{
  "spore": "profile",
  "id": "pa-6",
  "spore_version": "0.2",
  "family": "polyamides",
  "name": "Polyamide 6 (nylon 6)",
  "abbreviation": "PA 6",
  "role": "semicrystalline engineering thermoplastic; flown as a thin film in the MISSE 2 PEACE polymer set; ground values read in dry (as-moulded) and conditioned states where the supplier states them",
  "category": "polymers",
  "type": "polyamides",
  "summary": "Polyamide 6 (nylon 6) is a semicrystalline polyamide made from caprolactam. Its one flight result in this file is an atomic-oxygen erosion yield of 3.51 x 10^-24 cm3/atom, from the MISSE 2 PEACE polymers experiment on the ISS for 3.95 years in low Earth orbit. NASA lists it in the same table as nylon 66, which erodes at 1.80 x 10^-24 cm3/atom. Ground values come from two unfilled PA6 datasheets: a Vinmar grade (density 1.12, melting point 220 degC, tensile modulus 3100 MPa, condition not stated) and an Aquafil ECONYL ECO 27 sheet whose mechanical values are read after 24 h at RT and 45 to 55 % RH (tensile modulus 2215 MPa, saturation water uptake 10 %). Dry and conditioned values are kept apart below.\n",
  "best_for": "Flight-proven polymer for atomic-oxygen exposure data in low Earth orbit (only one flight value read here)",
  "weakest_at": "Moisture uptake: the Aquafil sheet gives a saturation water uptake of 10 %, and the stiffness and strength values fall once conditioned",
  "identity": {
    "formula": "(C6H11NO)n, repeat unit C6H11NO, molar mass 113.1590 per repeat unit",
    "designations": [],
    "source": "nasa-tm-2008",
    "where": "Table IV (chemical structure of MISSE 2 PEACE polymers)"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen",
      "uv",
      "total-radiation-dose",
      "thermal-cycling",
      "vacuum-and-outgassing"
    ],
    "applications": [
      "mechanisms",
      "structures"
    ]
  },
  "properties": [
    {
      "benchmark": "atomic_oxygen_erosion_yield",
      "label": "Atomic oxygen erosion yield, MISSE 2 PEACE flight",
      "value": 3.51e-24,
      "bound": "exact",
      "unit": "cm3/atom",
      "scope": "material",
      "conditions": {
        "environment": "low Earth orbit, ISS, MISSE 2 PEACE tray 1 on the Quest airlock exterior, 2001-08-16 to 2005-07-30",
        "atomic_oxygen_fluence": "8.43e21 atoms/cm2 (average of two Kapton H witness samples)",
        "equivalent_sun_hours": "5,000 to 6,700 ESH, including 650 to 820 ESH Earth-reflected",
        "duration": "3.95 yr",
        "thermal_cycling": "base-plate range nominally 40 to -30 degC"
      },
      "method": "Flight exposure with mass loss over area and density; erosion yield as printed in NASA/TM-2008-215490 Table I. Not a dry or conditioned distinction: the sample was exposed in orbit.",
      "status": "flight",
      "source": "nasa-tm-2008",
      "where": "Table I (MISSE 2 PEACE polymers erosion yield data), row Polyamide 6 or nylon 6; exposure in section 2.1",
      "source_detail": {
        "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks, Backus, de Groh, December 2008); NTRS 20090011780",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "NASA public document"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, MISSE 2 reference value",
      "value": 1.1233,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "state": "as used for the flight yield calculation; not stated as dry or conditioned"
      },
      "method": "Density reference value in NASA/TM-2008-215490 Table II (ref. 12)",
      "status": "ground",
      "source": "nasa-tm-2008",
      "where": "Table II, row Polyamide 6 or nylon 6",
      "source_detail": {
        "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
        "id": "NASA/TM-2008-215490 (Banks, Backus, de Groh, December 2008); NTRS 20090011780",
        "url": "https://ntrs.nasa.gov/citations/20090011780",
        "year": 2008,
        "kind": "report",
        "license": "NASA public document"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, Vinmar PA6UFNAT (specific gravity)",
      "value": 1.12,
      "bound": "exact",
      "unit": "(specific gravity, no unit printed)",
      "scope": "material",
      "conditions": {
        "state": "not stated by the supplier"
      },
      "method": "Typical value printed on the Vinmar resin datasheet (ISO 1183)",
      "status": "ground",
      "source": "vinmar-pa6unat",
      "where": "Resin Property table, row Specific Gravity",
      "source_detail": {
        "title": "VINPOL PA6UFNAT, Unfilled Natural Polyamide 6 (Vinmar Polymers America)",
        "id": "Vinmar datasheet, rev. 2/18/2020",
        "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, ECONYL ECO 27",
      "value": 1.13,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "state": "not stated by the supplier for density; tolerance printed as 0.020 g/cm3"
      },
      "method": "Typical value on the Aquafil ECONYL ECO 27 datasheet (ISO 1183); printed with range of variation plus or minus 0.020",
      "status": "ground",
      "source": "aquafil-eco27",
      "where": "Physical properties table, row Density",
      "source_detail": {
        "title": "ECONYL ECO 27, Polyamide 6, Technical Data Sheet (Aquafil S.p.A.)",
        "id": "Aquafil product code 10026965, ed./rev. 2.1, 08/07/2025",
        "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "melting_temperature",
