In contrast to knitting, weaving or stitching, warp knitting is only familiar to a few. However, innumerable textiles are manufactured using warp knitting: curtains and lace lingerie, luggage racks and seat heating as well as satellite antennas and camouflage netting. The possibilities for using warp knitting are almost unlimited and range from open net structures to closed surfaces, from highly elastic and high-strength textiles to spacer textiles with functions inspired from bionics. This variety is not least of all attributable to the broad range of deployable materials which, combined into innumerable patterns, incorporate specific properties into the respective textile. One particularly outstanding property of warp knitting that is of interest for composites is the ability to integrate completely stretched, non-deflected threads and position them in a manner that is secure against displacement so that textiles are created without stretching related to the design.
Ultra-thin, electrically conductive warped knitted netting makes it possible to produce extremely light and foldable large reflectors for satellites. Tec-Knit manufactures warp knitted netting from ultra-thin, gilded molybdenum yarns for the radar reconnaissance satellite TechSAR for the Israeli military. They are opened up like an umbrella in outer space. Above all, the structure of the knitted fabrics is crucial for the reflector properties. The reflector must also exhibit a certain degree of electrical conductivity in its deployed state. In order to precisely adjust these properties the client is on location at the start of production. A total of 20 centimeters are warp knitted, tested on site, the machine adjusted and then another 20 centimeters are warp knitted. This process usually takes several days in order to then produce 50 meters per year – a quantity that is unusually small for the textile industry. However, Tec-Knit is the only manufacturer of folding reflectors of this kind in Europe. The satellites are suitable for military deployment, but can also be used for civilian purposes – for example, for determining the ripeness of fruit.
Mareike Gast is an industrial designer with her own business in Frankfurt, specializing in new materials and technologies. In close cooperation with industry and research, she develops innovative products and product strategies. In addition to her work in product development, she also regularly teaches at various international universities.