PEEK (unfilled) vs PE-UHMW: Completely different performance classes among thermoplastics
PEEK (unfilled) vs PE-UHMW
Side-by-side chemical composition and mechanical property comparison.
Overview
PEEK (unfilled)
Polyetheretherketone — the premium engineering thermoplastic. Exceptional mechanical properties maintained to 260°C continuous use. Resistant to virtually all organic solvents and acids. Biocompatible (ASTM F2026). Used as metal replacement in aerospace, automotive engine parts, medical implants (spinal cages), semiconductor wafer handling, and oil/gas downhole seals.
PE-UHMW
Ultra-High Molecular Weight Polyethylene — the highest impact-strength thermoplastic. Molecular weight 2-6 million g/mol. Self-lubricating, extremely wear-resistant (15x better than carbon steel), and chemically inert. Used for hip/knee implant bearings, conveyor guides, dock fenders, chute liners, food processing equipment, and ballistic armor (Dyneema/Spectra fiber form).
| PEEK (unfilled) | PE-UHMW | |
|---|---|---|
| Material Number | — | — |
| Category | Polymers | Polymers |
| Standard | ISO 10350 | ISO 11542 |
Chemical composition (wt%) — Pro
| Element | PEEK (unfilled) | PE-UHMW | Overlap |
|---|---|---|---|
| Base Polymer (Polyether Ether Ketone) | 99–99.9% | — | — |
| Base Polymer (Polyethylene, UHMW) | — | 99.5–99.9% | — |
Mechanical properties — Pro
| Property | PEEK (unfilled) | PE-UHMW | Unit |
|---|---|---|---|
| Tensile Strength | 90–110 | 39–48 | MPa |
| Yield Strength | ≥ 90 | 19–23 | MPa |
| Elongation | 30–50 | 250–450 | % |
| Elastic Modulus | |||
| Density | |||
| Glass Transition Temp (Tg) | |||
| Melting Point | |||
| Continuous Use Temp | |||
| hardness_shore_d |
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PEEK has 10x the tensile strength (100 vs 40 MPa), 5x the modulus, and operates to 260°C (vs 80°C for PE-UHMW). PE-UHMW has 10x the elongation and 50% lower density. PEEK costs ~50-100x more per kg. Choose PE-UHMW for wear/impact; PEEK for structural/high-temp metal replacement.
Frequently Asked Questions
Is PEEK (unfilled) the same as PE-UHMW?
PEEK (unfilled) and PE-UHMW have a 20% composition overlap. Completely different performance classes among thermoplastics
Can I replace PEEK (unfilled) with PE-UHMW?
Generally not recommended. The compositions differ significantly (20% overlap). These materials have different alloying concepts and are intended for different applications.
What is the difference between PEEK (unfilled) and PE-UHMW?
The main differences are in the following elements: overall alloying content. PEEK (unfilled) is a Polymers grade, while PE-UHMW is a Polymers grade.
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Data provided for reference only. Always verify against the applicable specification for critical applications.
All data is for reference only. Equivalents indicate similarity, not identity. Always verify against the applicable specification for safety-critical applications. materialref.com accepts no liability for decisions based on this data.