{
  "spore": "profile",
  "id": "ptfe-coated-glass-fabric",
  "spore_version": "0.2",
  "family": "glass-and-composites",
  "name": "PTFE-coated glass fabric (Teflon-coated fibreglass)",
  "role": "woven fabric for spacecraft covers and multi-layer insulation outer layers (commercial equivalent of beta cloth)",
  "category": "textiles",
  "type": "beta-cloth",
  "summary": "PTFE-coated glass fabric is a woven glass or silica fibre cloth with a PTFE (Teflon) coating on the fibres. Wikipedia describes beta cloth as PTFE-impregnated silica fibre used on Apollo and Skylab suits. Angst+Pfister Type 5108 is 0.215 mm thick and weighs 455 g/m2, with typical tensile strengths of 2500 N/5cm warp and 1800 N/5cm weft and an operating range of -73 to +260 °C. The Goodfellow 0.08 mm sample has a density of 2.08 g/cm3, a tensile strength of 102 MPa and working temperatures of -130 to 260 °C.",
  "best_for": "Heat-resistant, release-coated cloth for covers and outer layers: an upper working temperature of 260 °C is printed by both Goodfellow and Angst+Pfister",
  "weakest_at": "Lower temperature limit and strength depend on the product: Goodfellow prints -130 °C and Angst+Pfister -73 °C. No atomic oxygen erosion yield for this fabric was found.",
  "identity": {
    "formula": "PTFE-coated woven glass fabric; Goodfellow sample printed as PTFE 75 / Glass 25",
    "designations": [],
    "source": "goodfellow-ptfe-glass",
    "where": "Goodfellow Details section, Formula row; Angst+Pfister Type 5108 Material Data Sheet, Description row"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen",
      "extreme-cold"
    ],
    "applications": [
      "thermal-control",
      "habitats-and-suits",
      "rovers-and-surface-systems"
    ]
  },
  "properties": [
    {
      "benchmark": "density",
      "label": "Density, PTFE-coated glass fabric (Goodfellow 0.08 mm sample)",
      "value": 2.08,
      "bound": "exact",
      "unit": "g/cm3",
      "scope": "material",
      "conditions": {
        "product": "PTFE-coated glass fabric, 0.08 mm sample, Goodfellow SKU 1000113522",
        "temperature": "not printed"
      },
      "method": "Value printed on the product page, Physical Properties tab",
      "status": "ground",
      "source": "goodfellow-ptfe-glass",
      "where": "Physical Properties tab, Density row",
      "source_detail": {
        "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
        "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
        "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, Goodfellow 0.08 mm sample",
      "value": 102,
      "bound": "exact",
      "unit": "MPa",
      "scope": "material",
      "conditions": {
        "product": "0.08 mm sample, Goodfellow SKU 1000113522",
        "test": "not printed on the page"
      },
      "method": "Value printed on the product page, Mechanical Properties tab; no test standard printed",
      "status": "ground",
      "source": "goodfellow-ptfe-glass",
      "where": "Mechanical Properties tab, Tensile strength row",
      "source_detail": {
        "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
        "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
        "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, linked not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation at break, Goodfellow 0.08 mm sample",
      "value": 8,
      "bound": "upper",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "0.08 mm sample, Goodfellow SKU 1000113522",
        "test": "not printed on the page"
      },
      "method": "Printed as less than 8 percent on the product page",
      "status": "ground",
      "source": "goodfellow-ptfe-glass",
      "where": "Mechanical Properties tab, Elongation at break row",
      "source_detail": {
        "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
        "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
        "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, linked not reproduced"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Lower working temperature, Goodfellow 0.08 mm sample",
      "value": -130,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "0.08 mm sample, Goodfellow SKU 1000113522",
        "basis": "working temperature as printed, not a test value"
      },
      "method": "Value printed on the product page as lower working temperature",
      "status": "ground",
      "source": "goodfellow-ptfe-glass",
      "where": "Thermal Properties tab, Lower working temperature row",
      "source_detail": {
        "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
        "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
