Non-wovens are flexible, porous, products consisting of one or more fibre layers. The separate fibres may either be preferentially oriented in one direction or may be deposited in a random manner. They are bonded by chemical, thermal or mechanical processes into textile products. Non-wovens are mainly planar structures. This relatively young branch of the textile industry has expanded enormously after the second world-war because of the high production rates and the resulting cost savings.