Description
What Is 30% Glass Fiber Reinforced PEEK?
What is it? PEEK GF30 is a high-performance engineering polymer reinforced with 30% glass fibers by weight, available as rod/bar, plate, and semi-finished stock.
Why it matters? Very high stiffness and strength, excellent dimensional and creep stability at elevated temperatures, strong chemical resistance, and good electrical insulation.
When to choose it? When you need a stiff, precise part that won’t deform under load at 150–240°C. Not ideal for dry sliding against metals.
PEEK CF 30 Advantages:
- Much higher modulus and stiffness than unfilled PEEK
- Excellent dimensional stability, lower CTE, and greatly reduced creep
- Outstanding thermal and chemical resistance; autoclavable
- Good electrical insulation and generally low flammability (often UL94 V-0)
PEEK CF 30 Limitations:
- Lower impact strength and toughness than neat PEEK
- Higher wear of the mating surface in tribological use (glass fibers are abrasive)
- Anisotropy and potential warpage in machined parts without stress-relief
- Higher tool wear during machining
PEEK GF30 Properties:
- Density: ~1.50–1.55 g/cm³
- Moisture uptake: low (≈0.1% in 24 h; low saturation)
- Tensile strength: ~150–190 MPa
- Tensile/flexural modulus: ~10–12 GPa
- Elongation at break: ~1.5–3%
- Flexural strength: ~230–300 MPa
- Short-term compressive strength: ~170–220 MPa
- Hardness: Shore D ~85–88 (Rockwell M ~100–110)
- Tg ≈ 143°C; Tm ≈ 343°C
- Continuous-use temperature: typically up to ~240°C (depends on load/environment)
- HDT (1.8 MPa): ~280–315°C
- Coefficient of thermal expansion (CTE):
- Parallel to flow: ~15–20 ×10⁻⁶/K
- Transverse to flow: ~40–50 ×10⁻⁶/K
- Thermal conductivity: ~0.3 W/m·K
- Electrical:
- Volume resistivity: ~10¹³–10¹⁵ Ω·cm
- Dielectric constant: ~3.2–3.5 (1 MHz)
- Dielectric strength: ~18–25 kV/mm
- CTI: typically mid-range (grade-dependent)
- Flammability: often UL94 V-0 at common thicknesses; LOI ~35–38%
- Chemical resistance: excellent vs hydrocarbons, oils, many non-oxidizing acids and bases; sensitive to concentrated sulfuric acid and strong oxidizers
PEEK GF30 Rod Dimensions and Notes:
- Common rod diameters: ~6 to 100+ mm (some suppliers up to ~150 mm)
- Standard lengths: typically 1000 mm (sometimes 500 or 2000 mm)
- Color: gray/greenish-gray or black (grade-dependent)
- Residual stresses: present in extruded rods; stress-relieve before precision machining
PEEK GF30 Applications by Industry
- Aerospace and transportation: fasteners, brackets, spacers, interior hardware with favorable FST
- Oil & gas/chemical: pump/valve components, insulators, high-temp spacers
- Electrical/electronics: sockets, spacers, thermally stable insulating parts
- Medical/lab: autoclavable fixtures and jigs (non-implant)
- Precision machinery: lightweight structural parts with high dimensional stability
Note: For dry sliding/bearing service, self-lubricated PEEK grades (HPV with PTFE/graphite/carbon) or CF30 often outperform GF30.
Machining PEEK GF30:
Tooling: fine-grain carbide with suitable coatings, or PCD/PCBN for high volumes. GF is abrasive; expect higher tool wear.
Cooling: mist/air or water-based emulsions; avoid overheating the polymer.
Starting parameters (tune to your setup):
Turning: Vc ~100–200 m/min, f ~0.1–0.3 mm/rev, ap ~0.5–3 mm
Drilling: 118°–135° point, Vc ~30–60 m/min, f ~0.05–0.20 mm/rev; step drilling and cooling help
Milling: sharp cutters, moderate surface speed, adequate chip load for cool cutting
Stress-relief (before finish pass/after roughing):
Example program: ramp to ~160°C (1–2 h), then 200–220°C (2–4 h), then slow cool in oven. Increase holds for thicker sections.
Tolerances: account for CTE and small but non-zero moisture uptake. For press fits, start with mild interference (~0.1–0.2% of diameter) and validate.
Safety: glass-fiber-laden dust can be irritating; use local extraction and appropriate PPE.
PEEK GF30 vs Alternatives:
Neat PEEK: tougher and more tribology-friendly, but lower stiffness, higher CTE, and more creep.
PEEK CF30 (30% carbon fiber):
Higher stiffness (~15–18 GPa), lower CTE, better thermal conductivity;
Electrical insulation is reduced up to conductive; may be unsuitable for electrical parts; generally better for sliding than GF.
PEEK HPV (self-lubricated with PTFE/graphite/carbon): ideal for bushings/sliding; modulus lower than GF/CF.
PPS GF40: more economical with decent modulus, but lower temperature capability/creep/chemical resistance than PEEK.
PA66 GF30: far cheaper, but high moisture uptake and much lower high-temp/long-term performance.
PEEK GF30 FAQs
Is it suitable for tribological parts? For dry contact against soft metals, usually no; consider self-lubricated or CF-filled grades.
Can it handle autoclave cycles? Yes, it typically withstands repeated 121–134°C steam cycles (grade and geometry dependent).
Is it conductive? No, it’s an insulator; GF may slightly reduce resistivity, but it remains an insulating material.
Outdoor use? The PEEK base is relatively UV-resistant, but for long-term exposure prefer black grades or protective coatings.
