Drafting in yarn manufacturing is the process of attenuating loose fibers called slivers by passing them through rollers. This straightens and makes the fibers more parallel. Drafting involves pulling fibers through rollers at different speeds to lengthen and thin them out. There are three types of drafts: mechanical draft from speed differences between rollers, actual/resultant draft accounting for slippage, and tension draft from fiber tension. Drafting arrangements, elements, and settings are important factors that influence yarn evenness and strength.

1. PRINCIPLE OF YARN
MANUFACTURING

2. DRAFTING IN
SPINNING
PROCESS
DIRECTED BY : SHUBHAM JOSHI SIR

3. MADE BY :
1704460052 SHASHANK YADAV
1704460053 SHIVAM JAISWAL
1704460054 SHIVANI GAUTAM
1704460055 SHIVI SINGH
1704460056 SRISHTI AGARWAL
1704460057 TARUN RAJPUT
1704460058 TRIPTI SINGH
1704460060 VIJAY PARAKASH
1704460061 VIKAS KUMAR YADAV

4. What is Drafting?
Drafting, in yarn manufacturing process
of attenuating the loose assemblage of
fibres called sliver by passing it through
a series of rollers, thus straightening the
individual fibres and making them more
parallel.

5. What is Drafting ?
Drafting is the creation of a drawing or other graphical representation of a
building , mechanical device or other structure for the purposes of
determining how the device should be created. Drafting is used as a part of
the design and fabrication processes. Drafting can be done by hand or
using specially designed computer programs and mechanical drawings.
Drafting arrangement is the most important part of the machine. It
influences mainly evenness and strength. The following points are therefore
very important
 Drafting type
 Design of drafting system
 Drafting settings
 Selection of drafting elements like cots , apron , traveler etc.
 Choice of appropriate draft
 Service and maintenance

8. Draw frame Drafting

9. Operations of Ring frame
 to draft the roving until the required increase is
achieved.
 To impart strength to the fibre by increasing
twist.
 To wind up the twisted strand (yarn) in a kym
suitable for storage, transportation and further
processing.

11. (b) SacoLowell Versamatic
Draw Frame
In this, the frame is with ¾ drafting system
–
can process staple length from 1” to 2”.
The middle top roller doesn’t touch the
second bottom roller giving ‘Slip Drafting’.

12. (c) Zinser Draw Frame
The front bottom roller and two top rollers a
modified version of 4/4 drafting offering
tubular shaped web collector. For small
setting, the second and fourth rollers are
made movable. The draft is split-up
between the back and the front zone.

13. (d) Polar Drafting
In laxmi-rieters has usual back pair of rollers followed
by two sets of ½ drafting systems. Second and third
bottom rollers are smaller in diameter to enable closer
setting. The loading is pneumatic and can be varied
infinitely-0.75 kg per sq.cm.is normal pressure). The
rollers are arranged in the arc of a circle enabling
their movement by resetting levers. The scales are
provided so that the rollers can be set without the
need for using roller gauges.

14. (e) Whitin’s Even Draft Draw
Frame
This has universal system of 4/5 drafting.
Succeeding to usual back roller pair, there is ½
drafting system in the middle, the setting
between third and forth bottom roller being
fixed. The use of small diameter second and
third roller permits closer settings.

15. Draft Calculations:
As the material passes through the rip of the rollers, it gets pulled or
attenuated. This motion of drawing or pulling of the stock continues
throughout the spinning process. In some cases, there is attempt made
to attenuate the material; while in some other cases, a very slight
pulling action is exercised. At most of the places in the Blowroom, the
latter action is followed, while the former action is used in may
subsequent processes till the spinning of final yarn. There are thus
three type of drafts
1) Mechanical Draft(M.D)
2) Resultant or Actual Draft(A.D/R.D)
3) Tension draft
The relative speed difference in the rate of feeding and the rate
of delivery results in mechanical drafting action. Since, this is
governed by the mechanical gears or pulley diameters, it is
called Mechanical Draft.

16. What is Drafting?
Drafting, in yarn manufacturing process
of attenuating the loose assemblage of
fibres called sliver by passing it through
a series of rollers, thus straightening the
individual fibres and making them more
parallel.

17. DRAFT CALCULATION
As the material passes through the rip of the
rollers, it gets pulled or attenuated. This motion of
drawing or pulling of the stock continues
throughout the spinning process. In some cases,
there is attempt made to attenuate the material;
while in some other cases, a very slight pulling
action is exercised. At most of the places in the
blowroom, the latter action is followed, while the
former action is used in may subsequent processes
till the spinning of final yarn.
There are thus three type of drafts
1) Mechanical Draft(M.D)
2) Resultant or Actual Draft(A.D/R.D)
3) Tension draft

18. Mechanical Draft
The relative speed difference in the rate of
feeding and the rate of delivery results in
mechanical drafting action. Since, this is
governed by the mechanical gears or pulley
diameters.
Mechanical Draft=length delivered/length fed

19. THANK FOR THE VISIT