Engineering Plastics Selection Guide: UHMW, PEEK, and PTFE Compared

Material selection is one of the most critical decisions in component design. The wrong choice can lead to premature failure, costly downtime, and safety concerns. This guide provides a systematic approach to evaluating engineering plastics for your specific application requirements.

Establishing Selection Criteria

Before evaluating specific materials, document your application’s operating parameters:

• Temperature Range: Both continuous operating temperature and peak exposure temperatures
• Chemical Environment: All fluids, gases, and cleaning agents the component will contact
• Mechanical Requirements: Static loads, dynamic forces, impact resistance, and fatigue considerations
• Wear Conditions: Sliding contact, abrasive media, or erosive environments
• Regulatory Requirements: FDA compliance, UL ratings, or industry-specific certifications

A clear understanding of these parameters eliminates unsuitable materials early and focuses evaluation on viable candidates.

UHMW-PE: The Workhorse of Industrial Plastics

Ultra-High Molecular Weight Polyethylene offers an exceptional combination of properties at a competitive price point. Its molecular weight of 3.5-7.5 million g/mol creates long polymer chains that provide outstanding wear resistance.

Key Properties:

• Coefficient of friction: 0.10-0.22 (self-lubricating)
• Operating temperature: -200°C to +80°C continuous
• Impact strength: Highest of any thermoplastic
• Chemical resistance: Excellent against most acids, bases, and solvents
• Moisture absorption: Near zero (0.01%)

Industrial Applications:

UHMW excels in material handling systems where its low friction and high abrasion resistance reduce wear on both the component and conveyed materials. Common applications include conveyor wear strips, chain guides, star wheels, and hopper liners.

Limitations:

UHMW’s relatively low continuous service temperature and poor creep resistance under sustained loads make it unsuitable for structural applications or high-temperature environments.

PEEK: Premium Performance for Demanding Applications

Polyether Ether Ketone represents the upper tier of engineering thermoplastics. Its semi-crystalline structure provides mechanical properties approaching some metals, with the processing advantages of a thermoplastic.

Key Properties:

• Continuous service temperature: Up to 250°C (480°F)
• Tensile strength: 90-100 MPa (comparable to aluminum alloys)
• Chemical resistance: Resistant to nearly all organic solvents
• Inherent flame resistance: V-0 rating without additives
• Biocompatibility: FDA and USP Class VI compliant grades available

Industrial Applications:

PEEK is specified where other plastics fail. Aerospace components, medical implants, semiconductor processing equipment, and oil and gas downhole tools regularly utilize PEEK’s unique combination of thermal stability, chemical resistance, and mechanical strength.

Cost Considerations:

PEEK commands a significant price premium—typically 10-20 times the cost of UHMW. This investment is justified when application requirements exceed the capabilities of lower-cost alternatives, but proper material selection should always consider whether PEEK’s properties are truly necessary.

PTFE: Unmatched Chemical Resistance

Polytetrafluoroethylene, commonly known by the DuPont trade name Teflon, offers the lowest coefficient of friction and broadest chemical resistance of any solid material.

Key Properties:

• Coefficient of friction: 0.05-0.10 (lowest of any solid)
• Operating temperature: -200°C to +260°C
• Chemical resistance: Inert to virtually all chemicals except molten alkali metals
• Dielectric strength: Excellent electrical insulator
• Non-stick surface: Nothing adheres to PTFE

Industrial Applications:

PTFE is the material of choice for seals, gaskets, and bearings in chemical processing equipment. Its electrical properties make it valuable for wire insulation and electronic components. Food processing equipment frequently specifies PTFE for its non-stick properties and FDA compliance.

Limitations:

Pure PTFE exhibits poor wear resistance and tends to cold flow under sustained loads. Filled grades incorporating glass fiber, carbon, or bronze address these limitations for demanding applications.

Comparative Analysis

Property	UHMW-PE	PEEK	PTFE
Max Continuous Temp	80°C	250°C	260°C
Tensile Strength	20-40 MPa	90-100 MPa	20-35 MPa
Coefficient of Friction	0.10-0.22	0.35-0.45	0.05-0.10
Relative Cost	$	$$$$	$$
Machinability	Excellent	Good	Fair

Decision Framework

Select UHMW when:

• Operating temperatures remain below 80°C
• Wear resistance and impact strength are primary concerns
• Cost-effectiveness is important
• FDA compliance is required without premium pricing

Select PEEK when:

• High temperatures or aggressive chemicals are present
• Structural strength approaching metals is required
• Long-term dimensional stability is critical
• Premium cost is justified by performance requirements

Select PTFE when:

• Chemical inertness is the primary requirement
• Lowest possible friction is needed
• Electrical insulation properties are important
• Non-stick surface characteristics are beneficial

Technical Support

Our materials engineering team provides application-specific recommendations based on your operating parameters and performance requirements. Contact us with your specifications, or explore our materials database to compare detailed property data across our full range of engineering plastics.