Yarn is a long continuous length of single fibre (e.g. polyamide monofilament for sequins), or it consists of filament fibres twisted or grouped together (e.g. wool darn with woven shirting fabric containg in cut around 100 single fibres of 10-50mm length). Process of darn production is called spinning. Industrial production of darn developed from hand spinning which had been one of the oldest manual activities in the history of humankind. (Linen fabric found in South America is probably more than 10 000 years old).Open end spinning or open-end spinning is a technology for creating yarn without using a spindle. It was invented and developed in Czechoslovakia. In 1965 Czech KS200 rotor spinning machine was introduced at 30000 rotor rpm. In 1982 there were nearly 4 mil of places using open-end spinnig, which make at least 10% of production capaciy of all spinning mills.