Glass fiber for polymer reinforcement — E-glass, ECR-glass, S-glass

Description

Glass Fiber for reinforcing polymer compounds and composites from Material Wizard — a wide range of glass types (E-glass, S-glass, ECR-glass), geometries (chopped 3–4.5 mm, long-fiber 10–12 mm, roving for pultrusion, milled fiber 0.2 mm) and sizings adapted to the specific polymer matrix type (PA, PBT, PC, PP, epoxy, vinyl ester). The base reinforcing filler for all GF-grade compounds in the MW catalog: Examid PA66 GF30/GF50, Exablend PBT GF30-W3201, PC GF30-930, Ultraplen PP GF30-530 and dozens of others.

Glass types — selected for the service environment

• E-glass (alumino-borosilicate) — the standard, 85 % of the global market. Fiber tensile strength ~3500 MPa, modulus ~73 GPa. Universal for PA/PBT/PP/PC.
• ECR-glass (E-Corrosion Resistant) — boron-free, improved resistance to acids, alkalis and seawater. For the chemical industry, offshore and agro applications.
• S-glass / R-glass / T-glass — high-strength (tensile ~4700 MPa, modulus ~86 GPa), for aerospace, ballistic protection and high-end composites. 3–5 times more expensive than E-glass.
• C-glass (chemical) — for chemical resistance in acidic environments (no alkalis)
• AR-glass (alkali-resistant) — for reinforcing cement composites (GFRC)

Geometry and supply form

• Chopped strands (chopped fiber): length 3.0, 4.5, 6.0 mm; for compounding with thermoplastics on a twin-screw extruder. After processing, the actual fiber length in the part is 0.2–0.4 mm.
• Long-fiber pellets (LFT-G): 10–12 mm pellets in which the fiber runs the full length of the granule. After molding, the fiber in the part is 3–8 mm long, providing substantially better impact and creep performance.
• Direct roving (assembled/single): 600–4800 tex, for pultrusion, filament winding and weaving into fabrics (woven roving).
• Milled fiber: 0.1–0.2 mm length, for thin-walled parts and SMC/BMC compounds.
• Chopped strand mat (CSM): for hand lay-up and contact molding.
• Continuous filament mat (CFM): for continuous molding.

Sizing — critical for adhesion to the matrix

Sizing is an ultra-thin polymer layer on the fiber surface that ensures compatibility with the specific polymer matrix and protects against abrasion. Without the correct sizing, a GF-grade compound loses 30–50 % of its mechanical properties.

• Aminosilane sizing — for PA6, PA66 (interacts with -NH₂ and -COOH end groups)
• Epoxy-compatible sizing — for epoxy composites and PC
• Polyester-compatible sizing — for PBT, PET
• Vinyl-ester / unsaturated polyester sizing — for GFRP composites
• Multi-compatible sizing — universal grades compatible with different matrices

Brand mapping of global manufacturers

• Owens Corning (OCV) — the global leader; flagship — Advantex® ECR-glass; Sustainwise® eco line
• Jushi Group (China) — the largest Chinese producer of E-glass for compounding
• Taishan Fiberglass (China) — Jushi's closest competitor
• 3B Fibreglass (Belgium) — premium E/ECR-glass for technical applications
• Nittobo (Japan) — premium high-modulus glass
• Johns Manville (USA) — wide range of E-glass and specialty grades
• NEG (Nippon Electric Glass) — high-performance glass for electronics

Typical loading in polymer compounds

• 10–15 % GF — light reinforcement, modulus increase of 1.5–2×, minimal impact reduction
• 20–30 % GF — the standard for engineering parts (our Examid PA66 GF30, Exablend PBT GF30-W3201, PC GF30-930)
• 40–50 % GF — high-modulus grades for metal replacement (our Examid PA66 GF50, PA66 CF40)
• 60+ % GF — extremely high reinforcement for special tasks (e.g. arc-quenching plates in switchgear)

Typical monofilament parameters (E-glass)

• Diameter: 10–14 µm (standard), 7–9 µm (fine), 17–20 µm (coarse)
• Density: 2.54 g/cm³
• Fiber tensile strength: ~3500 MPa
• Fiber tensile modulus: ~73 GPa
• Elongation at break: ~4 %
• CTE: 5 × 10⁻⁶ /K (one of the lowest among fillers)
• Softening: ~840 °C; melting: ~1200 °C

Use in our MW compounds

Glass fiber is used in all our GF-grade products:

• Examid® PA66 GF30 — the standard for engineering PA66
• Examid® PA66 GF50 — high-modulus metal replacement
• Exablend® PBT GF30-W3201 — V-0 GF30 for electrical engineering
• Exablend® PC GF30-930 — structural PC
• Ultraplen® PP GF30-530 — PP GF30 substitute for PA GF
• Ultraplen® PP GF30-4164 — PP GF30 copolymer
• Ultraplen® PP LGF55 — long-fiber concentrate

Limitations and trade-offs

• Shrinkage and modulus anisotropy along fiber flow lines — critical for precision and flat parts
• Visible fiber on the surface (white streaks) of thin-walled parts
• Increased wear of tooling and screws — stainless steel or DLC-coated recommended
• Reduced impact strength (the brittleness characteristic of GF-reinforced polymers)
• High-impact GF grades require impact modifiers in combination with GF

Test methods (for batch characterization)

ISO 1888 (monofilament diameter), ISO 5025 (LOI — sizing content burn-off), ISO 1889 (roving diameter and tex), ISO 3344 (sizing moisture content), ASTM D2256 (single-filament tensile strength), SEM microscopy for sizing morphology.

The listed values are typical for E-glass; specific values depend on the manufacturer, sizing type and batch. Please request the TDS for a specific batch before industrial use.