2. Lets have a look of Ring spun yarn
How to measure the size………??
3. Yarn Size
Linear density or reciprocal of linear density,
are used to calculate yarn size
…………because the length and mass of the
yarn can each be accurately measured.
Linear density = weight/length
4. Count Calculation
Direct System
Tex- weight in grams of 1000 m of yarn
Denier- weight in grams of 9000 m of yarn
Denier = 9 Tex
5. If 1,000 meters of yarn weighs 50 grams, it is
a 50 tex yarn.
Denier = 9 tex
So….
Same yarn is of 450 denier
6. Indirect System (English System)
Number of Hanks in one pound
The length of a hank depends upon the
spinning system:
Cotton system: 1 hank = 840 yards
Worsted system: 1 hank = 560 yards
7. If there are 10 hanks of cotton yarn that weigh
one pound, this is 10s yarn
So what does a 20s count yarn mean ??......
it measures 20 hank or 16800 yards in 1
pound
9. Folded yarn calculation
Indirect system
1 / R = 1 / R1 + 1 / R2 + 1/ R3 +………
where, R is the resultant count in indirect system
R1, R2, R3 are the count of single yarn in indirect system
e.g
When two cotton yarns are of 24 and 36 Ne are folded,
1/R = 1/24 +1/36
R = 14.4 Ne
so the resultant count of 24 and 36 Ne folded cotton yarn
is 14.4 Ne
10. Direct system
R = R1 + R2 + R3 +……..
Where R is the resultant count in direct system,
And R1, R2, R3 are the count of single yarn in direct
system
e.g
When two polyester filament yarns of 40 and 76 denier
are plied together, their resultant count,
R = 40 + 76
= 116 Denier
15. To achieve these aims……..
Good quality of yarns
Proper maintenance of machinery
Skilled worker
16. Material flow
Winding
Warping
Sizing
Drawing in Weaving
17. Winding
Objective
To produce a good
package that contains
long length of yarn and
unwound well during
warping.
To remove
objectionable yarn
faults
18. Requirement of winding
The fault level in the yarn must be reduced to an
acceptable level.
The yarn must not be damaged in any way in the
winding process.
Unwinding in the following process with minimum
difficulty.
Package size, shape, and built must be most
technologically suitable
22. Requirement of knotting
Be easy to tie,
Have good resistance to slippage, and
Be of a size and shape that gives it little chance of
catching or jamming in narrow openings
23. A high degree of yarn quality is impossible through
knot…..as the knot itself is objectionable due to its
physical dimension, appearance and problems during
downstream processes.
The knots are responsible for 30 to 60% of stoppages
in weaving.
26. Warping
Objective-
To arrange a convenient number numbers of warp
yarns so that they can be collected on a single
warper’s beam.
An operation where yarn is transferred from single
packages of yam to an even sheet of yam representing
hundreds of ends and then wound onto a warp beam
29. Producing An Even and Uniform Sheet Of Yarn
The packages in the warper creel must be uniform in
density, size, and wind configuration.
Tension applied in warping must be uniform throughout.
Contact surfaces which the yarn passes must be smooth
and must not impede the progress of the yam.
30. Sizing
Objective
To improve the abrasion resistance, and
incidentally, the tensile strength of the yarn
1. Strengthen the yarn
2. Make outer surface of yarn smoother
3. Lubricate the yarn
It causes fibers mutually to adhere in such a way as to make the
warp yarn stronger, smother and better lubricated
Adhesives : Starch and gum
Lubricants : Fatty and Oily substance
34. During slashing the exact no. of warp yarns
required in the fabric is wound onto the
weavers beam .
The warp ends are then passed through the
drop wires of the warp stop motion, the
healds of the harness frames and the dents
of the reed.
35. Drawing-in
This is the process of drawing every warp end through
its drop wire, heald eye and reed dents.
