Description
What is PEEK MOD rod?
PEEK MOD generally refers to “modified” PEEK grades that are enhanced with additives or fibers to deliver properties such as lower friction, higher wear resistance, greater stiffness, or controlled electrical conductivity. The most common modifications:
- Tribological (self-lubricating) grades: contain PTFE, graphite, and/or carbon fiber; often black. Purpose: reduce coefficient of friction and extend life in bearings and bushings.
- Reinforced grades: with glass fiber (GF) or carbon fiber (CF) to increase strength, modulus, and dimensional stability.
- ESD/conductive grades: to control static electricity in electronics and semiconductor equipment.
Note: In many local markets, “PEEK MOD” often refers specifically to tribological grades (similar to HPV/PVX).
Applications of PEEK MOD rod:
- Bearings, bushings, wear and guide rings in pumps and compressors
- Valve seats, seals, packings in oil & gas and petrochemical
- High-temperature gears, sliders, guide shoes
- Components exposed to steam and detergents in food/pharma (with proper approvals)
- Electronics/semiconductor equipment (ESD), assembly fixtures
- Automotive and aerospace parts with high mechanical and thermal load
- Sterilizable instruments and high-temperature handles (for approved grades)
Advantages of PEEK MOD rod:
- High temperature capability: continuous service roughly 240–260°C; melting point ≈ 343°C
- Low wear and friction (in tribological MOD grades)
- Excellent chemical resistance: hydrocarbons, many acids/bases, steam
- Dimensional stability and low creep (especially with CF/GF)
- Radiation resistance and sterilizability (steam, gamma, ETO) for suitable grades
- Good electrical insulation; ESD/conductive versions available
Disadvantages of PEEK MOD rod:
- Higher cost than most standard engineering plastics
- Machining requires temperature control and stress relief
- Some MOD grades may lack approvals for food/medical contact
- Bonding can be difficult without proper surface preparation
Technical specifications for PEEK MOD rod:
- Density: neat PEEK ≈ 1.30 g/cm³ | tribological MOD ≈ 1.35–1.45 | GF30 ≈ 1.50 | CF30 ≈ 1.40
- Tensile strength (23°C): neat ≈ 90–100 MPa | tribo MOD ≈ 90–110 | GF30 ≈ 120–140 | CF30 ≈ 150–180
- Tensile modulus: neat ≈ 3.6 GPa | tribo MOD ≈ 4.5–5.5 | GF30 ≈ 6.5–8.0 | CF30 ≈ 10–18
- Elongation at break: neat ≈ 15–20% | tribo MOD ≈ 5–12%
- Hardness: Shore D ≈ 85–90
- Continuous service temperature: ≈ 240–260°C
- HDT @1.8 MPa: neat ≈ 160–170°C | GF30 up to ≈ 300°C+
- Tg (glass transition): ≈ 143°C | Tm (melting): ≈ 343°C
- CTE (23–100°C): neat ≈ 47×10⁻⁶/K | GF30 ≈ 17–25×10⁻⁶ | CF30 ≈ 10–15×10⁻⁶
- Thermal conductivity: neat ≈ 0.25 W/m·K | CF30 up to ≈ 0.8–1.0
- Coefficient of friction (dry vs. steel): neat ≈ 0.30–0.40 | tribo MOD ≈ 0.12–0.20
- Volume resistivity: ≈ 10¹³–10¹⁵ Ω·cm (insulating) | ESD grades: 10³–10⁶ Ω
Types of MOD grades and commercial equivalents:
Tribological MOD (self-lubricated): similar to HPV/PVX (typically PTFE + graphite + CF blends). Common color: black. Goal: low friction, high wear resistance.
MOD GF30: 30% glass fiber; higher stiffness and thermal/dimensional stability.
MOD CF30: 30% carbon fiber; very high strength and modulus, lower CTE.
MOD ESD/Conductive: static control for cleanroom/electronics.
MOD Food/Medical: only some grades carry FDA/EU/USP Class VI; tribological grades are usually not food-grade unless explicitly stated.
