Rieter

Leveling drawframes with closed-loop control

Index

In this system, the evenness of the sliver delivered is measured rather than the infeed sliver, as is the case with openloop control. In contrast to the open-loop control system, where the adjusting point is located after the measuring point, the adjusting point in the closed-loop control system is located in front of the measuring point (Fig. 16). In this case measuring has to be performed at very high speeds and with relatively small fiber masses, making high demands on the sensing device and signal processing. Nevertheless, the adjustment is still made in the main drafting zone. Mechanical or pneumatic sensing devices are generally used.

Fig. 16 – Leveling drawframe with closed-loop control