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Optimisation of drawframe
       autoleveller



            Hitesh Choudhary
            www.facebook.com/hitesh.choudhary1
Objects of drawframe
What is autoleveller?

   It is a online monitering device in spinning
    process.
   It has become an integral part of the spinning
    process for production of high quality yarn.
   It helps in achieving consistent count cv%.
Need of autoleveller

   To survive in this age of high competition, it has
    become necessary to produce an internationally
    accepted standard yarn quality.
   Carded slivers fed to drawframe to drawframe
    have high degree of uneveness that cannot be
    tolerated.
   Comber contains infamous piecings.
   Higher CV% affects the appearence of dyed
    fabrics by absorbing the dye unevenly.
Norms for CV% at different stages

  Material   Wrapping length     Without         With
                 (yards)       autoleveller   autoleveller
   Yarn           120            2.5 – 3        1.5 - 2

  Roving           15           1.5 – 1.8      0.9 – 1.2

 Drawframe         5            0.7 – 0.8      0.4 – 0.5
   Sliver
 Drawframe         1            1.5 – 1.6      0.9 – 1.1
   Sliver
Object of autoleveller


To maintain consistent
  hank of sliver.

Principle: Adjust the
  Draft continuosly,
  which will depend on
  thickness of material
  fed.
Types of autoleveller
  Open Loop        Closed loop
Types of autoleveller

       Open Loop                     Closed Loop

This system is effective for   This system is effective for

short, medium and to some      long term variations
extent long term variations
Lack of self monitering        Selfmonitering

More popularly used            Rarely used
Servo Drives
Trützschler HSR 1000
Various parts of autoleveller

   Scanning roller
   Signal convertor
   Levelling processor
   Servo drive
   Quality monitor
    sensor
Important parameters for quality
levelling

   Levelling intensity
   Levelling action point
Levelling Intensity

   It indicates the amount of correction to be
    done.
   It is to decide the amount of draft change
    required to correct feed variation.
   The correlation between mass and
    volume for different fibres is not same.
Levelling action point

   The calculated correction should be done
    on the corresponding defective place.
   The time required for the defective
    material to reach the correction point
    should be known.
   Levelling action point depends on break
    draft, main draft roller setting and delivery
    speed
A% test
                            Sliver weight in ktex
                       (n-1) slivers       n slivers      (n+1) slivers
        1
        2
      mean
       A%                                      0

 Over-compensation:
For (n-1) slivers     Reduce levelling intensity by A%
                                       For (n+1) slivers
A% = (ktex(n-1) – ktex(n) X 100 levelling intensity by A% ktex(n) X 100
 Under-compensation: Increase         A% = (ktex(n+1) –
 Drawframes ktex(n)
              maintained in good conditions achieve ktex(n) between 0
                                                      deviation
and 0.5 or between -0.5 and 0
A% + : over-compensation               A% + : under-compensation
A% - : under-compensation              A% - : over-compensation
Quick test for levelling action point




                  a)   Levelling action is OK.
                  b)   Levelling action is too late
                  c)   Levelling action is too early
Quick test for levelling intensity




                 a)   Ideal diagram.
                 b)   Under compensation, increase
                      levelling amplification by A%
                 c)   Under compensation, increase
                      levelling amplification by A%
Calibration

 Need of calibration:
  Calibration is required because even the
  best instruments drift and loose their ability
  to give accurate measurements.
 On autolleveller callibration is done for
 Scanning rollers
 Pressure on scanning rollers
 Servo motor
Calibration for scanning rollers

 For rieter RSB-D30 scanning roller calibration is as follows

Scanning roller current levelling              Value
       Distance guage
              3mm                              3.3 V

              4mm                               5V

              5mm                              6.7 V

              6mm                              8.4 V
Pressure on scanning rollers
              Material                  Scanning roller pressure in KG

Smooth, elastic fibres, Combed cotton                  100


           Cotton carded                               120


High crimp and bulky fibres, such as                   130
     acrlyic, polyester (W-type)

Extremely high bulk, and micro fibres                  140


           Polypropylene                               160
Calibration for Servo motor

 Trim potentiometer “Tacho” is adjusted in such a way that actual
 value equals target value.

1)   Calibration servo drive
     -25% deviation > yes
     target 1487 actual 1486
2)   Calibration servo drive
      +25% deviation > yes
      target 892 actual 890
Laser based autoleveller

 Laser beam is used for measuring the sliver thickness.
   LDR is used for sensing the intensity of laser beam.

         Fast in response, No fibre rupture, no
         mechanical parts


         High cost
Advantages of autoleveller

   All variations are corrected.
   Count CV% will be consistent.
   Thin places in sliver and hence in the yarn
    will be low.
   Higher efficiency in further processes.
Conclusions

   For obtaining good yarn quality,
    installation of autoleveller is a must.
   As long as the autolevelling system is set
    properly, advantages mentioned above
    can be achieved. Otherwise, the negative
    impact will be very big compared to
    working without autoleveller
References
   RSB D-30 & RSB D-45 manual
   A project on “ Assesment of autoleveller on breaker and finisher
    drawframe” under guidance of Prof. S.D. Mahajan & Prof. M.S.
    Kulkarni
   A practical guide to Combing and Drawing – W. Klien
   www.textilespinning.blogspot.com
   Trützschler HSR 1000 brochure
   Technological study of autoleveller at drawframe on cotton yarn
    quality – nasir mahmood, journal of applied sciences, vol 6, year
    2006, pages 287-291
   Studies on autoleveller in drawframes – M.S.Indradoraiswamy,
    P.Chellamani, SITRA, 34th Joint technological conference page 13-
    19

