A polymer containing monomers of amides joined by peptide bonds is the description of a polyamide. These occur both naturally and artificially. Natural are for example proteins such as wool and silks. Artificial are made through step-growth polymerization or solid-phase synthesis, for example aramids, nylons and sodium poly (also called aspartate). Polyamides are commonly used in applications which need durable and strong textiles, such as automotive, carpet and sportswear.
Polyamide is mainly developed in the Far East, mostly in South-Korea and Japan, but lately also China started to follow. Polyamide is ultimately made from benzene, from the oil and gas industry. Benzene is highly toxic to humans. Production takes place at large chemical companies such as BASF, were rigorous safety requirements are taken. A synthetic material is made of the benzene which is released as a by-product water. The resulting 'pasta' is ready to use in the spinning process or it is pressed down to granules to storage and transport. The granules are melted in a spinning bath and pressed through a shower head type (spinneret) to spin yarn. Cold air on the spinning yarn makes the newly sprayed 'wires' hard: they are now filaments. In order to make them stronger, they are stretched and fixated with heat. By using different spinning head, the characteristics of the fiber can be adapted. The fibers are made into a fabric by weaving it. It can get all become all kinds of fabric: from smooth silky material to a beautiful lace. The fabric cannot handle heat very well, and it can turn yellow and loose its strength in the sun.