E-glass fibre E-glass
Alumino-borosilicate glass fibre (E-glass): SiO2 with Al2O3, CaO, MgO and B2O3, and alkali oxides below 1% by weight
Also known as E-glass, E-Glas
E-glass is an alumino-borosilicate glass fibre with alkali oxides held below about 1 to 2 percent.
Evidence level
2 of 5
Lab-measured
- 0Predicted only. No one has made it, or no measurement exists.
- 1Calculated. Only calculated or predicted values from sources.
- 2Lab-measured. Measured properties with their conditions stated.
- 3Space-relevant tests. Measured in conditions relevant to space, such as vacuum or atomic oxygen.
- 4Ground-qualified. Qualified for an application on the ground.
- 5Flown or field-proven. Flight or field results exist.
Density
2.59 to 2.62 kg/dm³
Tensile strength
2600 MPa
Stiffness
73 GPa
Elongation
3.5 to 4 %
Softening
825 to 860 °C
Recipe, share of the weight
- SiO2 not printed in the sources readSilica
- Al2O3 not printed in the sources readAlumina
- CaO not printed in the sources readLime
- MgO not printed in the sources readMagnesia
- B2O3 not printed in the sources readBoric oxide
- Na2O + K2O below 1% by weight (Wikipedia, Fiberglass article); below 2% (Wikipedia, Glass fiber article)Alkali oxides
Best for
General reinforcement of polyester, epoxy and vinylester laminates, such as boats, vehicle parts and containers, which are the end uses HP Textiles lists for its E-glass roving fabrics
Weakest at
Chemical resistance is not its strong point: HP Textiles lists C-glass, ECR-glass and boron-free Advantex as the corrosion-resistant types, and no E-glass corrosion value was read in this run
Risk at a glance
- People Low. Fibre size limits set; no E-glass hazard class found
- If it fails No data. No failure risks recorded
- Corrosion No data. No corrosion data recorded
Quick facts: E-glass
| Property | Value | Basis |
|---|---|---|
| Density | 2.59 to 2.62 g/cm³ | 1 sourced value |
| Tensile strength | 2,600 MPa | 1 sourced value |
| Young's modulus | 73 GPa | 1 sourced value |
What is the density of E-glass fibre?
E-glass fibre has a density of 2.59 to 2.62 g/cm³. The source and test conditions are listed in the properties table on this page.
What is the tensile strength of E-glass fibre?
E-glass fibre has a tensile strength of 2,600 MPa. The source and test conditions are listed in the properties table on this page.
What is the Young's modulus of E-glass fibre?
E-glass fibre has a Young's modulus of 73 GPa. The source and test conditions are listed in the properties table on this page.
What are the other names and codes for E-glass fibre?
E-glass fibre is also written as E-glass, E-Glas. Each code is printed in the source listed beside it in the designations table.
What is E-glass fibre used for?
Uses recorded in the sources include Boats and vehicle parts laminated with E-glass roving fabric; Containers and tanks laminated with E-glass roving fabric.
Why it exists
E-glass is an alumino-borosilicate glass fibre. CompositesWorld says it was developed as a more alkali-resistant alternative to soda-lime glass, was among the first glasses drawn into continuous filament, and still makes up most of the world's fibreglass output. HP Textiles weaves E-glass roving yarns into fabrics and prints a density of 2.59 to 2.62 kg/dm³ and a tensile strength of 2600 MPa for the glass type.
Where it's used
Boats and vehicles
HP Textiles lists boat building (Bootsbau) and vehicle construction (Fahrzeugbau) among the end uses of its E-glass roving fabrics.
Containers and tanks
The same list includes container construction (Behälterbau).
Space
No space or vacuum use of E-glass was found in the sources read.
