PTFE-coated glass fabric (Teflon-coated fibreglass)

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
  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
    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
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, Goodfellow 0.08 mm sample
    value: 102
    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
  - 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
  - benchmark: min_service_temp
    label: Lower working temperature, Goodfellow 0.08 mm sample
    value: -130
    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
  - benchmark: max_service_temp
    label: Upper working temperature, Goodfellow 0.08 mm sample
    value: 260
    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
  - benchmark: thickness
    label: Thickness, Goodfellow 0.08 mm sample
    value: 0.08
    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
  - benchmark: areal_density
    label: Fabric weight, Goodfellow 0.08 mm sample
    value: 145
    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
  - benchmark: min_service_temp
    label: Operating temperature lower limit, Angst+Pfister Type 5108
    value: -73
    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)
  - benchmark: max_service_temp
    label: Operating temperature upper limit, Angst+Pfister Type 5108
    value: 260
    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)
  - benchmark: areal_density
    label: Total PTFE coated fabric weight, Angst+Pfister Type 5108
    value: 455
    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
  - benchmark: coating_content
    label: Coating content, Angst+Pfister Type 5108
    value: 55
    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
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, warp, typical, Angst+Pfister Type 5108
    value: 2500
    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
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, weft, typical, Angst+Pfister Type 5108
    value: 1800
    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
  - benchmark: tear_strength
    label: Tear strength, warp, typical, Angst+Pfister Type 5108
    value: 40
    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
  - benchmark: coating_adhesion_strength
    label: Coating adhesion strength, Angst+Pfister Type 5108
    value: 30
    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
  - benchmark: dielectric_breakdown_voltage
    label: Dielectric breakdown, typical, Angst+Pfister Type 5108
    value: 5000
    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
  - 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
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
    recycling: 'USGS: synthetic fluorspar may be produced from neutralization of waste, but undesirable impurities constrain its use.'
    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.
license: CC-BY-4.0
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)
story:
  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
        share_note: Goodfellow formula printed as PTFE 75; Angst+Pfister coating 55 %
        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.
      - name: Glass or silica fibre
        share_note: Goodfellow formula printed as Glass 25
        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.
  risk_groups:
    - title: For people
      lead: No safety data sheet for this product was read in this run, so no GHS classification is recorded.
      level: 0
      verdict: Not classified in the sources read; no safety sheet read
      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.
    - 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.
  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.'
  can_do:
    - label: Temperature range
      value: '-73 to +260 °C'
      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.
    - label: Tensile strength
      value: 2500 N/5cm warp, typical
      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.
    - label: Electrical insulation
      value: 5000 V typical
      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.
    - label: Melting threshold
      value: Above 650 °C
      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.
  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
    - label: Upper service temperature
      benchmark: max_service_temp
    - label: Tensile strength
      benchmark: ultimate_tensile_strength
  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.