Method of controlling the tension of an advancing yarn
AssigneeBarmag AG
InventorHellmut Lorenz
Life of this patent
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Abstract
A method is described for controlling the tension of an advancing yarn, which is crimped in a friction false twist unit of a false twist crimping machine. In accordance with the method, the tension of the advancing yarn is measured downstream of the friction false twist unit and the yarn tension is converted via a time filter and by comparison with a predetermined desired value into an adjustment signal for correcting the friction false twist unit, the control range being determined by defined limit values of the adjustment signal. The adjustment signal is a current value and is corrected adaptively via a PI controller, the control behavior of which takes into account the quotient from the change of the yarn tension and the change of the current value of the adjustment signal.
Claims14
A yarn false twist texturizing process comprising the steps of
- advancing a yarn through a false twist unit which acts to impart a frictional force to the yarn which includes a twisting component and a tension component,
- monitoring the tension of the advancing yarn and generating a signal (T) representative of the monitored tension,
- processing the generated tension signal through a time filter to produce a time averaged signal (LW),
- comparing the time averaged signal (LW) with a set point signal (Soll) and producing an adjusting signal (VS) representing the difference therebetween,
- correcting the adjusting signal as a function of a disturbance variable (Z) acting upon the false twist unit, and
- controlling the operation of the false twist unit so that the frictional force imparted to the advancing yarn varies as a function of the value of the corrected adjusting signal.
Dependencies are inferred from the claim text.