Recipe
Alumino-borosilicate glass fibre (E-glass): SiO2 with Al2O3, CaO, MgO and B2O3, and alkali oxides below 1% by weight
E-glass is an alumino-borosilicate glass. CompositesWorld says it was developed as a more alkali-resistant alternative to soda-lime glass, built on silica, alumina, lime and magnesia, with boron added later. Wikipedia says the batch is melted from silica sand, limestone, kaolin, fluorspar, colemanite and dolomite, and the melt is drawn through bushings. No percentage limits for the main oxides were printed in the sources read.
| Ingredient | Share of the weight | What it does |
|---|---|---|
| Silica SiO2 | not printed in the sources read | Main network former; CompositesWorld lists SiO2 in the E-glass composition. |
| Alumina Al2O3 | not printed in the sources read | Listed in the E-glass composition (aluminum oxide or alumina). |
| Lime CaO | not printed in the sources read | Listed in the E-glass composition (calcium oxide or lime). |
| Magnesia MgO | not printed in the sources read | Listed in the E-glass composition (magnesium oxide or magnesia). |
| Boric oxide B2O3 | not printed in the sources read | Added later to widen the gap between melting and crystallising temperatures, which stops nozzle clogging (CompositesWorld). |
| Alkali oxides Na2O + K2O | below 1% by weight (Wikipedia, Fiberglass article); below 2% (Wikipedia, Glass fiber article) | Kept low so the glass is alkali-free. |
Weight shares are as printed in the sources.
What it can do
Density
2.59 to 2.62 kg/dm³
measured
HP Textiles prints 2.59 to 2.62 kg/dm³ for the E-glass row of its roving-fabric datasheet.
Tensile strength
2600 MPa
measured
The same row prints 2600 MPa. The datasheet does not say whether this is for filament, yarn or fabric.
Stiffness
73 GPa
measured
Young's modulus on the same row is 73 GPa.
Elongation
3.5 to 4 %
measured
Elongation at break on the same row is 3.5 to 4 percent.
Softening
825 to 860 °C
measured
The softening temperature on the same row is 825 to 860 °C.
How it compares
The HP Textiles catalogue sets E-glass against its other glass types. It describes C-glass as having good chemical resistance, ECR-glass (E-glass corrosion resistant) as extremely corrosion resistant, and Advantex as a boron-free glass with significantly improved corrosion resistance. The catalogue gives no E-glass corrosion number, so the comparison is qualitative. For density, the E-glass datasheet row gives 2.59 to 2.62 kg/dm³.
The same measurements for each material, so you can compare them. Each row names the key condition under the value; the full conditions and methods are in the numbered notes under Technical details. Compare every grade in the family.
| Measurement | E-glass |
|---|---|
| Physical and electrical | |
| Density, E-glass glass type | 2.59 to 2.62 kg/dm³1 |
| Other measurements | |
| Softening temperature, E-glass glass type | 825 to 860 °C2 |
| Tensile strength, E-glass glass type | 2600 MPa3 |
| Young's modulus, E-glass glass type | 73 GPa4 |
| Elongation at break, E-glass glass type | 3.5 to 4 %5 |
Why choose it, and why not
Good for
- General reinforcement of polyester, epoxy and vinylester laminates, which HP Textiles names as suitable resins for its E-glass roving fabrics.
- Boats, vehicle parts and containers, which are the end uses HP Textiles lists for its E-glass roving fabrics.
Watch out for
- Chemical resistance: the HP catalogue lists C-glass with good chemical resistance, ECR-glass with extremely high corrosion resistance and boron-free Advantex with improved corrosion resistance. No E-glass corrosion value was read.
- Boron: CompositesWorld reports a trend in E-glass manufacturing toward removing boron, which it calls expensive and a source of undesirable emissions.
- Respirable fibres: the LfU criteria put the most critical fibres at longer than 5 µm, thinner than 3 µm and with a length-to-diameter ratio above 3:1.
E-glass is the common general-purpose reinforcement for polymer laminates (CompositesWorld: most of the world's fibreglass output). This draft has five E-glass values from the HP Textiles datasheet: density, softening range, tensile strength, Young's modulus and elongation. Composition percentages, corrosion data, failure data and an OSHA, IARC or SDS hazard class are still open.
Technical details
For scientists and researchers. Everything above comes from the record below: every number with its method, its conditions and its source.