        "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, linked not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Upper working temperature, Goodfellow 0.08 mm sample",
      "value": 260,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "0.08 mm sample, Goodfellow SKU 1000113522",
        "basis": "working temperature as printed, not a test value"
      },
      "method": "Value printed on the product page as upper working temperature",
      "status": "ground",
      "source": "goodfellow-ptfe-glass",
      "where": "Thermal Properties tab, Upper working temperature row",
      "source_detail": {
        "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
        "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
        "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, linked not reproduced"
      }
    },
    {
      "benchmark": "thickness",
      "label": "Thickness, Goodfellow 0.08 mm sample",
      "value": 0.08,
      "bound": "exact",
      "unit": "mm",
      "scope": "material",
      "conditions": {
        "product": "0.08 mm sample, Goodfellow SKU 1000113522",
        "tolerance_as_printed": "plus or minus 25 %"
      },
      "method": "Value printed on the product page, Details section",
      "status": "ground",
      "source": "goodfellow-ptfe-glass",
      "where": "Details section, Thickness row; Tolerances section",
      "source_detail": {
        "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
        "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
        "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, linked not reproduced"
      }
    },
    {
      "benchmark": "areal_density",
      "label": "Fabric weight, Goodfellow 0.08 mm sample",
      "value": 145,
      "bound": "exact",
      "unit": "g/m2",
      "scope": "material",
      "conditions": {
        "product": "0.08 mm sample, plain weave, Goodfellow SKU 1000113522"
      },
      "method": "Value printed on the product page, Details section",
      "status": "ground",
      "source": "goodfellow-ptfe-glass",
      "where": "Details section, Fabric Weight row",
      "source_detail": {
        "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
        "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
        "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
        "year": 2026,
        "kind": "web",
        "license": "supplier web page, linked not reproduced"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Operating temperature lower limit, Angst+Pfister Type 5108",
      "value": -73,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "Type 5108 PTFE coated fabric",
        "basis": "operating temperature as printed, not a test value"
      },
      "method": "Value printed on the datasheet, Operating Temperature row",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Operating Temperature row (range -73 to +260 °C)",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Operating temperature upper limit, Angst+Pfister Type 5108",
      "value": 260,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "Type 5108 PTFE coated fabric",
        "basis": "operating temperature as printed, not a test value"
      },
      "method": "Value printed on the datasheet, Operating Temperature row",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Operating Temperature row (range -73 to +260 °C)",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "areal_density",
      "label": "Total PTFE coated fabric weight, Angst+Pfister Type 5108",
      "value": 455,
      "bound": "exact",
      "unit": "g/m2",
      "scope": "material",
      "conditions": {
        "product": "Type 5108 PTFE coated fabric",
        "tolerance_as_printed": "plus or minus 5 %"
      },
      "method": "Value printed on the datasheet",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Testing table, Total PTFE coated fabric weight row",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "coating_content",
      "label": "Coating content, Angst+Pfister Type 5108",
      "value": 55,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "product": "Type 5108 PTFE coated fabric",
        "tolerance_as_printed": "plus or minus 2 %"
      },
      "method": "Value printed on the datasheet",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Testing table, Coating row",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, warp, typical, Angst+Pfister Type 5108",
      "value": 2500,
      "bound": "exact",
      "unit": "N/5cm",
      "scope": "material",
      "conditions": {
        "direction": "warp",
        "value_basis": "typical",
        "test_standard": "ISO 1421",
        "strip_width": "5 cm as printed in N/5cm"
