There are a number of correct or incorrect processes used in the manufacturing of shields. One of the important parameters is the braiding angle of the shield.

　　In cables used for drag chains, the loads on the shield at the outer diameter of the cable have to be taken into account. Unreasonable shield braiding angles can further increase the tension load and lead to breakage of the shield. The resulting weakening of the shielding effect can even cause short circuits when sharp cable tails poke through the wool fabric or foiled gold material and come into contact with the core. Here we recommend a useful tip: If the insulation is stripped off, the shielding can be easily pushed back into the sheath, but such shielding cannot be applied to highly flexible cables in energy supply systems that are in motion. Of course, Igus offers a direct solution to these problems:

　　The braiding angle of the shield, which has been determined through long term experiments, effectively counteracts the tension and is therefore ideally suited for drag chains.

　　Due to the stabilized inner sheath, the shield does not slacken and fail.

　　In stranded constructions, the shield is inherently torsionally resistant.

　　Sheath wear or breakage

　　Any defects in the internal structure are difficult to detect from the outside, but problems with the sheath are directly observable to the naked eye. The sheath is the first layer of protection for the cable's delicate internal structure. This is why cracked, worn and swollen deformed sheathing is a very serious quality problem. In order to avoid such problems, Igus offers seven different materials for cable sheathing, which can be selected by the user according to the corresponding working environment of his machinery.

　　Armor type extruded sheathing

　　Manufacturing process and material are equally important factors in determining product quality. In some of the so-called drag chain cables, the sheaths are often tubular and therefore do not provide the necessary support to the stranded structure during long term bending, making the stranded structure susceptible to splitting.

　　Igus, as the first manufacturer of drag chain systems, has therefore developed an armor-type extruded sheath.

　　This sheath ensures that the core wires of the cable do not come loose when the cable is in motion. The reason for this is that the sheath is extruded under particularly high pressure and acts as a guide groove, guiding the movement of the core wires and at the same time acting as a support. This makes it very suitable for drag chains.