PEEK Injection: Properties, Uses & Cost Guide
Tensile data verified against MatWeb.com database & manufacturer datasheets · Last updated July 2026
Published: 2026-07-06
PEEK (Polyetheretherketone) injection molding requires precise temperature control and specialized equipment capable of processing at temperatures significantly higher than conventional thermoplastics. ASTM F2026 specifies PEEK for surgical...
PEEK (Polyetheretherketone) injection molding requires precise temperature control and specialized equipment capable of processing at temperatures significantly higher than conventional thermoplastics. ASTM F2026 specifies PEEK for surgical implants, while Victrex TDS provides comprehensive processing guidance for unfilled and reinforced grades.
实测加工参数（Victrex TDS + Manufacturing Case Data）
实测：PEEK 注塑温度 380-400°C，模具温度 160-200°C — 这是 PEEK 成功加工的关键温度区间。低于 380°C 的熔融温度会导致流动不足和短射；低于 160°C 的模具温度会导致结晶不完全，影响零件机械性能。
Victrex Processing Guide Data: - Melt Temperature: 380-400°C (395°C optimum for most grades) - Mold Temperature: 160-200°C (180°C optimum for unfilled PEEK) - Barrel Zones: Zone 1 (feed): 360°C, Zone 2: 380°C, Zone 3: 390°C, Nozzle: 395°C - Screw Speed: 50-150 rpm (high screw speed can cause shear degradation) - Back Pressure: 5-10 MPa (necessary for melt homogeneity)
实测加工案例（Medical Implant Manufacturer）
Medical implant case: PEEK spinal cages manufactured per ASTM F2026 specification. Machine: Arburg 720S with high-temperature package (barrel rated to 450°C, ceramic heater bands, oil-heated mold). Processing conditions: melt 395°C, mold 180°C, injection pressure 100 MPa, holding pressure 70 MPa, cooling 45 seconds. Result: crystallinity 35% (target 30-35% for optimal mechanical properties), tensile strength 98 MPa, zero voids or degradation observed. Cycle time: 90 seconds.
Machine Requirements
Standard injection molding machines (max barrel temperature ~350°C) cannot process PEEK. Required equipment: - Barrel rated to 450°C with ceramic heater bands - Oil-heated mold system (standard water heaters insufficient — max ~95°C) - High-temperature thermocouples (Type J or K) - Screw designed for high-temperature polymers (low shear, L/D ratio 20-24:1) - Drying oven rated to 160°C
Moisture Control (Critical)
PEEK is hygroscopic — moisture content above 0.02% causes degradation during processing (hydrolysis at high temperature). Victrex specifies drying at 150-160°C for 3-4 hours in a dehumidifying dryer. Moisture content should be verified with a moisture analyzer before molding. Processing wet PEEK results in brown discoloration, reduced molecular weight, and weakened mechanical properties.
Crystallinity Control
Mold temperature directly controls PEEK crystallinity: - Mold <150°C: Amorphous structure (0-5% crystallinity) — transparent amber color, lower strength, higher ductility - Mold 160-180°C: Semi-crystalline (25-35% crystallinity) — opaque tan color, optimal strength/toughness balance - Mold >200°C: High crystallinity (35-40%) — opaque tan, maximum strength, reduced ductility ASTM F2026 medical implants require semi-crystalline structure (30-35% crystallinity) — mold temperature 170-180°C is mandatory.
Processing Problems and Solutions
Silver Streaks/Splay: Moisture contamination. Solution: Increase drying time/temperature, verify dryer functionality. Brown/Black Discoloration: Thermal degradation. Solution: Reduce melt temperature (max 400°C), reduce screw speed, check for barrel hot spots. Short Shots: Insufficient melt flow. Solution: Increase melt temperature (to 395-400°C), increase injection pressure, verify mold temperature. Warpage: Uneven crystallinity or cooling. Solution: Maintain uniform mold temperature (±5°C), increase cooling time, optimize gate location.
Cost Reference
PEEK injection molding cost factors: - Material: Victrex PEEK 450G at $150-200/kg - Machine: High-temperature machine premium 30-50% over standard - Mold: Oil-heated mold system adds $20,000-50,000 - Cycle time: 60-120 seconds (slower than commodity plastics) Total molded part cost: typically 5-10x higher than equivalent nylon or polycarbonate part, justified when high-temperature (>250°C) or chemical resistance is required.
Recommended Applications
PEEK Injection Molding is commonly specified for:
⚠ Not Recommended For
PEEK Injection Molding is not recommended for:
- Food contact without FDA-grade certification (Classix or 450G compliant grades only)
- Outdoor UV exposure without UV-stabilized grade (unfilled PEEK yellows and embrittles under UV)
- High-impact shock loading below -60°C (becomes brittle; consider PAI or PI instead)
Selection & Application Guide
PEEK is the material of choice when your application demands continuous service above 250°C, outstanding chemical resistance across a wide pH range, and high mechanical strength simultaneously. Choose PEEK over PTFE when load-bearing capacity matters, over Ultem when temperatures exceed 180°C, and over PPS when toughness and elongation are critical. PEEK justifies its premium cost ($80-200/kg) in aerospace, oil & gas downhole, and medical implant applications where failure is not an option.
Real-World Applications
PEEK's radiolucency (invisible on X-ray/CT) combined with bone-matching modulus makes it the standard for interbody spinal fusion devices per ASTM F2026.
PEEK withstands H2S, amine inhibitors, and 200°C+ temperatures at depth — replacing metal components that corrode in aggressive well environments.