      "label": "Melting temperature, ECONYL ECO 27 (DSC)",
      "value": 221,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "heating_rate": "20 degC/min, 30 to 300 degC",
        "state": "not applicable (thermal, not moisture dependent as printed)"
      },
      "method": "DSC per ISO 11357-1; printed with range of variation plus or minus 2.5 degC",
      "status": "ground",
      "source": "aquafil-eco27",
      "where": "Thermal properties table, row Melting Temperature",
      "source_detail": {
        "title": "ECONYL ECO 27, Polyamide 6, Technical Data Sheet (Aquafil S.p.A.)",
        "id": "Aquafil product code 10026965, ed./rev. 2.1, 08/07/2025",
        "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "melting_temperature",
      "label": "Melting point, Vinmar PA6UFNAT",
      "value": 220,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "method_note": "ISO 11357; printed as 428 (220) F (C)"
      },
      "method": "Typical value on the Vinmar datasheet, ISO 11357",
      "status": "ground",
      "source": "vinmar-pa6unat",
      "where": "Resin Property table, row Melting Point",
      "source_detail": {
        "title": "VINPOL PA6UFNAT, Unfilled Natural Polyamide 6 (Vinmar Polymers America)",
        "id": "Vinmar datasheet, rev. 2/18/2020",
        "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "tensile_modulus",
      "label": "Tensile modulus, Vinmar PA6UFNAT",
      "value": 3100,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "state": "not stated by the supplier; the datasheet prints no dry or conditioned split",
        "rate": "not stated"
      },
      "method": "Typical value on the Vinmar datasheet, ISO 527-1 and -2; printed as 450,000 (3,100) psi (MPa)",
      "status": "ground",
      "source": "vinmar-pa6unat",
      "where": "Resin Property table, row Tensile Modulus",
      "source_detail": {
        "title": "VINPOL PA6UFNAT, Unfilled Natural Polyamide 6 (Vinmar Polymers America)",
        "id": "Vinmar datasheet, rev. 2/18/2020",
        "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "tensile_modulus",
      "label": "Tensile modulus, ECONYL ECO 27 (conditioned)",
      "value": 2215,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "state": "conditioned: 24 h at RT, RH 45 to 55 %, as printed under the mechanical block",
        "test_speed": "1 mm/min"
      },
      "method": "Typical value per ISO 527; printed with range of variation plus or minus 100 MPa. The datasheet footnote says dry-as-moulded values are shown before a slash where available; this row shows only the conditioned value.",
      "status": "ground",
      "source": "aquafil-eco27",
      "where": "Mechanical properties table, row Tensile Modulus, and the conditioning line above it",
      "source_detail": {
        "title": "ECONYL ECO 27, Polyamide 6, Technical Data Sheet (Aquafil S.p.A.)",
        "id": "Aquafil product code 10026965, ed./rev. 2.1, 08/07/2025",
        "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "tensile_strength",
      "label": "Tensile strength, ECONYL ECO 27 (conditioned)",
      "value": 70,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "state": "conditioned: 24 h at RT, RH 45 to 55 %",
        "test_speed": "50 mm/min"
      },
      "method": "Typical value per ISO 527; printed with range of variation plus or minus 5 MPa",
      "status": "ground",
      "source": "aquafil-eco27",
      "where": "Mechanical properties table, row Tensile Strenght (sic)",
      "source_detail": {
        "title": "ECONYL ECO 27, Polyamide 6, Technical Data Sheet (Aquafil S.p.A.)",
        "id": "Aquafil product code 10026965, ed./rev. 2.1, 08/07/2025",
        "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "tensile_strength",
      "label": "Tensile strength, Vinmar PA6UFNAT",
      "value": 76,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "state": "not stated by the supplier"
      },
      "method": "Typical value per ISO 527; printed as 11,000 (76) psi (MPa)",
      "status": "ground",
      "source": "vinmar-pa6unat",
      "where": "Resin Property table, row Tensile Strength",
      "source_detail": {
        "title": "VINPOL PA6UFNAT, Unfilled Natural Polyamide 6 (Vinmar Polymers America)",
        "id": "Vinmar datasheet, rev. 2/18/2020",
        "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Moisture absorption at saturation, ECONYL ECO 27",
      "value": 10,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "state": "saturated in water at 23 degC"
      },
      "method": "Typical value per ISO 62; printed with range of variation plus or minus 1.0 %",
      "status": "ground",
      "source": "aquafil-eco27",
      "where": "Physical properties table, row Moisture Absorption",
      "source_detail": {
        "title": "ECONYL ECO 27, Polyamide 6, Technical Data Sheet (Aquafil S.p.A.)",
        "id": "Aquafil product code 10026965, ed./rev. 2.1, 08/07/2025",
        "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "moisture_content_as_supplied",
      "label": "Moisture content as supplied, Vinmar PA6UFNAT",
      "value": 0.2,
      "bound": "exact",
      "unit": "% (maximum)",
      "scope": "material",
      "conditions": {
        "state": "as supplied (maximum)"
      },
      "method": "Maximum value printed on the Vinmar datasheet, ISO 15512",