      },
      "method": "Typical value printed on the datasheet; minimum 2000 N/5cm printed alongside",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Testing table, Tensile Strength Warp row",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength, weft, typical, Angst+Pfister Type 5108",
      "value": 1800,
      "bound": "exact",
      "unit": "N/5cm",
      "scope": "material",
      "conditions": {
        "direction": "weft",
        "value_basis": "typical",
        "test_standard": "ISO 1421",
        "strip_width": "5 cm as printed in N/5cm"
      },
      "method": "Typical value printed on the datasheet; minimum 1300 N/5cm printed alongside",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Testing table, Tensile Strength Weft row",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "tear_strength",
      "label": "Tear strength, warp, typical, Angst+Pfister Type 5108",
      "value": 40,
      "bound": "exact",
      "unit": "N",
      "scope": "material",
      "conditions": {
        "direction": "warp",
        "value_basis": "typical",
        "test_standard": "ISO 9073-4"
      },
      "method": "Typical value printed on the datasheet; minimum 25 N printed alongside",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Testing table, Tear Strength Warp row",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "coating_adhesion_strength",
      "label": "Coating adhesion strength, Angst+Pfister Type 5108",
      "value": 30,
      "bound": "exact",
      "unit": "N/5cm",
      "scope": "material",
      "conditions": {
        "value_basis": "typical",
        "test_standard": "ISO 2411",
        "strip_width": "5 cm as printed in N/5cm"
      },
      "method": "Typical value printed on the datasheet; minimum 25 N/5cm printed alongside",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Testing table, Coating Adhesion Strength row",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "dielectric_breakdown_voltage",
      "label": "Dielectric breakdown, typical, Angst+Pfister Type 5108",
      "value": 5000,
      "bound": "exact",
      "unit": "V",
      "scope": "material",
      "conditions": {
        "value_basis": "typical",
        "test_standard": "BS2782 part 2"
      },
      "method": "Typical value printed on the datasheet; minimum 2300 V printed alongside",
      "status": "ground",
      "source": "ang-pfister-5108",
      "where": "Testing table, Dielectric Breakdown row",
      "source_detail": {
        "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
        "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
        "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
        "year": 2025,
        "kind": "datasheet",
        "license": "manufacturer datasheet, linked not reproduced"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melting threshold of silica-fibre beta cloth",
      "value": 650,
      "bound": "lower",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "basis": "statement about beta cloth (silica fibre coated with Teflon), not a datasheet value for the coated fabric in this profile"
      },
      "method": "Statement in the Wikipedia lead section; the article gives no test method",
      "status": "ground",
      "note": "Wikipedia says it melts only at temperatures exceeding 650 °C. The article gives no value for the Goodfellow or Angst+Pfister products.",
      "source": "wikipedia-beta-cloth",
      "where": "Lead section",
      "source_detail": {
        "title": "Beta cloth, Wikipedia",
        "id": "Beta cloth article, lead, History and development, Spacecraft uses, Multi-layer insulation role",
        "url": "https://en.wikipedia.org/wiki/Beta_cloth",
        "year": 2026,
        "kind": "web",
        "license": "CC BY-SA 4.0, linked not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Chemical exposure at room temperature (Goodfellow chemical resistance tab)",
      "headline": "Good resistance to alcohols, dilute acids, aromatic hydrocarbons, oils and ketones; poor in concentrated acids.",
      "effect": "Goodfellow rates the 0.08 mm sample Poor for concentrated acids, Good for dilute acids, alcohols, aromatic hydrocarbons, greases and oils, halogenated hydrocarbons and ketones, Good-Fair for alkalis and Fair for halogens. The page gives no test method or exposure time.",
      "rating": "moderate",
      "conditions": {
        "basis": "supplier chemical resistance rating, test conditions not printed",
        "product": "0.08 mm sample, Goodfellow SKU 1000113522"
      },
      "source": "goodfellow-ptfe-glass",
      "where": "Chemical Resistance tab"
    },
    {
      "environment": "Atomic oxygen in low Earth orbit",