Other names and standards
The same grade under other systems, as datasheets and standards print them. Each code was checked against the page it comes from.
| System | Codes |
|---|---|
| Trade name | E-glass, E-Glas (German name for the same glass type) |
Notes
The method, full conditions and any caveat for the numbered rows above.
| # | Measurement | Method | Conditions | Caveat |
|---|---|---|---|---|
| 1 | Density, E-glass glass type | Printed as 2,59 - 2,62 kg/dm³ (German decimal commas) in the 'Eigenschaften von E-Glas' table of the datasheet. The same row is printed in the HP Textiles product catalogue. | form E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not statedtemperature not stated | — |
| 2 | Softening temperature, E-glass glass type | Printed as 825 - 860 °C in the Erweichungstemperatur column of the same table. The page names no test method. | form E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not statedbasis softening temperature as printed; test method not stated | — |
| 3 | Tensile strength, E-glass glass type | Printed as 2600 MPa in the Zugfestigkeit column of the same table. | form E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not statedtemperature not stated | — |
| 4 | Young's modulus, E-glass glass type | Printed as 73 in the Elastizitätsmodul column; the unit is printed as Gpa and is written here as GPa. | form E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not statedtemperature not stated | — |
| 5 | Elongation at break, E-glass glass type | Printed as 3,5 - 4 % in the Bruchdehnung column of the same table. | form E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not statedtemperature not stated | — |
Risks and side effects
Hazards to people, what happens when a cell overheats, and how the material is handled and stored.
For people
The only hazard text read in this run is the Bavarian LfU fibre-size guidance. No OSHA, IARC or SDS page for E-glass could be read.
- Fibre size
- Fibres longer than 5 µm, thinner than 3 µm and with a length-to-diameter ratio above 3:1 are the most critical (WHO fibres, LfU).
- Continuous filaments
- LfU lists textile glass fibres (continuous filaments) among the artificial mineral fibres but gives no hazard class for them.
- Waste
- Small amounts of KMF-containing waste must be packed at once in tear-resistant, dust-tight sacks or big bags (LfU).
Test details
The original wording and numbers from the sources, for readers who want them.
Handling and storage
- LfU: small amounts of KMF-containing waste must be packed at once in suitable containers, for example tear-resistant, dust-tight sacks or big bags, which must be labelled.
Supply and geography
How common the raw materials are and where they come from.
Silica sand (industrial silica, SiO2)
USGS: quartz-rich sand and sandstone, the main sources of industrial silica sand, occur throughout the world. USGS also says the United States was the world's leading producer and consumer of industrial sand and gravel.
- Top producers (2025)
- United States 27.9%, China 21.4%, Netherlands 15.8%, Turkey 3.3%, France 3%, Italy 3%
- Substitutes
- USGS: alternative materials that can be used for glassmaking, foundry and molding sands are chromite, olivine, staurolite and zircon sands.
Boron (borates)
USGS: in 2025 the glass and ceramics industries remained the leading domestic users of boron products, and more than three-quarters of world boron consumption went to ceramics, detergents, fertilizers and glass. 2025 production, thousand metric tons as printed: Turkey 1,500 (refined borates); Bolivia 380 (ulexite); Chile 300 (ulexite); Peru 220 (crude borates); China 230 (boric oxide equivalent); Argentina 170 (crude ore); Russia 80 (datolite ore); Germany 40 (compounds). USGS says a world total cannot be calculated, so no country shares are shown. US imports 2021 to 2024: Turkey 90%, Bolivia 6%, other 4%.
- Top producers (2025)
- Turkey, Bolivia, Chile, Peru, China, Argentina, Russia, Germany
- Critical mineral lists
- US: listed
Documents
Datasheets, safety data sheets, papers and standards you can open.
Full record
The complete spore, as stored. Free to reuse under CC-BY-4.0. Images keep the licence shown with each one.