Comparison: standard PEEK vs. PEEK MOD
Friction and wear: tribological MOD can deliver 5–10× longer life in sliding contact vs. neat PEEK.
Stiffness/dimensional stability: GF/CF MOD > neat; CF offers the best thermo-dimensional stability.
Chemical resistance: largely similar to base PEEK, minor effects from additives possible.
Cost: MOD typically costs more than neat PEEK; CF/GF often the highest.
Machining: tribological MOD machines more smoothly; GF/CF are more abrasive and wear tools faster.
Sizes, diameters, and common tolerances for PEEK MOD rod
- Typical diameters: ~6 to 150 mm (some brands up to 200 mm)
- Length: usually 1 meter (sometimes 2 or 3 meters)
- Color: black for most tribological MOD
Note: At very large diameters, risk of center porosity/residual stress increases; for critical parts, request quality certificates and consider UT inspection or cut-and-check.
Machining and processing guide for PEEK MOD rod
Pre-steps
- Stress relief (annealing): before and after machining is recommended; e.g., 200–210°C for ~1–2 hours per 25 mm thickness, with slow heat-up/cool-down ramps.
- Tooling: sharp carbide with positive rake; for GF/CF, use coated wear-resistant tools.
Starting parameters (tune to suit)
Turning: cutting speed 100–300 m/min (lower for GF/CF), feed 0.1–0.4 mm/rev, light-to-moderate DOC
Milling: set rpm by tool diameter; vc 150–250 m/min, fz 0.05–0.2 mm/tooth
Drilling: v = 50–150 m/min, f = 0.05–0.20 mm/rev; peck drilling for >10 mm diameters
Threading: prefer metal inserts (heat-set/Helicoil) for repeated assembly; for direct plastic threads, avoid >~60% thread engagement
Cooling: air/mist preferred; avoid flood coolants unless contamination control is assured
Heat control: avoid local hotspots > ~200°C to preserve surface finish and tolerances
Safety: fumes from excessive overheating are harmful; ensure proper ventilation
Design and assembly tips
Interference fits: account for CTE mismatch with metals; for wide temperature swings, favor geometric retention or metal sleeves over hard press fits.
Fastening: use brass/steel inserts for repeated screw joints; use generous fillets to reduce stress concentrations.
Bonding: surface prep (fine abrasion + plasma activation/PEEK primer); use high-temp epoxies or structural adhesives. Always test bond strength.
Sliding/wear: for tribological MOD, pair with hardened stainless/ceramic counterfaces and controlled roughness (e.g., Ra ≈ 0.2–0.6 µm) to maximize life.
Temperature: near 200–260°C, include thermal expansion in tolerance stack; CF gives best stability.
PEEK MOD rod price and cost drivers
- Brand and grade: tribological/CF/ESD typically pricier than neat
- Diameter and length: larger diameters impact price per kg and machining scrap
- Certifications: food/medical/aerospace documentation adds cost
- Market and import factors: FX rate, local stock, MOQs
- Value-add services: cutting, annealing, dimensional inspection/UT
Storage, handling, and safety
- Store in original packaging, away from direct sun and heat
- Low moisture uptake, but for tight tolerances, condition stock to the shop environment before machining
- Chips/dust with fibers (GF/CF) are abrasive; manage dust and use appropriate PPE
PEEK MOD FAQs:
Is PEEK MOD suitable for food contact?
Only if the datasheet explicitly states FDA/EU food-contact compliance. Tribological grades are often not approved unless specified.
What is the maximum operating temperature for PEEK MOD?
Continuous service around 240–260°C; short excursions higher. HDT varies by grade (GF30 can be very high)
Which grade is best for bushings and bearings?
Tribological MOD grades (HPV/PVX-like). For better thermo-dimensional stability, CF is an excellent option.
Is PEEK MOD resistant to acids?
It resists most chemicals well; concentrated sulfuric acid is one of the few aggressive chemicals to PEEK.
PEEK MOD or PTFE?
PTFE has lower friction, but PEEK MOD offers higher stiffness, load capability, temperature resistance, and wear life. For load-bearing parts, PEEK MOD is usually the better choice.
