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. You need to understand the full temperature range—both continuous operating temperature and peak exposure temperatures that might occur during upsets or cleaning cycles. Map out the complete chemical environment, including all fluids, gases, and cleaning agents the component will contact throughout its service life.

Mechanical requirements deserve careful attention: static loads, dynamic forces, impact resistance, and fatigue considerations all influence material selection. For moving parts, consider wear conditions such as sliding contact, abrasive media, or erosive environments. Finally, note any regulatory requirements like FDA compliance, UL ratings, or industry-specific certifications that constrain your material choices.

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—the material simply outlasts alternatives in sliding and abrasive applications.

The coefficient of friction runs between 0.10 and 0.22, making UHMW effectively self-lubricating in many applications. Operating temperature spans an impressive range from -200°C to +80°C continuous, covering cryogenic applications through moderate industrial environments. UHMW delivers the highest impact strength of any thermoplastic, absorbing shocks that would crack or shatter other materials. Chemical resistance is excellent against most acids, bases, and solvents, while moisture absorption sits near zero at 0.01%—the material simply doesn’t swell or change dimensions in wet environments.

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. You’ll find it in conveyor wear strips, chain guides, star wheels, and hopper liners throughout food processing, packaging, and bulk material handling industries. The material’s combination of wear resistance, low friction, and FDA compliance makes it a natural choice for applications where product contact occurs.

Limitations

UHMW’s relatively low continuous service temperature of 80°C and poor creep resistance under sustained loads make it unsuitable for structural applications or high-temperature environments. When loads remain constant for extended periods, UHMW gradually deforms—a behavior called creep—that disqualifies it from precision structural roles. The material also doesn’t bond well, making adhesive joining unreliable.

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.

PEEK handles continuous service temperatures up to 250°C (480°F), well beyond most engineering plastics. Tensile strength reaches 90-100 MPa, comparable to aluminum alloys and sufficient for genuinely structural applications. The material resists nearly all organic solvents and carries inherent V-0 flame resistance without additives—it simply won’t sustain combustion. FDA compliant grades are available for food contact applications requiring both high temperature capability and regulatory approval.

Industrial Applications

PEEK is specified where other plastics fail. Semiconductor processing equipment relies on PEEK for its combination of chemical resistance, high-temperature capability, and low particle generation. Oil and gas downhole tools use PEEK because it survives the combination of high temperature, aggressive fluids, and mechanical stress found thousands of feet below the surface. Chemical processing components and high-temperature industrial equipment regularly utilize PEEK’s unique combination of thermal stability, chemical resistance, and mechanical strength when no other plastic will do.

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. In many cases, a less expensive material handles the application adequately, and specifying PEEK wastes money without providing additional benefit.

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.

The coefficient of friction runs between 0.05 and 0.10—the lowest of any solid, allowing PTFE to slide against nearly any surface with minimal resistance. Operating temperature spans -200°C to +260°C, providing capability at both cryogenic and elevated temperatures. Chemical resistance is essentially universal; PTFE remains inert to virtually all chemicals except molten alkali metals and certain fluorine compounds. Excellent dielectric strength makes PTFE valuable as an electrical insulator, and the material’s non-stick surface means nothing adheres to it—not ice, not food, not aggressive process fluids.

Industrial Applications

PTFE is the material of choice for seals, gaskets, and bearings in chemical processing equipment where other materials would dissolve or degrade. Its electrical properties make it valuable for wire insulation and electronic components in demanding environments. Food processing equipment frequently specifies PTFE for its non-stick properties and FDA compliance—the same reasons it appears in cookware.

Limitations

Pure PTFE exhibits poor wear resistance despite its low friction; the material is soft and wears quickly under sliding contact. It also tends to cold flow under sustained loads, gradually deforming away from its original shape. Filled grades incorporating glass fiber, carbon, or bronze address these limitations for demanding applications, sacrificing some chemical resistance and increasing friction slightly in exchange for dramatically improved wear life and dimensional stability.

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

UHMW is the right choice for applications where operating temperatures remain below 80°C and wear resistance or impact strength drive the design. It delivers cost-effective performance when dimensional stability under sustained load isn’t critical, and FDA compliance is available without premium pricing. Most material handling, conveying, and wear-surface applications land here.

PEEK makes sense when high temperatures or aggressive chemicals are present, when structural strength approaching metals is required, or when long-term dimensional stability under load is critical. The premium cost is justified by performance requirements that other materials simply cannot meet—but only when those requirements genuinely exist.

PTFE earns its place when chemical inertness is the primary requirement, when you need the lowest possible friction coefficient, when electrical insulation properties matter, or when non-stick surface characteristics are beneficial. The material’s softness and tendency to creep limit its structural applications, but for sealing and sliding surfaces in aggressive environments, nothing else compares.

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.