Show the full YAML
spore: profile
id: e-glass
spore_version: 0.2
family: glass-and-composites
name: E-glass fibre
abbreviation: E-glass
role: reinforcement fibre
category: composites
type: glass-fiber-reinforced
summary: |
E-glass is an alumino-borosilicate glass fibre with alkali oxides held below about 1 to 2 percent. CompositesWorld says it still makes up most of the world's fibreglass output. The HP Textiles datasheet for its E-glass roving fabric gives a density of 2.59 to 2.62 kg/dm³, a tensile strength of 2600 MPa, a Young's modulus of 73 GPa and an elongation at break of 3.5 to 4 percent. This is a draft: only five E-glass values, the oxide percentages and any hazard class could not be read in this run.
best_for: General reinforcement of polyester, epoxy and vinylester laminates, such as boats, vehicle parts and containers, which are the end uses HP Textiles lists for its E-glass roving fabrics
weakest_at: 'Chemical resistance is not its strong point: HP Textiles lists C-glass, ECR-glass and boron-free Advantex as the corrosion-resistant types, and no E-glass corrosion value was read in this run'
identity:
formula: 'Alumino-borosilicate glass fibre (E-glass): SiO2 with Al2O3, CaO, MgO and B2O3, and alkali oxides below 1% by weight'
source: cw-glass-fiber
where: 'CompositesWorld, Batching step: the E-glass composition includes SiO2, Al2O3, CaO and MgO, with B2O3 added later. Alkali oxides below 1% w/w (Wikipedia, Fiberglass article); alkali-free, below 2% (Wikipedia, Glass fiber article; German Wikipedia, Glasfaser: ''weniger als 2 % Alkalioxiden'').'
designations:
- system: Trade name
code: E-glass
note: generic glass-type name; E stands for electrical, the first application
source: cw-glass-fiber
where: 'Batching step: ''E-glass, originally aimed at electrical applications'''
- system: Trade name
code: E-Glas
note: German name for the same glass type
source: hp-datasheet
where: Eigenschaften von E-Glas table, Glastype row
tags:
environments: []
stresses: []
applications:
- structures
- propulsion-and-tanks
properties:
- benchmark: density
label: Density, E-glass glass type
value: 2.59
value_high: 2.62
bound: range
unit: kg/dm³
scope: material
conditions:
form: E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not stated
temperature: not stated
method: Printed as 2,59 - 2,62 kg/dm³ (German decimal commas) in the 'Eigenschaften von E-Glas' table of the datasheet. The same row is printed in the HP Textiles product catalogue.
status: ground
source: hp-datasheet
where: Eigenschaften von E-Glas table, E-Glas row, Dichte column
- benchmark: softening_point
label: Softening temperature, E-glass glass type
value: 825
value_high: 860
bound: range
unit: °C
scope: material
conditions:
form: E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not stated
basis: softening temperature as printed; test method not stated
method: Printed as 825 - 860 °C in the Erweichungstemperatur column of the same table. The page names no test method.
status: ground
source: hp-datasheet
where: Eigenschaften von E-Glas table, E-Glas row, Erweichungstemperatur column
- benchmark: ultimate_tensile_strength
label: Tensile strength, E-glass glass type
value: 2600
unit: MPa
scope: material
conditions:
form: E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not stated
temperature: not stated
method: Printed as 2600 MPa in the Zugfestigkeit column of the same table.
status: ground
source: hp-datasheet
where: Eigenschaften von E-Glas table, E-Glas row, Zugfestigkeit column
- benchmark: elastic_modulus
label: Young's modulus, E-glass glass type
value: 73
unit: GPa
scope: material
conditions:
form: E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not stated
temperature: not stated
method: Printed as 73 in the Elastizitätsmodul column; the unit is printed as Gpa and is written here as GPa.
status: ground
source: hp-datasheet
where: Eigenschaften von E-Glas table, E-Glas row, Elastizitätsmodul column
- benchmark: elongation
label: Elongation at break, E-glass glass type
value: 3.5
value_high: 4
bound: range
unit: '%'
scope: material
conditions:
form: E-glass glass type in a roving-fabric datasheet; filament, yarn or fabric not stated
temperature: not stated
method: Printed as 3,5 - 4 % in the Bruchdehnung column of the same table.
status: ground
source: hp-datasheet
where: Eigenschaften von E-Glas table, E-Glas row, Bruchdehnung column
corrosion: []
risks:
hazards:
- text: 'Respirable fibres, Bavarian LfU (2018): fibres shorter than 250 µm and thinner than 3 µm can reach the lung. The most critical fibres are longer than 5 µm, thinner than 3 µm and have a length-to-diameter ratio above 3:1 (WHO fibres).'
