This document discusses the draw frame process for manufacturing yarn. The draw frame passes sliver through pairs of rollers to elongate and combine multiple slivers. This straightens and aligns fibers while improving uniformity. The draw frame doubles slivers, drafts them to increase length and reduce weight, and removes dust. Modern draw frames have higher speeds, better drafting systems, automatic functions, and monitoring systems to improve quality and efficiency in the yarn manufacturing process.

1. Draw frame
Yarn Manufacturing-I

2. Draw frame
• It is a process of yarn
manufacturing in which
the sliver is elongated
when passing through
pairs of rollers, each pair
faster than the previous
one.
• This permits combination
of several slivers and
drawing and elongating
them to straighten and to
create greater uniformity.
Objects of drawing
•To straighten the fibres in the
slivers.
•To make them lie is a manner
parallel to their neighbours and
to the sliver axis.
•To improve the uniformity and
evenness of the slivers.
•To reduce weight per unit
length of sliver.
•To reduce irregularities of fibre
by doubling and drafting.
•To remove dust from sliver.
•To make perfect blending of the
sliver.

3. Necessity of draw frame:
• To parallezation of fibre and blending carded sliver.
• In carded sliver, fibre present in hook form i.e. trailing
hooks and leading hooks.
• To parallel those hook, draw frame is used.
• Majority of the fibre hooks in a carded sliver are trailing
while leading hooks are comparatively less.
• Trailing hooks are also known Major hooks. While
leading hooks are known as Minor hooks.

4. Tasks of draw frame
• Equalizing.
• Parallelizing.
• Blending.
• Dust removal.

5. Actions involved in Draw frame
• Drafting: The process of attenuating or increasing length per unit
weight of sliver. It is mainly due to peripheral speed of the rollers.
• Doubling : The process of combining two or more carded sliver into a
single form is called doubling. In draw frame m/c generally six slivers
are fed and converted into one i.e. six doubling.
• Drawing : In the cotton Industry, the term is applied exclusively to
processing on the draw frame, where the operation is one of doubling
and drafting.

6. • Operating device:
• Creel (Sliver feed)
• The drafting
arrangement.
• Suction systems for the
drafting arrangement.
• Coiling.
• Can changers.
 Creel:
 The creel must be
designed so that:
 False drafts are
avoided.
 The m/c stops upon
occurrence of sliver
break.
 Sliver breaks can be
dealt with easily,
comfortably and
safely.

7. Requirements of drafting arrangements
• Simple, uncomplicated construction.
• Stable design with smooth running of the rollers.
• A mode of operation giving a high quality product even
at high running speeds.
• High degree of flexibility i.e. suitability for all raw mtls.
• Optimal control over the movement of the fibres during
the drafting operation.
• High precision both of operation and adjustment.
• Rapid and simple adjustability of roller spacing and draft
levels.
• Ease of maintenance and cleanings.
• Optimal ergonomic design.

8. Influence on the draft: Factors depending upon
fiber material
• Mass of the fibre in the strand cross-section.
• Degree of order of the fibre.
• Shape of cross section of the fibre strand.
• Compactness of the fibre strand.
• Adhesion betn the fibres depend upon-
• Surface structure.
• Crimp.
• Lubrication.
• Compression of the strand.
• Fibre length.
• Evenness of distribution of fibre lengths.
• Twist in the fibre strand.

9. Influence on the draft: Factors depending upon the drafting
arrangements
• Diameter of the rollers.
• Hardness of top rollers.
• Pressure exerted by the top rollers.
• Surface characteristics of the top rollers.
• Fluting the bottom rollers.
• Type and form of fibre guiding devices, such as pressure rods, pin bars,
aprons, condenser etc.
• Clamping distances(Roller setting)
• Level of the draft.
• Distribution of draft betn the various drafting stages.

10. Elements of drafting arrangements in short staple
spinning generally:
• 1.Bottom rollers: Positively driven, made of
metal.
• Axial flutes.
• Spiral flutes.
• Knurled flutes.
• 2. Top rollers: Not Positively Driven, one piece
rollers or twin rollers, Soft coats
• 3. Top roller pressure: Pressure can be
generated by loading by means of-
• Dead weights.
• Spring weighting.
• Hydraulic system.
• Pneumatic weighting.
• Magnetic weighting.

11. Forms of drafting arrangement used on draw
frame:
• 3 over 4 roller drafting arrangement

12. 3 over 4 roller drafting arrangement
Advantages: Disadvantages:
• The widely change of setting
range is possible.
• Control of fibre is increased due
to drafting over surface.
• Suitable for processing of long
fibre.
• Not suitable for processing of
short fibre.
• Not make so much close of nip
setting of back and front zone as
4 over 4 system.
• No drafting in the middle zone.

13. 3 over 3 drafting arrangement:

14. 4 over 3 roller drafting arrangement
Farhana Momotaz, Lecturer, Dept of TE, KUET

15. 5 over 4 roller drafting arrangement:
Farhana Momotaz, Lecturer, Dept of TE, KUET

16. Features of modern Draw Frame: (Recent
developments)
• High speed of production.
• High draft.
• Better control of short fibre.
• Autolevelling.
• Auto stop motion system.
• Electronic control and display unit.
• Auto drafting system.
• Improved drafting system.
• Can linking system.
• Rectangular can.
• Automatic can changer.
• Suction system for the drafting arrangement.

17. Fault locating indication lamp
Red Stop without problem
Green Sliver breaks, Roller lapping
Yellow After fill up of sliver can, no empty can



Machine monitor
Monitoring system Production monitor.
Quality monitor.







FEATURES OF MODERN DRAW FRAME: (RECENT
DEVELOPMENTS)

18. Effect of Draft, Doubling on sliver quality:
Doubling
Drafting
C.V%
C.V%