Retractable Coil Cord Design & Flexibility Benefits
Retractable cords, or coil cords, have a spring-like form that allows them to bend and stretch with minimal stress on the inner wires. Coil cords can typically be extended to a length several times greater than their at-rest length, but return to their original length when released making them suitable for situations that require extreme flex-life and repetitive movement.
Manufacturing Capabilities & Material Jacket Options
New England Wire Technologies manufactures specialty silicone rubber-jacketed coiled cords suitable for high temperature applications at our facilities in Lisbon, New Hampshire. Our subsidiary companies of Bay Associates Wire Technologies (Bay Cable), located in Fremont, CA, and New England Interconnect Systems, located in Santa Ana, MX both offer custom coiled cords made with New England Wire Technologies cable jacketed with PVC, Polyurethane, Polyester, and TPE.
Engineers Ask: Custom Coiled Cords FAQs
How do I avoid overextending or prematurely fatiguing the cord?
Essentially, the cord should be designed for the application with a reasonable retracted length to meet the extended length needs. Reasonable life expectancy expectations should be established given the application and environment. Prototyping and testing provide an excellent path to ensure a custom coil cord will meet product life cycle expectations.
Material selection is very important, as some jacket materials have very good elasticity and allow the coil cord to “snap” back in place. Others offer moderate coiling properties and some materials should be avoided given their inability to recover from being stretched. Polyurethanes are generally considered the best choice. Many TPR materials can offer excellent coil memory. While PVCs can be a budget friendly option, they typically lack lasting retractile properties.
How does temperature impact performance?
Lower temperatures limit an insulation’s ability to snap back, can cause cracking or crazing, and can cause materials to become brittle. Likewise, excessive heat can change materials on a molecular level, causing softening, deformation, tackiness, and relaxing jackets excessively which can prevent retraction.
How do I specify a custom coil cord?
Provide as much information as possible. What is the desired retracted length, what length does the coil cord need to extend? Are there construction size limitations, both for the construction and the coil diameter? What are the operating temperatures? Will the coil cord be exposed to any severe conditions such as temperature, voltage, chemicals? Will the leads be axial or tangential and what are the required lengths?
Every application is different and understanding the performance criteria needed is essential. With this information in hand, efforts to optimize a design for the most critical criteria can be made.
