They're used in aviation and the space industry, in ships and wind-turbines -- even in sports equipment. Stretched fibres that are stronger than steel and lighter than aluminum.
They're made by the Saertex company, in the state of North Rhine-Westphalia. Saertex was founded by textile engineer Bruno Lammers. Today, the firm employs about 1,000 people and has become an international market leader. Report by Anja Kimmig.