      "headline": "The Beta cloth article says the tight weave resists atomic oxygen; no erosion yield for this fabric was found.",
      "effect": "Wikipedia states that the tight weave makes beta cloth more resistant to atomic oxygen, and that is why it is commonly used as the outermost multi-layer insulation layer. The article gives no erosion yield or test condition.",
      "rating": "low",
      "conditions": {
        "basis": "qualitative statement in a Wikipedia article, no test data"
      },
      "source": "wikipedia-beta-cloth",
      "where": "Multi-layer insulation role section"
    },
    {
      "environment": "Storage in light and humidity before use",
      "headline": "Store indoors at about 20 °C and about 50 % relative humidity, away from direct sunlight and liquid water.",
      "effect": "Angst+Pfister recommends indoor storage in clean rooms at about 20 °C and about 50 % relative humidity, storage away from direct sunlight, and avoiding direct contact with liquid water before application. Minimum shelf life is 18 months after production date.",
      "rating": "low",
      "conditions": {
        "basis": "manufacturer storage recommendation, not an ageing test"
      },
      "source": "ang-pfister-5108",
      "where": "Conditions of storage and Shelf life rows"
    },
    {
      "environment": "Atomic oxygen in low Earth orbit, tight versus looser weave",
      "headline": "NASA says a tight weave is essential for long-term durability of beta cloth in atomic oxygen.",
      "effect": "NASA's multilayer insulation guidelines state that a tight weave is essential for long-term durability of Beta cloth in atomic oxygen (AO), and that a looser-weave Beta cloth (Sheldahl G414500) failed to protect underlying layers from AO attack. Looser-weave Beta cloth may be acceptable for areas not exposed to AO. No erosion yield for this fabric was found in the passages read.",
      "rating": "moderate",
      "conditions": {
        "basis": "guideline statement that cites NASA test data for a looser-weave product (Sheldahl G414500); the report does not say whether that product is one of the two products in this profile"
      },
      "source": "nasa-tp-1999-209263",
      "where": "Outer cover discussion, before Table 1"
    },
    {
      "environment": "Low Earth orbit flight exposure (Optical Properties Monitor)",
      "headline": "NASA reports unexpected darkening of beta cloth in the Optical Properties Monitor.",
      "effect": "NASA/TM-1999-209575 discusses beta cloth as an MLI outer cover in the low-Earth orbit (LEO) environment and states: 'Unexpected darkening of the beta cloth in the Optical Properties Monitor'. The passages read give no numeric change in solar absorptance for this fabric.",
      "rating": "moderate",
      "conditions": {
        "basis": "flight observation for beta cloth, qualitative in the passages read; the product grade is not stated"
      },
      "source": "nasa-tm-1999-209575",
      "where": "Introduction, paragraph on beta cloth durability in LEO (text near the start of the report)"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "Wikipedia's PTFE article states that PTFE 'begins to deteriorate at temperatures of about 260 °C (500 °F)' and 'decomposes above 350 °C (662 °F)', with fluorocarbon gases as the main decomposition products. These statements describe the PTFE polymer, not the coated glass fabric; no supplier safety data sheet for this fabric was read.",
        "ghs": [],
        "source": "wikipedia-ptfe",
        "where": "Safety section"
      },
      {
        "text": "The same Wikipedia section says: 'Above those temperatures the degradation by-products can be lethal to birds', and that PTFE fumes can 'cause flu-like symptoms in humans (polymer fume fever)'.",
        "ghs": [],
        "source": "wikipedia-ptfe",
        "where": "Safety section"
      }
    ],
    "failure_risks": [],
    "side_effects": [],
    "handling": [
      {
        "text": "Angst+Pfister recommends indoor storage at about 20 °C and about 50 % relative humidity, away from direct sunlight, and no direct contact with liquid water before application.",
        "source": "ang-pfister-5108",
        "where": "Conditions of storage row"
      },
      {
        "text": "Minimum shelf life is 18 months after the production date, as printed on the Angst+Pfister datasheet.",
        "source": "ang-pfister-5108",
        "where": "Shelf life row"
      }
    ],
    "mitigations": []
  },
  "uses": [
    {
      "application": "thermal-control",
      "device": "Outermost layer of multi-layer insulation on the Space Shuttle and the International Space Station",
