The different end-uses require yarns of different thickness. The accepted way to indicate the thickness of a yarn or material in various stages of yarn manufacturing is to give the yarn count or linear density. The length of the material is measured out, and then weighed. Count is expressed as the length per unit mass.The linear density is expressed as mass per unit length. Each system is referred to as being either indirect or direct.

Objectives of this study:

1. To know about yarn count.
2. To know about the calculation of yarn count.

Theory:

Yarn count:
The yarn count is a numerical expression which defines its fineness or coarseness. It also expresses weather the yarn is thick or thin. A definition is given by the textile institute – “Count is a number which indicates the mass per unit length or the length per unit mass of yarn.

                          Length in yard x Weight Unit
Cotton count = ---------------------------------------------------- ………… (1)
                          840 yard x Weight in pound

Required apparatus:

• Digital Balance.
• Sample of yarn.
• Calculator.

Experimental procedure:
At first, a lea of yarn has been taken. Then the lea was weighted by digital balance. The weight gram was converted to pound. Then the data were put in equation (1). The count was calculated by the equation. Finally average count have been calculated which is the cotton count of this sample.

Experimental Data: 
 Table 1: Measurement of Yarn Count

Table 2: Measurement of Yarn Count CV%

Results:
The average count is 42 and the CV% is 5.95.

Discussion:
In this experiment, the yarn count of the given cotton sample was determined by wrap reel and analytical balance. It is a very easy process of determining yarn count. We must be careful about some steps of this process. We should maintain proper tension of yarn when yarns are wind on wrap reel. The weights should also be taken very carefully. Otherwise the count can have error. We also should be aware about our body movement in the lab. Otherwise any accident can be occurred.

Conclusion:
It is a very easy process of determining yarn count. But a disadvantage of this process is, it is slower than any other process. There need more time than another process. However, it is so much used process as it is so easy to be done.

www.sagartexbd.com