In yarn manufacturing, its very important to know or determine fiber qualities. Because the lion share cost of yarn manufacturing goes to raw materials. So attaining a quality garments its very argent to dignify raw material’s qualities. Thats why we have some specific measurement points by which we can specify actual yarn quality. Some of them are given below with small description.
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| Cotton fiber bell |
Mean fiber length 100
Uniformity ratio = …………..……………. × ………
Upper half mean length 1
Mean length is the average length of all fibres approximately ¼’’ and longer,and upper half mean length is the estimate of the lengths of fibres in the upper half portion as measured by the fibrograph.
Rating of cotton fibres with respect to uniformity ratio
Uniformity Ratio
|
Rating
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Above 80
|
Uniform
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76-80
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Average Uniform
|
71-75
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Slight irregular
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70 and below
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Irregular
|
CV is relative measure of the length variation.The larger the value, the greater the variation in fibre lengths, and, conversely the smaller the value, the more uniform are the fobre lengths.
Rating of cotton samples with regard to fibre length variation
CV%
|
Rating
|
Below 27
|
Low variability
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27-34
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Average variability
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35 and above
|
High variability
|
Fibre Fineness
|
Rating
|
Very fine
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Below 3.0
|
Fine
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3.0 to 3.9
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Average
|
4.0 to 4.9
|
Course
|
5.0 to 5.9
|
Very course
|
6 and above
|
Rating
|
Maturity Ratio
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Very mature
|
Above 84%
|
Mature
|
77 to 84%
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Average
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68 to 76%
|
Immature
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60 to 67%
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Very Immature
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Below 60%
|
Rating
|
Strength rating in 1000 lbs.
|
Superior
|
93 and above
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Very superior
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87 to 92
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strong
|
81 to 86
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Average
|
75 to 80
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Fair
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70 to 74
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Weak
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Below 70
|
For good spinning 14% short fibre is accepted as allowable
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Short fibre%
|
8%
|
13%
|
15%
|
Break Factor
|
1904
|
1723
|
1620
|
Elongation
|
8.3
|
7.8
|
7.2
|
Break per 100
|
32
|
52
|
54.8
|
Spindle hourse
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