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Optimisation of drawframe autoleveller

  • 1. Optimisation of drawframe autoleveller Hitesh Choudhary www.facebook.com/hitesh.choudhary1
  • 3. What is autoleveller?  It is a online monitering device in spinning process.  It has become an integral part of the spinning process for production of high quality yarn.  It helps in achieving consistent count cv%.
  • 4. Need of autoleveller  To survive in this age of high competition, it has become necessary to produce an internationally accepted standard yarn quality.  Carded slivers fed to drawframe to drawframe have high degree of uneveness that cannot be tolerated.  Comber contains infamous piecings.  Higher CV% affects the appearence of dyed fabrics by absorbing the dye unevenly.
  • 5. Norms for CV% at different stages Material Wrapping length Without With (yards) autoleveller autoleveller Yarn 120 2.5 – 3 1.5 - 2 Roving 15 1.5 – 1.8 0.9 – 1.2 Drawframe 5 0.7 – 0.8 0.4 – 0.5 Sliver Drawframe 1 1.5 – 1.6 0.9 – 1.1 Sliver
  • 6. Object of autoleveller To maintain consistent hank of sliver. Principle: Adjust the Draft continuosly, which will depend on thickness of material fed.
  • 7. Types of autoleveller Open Loop Closed loop
  • 8. Types of autoleveller Open Loop Closed Loop This system is effective for This system is effective for  short, medium and to some long term variations extent long term variations Lack of self monitering Selfmonitering More popularly used Rarely used
  • 10. Various parts of autoleveller  Scanning roller  Signal convertor  Levelling processor  Servo drive  Quality monitor sensor
  • 11. Important parameters for quality levelling  Levelling intensity  Levelling action point
  • 12. Levelling Intensity  It indicates the amount of correction to be done.  It is to decide the amount of draft change required to correct feed variation.  The correlation between mass and volume for different fibres is not same.
  • 13. Levelling action point  The calculated correction should be done on the corresponding defective place.  The time required for the defective material to reach the correction point should be known.  Levelling action point depends on break draft, main draft roller setting and delivery speed
  • 14. A% test Sliver weight in ktex (n-1) slivers n slivers (n+1) slivers 1 2 mean A% 0  Over-compensation: For (n-1) slivers Reduce levelling intensity by A% For (n+1) slivers A% = (ktex(n-1) – ktex(n) X 100 levelling intensity by A% ktex(n) X 100  Under-compensation: Increase A% = (ktex(n+1) –  Drawframes ktex(n) maintained in good conditions achieve ktex(n) between 0 deviation and 0.5 or between -0.5 and 0 A% + : over-compensation A% + : under-compensation A% - : under-compensation A% - : over-compensation
  • 15. Quick test for levelling action point a) Levelling action is OK. b) Levelling action is too late c) Levelling action is too early
  • 16. Quick test for levelling intensity a) Ideal diagram. b) Under compensation, increase levelling amplification by A% c) Under compensation, increase levelling amplification by A%
  • 17. Calibration  Need of calibration: Calibration is required because even the best instruments drift and loose their ability to give accurate measurements.  On autolleveller callibration is done for  Scanning rollers  Pressure on scanning rollers  Servo motor
  • 18. Calibration for scanning rollers For rieter RSB-D30 scanning roller calibration is as follows Scanning roller current levelling Value Distance guage 3mm 3.3 V 4mm 5V 5mm 6.7 V 6mm 8.4 V
  • 19. Pressure on scanning rollers Material Scanning roller pressure in KG Smooth, elastic fibres, Combed cotton 100 Cotton carded 120 High crimp and bulky fibres, such as 130 acrlyic, polyester (W-type) Extremely high bulk, and micro fibres 140 Polypropylene 160
  • 20. Calibration for Servo motor Trim potentiometer “Tacho” is adjusted in such a way that actual value equals target value. 1) Calibration servo drive -25% deviation > yes target 1487 actual 1486 2) Calibration servo drive +25% deviation > yes target 892 actual 890
  • 21. Laser based autoleveller  Laser beam is used for measuring the sliver thickness.  LDR is used for sensing the intensity of laser beam. Fast in response, No fibre rupture, no mechanical parts High cost
  • 22. Advantages of autoleveller  All variations are corrected.  Count CV% will be consistent.  Thin places in sliver and hence in the yarn will be low.  Higher efficiency in further processes.
  • 23. Conclusions  For obtaining good yarn quality, installation of autoleveller is a must.  As long as the autolevelling system is set properly, advantages mentioned above can be achieved. Otherwise, the negative impact will be very big compared to working without autoleveller
  • 24. References  RSB D-30 & RSB D-45 manual  A project on “ Assesment of autoleveller on breaker and finisher drawframe” under guidance of Prof. S.D. Mahajan & Prof. M.S. Kulkarni  A practical guide to Combing and Drawing – W. Klien  www.textilespinning.blogspot.com  Trützschler HSR 1000 brochure  Technological study of autoleveller at drawframe on cotton yarn quality – nasir mahmood, journal of applied sciences, vol 6, year 2006, pages 287-291  Studies on autoleveller in drawframes – M.S.Indradoraiswamy, P.Chellamani, SITRA, 34th Joint technological conference page 13- 19