Rieter

False twist at other places in the spinning process

Index

The creation of false twist is not limited to the example given before. False twist arises, whether or not it is wanted, at various other points in the spinning process; for example, at the crown of the flyer in the roving frame and at the rotor navel in the rotor spinning machine.

At any point where a twisting element is operative between two clamping points, false twist will be produced. The clamping points can be stationary as in the example given (e.g. the yarn contact point E in the rotor and the withdrawal rollers Z, as shown in Fig. 66), and the twist element (the navel T) can rotate, as described in Section  Operating principleOperating principle. Alternatively, the twisting element (T) can be stationary, as actually occurs in rotor spinning, and the thread can be continuously rolled on the contact surface of the navel owing to the movement created by the rotor revolution at the point E. The effect is the same. False twist occurs between E and T. Without this false twist effect, it would probably not be possible to operate with the high rotor speeds that are normal today.

Fig. 66 – Creation of false twist in the rotor