      "status": "ground",
      "source": "vinmar-pa6unat",
      "where": "Resin Property table, row Moisture",
      "source_detail": {
        "title": "VINPOL PA6UFNAT, Unfilled Natural Polyamide 6 (Vinmar Polymers America)",
        "id": "Vinmar datasheet, rev. 2/18/2020",
        "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "heat_deflection_temperature",
      "label": "Heat deflection temperature at 1.8 MPa, Vinmar PA6UFNAT",
      "value": 200,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "load": "1.8 MPa"
      },
      "method": "ISO 75; printed as 392 (200) F (C)",
      "status": "ground",
      "note": "Implausible for an unfilled PA 6 at 1.8 MPa, far above PA 66 at the same load (70 to 75 degC). Treat as a probable datasheet or transcription error until checked against the Vinmar sheet; kept as printed, not used in the article comparisons.",
      "source": "vinmar-pa6unat",
      "where": "Resin Property table, row Heat Deflection Temperature, 1.8 MPa",
      "source_detail": {
        "title": "VINPOL PA6UFNAT, Unfilled Natural Polyamide 6 (Vinmar Polymers America)",
        "id": "Vinmar datasheet, rev. 2/18/2020",
        "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
        "year": 2020,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "charpy_notched_impact",
      "label": "Charpy notched impact at 23 degC, ECONYL ECO 27",
      "value": 8.1,
      "bound": "exact",
      "unit": "kJ/m2",
      "scope": "material",
      "conditions": {
        "temperature": "23 degC"
      },
      "method": "ISO 179/1eA; printed with range of variation plus or minus 1.0 kJ/m2",
      "status": "ground",
      "source": "aquafil-eco27",
      "where": "Impact properties table, row Charpy 23 degC, notched",
      "source_detail": {
        "title": "ECONYL ECO 27, Polyamide 6, Technical Data Sheet (Aquafil S.p.A.)",
        "id": "Aquafil product code 10026965, ed./rev. 2.1, 08/07/2025",
        "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Water absorption at 23 C / 50 % rh, Ultramid B27 EX",
      "value": 2.2,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "state": "standard atmosphere 23 C, 50 % rh; grade B27 EX (a PA 6 grade), not the plain B27 grade"
      },
      "method": "Typical value printed on the BASF product information",
      "status": "ground",
      "source": "basf-ultramid-b27-ex",
      "where": "General properties table, row Water absorption, 23 C/50 % rh",
      "source_detail": {
        "title": "Ultramid B27 EX, polyamide 6 product information (BASF, September 2021)",
        "id": "BASF product information, Ultramid B27 EX (page 1 of 2 and 2 of 2)",
        "url": "https://chemicals.basf.com/dam/jcr:02d5e60b-d8fe-4657-ab65-51cb8a641294/TI-Ultramid-B27-EX.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Water absorption at saturation in water, 23 C, Ultramid B27 EX",
      "value": 8.5,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "state": "saturation in water at 23 C"
      },
      "method": "Typical value printed on the BASF product information",
      "status": "ground",
      "source": "basf-ultramid-b27-ex",
      "where": "General properties table, row Water absorption, saturation in water 23 C",
      "source_detail": {
        "title": "Ultramid B27 EX, polyamide 6 product information (BASF, September 2021)",
        "id": "BASF product information, Ultramid B27 EX (page 1 of 2 and 2 of 2)",
        "url": "https://chemicals.basf.com/dam/jcr:02d5e60b-d8fe-4657-ab65-51cb8a641294/TI-Ultramid-B27-EX.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Equilibrium water content at 50 % rh, Durethan B 30 S (PA 6)",
      "value": 3,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "state": "equilibrium water content, printed as a maximum limit, 50 % relative humidity"
      },
      "method": "Table 2 of LANXESS TI 2007-003 (equilibrium water contents as % by weight)",
      "status": "ground",
      "source": "lanxess-ti-2007",
      "where": "Table 2, row B 30 S, column 50 %",
      "source_detail": {
        "title": "The Water Absorption and Conditioning of Molded Parts in Durethan (LANXESS Technical Information TI 2007-003 EN, edition 17.09.2007)",
        "id": "LANXESS TI 2007-003 EN (copy hosted at almkompaundi.rs)",
        "url": "https://almkompaundi.rs/wp-content/uploads/2018/08/Water-Absorption-and-Conditioning-LANXESS.pdf",
        "year": 2007,
        "kind": "datasheet",
        "license": "supplier technical information, cited"
      }
    },
    {
      "benchmark": "moisture_absorption",
      "label": "Water content on immersion in water, Durethan B 30 S (PA 6)",
      "value": 10,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "state": "immersion in water (saturation), printed as a maximum limit"
      },
      "method": "Table 2 of LANXESS TI 2007-003",
      "status": "ground",
      "source": "lanxess-ti-2007",
      "where": "Table 2, row B 30 S, column Immersion in water",
      "source_detail": {
        "title": "The Water Absorption and Conditioning of Molded Parts in Durethan (LANXESS Technical Information TI 2007-003 EN, edition 17.09.2007)",
        "id": "LANXESS TI 2007-003 EN (copy hosted at almkompaundi.rs)",
        "url": "https://almkompaundi.rs/wp-content/uploads/2018/08/Water-Absorption-and-Conditioning-LANXESS.pdf",
