Determination of English Count of cotton yarn by wrap reel and electric balance.

Experiment No: 02

Experiment Name: Determination of English Count of cotton yarn by wrap reel and electric balance.

Introduction:

Count:
Count is a numerical value which expresses the coarseness or fineness of yarn in length per unit mass or mass per unit length.

Two types of count: 

(a) Indirect system. (English count, Metric count, Worsted count)
(b) Direct system. (Tex, Denier, Pound/Spindle)

English count:
It is the number of hanks of 840 yards for 1 pound of yarn.
Yarn count is denoted by ‘N’.
Mathematically,
N = (L×w)/(l×W)
Here,
N = Yarn count.
L = Sample length.
l = Unit length.
W = Sample weight.
W = Unit weight.

Unit length = 840 yds. (For English count)
Unit weight = 1 lb = 463.6 gm. (For English count)

Objectives:

(1) To know about the yarn count.
(2) To know about the wrap reel machine.
(3) To calculate the yarn fineness.
(4) To calculate the yarn smoothness.
(5) To know about English count.

Machine description:

In this experiment we use a wrap reel machine and an electric balance. The wrap reel machine is used measure the length of yarn. In this machine there is bobbin carrier where bobbin is kept and the yarn is taken from the bobbin and passed through guide to the wrap reel wheel where circumference is 1.5 yards. After measuring the length the electric balance is used to determine the weight of the yarn.
Working principle:
At first we will take a yarn package and put it to the bobbin carrier. Then we will pass the yarn through yarn tensioner and guide to wrap reel. Then we will rotate the machine wheel for 80 times to get the designed length. Then we will take the weight of the yarn. Then we will complete the calculation and find the yarn count.

Table:

Observation no.	Sample length	Unit length	Sample weight	Unit weight	Yarn count	Average count
1.	120 yards	840 yards	2.55 g	453.6 g	25.42 s
2.	120 yards	840 yards	2.54 g	453.6 g	25.51 s
3.	120 yards	840 yards	2.53 g	453.6 g	23.61 s	25.41 s
4.	120 yards	840 yards	2.52 g	453.6 g	23.31 s
5.	120 yards	840 yards	2.51 g	453.6 g	23.32 s

Table calculation:

We know,
Yarn count = (Sample length×Unit weight)/(Unit length×Sample weight)

For observation 1,
N = (L×w)/(l×W) = (120×453.6)/(840×2.55) = 25.42 s

For observation 2,
N = (L×w)/(l×W) = (120×453.6)/(840×2.54) = 25.51 s

For observation 3,
N = (L×w)/(l×W) = (120×453.6)/(840×2.53) = 25.61 s

For observation 4,
N = (L×w)/(l×W) = (120×453.6)/(840×2.52) = 25.31 s

For observation 5,
N = (L×w)/(l×W) = (120×453.6)/(840×2.51) = 25.32 s

Average count = 25.41 s

Result:

The average yarn count is 25.41 s.