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Choosing the fibre core: aramid, polyester and the alternatives
The core carries the tensile load and sets the flex life, which makes it a bigger decision than the copper wrapped around it.
The core is the structural member of a tinsel conductor. It takes the pull when the cable is yanked and the strain when it is bent, and the copper foil is along for the ride. Choosing it is therefore a mechanical decision rather than an electrical one.
Aramid gives the highest tensile strength and the best flex life, and costs the most. Polyester is the volume choice for consumer cords where the loads are modest. Liquid crystal polymer sits at the top end where both strength and dimensional stability under temperature are needed.
The core also sets the minimum achievable diameter. A conductor cannot be thinner than its core plus two foil thicknesses, so a very fine conductor forces a fine core, which in turn limits how much tensile load it can carry. That interaction is why very fine conductors are specified with a tensile target alongside the resistance target.
Specifications
| Aramid | Highest tensile strength and flex life, highest cost |
|---|---|
| Polyester | Volume choice for consumer cords |
| Sets | Minimum achievable conductor diameter |
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Send us the targets your conductor has to hit
Tell us the resistance, outer diameter, tensile strength, swing and solderability targets together. Samples are available with no minimum order quantity.