre reinforced composites (Journal of Materials Science, 2002)",
      "type": "paper",
      "url": "https://research.wur.nl/en/publications/tensile-and-compressive-properties-of-flax-fibres-for-natural-fib/",
      "year": 2002
    }
  ],
  "gaps": [
    "Density not recorded: the review quotes a fibre density of 1.53 with no unit printed, so the value was left out rather than assumed to be g/cm3.",
    "Only two sources were read in this run. The site bar asks for 8 sources and 12 properties; this profile has 2 sources and 9 properties.",
    "Supply (producing countries with shares, abundance, critical-mineral lists) not found in any source read. The review covers plant growth and fibre structure, not production statistics.",
    "No corrosion, ageing, moisture absorption, UV or hygrothermal degradation data for flax fibre found in the two sources read.",
    "No vacuum, radiation, thermal-cycling, outgassing or flight data for flax fibre found. No space application source was found; the only use listed is terrestrial composite reinforcement.",
    "No safety data sheet, PubChem GHS record or occupational dust-exposure data for flax fibre were read. The hazard entry only quotes the review.",
    "Glass-fibre comparison values were not read. The review says flax and glass fibres have a similar range of specific properties, without a glass figure in the text read.",
    "Conflict held side by side: 976 MPa strength at break (quoted in the review) against 1500 to 1800 MPa tensile strength (Bos et al. 2002). The isolation and test behind 976 MPa is not stated.",
    "Handling and storage of flax fibre: not found in the sources read.",
    "Property names not in the canonical list: compressive_strength, fibre_diameter, fibre_cell_wall_thickness, cellulose_content, microfibril_angle.",
    "Taxonomy has no natural-fibre composite type. Type set to glass-fiber-reinforced as the closest fibre-reinforced composite type.",
    "Source papers behind the review's quoted figures (Lefeuvre and van Dam and Gorshkova) were not opened: the publisher links returned redirect pages with no text."
  ],
  "story": {
    "why": "Flax fibre is the bast fibre from the stem of the flax plant, used in composites as a plant-based alternative to glass fibre. Its cell walls are thick, and the review describes the G-layer, the fibre-specific cell-wall layer, as rich in cellulose. The review describes flax as a renewable reinforcement with mechanical properties in a similar range to glass fibres, but this profile records the figures the two sources actually give.",
    "uses": [
      {
        "where": "Composite reinforcement",
        "line": "The review states that flax fibres reinforce composite materials, as technical fibre bundles or as short fibres impregnated with a polymer matrix. No space application was found in the sources read."
      }
    ],
    "can_do": [
      {
        "label": "Tensile strength",
        "line": "Elementary flax fibres reached 1500 to 1800 MPa in tension, depending on the isolation procedure (Bos et al. 2002).",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Compressive strength",
        "line": "Elementary flax fibres reached around 1200 MPa in a loop test, but the same paper says standard decortication can lower compressive strength severely.",
        "benchmark": "compressive_strength",
        "scope": "material"
      },
      {
        "label": "Stiffness",
        "line": "The review quotes an average elastic modulus of 52.4 GPa for flax fibre. The review quotes this figure from earlier work and does not measure it.",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Stretch before break",
        "line": "The review quotes a strain at break of 2.15% for flax fibre, again from earlier work.",
        "benchmark": "elongation",
        "scope": "material"
      }
    ],
    "compare": "The review says flax fibres have a similar range of specific mechanical properties to glass fibres, which is why it presents them as a substitute. The sources read for this profile do not give a glass-fibre figure to set beside the flax values, so no side-by-side number is shown. The compare rows below list the three flax benchmarks that have a value in the record.",
    "compare_rows": [
      {
        "label": "Tensile strength of elementary fibres",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      },
      {
        "label": "Elastic modulus",
        "benchmark": "elastic_modulus",
        "scope": "material"
      },
      {
        "label": "Strain at break",
        "benchmark": "elongation",
        "scope": "material"
      }
    ],
    "handling": [],
    "good_for": [
      "Plant-based reinforcement for composites. The review says flax can substitute for glass fibres in this role.",
      "High tensile strength for a plant fibre. Elementary fibres reached 1500 to 1800 MPa (Bos et al. 2002)."
    ],
    "watch_out": [
      "Strength depends on how the fibre is isolated. The review quotes 976 MPa, and Bos et al. 2002 measured 1500 to 1800 MPa, and the two are not the same test.",
      "Standard decortication can lower compressive strength severely (Bos et al. 2002), so compression values apply to hand-isolated fibres."
    ],
    "verdict": "Strong and stiff for a plant fibre on the two sources read, but the record is thin: no density, supply or ageing data yet.",
    "recipe": {
      "line": "Flax fibre is a bundle of elongated plant cells. The thick cell walls are mostly cellulose in the G-layer, the fibre-specific layer, where the cellulose microfibrils run almost along the fibre axis.",
      "parts": [
        {
          "name": "Cellulose",
          "role": "Main load-bearing polymer. In the G-layer it is highly crystalline and its microfibrils lie at a small angle to the fibre axis.",
          "share_note": "Up to 90% of the G-layer; the whole-fibre share was not found in the sources read",
          "source": "goudenhooft2019",
          "where": "Cell wall layers section (G-layer description)"
        },
        {
          "name": "Lignin and xylan",
          "role": "Absent from the G-layer, according to the review. Their share in the rest of the cell wall was not found.",
          "share_note": "Absent from the G-layer; other layers not covered",
          "source": "goudenhooft2019",
          "where": "Cell wall layers section (G-layer description)"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The review describes plant fibre manufacturing as a low hazard process for human health, but no safety data sheet was read for flax fibre.",
        "points": [
          {
            "label": "Decortication",
            "line": "Bos et al. 2002 report that the standard decortication process induces kink bands in the fibres, and that these lower compressive strength severely."
          }
        ],
        "gap": "No safety data sheet, PubChem record or dust exposure data for flax fibre was read in this run.",
        "verdict": "No safety data read"
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 9,
    "unreachable": 0,
    "caveats": 1,
    "note": "Read by an AI assistant on 2026-11-01 from the Frontiers review and the WUR abstract page only. Below the site bar: 2 sources, 9 properties, no supply, no ageing data. The 976 MPa row is a second-hand quote and conflicts with the 1500 to 1800 MPa range from Bos et al. 2002."
  },
  "sources": {
    "goudenhooft2019": {
      "title": "Flax (Linum usitatissimum L.) Fibers for Composite Reinforcement: Exploring the Link Between Plant Growth, Cell Walls Development, and Fiber Properties",
      "id": "doi:10.3389/fpls.2019.00411 (Front. Plant Sci. 10, 411); authors C. Goudenhooft, A. Bourmaud, C. Baley",
      "url": "https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2019.00411/full",
      "year": 2019,
      "kind": "paper",
      "license": "open access, Frontiers in Plant Science"
    },
    "bos2002": {
      "title": "Tensile and compressive properties of flax fibres for natural fibre reinforced composites",
      "id": "doi:10.1023/A:1014925621252 (J. Mater. Sci. 37(8), 1683-1692); authors H.L. Bos, M.J.A. van den Oever, O.C.J.J. Peters",
      "url": "https://research.wur.nl/en/publications/tensile-and-compressive-properties-of-flax-fibres-for-natural-fib/",
      "year": 2002,
      "kind": "paper"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/flax-fibre/"
}