      "example": "The Beta cloth article says its tight weave makes it more resistant to atomic oxygen, so it is commonly used as the outermost layer of multi-layer insulation, including on the Space Shuttle and the ISS.",
      "source": "wikipedia-beta-cloth",
      "where": "Multi-layer insulation role section"
    },
    {
      "application": "habitats-and-suits",
      "device": "Apollo and Skylab space suits and the Apollo Thermal Micrometeoroid Garment",
      "example": "The Beta cloth article says NASA adopted the woven, Teflon-coated silica fibre fabric after the 1967 Apollo 1 launch pad fire, for suits and the Apollo Thermal Micrometeoroid Garment.",
      "source": "wikipedia-beta-cloth",
      "where": "History and development section; lead"
    },
    {
      "application": "rovers-and-surface-systems",
      "device": "Curiosity Mars rover",
      "example": "The Beta cloth article lists the Curiosity Mars rover among the uses of beta cloth, without naming the component or giving a number.",
      "source": "wikipedia-beta-cloth",
      "where": "Spacecraft uses section"
    },
    {
      "application": "thermal-control",
      "device": "Platen and element covers, and chute linings in industrial feed equipment",
      "example": "Angst+Pfister says Type 5108 is used for platen and element covers in a variety of industries and for lining chutes and other feed mechanisms.",
      "source": "ang-pfister-5108",
      "where": "Preferred fields row"
    }
  ],
  "supply": [
    {
      "subject": "Fluorspar (calcium fluoride), the source of the hydrogen fluoride used to make fluoropolymers such as PTFE",
      "producers": [
        {
          "country": "China",
          "share_percent": 60,
          "year": 2025
        },
        {
          "country": "Mexico",
          "share_percent": 15,
          "year": 2025
        },
        {
          "country": "Mongolia",
          "share_percent": 15,
          "year": 2025
        },
        {
          "country": "South Africa",
          "share_percent": 4.1,
          "year": 2025
        }
      ],
      "critical_lists": [],
      "recycling": "USGS: synthetic fluorspar may be produced from neutralization of waste, but undesirable impurities constrain its use.",
      "substitutes": [],
      "source": "usgs-fluorspar-2026",
      "where": "World Mine Production and Reserves table, 2025 column (thousand metric tons; world total printed as 10,000). Shares calculated by Space Mushroom as country output divided by the printed world total. Aqueous HF as feedstock for fluoropolymers: Domestic Production and Use section. Recycling: Recycling section."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Goodfellow product page, PTFE-coated glass fabric (SKU 1000113522), sizes page",
      "type": "datasheet",
      "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
      "year": 2026
    },
    {
      "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108 (issued 27.01.2025)",
      "type": "datasheet",
      "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
      "year": 2025
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026, Fluorspar",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf",
      "year": 2026
    },
    {
      "title": "NASA/TP-1999-209263, Multilayer Insulation Material Guidelines",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/19990047691/downloads/19990047691.pdf",
      "year": 1999
    },
    {
      "title": "NASA/TM-1999-209575, Comparison of Observed Beta Cloth Interactions With Simulated and Actual Space Environment",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/19990103958/downloads/19990103958.pdf",
      "year": 1999
    }
  ],
  "gaps": [
    "No vacuum, outgassing, UV or radiation test for this fabric was read in this run.",
    "No atomic oxygen erosion yield for PTFE-coated glass fabric was found; the Wikipedia statement is qualitative only.",
    "Supply covers only fluorspar, the fluorine feedstock for PTFE, from USGS. No producer or feedstock source for the glass or silica fibre was read, and no critical-mineral list was checked for PTFE or glass.",
    "No safety data sheet for this fabric was read. PubChem name lookups for PTFE returned no CID, so the hazard entries use the Wikipedia PTFE safety section, which describes the resin rather than the coated fabric. The Goodfellow page refers to a German safety sheet but prints none of its hazard text.",
    "No failure-mode test (flex fatigue, creasing, tear after heat ageing) was read; Wikipedia gives qualitative statements only.",
    "The equivalence to NASA beta cloth is not stated by Goodfellow or Angst+Pfister. The match rests on the Wikipedia definition of beta cloth as PTFE-coated silica fibre.",