ghs: []
source: lfu-kmf-2018
where: Section 3, 'Kritische Fasern 1, WHO 2-Fasern'
- text: LfU lists textile glass fibres (continuous filaments, Endlosfasern) among the artificial mineral fibres (KMF) and gives no hazard class for E-glass filaments.
ghs: []
source: lfu-kmf-2018
where: Section 2.3, Textilglasfasern (Endlosfasern)
failure_risks: []
side_effects: []
handling:
- text: 'LfU: small amounts of KMF-containing waste must be packed at once in suitable containers, for example tear-resistant, dust-tight sacks or big bags, which must be labelled.'
source: lfu-kmf-2018
where: Waste section, paragraph under Abb. 7
mitigations: []
uses:
- application: structures
device: Boats and vehicle parts laminated with E-glass roving fabric
example: HP Textiles lists boat building (Bootsbau) and vehicle construction (Fahrzeugbau) among the end uses of its E-glass roving fabrics.
source: hp-datasheet
where: Endanwendungen list, datasheet page 1
- application: propulsion-and-tanks
device: Containers and tanks laminated with E-glass roving fabric
example: The same end-use list includes container construction (Behälterbau).
source: hp-datasheet
where: Endanwendungen list, datasheet page 1
supply:
- subject: Silica sand (industrial silica, SiO2)
abundance: 'USGS: quartz-rich sand and sandstone, the main sources of industrial silica sand, occur throughout the world. USGS also says the United States was the world''s leading producer and consumer of industrial sand and gravel.'
producers:
- country: United States
share_percent: 27.9
year: 2025
- country: China
share_percent: 21.4
year: 2025
- country: Netherlands
share_percent: 15.8
year: 2025
- country: Turkey
share_percent: 3.3
year: 2025
- country: France
share_percent: 3
year: 2025
- country: Italy
share_percent: 3
year: 2025
critical_lists: []
substitutes:
- 'USGS: alternative materials that can be used for glassmaking, foundry and molding sands are chromite, olivine, staurolite and zircon sands.'
source: usgs-mcs2026
where: Sand and Gravel (Industrial), World Mine Production and Reserves table, 2024 and 2025. Shares calculated by Space Mushroom against the printed world total of 430,000 (rounded); the unit is not printed in this section, so no tonnage is written. Substitutes paragraph. Table 6 (2025 critical list) names silicon metal and ferrosilicon, not silica sand.
- subject: Boron (borates)
abundance: 'USGS: in 2025 the glass and ceramics industries remained the leading domestic users of boron products, and more than three-quarters of world boron consumption went to ceramics, detergents, fertilizers and glass. 2025 production, thousand metric tons as printed: Turkey 1,500 (refined borates); Bolivia 380 (ulexite); Chile 300 (ulexite); Peru 220 (crude borates); China 230 (boric oxide equivalent); Argentina 170 (crude ore); Russia 80 (datolite ore); Germany 40 (compounds). USGS says a world total cannot be calculated, so no country shares are shown. US imports 2021 to 2024: Turkey 90%, Bolivia 6%, other 4%.'
producers:
- country: Turkey
year: 2025
- country: Bolivia
year: 2025
- country: Chile
year: 2025
- country: Peru
year: 2025
- country: China
year: 2025
- country: Argentina
year: 2025
- country: Russia
year: 2025
- country: Germany
year: 2025
critical_lists:
- list: USGS 2025 Final List of Critical Minerals (published 7 November 2025)
listed: true
substitutes: []
source: usgs-boron
where: Salient statistics; World Production and Reserves table (2024 and 2025); critical minerals paragraph (boron added to the final 2025 list); import sources 2021-24; footnote 4 (world totals cannot be calculated).
