Exploring the Application of New Material PEEK

Engineering Selection and OEM Considerations

1. Temperature Resistance Is One of the Main Reasons to Consider PEEK

One of the most important advantages of PEEK is its ability to maintain useful mechanical and electrical properties at elevated temperatures.

This can make it suitable for applications where the cable may experience:

• Elevated operating temperatures
• Thermal cycling
• Heat generated by nearby electronics
• High-temperature processing
• Long-duration thermal exposure

If the cable is exposed to temperatures beyond the practical range of more conventional insulation materials, then PEEK may be worth evaluating, because its thermal stability can provide greater design margin.

The exact suitability still depends on the actual temperature profile rather than on the material name alone.

OEM engineers should define:

continuous operating temperature + peak temperature + exposure duration + thermal cycling conditions

2. Chemical Resistance Can Be Important in Medical and Industrial Environments

PEEK has strong resistance to many chemicals, which can be valuable in demanding environments.

Potential exposure can include:

• Cleaning agents
• Disinfectants
• Oils
• Solvents
• Process chemicals
• Other application-specific fluids

If the cable is exposed repeatedly to aggressive chemicals, then the insulation material should be evaluated against the actual chemicals and exposure conditions, because general chemical-resistance claims do not guarantee compatibility with every formulation or concentration.

For medical cable applications, this becomes particularly relevant when assemblies are repeatedly cleaned or otherwise exposed to defined processing chemicals.

See HOTTEN's Medical Devices and Medical Cable Assembly solutions.

3. Mechanical Strength Matters for Fine and Ultra-Fine Conductors

PEEK provides relatively high mechanical strength compared with many common thermoplastics.

This can be valuable when insulation must protect a fine conductor from:

• Abrasion
• Compression
• Handling
• Installation stress
• Repeated mechanical contact

If a fine conductor needs a robust protective insulation layer without substantially increasing cable dimensions, then PEEK may be considered, because its mechanical properties can provide a strong insulation structure in demanding applications.

However, mechanical strength should not be confused with flexibility.

4. PEEK Is Not Always the Best Choice for Highly Flexible Cables

A material can be mechanically strong while still not being the optimal choice for an application that requires extremely flexible cable behavior.

For highly dynamic applications, OEMs should compare PEEK with alternative insulation materials according to:

If the cable must withstand continuous bending or tight dynamic routing, then flexibility and flex-life performance should be evaluated before selecting PEEK, because a high-performance insulation material still has to match the cable's mechanical duty cycle.

5. PEEK Selection Should Be Based on the Complete Cable Structure

Insulation material cannot be selected independently from the conductor and cable architecture.

The complete construction may include:

conductor → insulation → dielectric → shielding → jacket

Each layer affects the final product.

If PEEK is selected for a fine wire or micro coaxial cable, then its thickness, extrusion behavior, conductor size, and surrounding structure should be evaluated together, because changing the insulation can affect cable OD, flexibility, capacitance, impedance, and termination.

This is especially important for ultra-fine cable where dimensional margins are small.

6. Insulation Thickness Affects Cable Size and Electrical Performance

For fine-wire applications, the insulation layer may represent a significant portion of the finished cable diameter.

Important parameters include:

• Insulation thickness
• Concentricity
• Uniformity
• Surface quality
• Extrusion stability

If the cable has a very tight OD requirement, then insulation thickness must be tightly controlled, because a small increase in insulation size can affect the finished cable dimensions and available routing space.

For micro coaxial cable, insulation geometry can also influence electrical characteristics.

7. PEEK Can Be Useful in High-Temperature Electrical Insulation

PEEK can serve as an electrical insulation material where the operating environment demands elevated thermal performance.

Potential applications include:

• High-temperature electronic assemblies
• Specialized sensors
• Aerospace-related electronics
• Industrial measurement equipment
• Medical equipment with demanding thermal conditions
• Other specialized electrical interconnects

If the cable operates near a heat source or must survive repeated elevated-temperature exposure, then insulation should be evaluated for both electrical and mechanical stability at the actual operating temperature, because ambient temperature ratings alone may not describe the complete cable behavior.

8. PEEK Processing Can Be More Demanding Than Standard Cable Materials

PEEK is a high-performance engineering thermoplastic and may require more controlled processing conditions than more common insulation materials.

For cable manufacturing, process control can include:

• Extrusion temperature
• Melt behavior
• Line speed
• Die design
• Cooling conditions
• Insulation thickness
• Concentricity
• Surface quality

If PEEK is used for an ultra-fine cable, then extrusion and dimensional control become particularly important, because small variations in insulation geometry can affect the final electrical and mechanical properties.

This is one reason material selection should be linked to the manufacturer's actual processing capability.

9. PEEK Can Influence Cable Flexibility and Bend Performance

The finished cable's bending behavior depends on more than the conductor.

