34—THE YARN TWIST INSIDE THE ROTOR IN OPEN-END SPINNING

A method for determining the twist level inside the rotor in open-end spinning is described. This requires a correction factor to be applied to the results obtained by means of a photographic technique. This correction factor is shown to be accurate by using a positive false-twister at the exit of the outlet tube. As a result of the use of this technique, it is demonstrated that the twist level inside the rotor is always greater than the machine twist. It is concluded that the outlet tube acts as a false-twister. It is also shown that the ability of the outlet tube to alter the level of the minimum twist at which yarns can be spun in rotor-spinning is largely due to the false-twister action.