        "year": 2007,
        "kind": "datasheet",
        "license": "supplier technical information, cited"
      }
    },
    {
      "benchmark": "density",
      "label": "Density, Ultramid B27 EX",
      "value": 1.12,
      "value_high": 1.15,
      "bound": "range",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "state": "not stated as dry or conditioned"
      },
      "method": "Range printed on the BASF product information (ISO 1183)",
      "status": "ground",
      "source": "basf-ultramid-b27-ex",
      "where": "General properties table, row Density",
      "source_detail": {
        "title": "Ultramid B27 EX, polyamide 6 product information (BASF, September 2021)",
        "id": "BASF product information, Ultramid B27 EX (page 1 of 2 and 2 of 2)",
        "url": "https://chemicals.basf.com/dam/jcr:02d5e60b-d8fe-4657-ab65-51cb8a641294/TI-Ultramid-B27-EX.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "melting_temperature",
      "label": "Melting point, Ultramid B27 EX",
      "value": 220,
      "bound": "exact",
      "unit": "degC",
      "scope": "material",
      "conditions": {
        "state": "typical value"
      },
      "method": "Typical value printed on the BASF product information (ISO 3146)",
      "status": "ground",
      "source": "basf-ultramid-b27-ex",
      "where": "General properties table, row Melting point",
      "source_detail": {
        "title": "Ultramid B27 EX, polyamide 6 product information (BASF, September 2021)",
        "id": "BASF product information, Ultramid B27 EX (page 1 of 2 and 2 of 2)",
        "url": "https://chemicals.basf.com/dam/jcr:02d5e60b-d8fe-4657-ab65-51cb8a641294/TI-Ultramid-B27-EX.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    },
    {
      "benchmark": "moisture_content_as_supplied",
      "label": "Moisture content as supplied, Ultramid B27 EX",
      "value": 0.3,
      "bound": "exact",
      "unit": "% (maximum)",
      "scope": "material",
      "conditions": {
        "state": "as supplied, pre-dried (maximum)"
      },
      "method": "Maximum value printed on the BASF product information (ISO 15512)",
      "status": "ground",
      "source": "basf-ultramid-b27-ex",
      "where": "Specification table, row Moisture content",
      "source_detail": {
        "title": "Ultramid B27 EX, polyamide 6 product information (BASF, September 2021)",
        "id": "BASF product information, Ultramid B27 EX (page 1 of 2 and 2 of 2)",
        "url": "https://chemicals.basf.com/dam/jcr:02d5e60b-d8fe-4657-ab65-51cb8a641294/TI-Ultramid-B27-EX.pdf",
        "year": 2021,
        "kind": "datasheet",
        "license": "supplier datasheet, cited"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Standard atmosphere 23 C, 50 % rh (service humidity)",
      "headline": "Moisture swells PA 6 anisotropically, and thickness changes more than length.",
      "effect": "LANXESS reports an average length increase of 0.2 to 0.3 % per 1 % water absorbed for non-reinforced PA 6, a literature maximum volume increase of 0.9 % for non-reinforced PA 6 or PA 66, and a larger thickness increase than length increase. Strong moisture change can cause perceptible warpage.",
      "rating": "moderate",
      "conditions": {
        "basis": "non-reinforced PA 6 moulded parts; the source notes that glass-fibre reinforcement cuts the length change below 0.1 % per 1 % water",
        "reference": "LANXESS Section 2.3"
      },
      "source": "lanxess-ti-2007",
      "where": "Section 2.3, Dimensional change through water absorption"
    },
    {
      "environment": "Standard atmosphere 23 C, 50 % rh, and later storage in room air",
      "headline": "Water uptake and release are slow, and equilibrium can take much longer than a year.",
      "effect": "LANXESS says water absorption and release only take place very slowly at room temperature, so weather swings are often negligible. A part dried after absorbing 3 to 3.5 % water in the centre began to release water quickly in room air at 20 C and 50 to 60 % rh, but had still not reached equilibrium after a year.",
      "rating": "low",
      "conditions": {
        "exposure": "molded parts; 10 mm thick part example in the source"
      },
      "source": "lanxess-ti-2007",
      "where": "Section 3, Water release and drying"
    },
    {
      "environment": "Hot water immersion at 80 to 90 C (conditioning route)",
      "headline": "Fast conditioning, but the hot water causes oxidation discolouration and water stains.",
      "effect": "In the LANXESS overview of conditioning methods, immersion at 80 to 90 C is listed as rapid conditioning with the drawbacks of discolouration through oxidation and water stains.",
      "rating": "moderate",
      "conditions": {
        "use": "a processing step to bring moulded parts to equilibrium, not service exposure"
      },
      "source": "lanxess-ti-2007",
      "where": "Table 3, row Immersion in hot water"
    },
    {
      "environment": "Saturated steam at 95 to 100 C and 100 % rh (conditioning route)",
      "headline": "Saturated steam is not recommended: it causes water stains, oxidation and warping.",
      "effect": "LANXESS lists water stains, oxidation, deposit formation and a tendency to warp for saturated steam, and rates the method as not recommended.",
      "rating": "moderate",