media: []
documents:
- title: HP Textiles product datasheet, Glasrovinggewebe (E-glass roving fabric)
type: datasheet
url: https://www.hp-textiles.com/proddat/Glasrovinggewebe.pdf
- title: HP Textiles product catalogue (Produktkatalog)
type: datasheet
url: https://www.hp-textiles.com/Flyer/Produktkatalog.pdf
- title: The making of glass fiber (CompositesWorld)
type: report
url: https://www.compositesworld.com/articles/the-making-of-glass-fiber
- title: 'Mineral Commodity Summaries 2026: Boron (USGS)'
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-boron.pdf
year: 2026
- title: Mineral Commodity Summaries 2026, full report (USGS)
type: report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026.pdf
year: 2026
- title: 'UmweltWissen: Künstliche Mineralfasern (Bayerisches Landesamt für Umwelt, 2018)'
type: report
url: https://www.lfu.bayern.de/buerger/doc/uw_32_kuenstliche_mineralfasern.pdf
year: 2018
- title: Glass fiber (Wikipedia)
type: report
url: https://en.wikipedia.org/wiki/Glass_fiber
- title: Fiberglass (Wikipedia)
type: report
url: https://en.wikipedia.org/wiki/Fiberglass
- title: Glasfaser (German Wikipedia)
type: report
url: https://de.wikipedia.org/wiki/Glasfaser
gaps:
- 'Not found in the sources read: coefficient of thermal expansion, dielectric constant and loss tangent, electrical resistivity, dielectric strength, refractive index, specific heat, Poisson''s ratio, compressive strength, annealing and strain points, maximum service temperature, and any virgin-filament, strand or laminate value.'
- 'Thermal conductivity 0,15 W(m.K) is printed in the HP Textiles datasheet but is left out of the file: the verify step strips decimal commas, so this German value cannot be matched to the page.'
- softening_point is not in spores/property-canon.yaml; it is used as a short snake_case name.
- Composition limits in wt% for SiO2, Al2O3, CaO, MgO and B2O3 were not printed in the sources read; only the alkali-oxide limits (below 1% or below 2%) are given.
- No ASTM D578 class, ISO, DIN or UNS code for E-glass was printed in the pages read; the designations are E-glass (CompositesWorld) and E-Glas (HP Textiles).
- 'No OSHA, IARC or manufacturer SDS page could be read: the OSHA page returned HTTP 403, the IARC classification list is script-rendered, and no E-glass safety data sheet was found. The hazard entries use the Bavarian LfU (2018) fibre-size guidance instead.'
- 'Corrosion, moisture and alkali attack: no E-glass test value was printed in a source read, so corrosion is empty.'
- 'Failure risks, side effects and mitigations: none read.'
- 'Media: none; no licensed E-glass image was checked.'
- 'Space use: no space, vacuum or radiation data for E-glass was found; the uses listed are boat, vehicle and container work.'
- Wikipedia pages (Glass fiber, Fiberglass, German Glasfaser) are cited only for composition, as the brief allows; their property tables were not used.
- The HP Textiles datasheet does not say whether its E-glass row describes filament, yarn, roving or fabric, so the form condition is recorded as not stated.
sources:
hp-datasheet:
title: HP Textiles product datasheet, Glasrovinggewebe (E-glass roving fabric)
id: HP Textiles, Glasrovinggewebe.pdf
url: https://www.hp-textiles.com/proddat/Glasrovinggewebe.pdf
kind: datasheet
license: manufacturer document, cited not reproduced
hp-catalogue:
title: HP Textiles product catalogue (Produktkatalog)
id: HP Textiles, Produktkatalog.pdf
url: https://www.hp-textiles.com/Flyer/Produktkatalog.pdf
kind: datasheet
license: manufacturer document, cited not reproduced
cw-glass-fiber:
title: The making of glass fiber (CompositesWorld)
id: CompositesWorld article
url: https://www.compositesworld.com/articles/the-making-of-glass-fiber
kind: web
license: trade-press article, cited not reproduced
usgs-boron:
title: 'Mineral Commodity Summaries 2026: Boron'
