Rieter

Options on the ring spinning machine

Index

Fig. 14 – Fiber guidance options

The fiber bundle in the main drafting zone consists of only relatively few fibers. There is virtually no friction zone, and fiber guidance by rollers alone is inadequate. The shorter fibers in particular also have to be controlled in terms of speed within the drafting zone. Special fiber guidance devices are therefore required in order to perform satisfactory drafting. The following guidance options can be envisaged for a ring spinning drafting system (Fig. 14):

  • line guidance:
    A small aluminum or wooden roller (1), the so-called dummy roller, presses with its low dead weight against the bottom roller. This device is no longer used in modern drafting systems (a).
  • surface guidance: (two-dimensional)
    This can take place in the form of deflection around rollers (b), single aprons (c) or double aprons (d). New ring spinning machine drafting systems are equipped with double aprons, while INA also employs version (b) at the feed rollers.
  • spatial guidance: (three-dimensional, e) (fiber channel)
    Only this device can provide optimum fiber control and thus fewer irregularities. However, it is difficult to work with, since the size of the channel, for example, should always be adjusted to the bulk of the material. Nevertheless, this principle has already been implemented in the Ambler drafting system of the English worsted spinning process. Spatial guidance would be ideal with moving surfaces rather than the stationary surfaces illustrated in the drawing.