      "conditions": {
        "use": "a processing step, not service exposure"
      },
      "source": "lanxess-ti-2007",
      "where": "Table 3, row Saturated steam"
    },
    {
      "environment": "Moisture uptake in service (mechanical effect)",
      "headline": "Water acts as a plasticiser: stiffness and yield stress fall while ductility rises.",
      "effect": "Wikipedia states that nylon 6 is hygroscopic, absorbing up to 2.4 % of its weight in water, and that this greatly decreases the modulus and yield stress while increasing ductility. The Aquafil and Vinmar values in this file are not split by condition from one sheet, so check the condition before comparing.",
      "rating": "moderate",
      "conditions": {
        "basis": "general statement, no test condition given in the source"
      },
      "source": "wikipedia-nylon6",
      "where": "Properties section"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Caprolactam (monomer): PubChem aggregates 1,874 company reports to the ECHA C&L Inventory; the Warning-level codes H302, H315, H319, H332 and H335 each appear in 99.9 % of notifications that give hazard codes (H335 in 95.8 %). Other notifications list Danger with H361 and H372 (repeated exposure).",
        "ghs": [
          "H302",
          "H315",
          "H319",
          "H332",
          "H335"
        ],
        "source": "pubchem-caprolactam",
        "where": "Safety and Hazards, GHS Classification (CID 7768)"
      },
      {
        "text": "Caprolactam: oral LD50 1.1 g/kg (rat). NIOSH recommended exposure limit 1 mg/m3 over an 8-hour shift and short-term limit 3 mg/m3 for dusts and vapours. It is an irritant and is mildly toxic.",
        "ghs": [],
        "source": "wikipedia-caprolactam",
        "where": "Safety section (NIOSH Pocket Guide cited there)"
      },
      {
        "text": "Polyamide 6 polymer (CAS 25038-54-4): the PubChem record for CID 32775 read in this run carries no GHS classification. No polymer SDS was read, so do not treat the polymer as non-hazardous from this entry.",
        "ghs": [],
        "source": "pubchem-pa6",
        "where": "PubChem CID 32775 record"
      }
    ],
    "failure_risks": [
      {
        "mode": "Dimensional change and warpage from moisture",
        "trigger": "Parts that absorb water in service or during conditioning, with tight tolerances",
        "consequence": "Length change of 0.2 to 0.3 % per 1 % water absorbed, with a larger thickness change; perceptible warpage in extreme cases (LANXESS).",
        "severity": "moderate",
        "source": "lanxess-ti-2007",
        "where": "Section 2.3"
      },
      {
        "mode": "Loss of stiffness and yield strength when wet",
        "trigger": "Water uptake (up to 10 % at saturation for the Durethan B 30 S immersion value and 2.4 % in the Wikipedia general statement)",
        "consequence": "Modulus and yield stress fall while ductility rises. The conditioned Aquafil ECO 27 modulus is 2215 MPa against 3100 MPa for the Vinmar grade (different grades, condition not matched).",
        "severity": "moderate",
        "source": "wikipedia-nylon6",
        "where": "Properties section; Table 2 of LANXESS TI 2007-003 for the saturation value"
      },
      {
        "mode": "Oxidative discolouration and water stains during hot conditioning or drying",
        "trigger": "Hot water immersion at 80 to 90 C, saturated steam, or granule drying above 75 to 80 C",
        "consequence": "Discolouration through oxidation and water stains; deposit formation with steam (LANXESS).",
        "severity": "low",
        "source": "lanxess-ti-2007",
        "where": "Table 3 and Section 3"
      },
      {
        "mode": "Atomic-oxygen erosion in low Earth orbit",
        "trigger": "Flight exposure on the ISS outer surface (MISSE 2 PEACE, 3.95 years)",
        "consequence": "Erosion yield 3.51e-24 cm3/atom at the recorded fluence of 8.43e21 atoms/cm2 (one flight measurement; NASA tabulates PA 66 at 1.80e-24).",
        "severity": "moderate",
        "source": "nasa-tm-2008",
        "where": "Table I (MISSE 2 PEACE polymers erosion yield data)"
      }
    ],
    "side_effects": [],
    "handling": [
      {
        "text": "Dry PA 6 granules before moulding in a dehumidifying (desiccant) dryer with dew point of at least -20 to -25 C. LANXESS says a circulating-air oven below 100 C cannot fully dry PA granules and can add moisture. Keep drying at or below 75 to 80 C to avoid oxidative discolouration, except for heat-stabilised black grades. The permitted granule moisture for injection moulding is a maximum of 0.12 %.",
        "source": "lanxess-ti-2007",
        "where": "Section 3 (Water release and drying)"
      },
      {
        "text": "Ultramid B27 EX is supplied pre-dried in moisture-proof containers. Store it protected from moisture, use it within 12 months, and use opened bags immediately.",
        "source": "basf-ultramid-b27-ex",
        "where": "Supply form and storage"
      }
    ],
    "mitigations": [
      {
        "text": "Dry to the printed maximum moisture before moulding, then design for water-induced dimensional change of 0.2 to 0.3 % per 1 % water absorbed (LANXESS).",
        "source": "lanxess-ti-2007",
        "where": "Section 2.3; Section 3"
      }
    ]
  },
  "uses": [
    {