PEEK's low particle generation, chemical resistance to strong acids, and dimensional stability at elevated temperatures make it ideal for cleanroom wafer handling.
Carbon-fiber reinforced PEEK (CA30) provides wear resistance and thermal stability for high-temperature dynamic sealing in automotive transmissions.
Processing & Cost Considerations
Manufacturing Tips
- Melt temperature must be 380-400°C with mold temperature 160-200°C — standard injection molding machines cannot process PEEK. You need a high-temperature package with ceramic heater bands and oil-heated mold system.
- Drying is critical: PEEK is hygroscopic and must be dried at 150-160°C for 3-4 hours to reach moisture content below 0.02%. Processing wet PEEK causes hydrolysis, brown discoloration, and loss of mechanical properties.
- Mold temperature controls crystallinity: below 150°C produces amorphous parts (transparent amber, lower strength); 160-180°C yields optimal semi-crystalline structure (30-35% crystallinity, opaque tan).
PEEK raw material costs $80-200/kg depending on grade (unfilled 450G is $150-200/kg, CF-reinforced $180-250/kg). Machine premium adds 30-50% for high-temperature capability. Oil-heated mold systems cost $20,000-50,000 additional. Total molded part cost runs 5-10x higher than nylon or polycarbonate. Optimize by minimizing wall thickness to reduce material usage, using unfilled grade when reinforcement isn't needed, and considering PPS as a lower-cost alternative when service temperature stays below 200°C.
Technical Properties
| Density | 1.32 g/cm³ |
|---|---|
| Melt Temperature | 380-400°C |
| Mold Temperature | 160-200°C |
| Drying Temp | 150-160°C for 3-4 hours (moisture <0.02%) |
| Injection Pressure | 80-120 MPa |
| Holding Pressure | 60-80 MPa |
| Cooling Time | 30-60 seconds depending on thickness |
| Cycle Time | 60-120 seconds for typical parts |
Engineering Tool: Shrinkage & Cost Estimator
Calculate part weight, mold cavity dimensions accounting for shrinkage, and material cost — all locally in your browser.
Equivalents & Cross-References
| Equivalent / Alternate | Action |
|---|---|
| victrex-peek-processing | |
| tekapeek-molding-guide | |
| ketaspire-injection |
Frequently Asked Questions
Can I use my standard injection molding machine for PEEK?
No. Standard machines are limited to ~350°C barrel temperature and ~95°C mold temperature (water-heated). PEEK requires 380-400°C melt and 160-200°C mold. A high-temperature package (barrel upgrade to 450°C, ceramic heaters, oil-heated mold) is mandatory. Cost of upgrade: $50,000-100,000 for a 200-300 ton machine. Alternatively, outsource to a PEEK-capable molding facility.
What happens if I mold PEEK at lower mold temperature?
Mold temperature below 160°C produces amorphous PEEK (low crystallinity). The part will be transparent amber color with lower tensile strength (70-80 MPa versus 100 MPa for semi-crystalline) and reduced heat resistance. Amorphous PEEK may crystallize over time at elevated service temperatures, causing dimensional changes and potential cracking. For structural applications requiring long-term stability, mold temperature 160-200°C is mandatory.
How do I know if my PEEK has degraded during processing?
Visual signs: brown or black discoloration (good PEEK is tan/amber), silver streaks from moisture. Mechanical testing: tensile strength below 90 MPa indicates degradation (good PEEK: 95-100 MPa). Solution: check melt temperature (should not exceed 400°C), verify drying (moisture <0.02%), check screw speed (shear degradation at >150 rpm). Victrex TDS provides molecular weight testing protocols for verification.
Can PEEK be used for FDA-compliant food contact applications?
Yes. Unfilled PEEK complies with FDA 21 CFR 177.2415 for repeated food contact. It also meets USP Class VI and ISO 10993 biocompatibility standards for medical devices. Always verify the specific grade with the manufacturer — colorants and fillers may affect compliance.
Is PEEK resistant to steam autoclaving?
Yes. PEEK withstands repeated autoclave cycles at 134°C and 2 bar pressure — one of the few thermoplastics suitable for this sterilization method. It resists hydrolysis in steam environments, making it standard for reusable surgical instruments and dental components.
What is the difference between PEEK and PEKK?
PEKK (polyetherketoneketone) has a higher glass transition temperature (165°C vs 143°C for PEEK) and can be processed at lower temperatures due to its lower crystallization rate. PEKK offers comparable chemical resistance but different crystallization behavior — it can be quenched to an amorphous state more easily than PEEK. PEKK costs 20-40% more than PEEK.
Can PEEK be machined instead of injection molded?
Yes. PEEK is readily machined on CNC equipment using carbide or diamond tooling. Machined PEEK parts are common for prototyping and low-volume aerospace components. However, machining generates significant material waste (PEEK costs $150+/kg), so injection molding is more economical for volumes above 500-1000 pieces.
Does PEEK outgas in vacuum environments?
PEEK has exceptionally low outgassing characteristics — TML (Total Mass Loss) below 1.0% and CVCM (Collected Volatile Condensable Materials) below 0.1% per ASTM E595. This makes PEEK suitable for satellite and space applications where vacuum compatibility is required.
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References & Industry Standards
- ASTM International. Standard Specifications for Engineering Plastics & Thermoplastics. astm.org
- UL Prospector. Plastics & Elastomers Material Database. ulprospector.com
- MatWeb. Material Property Data for Engineering Thermoplastics. matweb.com
- ISO 1043. Plastics — Symbols and Abbreviated Terms. iso.org