id: USGS MCS 2026
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-boron.pdf
year: 2026
kind: report
license: US government work, public domain
usgs-mcs2026:
title: Mineral Commodity Summaries 2026, full report (Sand and Gravel (Industrial), Table 6 critical list)
id: USGS MCS 2026, full report
url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026.pdf
year: 2026
kind: report
license: US government work, public domain
lfu-kmf-2018:
title: 'UmweltWissen: Künstliche Mineralfasern (Bayerisches Landesamt für Umwelt)'
id: LfU Bayern, UmweltWissen Abfall, 2018
url: https://www.lfu.bayern.de/buerger/doc/uw_32_kuenstliche_mineralfasern.pdf
year: 2018
kind: report
license: Bavarian state publication, cited not reproduced
wiki-glass-fiber:
title: Glass fiber (Wikipedia)
id: Wikipedia, Glass fiber
url: https://en.wikipedia.org/wiki/Glass_fiber
kind: web
license: CC BY-SA 4.0
wiki-fiberglass:
title: Fiberglass (Wikipedia)
id: Wikipedia, Fiberglass
url: https://en.wikipedia.org/wiki/Fiberglass
kind: web
license: CC BY-SA 4.0
de-glasfaser:
title: Glasfaser (German Wikipedia)
id: Wikipedia (de), Glasfaser
url: https://de.wikipedia.org/wiki/Glasfaser
kind: web
license: CC BY-SA 4.0
license: CC-BY-4.0
updated: '2026-10-24'
review:
status: draft
method: assistant
checked_values: 5
unreachable: 0
caveats: 3
note: Written by an AI assistant on 2026-10-24 from the HP Textiles datasheet and catalogue, CompositesWorld, USGS MCS 2026 (boron and industrial sand), the Bavarian LfU (2018), and Wikipedia for composition only. Five properties; the rest are listed in gaps.
story:
recipe:
line: E-glass is an alumino-borosilicate glass. CompositesWorld says it was developed as a more alkali-resistant alternative to soda-lime glass, built on silica, alumina, lime and magnesia, with boron added later. Wikipedia says the batch is melted from silica sand, limestone, kaolin, fluorspar, colemanite and dolomite, and the melt is drawn through bushings. No percentage limits for the main oxides were printed in the sources read.
parts:
- name: Silica
symbol: SiO2
role: Main network former; CompositesWorld lists SiO2 in the E-glass composition.
share_note: not printed in the sources read
source: cw-glass-fiber
where: Batching step
- name: Alumina
symbol: Al2O3
role: Listed in the E-glass composition (aluminum oxide or alumina).
share_note: not printed in the sources read
source: cw-glass-fiber
where: Batching step
- name: Lime
symbol: CaO
role: Listed in the E-glass composition (calcium oxide or lime).
share_note: not printed in the sources read
source: cw-glass-fiber
where: Batching step
- name: Magnesia
symbol: MgO
role: Listed in the E-glass composition (magnesium oxide or magnesia).
share_note: not printed in the sources read
source: cw-glass-fiber
where: Batching step
- name: Boric oxide
symbol: B2O3
role: Added later to widen the gap between melting and crystallising temperatures, which stops nozzle clogging (CompositesWorld).
share_note: not printed in the sources read
source: cw-glass-fiber
where: Batching step
- name: Alkali oxides
symbol: Na2O + K2O
role: Kept low so the glass is alkali-free.
share_note: below 1% by weight (Wikipedia, Fiberglass article); below 2% (Wikipedia, Glass fiber article)
source: wiki-fiberglass
where: E-glass paragraph
risk_groups:
- title: For people
level: 1
verdict: Fibre size limits set; no E-glass hazard class found
lead: The only hazard text read in this run is the Bavarian LfU fibre-size guidance. No OSHA, IARC or SDS page for E-glass could be read.
points:
- label: Fibre size
line: Fibres longer than 5 µm, thinner than 3 µm and with a length-to-diameter ratio above 3:1 are the most critical (WHO fibres, LfU).
- label: Continuous filaments
line: LfU lists textile glass fibres (continuous filaments) among the artificial mineral fibres but gives no hazard class for them.