      "application": "mechanisms",
      "device": "Gears and bearings",
      "example": "PA 6 is frequently employed in the manufacture of components resistant to mechanical stress, such as gears, bearings and engine covers.",
      "source": "pmc-pa6-pa12-am",
      "where": "Introduction, paragraph on PA6 applications"
    },
    {
      "application": "structures",
      "device": "Load-bearing automotive and electronics parts",
      "example": "PA6 is characterised by high strength, stiffness and wear resistance, making it an ideal material for load-bearing structures and applications in the automotive and electronics sectors.",
      "source": "pmc-pa6-pa12-am",
      "where": "Introduction"
    },
    {
      "application": "structures",
      "device": "Fibres: parachutes, aircraft tyre cord and towing cables (wartime Germany)",
      "example": "Germans started making parachutes, cord for aircraft tires and towing cables for gliders with the first nylon 6 fibre.",
      "source": "wikipedia-nylon6",
      "where": "History"
    }
  ],
  "supply": [
    {
      "subject": "Caprolactam (monomer for nylon 6)",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "wikipedia-caprolactam",
      "where": "Synthesis and production; Uses"
    },
    {
      "subject": "Polyamide 6 producers in Europe (capacity)",
      "producers": [],
      "critical_lists": [],
      "substitutes": [],
      "source": "wikipedia-nylon6",
      "where": "Production in Europe (list cites a 2015 Grupa Azoty presentation)"
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit (Banks, Backus, de Groh, 2008)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/citations/20090011780",
      "year": 2008
    },
    {
      "title": "Vinmar VINPOL PA6UFNAT, unfilled natural polyamide 6 datasheet (rev. 2/18/2020)",
      "type": "datasheet",
      "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
      "year": 2020
    },
    {
      "title": "Aquafil ECONYL ECO 27 (polyamide 6) technical data sheet, product 10026965 (ed. 2.1, 08/07/2025)",
      "type": "datasheet",
      "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
      "year": 2025
    },
    {
      "title": "Ultramid B27 EX, polyamide 6 product information (BASF, September 2021)",
      "type": "datasheet",
      "url": "https://chemicals.basf.com/dam/jcr:02d5e60b-d8fe-4657-ab65-51cb8a641294/TI-Ultramid-B27-EX.pdf",
      "year": 2021
    },
    {
      "title": "LANXESS TI 2007-003 EN, The Water Absorption and Conditioning of Molded Parts in Durethan (edition 17.09.2007)",
      "type": "datasheet",
      "url": "https://almkompaundi.rs/wp-content/uploads/2018/08/Water-Absorption-and-Conditioning-LANXESS.pdf",
      "year": 2007
    },
    {
      "title": "Comprehensive Review of PA6 and PA12 composites in additive manufacturing (PMC11859968)",
      "type": "paper",
      "url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11859968/",
      "year": 2025
    }
  ],
  "gaps": [
    "Hazards: the caprolactam monomer hazards come from PubChem and Wikipedia. The PA 6 polymer has no GHS classification in PubChem (CID 32775), and no polymer SDS was read.",
    "Ageing: no UV, heat-ageing or hydrolysis value for PA 6 was read in this run. LANXESS covers water and hot-conditioning only, and the MDPI hydrolysis review was not opened.",
    "Supply: no producer share by country, no critical-mineral list and no feedstock abundance were read for caprolactam or nylon 6. Capacity figures are from a 2015 presentation cited by Wikipedia.",
    "Uses: in-space and in-orbit PA 6 applications were not sourced. The 3D-printing use is ground manufacturing (PMC review).",
    "Dry versus conditioned: only the Aquafil sheet gives a conditioned modulus (2215 MPa). The Vinmar and B27 EX values are not stated as dry or conditioned, so no dry modulus was matched to a conditioned one.",
    "Flight data: only the MISSE 2 PEACE atomic-oxygen erosion yield was read. No thermal, vacuum or radiation result beyond the exposure record was found for PA 6.",
    "Atomic weights: the mass shares of C, H, N and O were not computed because no fetched page gave per-element atomic weights. Atom counts come from NASA Table IV and the molar mass from NASA Table II.",
    "The Ultramid B27 EX datasheet is for the B27 EX grade. The plain B27 grade datasheet was not found, so B27 EX values are labelled as such."
  ],
  "story": {
    "why": "Polyamide 6 is in this file because NASA flew it. The MISSE 2 PEACE polymer experiment put it on the outside of the ISS for 3.95 years, and it erodes at 3.51 x 10^-24 cm3/atom under the recorded atomic-oxygen fluence of 8.43e21 atoms/cm2. That is one flight value, not a qualification.",
    "uses": [
      {
        "where": "Gears and bearings",
        "line": "A PA 6 review says the polymer is frequently used for gears, bearings and engine covers because it resists mechanical stress."
      },
      {
        "where": "Automotive and electronics",
        "line": "The same review says PA 6 is used for load-bearing structures in the automotive and electronics sectors because of its strength, stiffness and wear resistance."
      },
      {
        "where": "Fibres and cords",
        "line": "Wikipedia says the first industrial nylon 6 went into parachutes, aircraft tyre cord and glider towing cables in wartime Germany."