44. Take up
To pull the cloth forward after the beat-up of
weft, maintaining the same pick density and
spacing throughout weaving of a cloth and
winding the woven cloth on to a roller
45. Let off
To allow the warp to unwind from the warp
beam during weaving of a cloth and also to
maintain an average constant tension of warp
as it weaves down
Types:
- Negative let off
- Positive let off
48. Weft stop
To stop the loom when a weft breaks or the
weft runs out of the package
49.
50. Weaving Machines
Classification on basis of Weft Insertion
Conventional Loom (shuttle loom)
Unconventional Loom ( shuttleless loom)
Projectile loom
Rapier loom
Air Jet loom
Water Jet loom
51. Weft insertion device in conventional looms
In conventional looms
a shuttle weighing
around half a Kg is
inserted through warp
shed to insert a length
of weft weighing only a
few grams.
Shuttle
For weft insertion in conventional looms
52. Limitations of Conventional Looms
1. Small weft package size, requiring frequent
replenishment
2. Heavy consumption of spare parts,
particularly of picking and checking motions
3. Limited scope for increase in the speed and
performance
4. Complicated mechanism for multi colour weft
5. High noise level.
53. Unconventional Looms
Shuttleless looms
Certain features of unconventional looms:
- Large weft package supply, mostly in forms of
cheese/cone
- Improved weft insertion system
- Unconventional selvedge formation
56. Projectile loom
Projectile weaving machines use projectile equipped
with a gripper to insert the weft yarn across the shed
It allows use of any yarn cotton, wool, mono or
multifilament and even hard fibers like jute and linen.
Projectile weaving m/c are available in two or four
color with working width of 190-540 cm.
63. Features of rapier loom
The rapier loom can weave very light fabric of 20 gsm
to heavy 850 gsm
The gripper head can take a wide range of yarn count
ranging from 5 to 1000 tex.
Upto 16 different weft yarn can be inserted
64. Air Jet loom
High speed weaving machines
Insertion of weft yarn into the warp shed with
compressed air.
65. Earlier air jet wet insertion
Buckling of weft yarn
Maximum width 110 cm
66. Relay nozzles
• With relay nozzles it is possible to propel the weft thread across
the greater width
• Machine upto 400 cm width are available
68. Water jet loom
Weft is inserted into shed with highly pressurized
water.
Hydrophobic warp and weft.
The range of jet and the width of water jet loom
depends on the water pressure and the diameter of
the jet.
………..Modern looms have speed of 1500 ppm
69. Demerits of water jet looms
Least flexible as compared to other shuttleless
looms
Maximum width of 3 m.
70. Making of Terry Towel
Required properties of yarns which are used in
towel are:
1. High absorbency
2. High wet strength
3. Ability to dye well
4. Good colour fastness
5. Wash-ability
6. Soft hand
7. Hypoallergenic
72. Four group of yarn are used in terry towel
Pile warp
Ground warp
Weft
Border weft
73. Pile warp
100% cotton yarns
16 and 20 Ne
When high quality of towel is needed……two or more
ply yarn are used
Rotor spun yarns are also used.
Ground warp
100% cotton
Carded yarn 20/2 or 24/2 are generally used
Two ply yarns are preferred
Sometimes cotton/polyester blend is used for greater
strength
74. Weft
100% cotton
Carded 16s and 20s Ne
Rotor spun yarns are also used
Border
Decorative, shinny and bulky yarns of rayon, viscose,
polyester, and mercerized cotton are used with
different yarn sizes
80. Fabric weight
WEIGHT OF WARP IN LB.
warp length in yds* Ends per inch * Reed width (“)
840 * Count of warp
WEIGHT OF WEFT IN LB.
Cloth length in yds.* Picks per inch * Reed width (“)
840 * Count of weft
WEIGHT OF FABRIC IN LB.
Warp weight in lbs . + Weft weight in lbs.
81. Theoretical Loom Production
Loom production in yards per hour
Loom Speed (or picks per min) 60
Pick density (or picks per inch) 36
Production in square yards per hour
Loom Speed (or picks per min) 60 loom width (inch)
Pick density (or picks per inch) 36 36
