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.
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 Selfmonitering
More popularly used Rarely used
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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