- label: Waste
line: Small amounts of KMF-containing waste must be packed at once in tear-resistant, dust-tight sacks or big bags (LfU).
why: E-glass is an alumino-borosilicate glass fibre. CompositesWorld says it was developed as a more alkali-resistant alternative to soda-lime glass, was among the first glasses drawn into continuous filament, and still makes up most of the world's fibreglass output. HP Textiles weaves E-glass roving yarns into fabrics and prints a density of 2.59 to 2.62 kg/dm³ and a tensile strength of 2600 MPa for the glass type.
uses:
- where: Boats and vehicles
line: HP Textiles lists boat building (Bootsbau) and vehicle construction (Fahrzeugbau) among the end uses of its E-glass roving fabrics.
- where: Containers and tanks
line: The same list includes container construction (Behälterbau).
- where: Space
line: No space or vacuum use of E-glass was found in the sources read.
can_do:
- label: Density
benchmark: density
line: HP Textiles prints 2.59 to 2.62 kg/dm³ for the E-glass row of its roving-fabric datasheet.
- label: Tensile strength
benchmark: ultimate_tensile_strength
line: The same row prints 2600 MPa. The datasheet does not say whether this is for filament, yarn or fabric.
- label: Stiffness
benchmark: elastic_modulus
line: Young's modulus on the same row is 73 GPa.
- label: Elongation
benchmark: elongation
line: Elongation at break on the same row is 3.5 to 4 percent.
- label: Softening
benchmark: softening_point
line: The softening temperature on the same row is 825 to 860 °C.
compare: The HP Textiles catalogue sets E-glass against its other glass types. It describes C-glass as having good chemical resistance, ECR-glass (E-glass corrosion resistant) as extremely corrosion resistant, and Advantex as a boron-free glass with significantly improved corrosion resistance. The catalogue gives no E-glass corrosion number, so the comparison is qualitative. For density, the E-glass datasheet row gives 2.59 to 2.62 kg/dm³.
compare_rows:
- label: Density
benchmark: density
scope: material
- label: Tensile strength
benchmark: ultimate_tensile_strength
scope: material
- label: Young's modulus
benchmark: elastic_modulus
scope: material
handling:
- Small amounts of KMF-containing waste go at once into tear-resistant, dust-tight sacks or big bags, which must be labelled (LfU).
good_for:
- General reinforcement of polyester, epoxy and vinylester laminates, which HP Textiles names as suitable resins for its E-glass roving fabrics.
- Boats, vehicle parts and containers, which are the end uses HP Textiles lists for its E-glass roving fabrics.
watch_out:
- 'Chemical resistance: the HP catalogue lists C-glass with good chemical resistance, ECR-glass with extremely high corrosion resistance and boron-free Advantex with improved corrosion resistance. No E-glass corrosion value was read.'
- 'Boron: CompositesWorld reports a trend in E-glass manufacturing toward removing boron, which it calls expensive and a source of undesirable emissions.'
- 'Respirable fibres: the LfU criteria put the most critical fibres at longer than 5 µm, thinner than 3 µm and with a length-to-diameter ratio above 3:1.'
verdict: 'E-glass is the common general-purpose reinforcement for polymer laminates (CompositesWorld: most of the world''s fibreglass output). This draft has five E-glass values from the HP Textiles datasheet: density, softening range, tensile strength, Young''s modulus and elongation. Composition percentages, corrosion data, failure data and an OSHA, IARC or SDS hazard class are still open.'
References
Every number above carries a reference number. Click one to see the source and where in it the value comes from.
| # | Source | Type | Year | Used for |
|---|---|---|---|---|
| HP Textiles product datasheet, Glasrovinggewebe (E-glass roving fabric) | datasheet | 7 values | ||
| HP Textiles product catalogue (Produktkatalog) | datasheet | 0 values | ||
| The making of glass fiber (CompositesWorld) | web | 1 value | ||
| Mineral Commodity Summaries 2026: Boron | report | 2026 | 1 value | |
| Mineral Commodity Summaries 2026, full report (Sand and Gravel (Industrial), Table 6 critical list) | report | 2026 | 1 value | |
| UmweltWissen: Künstliche Mineralfasern (Bayerisches Landesamt für Umwelt) | report | 2018 | 3 values | |
| Glass fiber (Wikipedia) | web | 0 values | ||
| Fiberglass (Wikipedia) | web | 0 values | ||
| Glasfaser (German Wikipedia) | web | 0 values |