Cotton yarn count by Beesely Balance
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.
Objectives of Experiment:
- To know about yarn count.
- To know about template & beesley balance.
- To know how to determine the count by template & beesley balance.
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:
- 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
The number of hanks (840 yds) per pound.
Beesleys Balance :
A number of special yarn balances are available which are designed to furnish a quick estimate of the count, especially when only small samples are at hand. This instrument consists of a simple beam with a sample hook at one end and a pointer opposite a datum line.
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.
- Beesleys balance.
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 %
A standard weight is hung in a notch on the beam arm on the pointer side of the pivot. A template is used to cut short lengths of yarn , the length depending upon the count system required. These short lengths are added to the hook until the pointer is opposite the datum line. The count is the number of the short lengths required to balance the beam.
When used in the analysis of small samples of fabric, a rough estimate of the crimp should be made and the count corrected.
Experimental Data: –
|No of exp||Length L||Count in Tex|
The count is 11
By this method we can easily defined the count of the yarn. The Beesleys balance in our lab is not an air tight condition so the weight of the yarn is not appropriate for the movement of the air.