    "Glass or silica fibre type, coating process and PTFE grade are not stated on any page read.",
    "Goodfellow mechanical and electrical values print no test method or standard. Angst+Pfister values are typical values with minimums in the same table.",
    "Tensile strengths are printed in N/5cm (strip force), not MPa; they are kept as printed and not converted, because no safe conversion without the strip width and thickness is printed.",
    "Coating content, tear strength, coating adhesion, areal density and dielectric breakdown voltage use names not listed in property-canon.yaml (dielectric breakdown is in V, not the canonical kV/mm). Areal density and thickness follow names used in other profiles.",
    "Goodfellow sample (0.08 mm, 145 g/m2, PTFE 75 / glass 25) and Angst+Pfister Type 5108 (0.215 mm, 455 g/m2, 55 % coating) are different products. Their values are kept apart and not merged.",
    "The 650 °C melting threshold is a Wikipedia statement about silica-fibre beta cloth, not a datasheet value for the coated fabric.",
    "No product designation code (UNS, EN, ASTM or similar) was found for this fabric. The Goodfellow SKU and product code are supplier codes, not grade designations.",
    "No image was added in this run (media is empty).",
    "Search budget for this turn was used up after one search, so the NASA technical reports and ISO 1421 text on beta cloth were not checked; only the five pages named in sources were read."
  ],
  "story": {
    "why": "PTFE-coated glass fabric is a woven glass or silica cloth coated with PTFE, the fluoropolymer also sold as Teflon. The Wikipedia article calls the silica-fibre version beta cloth. NASA adopted it after the 1967 Apollo 1 fire, and its outer layers of multi-layer insulation must be stronger than the thin inner films, which Wikipedia describes as often thicker plastic reinforced with a scrim such as fiberglass. The two datasheets read here describe different products: a 0.08 mm Goodfellow sample weighing 145 g/m2, and the 0.215 mm, 455 g/m2 Angst+Pfister Type 5108.",
    "uses": [],
    "can_do": [
      {
        "label": "Temperature range",
        "line": "Angst+Pfister gives an operating range of -73 to +260 °C for Type 5108. Goodfellow prints -130 to 260 °C for its 0.08 mm sample, so the lower limits differ between the two products.",
        "scope": "material",
        "value": "-73 to +260 °C"
      },
      {
        "label": "Tensile strength",
        "line": "Angst+Pfister prints typical tensile strengths of 2500 N/5cm in warp and 1800 N/5cm in weft, tested to ISO 1421, with minimums of 2000 and 1300 N/5cm. Goodfellow's 0.08 mm sample is printed at 102 MPa.",
        "scope": "material",
        "value": "2500 N/5cm warp, typical"
      },
      {
        "label": "Electrical insulation",
        "line": "Angst+Pfister prints a typical dielectric breakdown of 5000 V, with a minimum of 2300 V under BS2782 part 2. Goodfellow prints surface and volume resistivity as lower bounds only.",
        "scope": "material",
        "value": "5000 V typical"
      },
      {
        "label": "Melting threshold",
        "line": "The Beta cloth article states that the silica-fibre fabric melts only at temperatures above 650 °C. No datasheet melting value for the coated products was found.",
        "scope": "material",
        "value": "Above 650 °C"
      }
    ],
    "compare": "Among the flexible outer layers and covers in this collection, PTFE-coated glass fabric is a woven cloth rated to 260 °C as its upper working temperature in both datasheets. Its strength is directional, 2500 N/5cm in warp against 1800 N/5cm in weft, so warp and weft should be compared separately. The Goodfellow and Angst+Pfister figures are for different products and thicknesses, so read them as separate examples rather than as a ranking.",
    "compare_rows": [
      {
        "label": "Density",
        "benchmark": "density",
        "scope": "material"
      },
      {
        "label": "Upper service temperature",
        "benchmark": "max_service_temp",
        "scope": "material"
      },
      {
        "label": "Tensile strength",
        "benchmark": "ultimate_tensile_strength",
        "scope": "material"
      }
    ],
    "handling": [
      "Store indoors at about 20 °C and about 50 % relative humidity, away from direct sunlight and liquid water.",
      "Use within 18 months of the production date, as printed on the Angst+Pfister datasheet.",
      "Specify the product, since the Goodfellow sample and Angst+Pfister Type 5108 differ in thickness, weight and lower temperature limit."
