Flexible wire in terms of how limp it is starts with the wire design options. The choices you make can greatly impact how flexible the wire or cable will be. The right choices can make the difference between flexible wire or a super flexible wire. Designing a flexible wire or flexible cable begins with the design. We start at the core, conductor stranding and construction.
1. Conductor stranding: Conductors are made up of fine strands of wire assembled together into several configurations. The more strands in the construction, the more flexible and resistant to repetitive flexing the conductor will be. Conductor stranding options range from a solid strand (one strand) to over a thousand strands depending on the wire gauge. The construction of conductor stranding is important as well. Stranded conductors can be manufactured in a variety of configurations, the most common being concentric (true concentric, equilay concentric, unidirectional concentric, and unilay concentric), bunched and rope.
Conductor stranding with rope construction makes for a more flexible wire. This construction has the advantage of increasing flexibility by using a larger number of finer strands while maintaining a tighter diameter tolerance than a simple bunched construction. Ropes are more evident in the larger AWG sizes, such as 8 AWG and larger, but there are also many applications that require the flexibility of rope constructions in the smaller gauges. Constructions vary and can contain hundreds or thousands of strands. To achieve the most flexible wire design, be sure to use the higher stranded conductors. For flexible wire with repetitive flexing applications, consider using an alloy for fatigue resistance.
2. Insulation: Flexible wire and cable requires a flexible insulation material. There are many choices for insulating materials. The most flexible wire insulation is silicone, together with the right conductor stranding can be as limp as a wet noodle. While silicone is the most flexible wire insulator, it does have poor abrasion resistance. Choosing the right material will depend on your application and use, consult your wire and cable manufacturer to determine which material will work best for your application. Flexible insulation and jacket materials include TPE/TPR, polyurethane and even PVC, Calmont’s Superflex® uses a special PVC formula for increased flexibility. When choosing an insulation or jacket material, consider your requirements. Is your application requiring sterilization? Is abrasion resistance required? Temperature, chemical contact and bio-compatibility are other requirements to consider. Calmont’s insulation and jacket material chart is a helpful tool.
3. Cable construction: Cable construction is another component for super flexible cables. Cable lay length and shielding can increase the cable’s flexibility. The cable lay is how the conductors are cabled together, the wires can run parallel or be twisted around each other. The length between each twist can be adjusted for maximum cable flexibility. Shield options include spiral, braid and Mylar or foil wrap. The application is important when considering shield types. For flexible cables which undergo repetitive flexing, spiral and foil type shield are not good options as the shield coverage will be compromised over time.
If you want a more flexible cable design, contact Calmont Wire & Cable to learn more about material choices.