1. Optimisation of drawframe
autoleveller
Hitesh Choudhary
www.facebook.com/hitesh.choudhary1

2. Objects of drawframe

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

9. Servo Drives
Trützschler HSR 1000

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-
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