    ],
    "good_for": [
      "Covers and outer layers that must hold up to 260 °C in use, printed as the upper working temperature by both suppliers.",
      "Release-coated surfaces: Angst+Pfister describes good release properties in demanding high-temperature applications."
    ],
    "watch_out": [
      "Lower limit: -130 °C for the Goodfellow sample and -73 °C for Angst+Pfister Type 5108.",
      "Concentrated acids are rated Poor by Goodfellow.",
      "No atomic oxygen erosion yield, outgassing or UV test for this fabric was found."
    ],
    "verdict": "PTFE-coated glass fabric is a heat-resistant, release-coated cloth. Angst+Pfister Type 5108 and the Goodfellow sample both print a 260 °C upper working temperature, but their lower limits, thickness and weight differ. The strongest sourced values are the Angst+Pfister strengths and operating range. Hazard data are limited to Wikipedia's PTFE safety statements, supply is limited to the fluorspar feedstock chain, and no supplier safety data sheet or space-exposure test data for this fabric are in this profile.",
    "recipe": {
      "line": "PTFE-coated glass fabric is a plain-woven cloth of glass or silica fibre with a PTFE (Teflon) coating on the fibres. Wikipedia describes beta cloth as PTFE-impregnated silica fibre. The Goodfellow sample is printed as PTFE 75 / Glass 25, and Angst+Pfister gives a coating content of 55 % for Type 5108. The sources read do not describe the coating process.",
      "parts": [
        {
          "name": "PTFE coating",
          "role": "Coats the fibres. Wikipedia gives the PTFE repeat unit as -(F2C-CF2)n-, and says the coating reduces creasing and tearing of beta cloth.",
          "share_note": "Goodfellow formula printed as PTFE 75; Angst+Pfister coating 55 %"
        },
        {
          "name": "Glass or silica fibre",
          "role": "Woven base cloth. Goodfellow calls it glass and Wikipedia calls it silica fibre, similar to glass fibre; the Wikipedia article says it melts only above 650 °C.",
          "share_note": "Goodfellow formula printed as Glass 25"
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "No safety data sheet for this product was read in this run, so no GHS classification is recorded.",
        "points": [
          {
            "label": "Handling",
            "line": "Angst+Pfister recommends indoor storage at about 20 °C and about 50 % relative humidity, and keeping the fabric away from direct sunlight and liquid water before use."
          }
        ],
        "level": 0,
        "verdict": "Not classified in the sources read; no safety sheet read"
      },
      {
        "title": "If it fails",
        "lead": "The sources read give no failure test with a number for this fabric. Heat and atomic oxygen are the two limits they describe.",
        "points": [
          {
            "label": "Heat",
            "line": "Wikipedia states that beta cloth melts only at temperatures exceeding 650 °C. Goodfellow prints an upper working temperature of 260 °C and Angst+Pfister an operating range of -73 to +260 °C."
