If the „package change“ and „spinning start-up after package change“ operations are performed by two robots working independently, these two operations can also only be performed consecutively and not synchronized, i.e. simultaneously.
The operating robot called up via the machine control unit for package change (automatic doffer) places the full package on the package conveyor belt in the center of the machine and replaces it by one of the pre-wound starter tubes it has brought with it.
The spinning position remains stationary until the requested operating robot for piecing (automatic piecer) has served the spinning position and initiates spinning start-up at the spinning position by re-introducing the end of the thread on the starter package into the rotor and starting sliver feed.
In this concept the spinning position being served has to wait both for the automatic doffer and then again for the automatic piecer; i.e. it is affected by two waiting times, compared with one waiting time with integrated automation.
As already explained elsewhere, machinery manufacturers which previously used operating robots working independently also offer automation featuring integrated operating robots on their new models.