Selecting the Best Cable Materials for Extreme Temperatures

Selecting the Best Cable Materials for Extreme Temperatures

Discover the best cable material and component selections for demanding applications in extreme temperature conditions.

Conductors

At the core of the cable are conductor materials. Selecting the right material makes a big difference on longevity and signal reliability of the cable.

Conductors for High-Temperature Environments

When designing cables for high temperature environments, consider nicklel-plated copper or alloy conductor materials:

• Nickel-plated copper is often used in high-temperature applications and withstands up to 450°C. Nickel plating also offers corrosion and wear resistance
• Alloys are a combination of two or more metals such as silver, nickel, copper, beryllium, cadmium, or RoHS-compliant chromium; metals are selected for their overall toughness, break strength, and flex-life and are a great option for high-temperature applications

Conductors for Frigid Temperature Environments

If the cable is designed for frigid temperatures, you'll want to keep flexibility in mind, because a solid conductor will be more rigid and prone to break easier when stressed.

If flexibility is important for your application, select a conductor with a high strand count. As a general rule, the higher the strand count, the more flexible the conductor will be.

Tubing

Tubing is a component offering a variety of functions within a custom cable. For example, tubing could be used to dissipate heat or to vent pressure or steam. Tubing could even be used to carry warm water to help protect the cable maintain performance by preventing it from getting too cold.

Tubing for High-Temperature Applications

Depending on the specific high-temp application, your cable design engineer will want to ensure that the tube wall thickness and material are suitable for the high-heat exposure. This will ensure that the tubing will not break down and potentially expose the conductors.

Tubing for Cold Applications

Tubing may be used inside a custom cable to vacuum liquids or supply air or other gases. If exposed to a cold environment, tube material and construction will be selected to ensure the tube will not kink or collapse. Material durometer or shore hardness is an important factor. A low durometer may be more flexible, yet some materials can become brittle and crack and break in cold temperatures. A Northwire Cable Design Engineer will help you make the right choice for your tubing material.

Insulation and Jacketing

When choosing conductor insulation and cable jacket materials for extreme temperature environments, fluoropolymers offer many benefits for both extreme heat and frigid cold. Keep durometer or shore hardness in mind when selecting your conductor insulation and cable jacketing material.

While fluoropolymers perform well in cold temperatures, they become more rigid. A lower durometer material offers more flexibility, but is more prone to cracking.

Compare common fluoropolymer materials

PTFE

• The most fluorinated of all fluoropolymers
• Offers superior performance in extreme temperatures
• Resistant to chemicals, oils, solvents, cut, crush, and abrasion
• Northwire extrudable PTFE offers a more consistent wall thickness and no length restrictions! 

PFA

• PFA offers superior performance, yet is more costly

FEP

• The first melt processable fluoropolymer to be released
• Is a cost-effective alternative to PFA when chemical resistance is not imperative

ETFE

• Features improved cold flow resistance, higher tensile strength, and increased abrasion resistance
• Maintains high temperature performance
• Very good electrical properties
• Chemical inertness

Other materials that perform well in extreme temperatures:

• Santoprene
• TPEs
• Northwire BioCompatic Silicone Alternative

Harsh environments can add stress to devices and the cable connectivity. Below are additional factors to consideration when designing cables for extreme temperatures.

Flexibility

• Will the cable be used in a static application or will it be moving? Cold temperatures can decrease the flexibility of a cable and make it very brittle. If flexibility is important, consider a TPE (thermoplastic elastomer) or a TPU (urethane) as both jacket materials are rugged and perform well in low temperatures.
• If instead, the cable would be in a static environment, a good question to ask is whether the cable will be supported/contained or free to move in the wind? If the cable is able to move, brittle point is important because the jacket could crack if the cable could come into contact with other objects at sub-zero temperatures. If that is a possibility, be sure to check the cold bend radius of the material being selected.

Temperature Variation

• Will the temperature stay relatively constant or will it fluctuate from cold to warm to hot and back to cold? If so, what is the fluctuating cycle time?

Liquid Exposure

• Another consideration is whether the cable will be exposed to liquid--especially if the temperature reaches the freezing point!
• Keep the termination to the connector in mind. If exposed to liquid, consider an over-mold to help protect the connection points while being flexed and help protect them from liquid exposure. A water-tight connector may be needed to prevent water ingress.

Connector Choice

• Will the cable assembly be installed and frequently handled in freezing temperatures? If so, select a connector that features a high mating cycle count. This will ensure that the connector housing or internal pins do not crack and break when being connected and disconnected.

There are a variety of cable materials and component options to consider when designing a custom cable for your end application. 

Contact us today. Northwire design engineers will help you select the right materials and components for reliable connectivity to your unique end application.