          },
          {
            "label": "Atomic oxygen",
            "line": "Wikipedia states that the tight weave resists atomic oxygen. No erosion yield for this fabric was found."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 17,
    "unreachable": 0,
    "caveats": 3,
    "note": "Read by an AI assistant on 2026-11-01 from the Goodfellow product page, the Angst+Pfister Type 5108 datasheet (PDF text extracted with pdftotext) and three Wikipedia pages (Beta cloth, Polytetrafluoroethylene, Multi-layer insulation). Caveats: Goodfellow and Angst+Pfister describe different products; Wikipedia values are not datasheet values; tensile values are in N/5cm."
  },
  "sources": {
    "goodfellow-ptfe-glass": {
      "title": "Goodfellow, PTFE-coated glass fabric, 0.08 mm sample (SKU 1000113522), sizes page",
      "id": "Goodfellow product 1000113522, product code FP31-FC-000110",
      "url": "https://www.goodfellow.com/eu/ptfe-coated-glass-fabric-sizes-1000113522",
      "year": 2026,
      "kind": "web",
      "license": "supplier web page, linked not reproduced"
    },
    "ang-pfister-5108": {
      "title": "Angst+Pfister Material Data Sheet, PTFE coated glass fabric, Type 5108",
      "id": "Angst+Pfister TDS 5108, issued 27.01.2025 (PDF text extracted from apsoparts.com copy)",
      "url": "https://apsoparts.com/media/downloads/asset//std.lang.all/c_/v1/TDS_5108_PTFE%20Coated%20Fabric_V1.pdf",
      "year": 2025,
      "kind": "datasheet",
      "license": "manufacturer datasheet, linked not reproduced"
    },
    "wikipedia-beta-cloth": {
      "title": "Beta cloth, Wikipedia",
      "id": "Beta cloth article, lead, History and development, Spacecraft uses, Multi-layer insulation role",
      "url": "https://en.wikipedia.org/wiki/Beta_cloth",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0, linked not reproduced"
    },
    "wikipedia-ptfe": {
      "title": "Polytetrafluoroethylene, Wikipedia",
      "id": "PTFE article, infobox, Production, Properties and Safety sections",
      "url": "https://en.wikipedia.org/wiki/Polytetrafluoroethylene",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0, linked not reproduced"
    },
    "wikipedia-mli": {
      "title": "Multi-layer insulation, Wikipedia",
      "id": "MLI article, Function and design section",
      "url": "https://en.wikipedia.org/wiki/Multi-layer_insulation",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0, linked not reproduced"
    },
    "usgs-fluorspar-2026": {
      "title": "USGS Mineral Commodity Summaries 2026, Fluorspar",
      "id": "Fluorspar chapter, Domestic Production and Use, World Mine Production and Reserves, Events Trends and Issues (PDF text extracted)",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-fluorspar.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (U.S. Government work)"
    },
    "nasa-tp-1999-209263": {
      "title": "NASA/TP-1999-209263, Multilayer Insulation Material Guidelines (Finckenor, Marshall Space Flight Center)",
      "id": "NTRS 19990047691; outer cover discussion and Table 1",
      "url": "https://ntrs.nasa.gov/api/citations/19990047691/downloads/19990047691.pdf",
      "year": 1999,
      "kind": "report",
      "license": "NASA technical report (public)"
    },
    "nasa-tm-1999-209575": {
      "title": "NASA/TM-1999-209575, Comparison of Observed Beta Cloth Interactions With Simulated and Actual Space Environment (Kamenetzky and Finckenor)",
      "id": "NTRS 19990103958; introduction on beta cloth durability in LEO",
      "url": "https://ntrs.nasa.gov/api/citations/19990103958/downloads/19990103958.pdf",
      "year": 1999,
      "kind": "report",
      "license": "NASA technical report (public)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/ptfe-coated-glass-fabric/"
}