It is affected by:

conductor + insulation + shielding + jacket + cable diameter + construction

If PEEK insulation is used in a flexible cable, then the complete cable construction should be tested at the required bend radius, because the insulation material contributes to the bending stiffness of the finished cable.

This is particularly important for:

• Medical probes
• Robotics
• UAV imaging
• Camera assemblies
• Other dynamically routed cables

For flexible applications, see UAV & Robotics.

10. Electrical Properties Should Be Evaluated Together With Thermal Performance

PEEK can provide strong insulation performance, but OEM engineers still need to define the actual electrical requirements.

Depending on the cable architecture, relevant parameters may include:

If the cable is used in a high-frequency application, then insulation material should be evaluated together with dielectric characteristics and cable geometry, because material selection can influence capacitance and impedance.

For high-frequency applications, see HOTTEN's RF Coaxial Cable Assembly.

11. PEEK Should Be Compared With Alternative Insulation Materials

An OEM should not start with:

“We need PEEK.”

A better starting point is:

“What performance must the insulation provide?”

Possible comparison materials include:

If the main requirement is extreme flexibility, then silicone or TPU may be worth comparing with PEEK, because mechanical flexibility may be more important than high-temperature capability.

If the main requirement is chemical and thermal stability, then PEEK, PTFE, or FEP may be considered depending on the exact application, because the required environmental properties become the primary material-selection criteria.

12. PEEK May Be Relevant to Medical Cable Applications, But “Medical Grade” Must Be Defined Carefully

PEEK is used in various demanding medical applications, but simply identifying a cable as “PEEK” does not establish that the finished cable is suitable for every medical device.

For medical OEM projects, buyers should review:

• Intended patient contact
• Material composition
• Manufacturing process
• Cleaning exposure
• Sterilization process
• Biological evaluation requirements
• Finished-device configuration

If the cable is part of a patient-contacting medical device, then the OEM should evaluate the actual finished-device material configuration within its applicable biological-safety and risk-management process, because material selection alone does not establish universal biocompatibility.

For medical cable applications, see Medical Cable Assembly.

13. PEEK and Sterilization Requirements Should Be Evaluated Together

Some medical devices expose cable assemblies to repeated reprocessing or sterilization.

The relevant engineering question is:

Can the complete cable assembly maintain its required properties after the defined process?

Potential areas to evaluate include:

• Insulation condition
• Flexibility
• Adhesion
• Jacket / overmold
• Connector transition
• Electrical insulation
• Signal performance

If a cable is repeatedly sterilized, then the finished assembly should be tested under the actual sterilization process and lifecycle conditions, because the complete assembly contains more than the PEEK insulation itself.

14. OEM RFQs Should Define the Material Requirement by Performance

For an OEM custom cable project, a useful RFQ should define the material requirement in measurable terms.

If the OEM knows the required operating environment but has not fixed the insulation material, then providing the performance requirements can allow the cable manufacturer to compare PEEK with alternative materials, because the best insulation depends on the application's actual constraints.

15. The Right PEEK Application Depends on the Trade-Off

PEEK becomes most useful when its specific material strengths solve a real engineering problem.

If the project has demanding thermal, chemical, and mechanical requirements, then PEEK may provide useful design margin, because those are areas where its material properties can justify the additional material and processing requirements.

If the application has mild environmental conditions and primarily requires low cost or maximum flexibility, then alternative insulation materials should also be evaluated, because PEEK's higher performance may not provide enough benefit to justify its trade-offs.

16. Supplier Capability Matters When PEEK Is Used in Fine Wire

For HOTTEN's product strategy, PEEK is most relevant when it is part of a fine-wire or micro coaxial cable solution, not as an isolated material product.

A supplier should be able to control:

fine conductor → PEEK insulation → cable geometry → shielding → cutting / stripping → termination → finished cable assembly

Important qualification questions include:

• Can the supplier process the required fine conductor size?
• Can insulation thickness be controlled?
• Can concentricity be maintained?
• Can the cable be reliably stripped?
• Can the finished cable be terminated?
• Can the cable be tested after processing?
• Can the construction be reproduced during volume production?

If PEEK is specified for an ultra-fine cable, then both material capability and fine-wire manufacturing capability should be evaluated, because the material advantage has little value if the supplier cannot consistently process the complete cable structure.

17. A Practical PEEK Cable Selection Checklist

Before selecting PEEK insulation for an OEM cable, confirm:

PEEK should therefore be treated as an engineering material choice, not simply a premium insulation material.

For demanding cable applications, the correct selection depends on the balance between temperature, chemical exposure, mechanical strength, flexibility, electrical requirements, cable dimensions, processing capability, and total cost.

For OEM projects requiring fine-wire and custom cable assemblies, see HOTTEN's Micro Coaxial Cable, Micro Coaxial Cable Assembly, and Medical Cable Assembly solutions.