<p>The helical chain consist of a number of plastic spirals consisting of flat coil webs and coil bows. The coil bows of a spiral engage with the coil bows of the adjacent spirals. Plug wires are inserted into the ducts formed by the engaged coil bows of two adjacent spirals. At least one section of the spirals is made of filament material featuring at least two components over its whole length. The spirals are wound in such a way that the first component lies on the inside of the spiral and the second component on the outside of the spiral.</p>
