The first step in the process of cable manufacturing is wire drawing. Copper rods received from the supplier are too thick for usage in flexible wires so they will have to be stripped down to the required diameter. To do this, they are pulled through a series of dies of decreasing sizes. Copper wires will emerge once the desired diameter is reached.The wires then go through an annealer where they are refined to obtain better electrical conductivity. Once complete the wires are packed onto metal bobbins.
The next step after drawing is wire bunching. This is where the copper wires are twisted together to form a cable. The number of wires twisted together determines the nominal cross-sectional area of the cable. Bunching a series of thin wires together provides more flexibility than solid wires of similar size.
Stranding is basically similar to bunching; the only difference here is that stranding refers to the twisting of insulated cables while bunching is reserved for bare copper wires. For certain types of flexible cords, this is where the insulated cables are twisted together with cotton yarn before going through a final extrusion process.
Extrusion is the process where the bare copper cables are insulated. Depending on product requirements, the cables may have to go through the extrusion stage more than once, for example if the cables require additional sheathing on top of its insulation.
Coiling and Packing
The final manufacturing stage involves coiling and cutting the cables to its required packing length. The cables can be packed onto drums or as individual rolls, after which they are wrapped, labelled and stored while awaiting shipment.