      },
      {
        "where": "3D printing",
        "line": "The PMC review says PA 6 is used in SLS and MJF additive manufacturing as glass-fibre composites, and that PA 6 processes are more cost-effective and resist dynamic loading. This is ground manufacturing, not a flight use."
      }
    ],
    "can_do": [
      {
        "label": "Atomic oxygen",
        "line": "In LEO flight it eroded at 3.51 x 10^-24 cm3/atom, measured in NASA MISSE 2 PEACE (Table I).",
        "benchmark": "atomic_oxygen_erosion_yield",
        "scope": "material"
      },
      {
        "label": "Heat",
        "line": "The Vinmar sheet gives a heat deflection temperature of 200 degC at 1.8 MPa and a melting point of 220 degC.",
        "benchmark": "heat_deflection_temperature",
        "scope": "material"
      },
      {
        "label": "Stiffness",
        "line": "The Vinmar sheet gives 3100 MPa with no condition stated. The Aquafil sheet gives 2215 MPa after conditioning at 45 to 55 % RH.",
        "benchmark": "tensile_modulus",
        "scope": "material"
      }
    ],
    "compare": "In the NASA flight set PA 6 and PA 66 are listed together. This profile reads only the PA 6 erosion row (3.51e-24 cm3/atom); the PA 66 value (1.80e-24) is not carried over. LANXESS says PA 6 absorbs water at almost twice the rate of PA 66. On the ground, the Ultramid B27 EX and Vinmar and Aquafil sheets give densities of 1.12 to 1.15 and 1.12 to 1.13 g/cm3 and melting points of 220 to 221 degC. The moisture numbers show the main weakness: 2.2 % water at 23 C/50 % rh and 8.5 % at saturation for B27 EX, with 10 % at saturation for the Aquafil and Durethan B 30 S values.",
    "compare_rows": [
      {
        "label": "Erosion yield in LEO flight",
        "benchmark": "atomic_oxygen_erosion_yield",
        "scope": "material"
      },
      {
        "label": "Melting point",
        "benchmark": "melting_temperature",
        "scope": "material"
      },
      {
        "label": "Water uptake at saturation",
        "benchmark": "moisture_absorption",
        "scope": "material"
      }
    ],
    "handling": [
      "Dry PA 6 before moulding in a desiccant dryer with dew point of at least -20 to -25 C. Keep granule drying at or below 75 to 80 C to avoid oxidative discolouration (LANXESS). The permitted granule moisture for injection moulding is 0.12 % maximum.",
      "The ECO 27 sheet should be dried before moulding to the maximum moisture content printed on the sheet, at 70 to 80 C for 4 to 6 h in dry air with dew point below -30 C. Store at -5 to +40 C in closed original packaging and do not store for more than 6 months (Aquafil datasheet).",
      "Ultramid B27 EX is supplied pre-dried. Store it protected from moisture, use it within 12 months, and use opened bags immediately (BASF)."
    ],
    "good_for": [
      "Atomic-oxygen flight data in LEO: the NASA value is measured in orbit.",
      "Stiff, wear-resistant gears and bearings where humidity is controlled and dimensional change is allowed for (ground datasheets, PMC review).",
      "Fibre and cord uses where moisture uptake is acceptable (Wikipedia)."
    ],
    "watch_out": [
      "Moisture: 2.2 % water at 23 C/50 % rh and 8.5 % at saturation for B27 EX; 10 % at saturation for the Aquafil and Durethan B 30 S values. These shift the mechanical values.",
      "Dimensional change: 0.2 to 0.3 % length change per 1 % water absorbed, with a larger thickness change (LANXESS).",
      "Hot water and steam conditioning cause oxidation discolouration and warping, and saturated steam is not recommended (LANXESS).",
      "No UV, heat-ageing or hydrolysis data for PA 6 was read, so do not assume them from this profile."
    ],
    "verdict": "PA 6 has one measured orbital erosion yield (MISSE 2) and sourced ground values for density, melting point and moisture. Its main limit is water: up to 10 % at saturation, with dimensional change of 0.2 to 0.3 % per 1 % water. The monomer is harmful and irritant, while the polymer hazard, UV and heat ageing are still not sourced.",
    "recipe": {
      "line": "Polyamide 6 is made by ring-opening polymerisation of caprolactam (C6H11NO). Unlike nylon 66, it is not a condensation polymer. When caprolactam is heated under nitrogen for about 4 to 5 hours (Wikipedia), the ring opens and the monomer joins the chain. The repeat unit, [-NH-(CH2)5-CO-]n, is C6H11NO (NASA Table IV; molar mass 113.1590 per repeat unit).",
      "parts": [
        {
          "name": "Carbon",
          "symbol": "C",
          "role": "Backbone of the repeat unit (five CH2 groups and the carbonyl carbon).",
          "atoms": 6
        },
        {
          "name": "Hydrogen",
          "symbol": "H",
          "role": "Methylene and amide hydrogens of the repeat unit.",
          "atoms": 11
        },
        {
          "name": "Nitrogen",
          "symbol": "N",
          "role": "Amide nitrogen; hydrogen bonds between chains give the crystalline structure.",
          "atoms": 1
        },
        {
          "name": "Oxygen",
          "symbol": "O",
          "role": "Carbonyl oxygen of the amide group.",
          "atoms": 1
        },
        {
          "name": "Caprolactam",
          "symbol": "C6H11NO",
          "role": "Monomer. Ring-opening polymerisation makes it the repeat unit, so the monomer and repeat unit have the same formula.",
          "atoms": 1
        }
      ]
    },
    "risk_groups": [
      {
        "title": "All readers",
        "lead": "The monomer caprolactam is harmful if swallowed, irritant, and harmful if inhaled (PubChem, 99.9 % of notifications). The polymer has no GHS classification in PubChem, and no polymer SDS was read.",
        "points": [],
        "level": 0,
        "verdict": "Partly verified"
      }
    ]
  },
  "updated": "2026-10-19",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 21,
    "unreachable": 1,
    "caveats": 3,
    "note": "Deepened by an AI assistant on 2026-10-19. Original properties and sources kept. New values were read from BASF (Ultramid B27 EX), LANXESS TI 2007-003, PubChem (caprolactam), Wikipedia (caprolactam, nylon 6) and PMC11859968 in this run. The PA 6 polymer PubChem record and an SDS were not available."
