Permanent performance increases of Air-jet weaving machines make the use of control systems indispensable. Reason: filling yarn supply packages often cannot ensure constant load transmission to the yarn surface by the air flow.

This is due to yarn differences which can arise in a yarn package as well as between spinning or color lots or yarn suppliers. Until now, machines could not react to these variations within a package or between lots, especially with different colors, and operators had to make corrections. This meant the running behavior of Air-jet machines was partially dependent on the quality of settings. 

To allow Air-jet machines to react more sensitively and be independent from settings, they must have an intelligent system which supports automatic, independent filling insertion control. Such a system is necessary to attain constant thread arrival times with a uniform stretching phase and thus minimize the thread load.

With ServoControl™, DORNIER presents a patented system which works with just one servo valve with an extremely fast reaction time. This controls the pressure in a regulation circuit for all main nozzles depending on the defined thread arrival time.

Special DORNIER Characteristics
The compact servo valve with extremely fast reaction time is located in the throttle block of the main nozzles. This results in a low compressed air volume in the regulation circuit which ensures fast reaction times. Contrary to the eight control valves for the eight filling insertion nozzles required on conventional systems, the ServoControl™ requires only one servo valve to control filling insertion. This compact design also supports controlling tandem nozzles in the same manner as the main nozzles. Minimum pressure is used for the required load transmission to the yarn which means a decisive reduction in load peaks.

The extended setting range for filling insertion and the lower pressure required permits speed increases, especially for yarns with low strength, of up to 15% at the same or even lower yarn break rate. This also means less napping and therefore better final fabric quality.

With DORNIER "ServoControl™", the absolute pressure values are displayed digitally on the machine display and can be stored in the Style master file and then reused when the style is woven again. 

You can retrofit "ServoControl™" on your Air-jet machines type A which are equipped with inclined throttle block (as from September 2001).