Thursday, 4 December 2014

To compare the single yarn strength of given sample of yarns having different twists and same count (20s).


Abstract
The strength of a yarn greatly depend upon its twists per unit inch also called TPI. Yarn is simply a strand of fibers. Fibers are joined together to form a yarn. The binding force between the fibers is the twist given to the yarn at the time of spinning. The twist gave the fibers a binding force to make a yarn. This twist is very important for the yarn because it determines many characteristic properties of the yarn like air permeability, moisture absorption, feeling, dye ability and strength.
This experiment is conducted to check the strength of yarn at different twists levels. The yarn twist has an optimum value by-passing which the strength of yarn starts decreasing. This is called the optimum twist. Yarn length also start deceasing by over-twisting.


Objectives:
  • To check the strength at different twists.
  • To compare strength of different yarn having different twist.
Materials & Equipment:
  • 100% Cotton yarn package (TM = 3.8).
  • 100% Cotton yarn package (Tm = 3.9).
  • Uster TensoRapid Machine.
Procedure:
  • 100% cotton yarn package having TM value 3.8 was taken and loaded on the Uster TensoRapid.
  • The yarn was passed through the passage in the machine.
  • The machine was turned on and 10 readings were taken from that yarn.
  • Another 100% cotton yarn package having TM value 3.9 was taken and loaded on the Uster TensoRapid.
  • The yarn was passed through the passage in the machine.
  • The machine was turned on and 10 readings were taken from this yarn.
Observations & Calculations:
English Count (Ne) = 64.428/(lea weight in grams) = 20
Tex=590.5 / (English Count)
1 Kg=2.2 lbs.
Co-efficient of Variation = (S.D)/ X ̅ ×100
TPI=TM√Count
Tenacity = no. of fibers×GPT×.70
100% Cotton yarn having TM value 3.8
Sr. #
Time (sec)
Breaking Work (cN.cm)
Breaking Force (cN)
Tenacity (cN/Tex)
Elong. (%)
1
0.38
485
344
11.67
5.25
2
0.37
487
352
11.94
5.15
3
0.34
412
321
10.88
4.74
4
0.36
327
297
10.07
4.77
5
0.32
328
270
9.18
4.42
6
0.34
390
302
10.23
4.68
7
0.34
447
346
11.74
4.76
8
0.38
524
372
12.62
5.30
9
0.38
487
342
11.58
5.23
10
0.34
407
313
10.63
4.82
Mean
-
434.8
326.4
11.05
4.91
CV %
-
14.15
9.42
9.42
6.09
TM =
3.8
TPI =
16.99

 
100% Cotton yarn having TM value 3.9
Sr. #
Time (sec)
Breaking Work (cN.cm)
Breaking Force (cN)
Tenacity (cN/Tex)
Elong. (%)
1
0.34
398
313
10.63
4.68
2
0.35
443
342
11.58
4.19
3
0.34
395
317
10.74
4.61
4
0.36
459
339
11.50
5.01
5
0.38
524
366
12.41
5.31
6
0.34
404
319
10.82
4.72
7
0.38
545
380
12.87
5.28
8
0.34
375
303
10.26
4.64
9
0.32
377
312
10.57
4.48
10
0.35
439
334
11.34
4.87
Mean
-
436
332
11.27
4.84
CV %
-
13.55
7.49
7.49
5.78
TM =
3.9
TPI =
17.44

 
Results:
Strength of yarn having twist 16.99 = 11.05
Strength of yarn having twist 17.44 = 11.27
Discussion:
Yarn having higher twist has less empty spaces in its structure, more compact and higher substance area utilization of yarn. Owing to these properties, high twist yarn has more tenacity as compared to low twist yarn. Being more compact, high twist yarn has harsher feel and provides less comfort as compared to its counterpart. Air permeability and moisture absorption of higher twist yarn is lower due to higher compactness.

No comments:

Post a Comment

New Website

Dear viewers, We wanted to let you know that we are moving to a new website, and we'd love for you to come along! Starting on 20 March 2...