Nozzle filament assembly general twist with yarn denier nylon number changes of fabric and style of different requirements to make the corresponding adjustment, elongation of machine package also mainly by the spandex core yarn properties determined, twist, outer fibers wrapped too tight, rates are also mainly by the spandex core yarn properties determined, twist, outer fibers wrapped too tight, spandex elastic effect but can not fully play, ultimate elongation decreases. It can not be fully played, so that the elongation decreased.

Mainly used: weaving, stretch denim, ribbon, socks, underwear, lace and sporting goods etc.. Spandex name poly carbamate fibers, also called polyurethane elastic fiber, commonly known as spandex, the referred to as "spandex" (spandex). First developed by Bayer company in Germany in 1937, but did not form industrial production. Until 1985, the United States DuPont Co developed spandex yarn, and large batch production.

Spandex is a special fiber with high elasticity and is currently known to the world's most resilient synthetic fibers, the stretched length of up to 5-8 times, with excellent resistance to fatigue and high elastic recovery rate, elastic constant, any synthetic fibres are unable to and compared. Spandex yarn under tensile 2 times the response rate is almost 100%, elongation of 5 times, the spring rate for 95-99%. This is unmatched by other fibers. In addition the polyether polyester spandex spandex elastic ratio and rebound rate is higher.

At present, knitting loom and finishing equipment in the use of special controller multi drive used more generally relatively centralized driving through a mechanical transfer mechanism and the distribution of power systems by multi transmission energy effectively reduce the equipment complexity improves driving efficiency and convenient process control and reduce maintenance complexity and shorten the design cycle of the new equipment of roving machine spinning machine, winding machine and all kinds of chemical fiber machinery are already using multi transmission technology of fieldbus technology and common DC bus technology make the transmission more advantages of cost is to limit the use of a large number of key factors of multi drive drive prices gradually reduce will enable more users try to drive products.