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Influence of the Rotor Speed on the Yarn Manufacturing Process.

By :- Dr. H. Stadler{1975}

  • The analysis of the various aspects of the rotor spinning clearly indicates that any increase of the production rate inevitably results in a number of additional problems.
  • Depending on the circumstances, some of these difficulties may be quite considerable or even insuperable.
  •  Partly, indeed, the problems are related to basic & unchangeable physical properties of the rotor spinning system.
  •  This situation has to be seen in connection with the motivation for any increase of the production rate.
  •  The motivation consists in the trend to produce a good quality yarn at low costs.
  • In this instance, the cost reduction in the yarn manufacturing process would be achieved by reduced capital costs.
  •  In order to decide whether or not an increase of the production rate is able to bring the desired effect of a cost reduction, it is necessary to examine the basic possibilities for such an increase.
  • Two ways are open :
    • A] rotor speeds of up to approximately 60000 rpm :-.
      •  An increase of the rotor  speed from the actual 40000 to 45000 rpm to a level of 60000 rpm can at least theoretically be achieved with the existing OE machine type, which is characterized by a common drive system for the spinning elements.
      • In mill conditions, however, such an increase creates numerous additional difficulties. The mechanical possibility of a rotor speed in the range of 60000 rpm alone, can not be considered as a real step forward .
      • Such an increase of the speed represents only then a reasonable solution if at the same time the additional problems are solved, totally or at least to a large extent.
    •  B] rotor speeds of more than 60000 rpm. :-.
      •  For speeds of more than 60000rpm, it is necessary to switch to a completely new machine design.
      •  With regard to the machine to the machine operation , it is inevitable in these circumstances to use an individual drive system for each spinning unit.
      •  Along with this complication, there are of course other difficult problems to be solved , such as maintained the yarn quality at a certain standard or keeping the end breakage rate at an acceptable level.
      •  Along with this complication, there are of course other difficulties to be solved, such as maintaining the yarn quality at a certain standard or keeping the end breakage rate at an acceptable level.
  • A reasonable solution of the problems arising in both speed ranges therefore definitely requires OE machines which are much sophisticated .
  •  These machines, accordingly become more expensive. It is questionable, whether a speed increase can lead to a sufficient reduction of the capital costs in order to allow a cheaper yarn manufacturing process.
  •  A revolution of the cost situation of the spinning process by an increase of the speed above about 45000 rpm is thus quite impossible. Even a marginal reduction of the spinning costs through a higher production rate is doubtful.
  • Due to this marginal influence of the speed for practical mill operation is not yet exactly known. It depends on a large number of parameters & will vary from case to case.
  • In order to answer the question of the optimum speed level more accurately , a large amount of research work is going on.
  •  Since so many problems are related to any speed increase, this work is very diversified & complicated.
  •  In order to provide the spinner with the most suitable machine rieter`s research has made considerable headway.
  •  The progress in rotor spinning therefore goes on.
  •  Better solutions will certainly be found, maybe by making accessible higher speed levels, maybe by some other means.

 



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