Determination of Roving Count and Count Variation by Measuring Drum
Determination of Roving Count and Count Variation by Measuring Drum
Theory: –
Yarn count: The count of a yarn is a numerical expression which defines its fineness. It means, by yarn count we come to learn about the thinness or thickness of a fibre or yarn.
The count of the yarn is the number of such yarns which are required to form one strand of a three – strand 3 in circumference rope.
Indirect System:-
Count is the number of ‘unit length’ per ‘unit weight’ i.e. unit length/unit weight.
Here again there are various units of length and weight and numerous systems. Generalising:
Let
- N = the yarn number or count,
- W = the weight of the sample at the official regain in the units of the system.
- w = the unit of weight of the system
- L = the length of the sample and
- l = the ‘unit of length’ of the system
Then,
English (Ne):
The number of hanks (840 yds) per pound.
Standard Deviation to coefficient of variation: –
The standard deviation is the square root of the mean of the squares of the deviations of the observations from their mean, i.e.
Apparatus: –
- Measuring Drum.
- Roving
- Wet m/c.
- Calculator
Atmospheric condition: –
- Wet condition: -26 ° c.
- Dry condition: -30° c.
- Difference between wet and dry bulb = 30° c-26 ° c. = 4° c
- So, relative humidity (RH) = 70 %
Procedure: –
A Roving is passing through the measuring drum. Then the Roving is taking 6 yrds. Then the weight of the Roving is taking. Then the count is taking from the formula.
Experimental Data: –
No of exp | Length L | Weight W | w gm | Count in Tex | Avg. |
|
10 | 4.40 |
453.6 |
1.2272 |
1.23937 |
2 | 10 | 4.38 | 1.2328 | ||
3 | 10 | 4.35 | 1.2385 | ||
4 | 10 | 4.50 | 1.2328 | ||
5 | 10 | 4.30 | 1.2356 | ||
6 | 10 | 4.35 | 1.2558 | ||
7 | 10 | 4.40 | 1.2529 | ||
8 | 10 | 4.38 | 1.25 | ||
9 | 10 | 4.35 | 1.2272 | ||
10 | 10 | 4.36 | 1.2413 |
Calculation: –
The count is 1.23937
Conclusion:-
By this method we can easily defined the count of the yarn. The measuring drum in our lab is not an air tight condition so the weight of the yarn is not appropriate for the movement of the air.
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