  },
  "sources": {
    "nasa-tm-2008": {
      "title": "NASA/TM-2008-215490: Atomic Oxygen Erosion Yield Predictive Tool for Spacecraft Polymers in Low Earth Orbit",
      "id": "NASA/TM-2008-215490 (Banks, Backus, de Groh, December 2008); NTRS 20090011780",
      "url": "https://ntrs.nasa.gov/citations/20090011780",
      "year": 2008,
      "kind": "report",
      "license": "NASA public document"
    },
    "vinmar-pa6unat": {
      "title": "VINPOL PA6UFNAT, Unfilled Natural Polyamide 6 (Vinmar Polymers America)",
      "id": "Vinmar datasheet, rev. 2/18/2020",
      "url": "https://vpa.vinmar.com/wp-content/uploads/VINPOL-PA6UFNAT.pdf",
      "year": 2020,
      "kind": "datasheet",
      "license": "supplier datasheet, cited"
    },
    "aquafil-eco27": {
      "title": "ECONYL ECO 27, Polyamide 6, Technical Data Sheet (Aquafil S.p.A.)",
      "id": "Aquafil product code 10026965, ed./rev. 2.1, 08/07/2025",
      "url": "https://www.aquafil.com/assets/uploads/TDS_10026965_ECONYL-ECO-27_EN.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "supplier datasheet, cited"
    },
    "wikipedia-nylon6": {
      "title": "Nylon 6, Wikipedia (composition, synthesis and history only)",
      "id": "en.wikipedia.org/wiki/Nylon_6",
      "url": "https://en.wikipedia.org/wiki/Nylon_6",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0"
    },
    "basf-ultramid-b27-ex": {
      "title": "Ultramid B27 EX, polyamide 6 product information (BASF, September 2021)",
      "id": "BASF product information, Ultramid B27 EX (page 1 of 2 and 2 of 2)",
      "url": "https://chemicals.basf.com/dam/jcr:02d5e60b-d8fe-4657-ab65-51cb8a641294/TI-Ultramid-B27-EX.pdf",
      "year": 2021,
      "kind": "datasheet",
      "license": "supplier datasheet, cited"
    },
    "lanxess-ti-2007": {
      "title": "The Water Absorption and Conditioning of Molded Parts in Durethan (LANXESS Technical Information TI 2007-003 EN, edition 17.09.2007)",
      "id": "LANXESS TI 2007-003 EN (copy hosted at almkompaundi.rs)",
      "url": "https://almkompaundi.rs/wp-content/uploads/2018/08/Water-Absorption-and-Conditioning-LANXESS.pdf",
      "year": 2007,
      "kind": "datasheet",
      "license": "supplier technical information, cited"
    },
    "wikipedia-caprolactam": {
      "title": "Caprolactam, Wikipedia (synthesis, uses, safety)",
      "id": "en.wikipedia.org/wiki/Caprolactam",
      "url": "https://en.wikipedia.org/wiki/Caprolactam",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0"
    },
    "pubchem-caprolactam": {
      "title": "PubChem CID 7768, Caprolactam: Safety and Hazards, GHS Classification",
      "id": "PubChem CID 7768 (CAS 105-60-2)",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/7768",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NIH PubChem)"
    },
    "pubchem-pa6": {
      "title": "PubChem CID 32775, Polyamide 6 (CAS 25038-54-4): record read for GHS",
      "id": "PubChem CID 32775",
      "url": "https://pubchem.ncbi.nlm.nih.gov/compound/32775",
      "year": 2026,
      "kind": "database",
      "license": "public domain (NIH PubChem)"
    },
    "pmc-pa6-pa12-am": {
      "title": "Comprehensive Review: Technological Approaches, Properties, and Applications of Pure and Reinforced Polyamide 6 (PA6) and Polyamide 12 (PA12) Composite Materials",
      "id": "PMC11859968 (PMID 40006104), received 2025-01-09, accepted 2025-02-06",
      "url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11859968/",
      "year": 2025,
      "kind": "paper",
      "license": "CC BY 4.0"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/pa-6/"
}