Determination of sliver and roving count by using wrap block and electric balance.

Introduction: Sliver is the production of carding machine raw material of Sliver is lab .Lab is intered the carding m/c and after processing.  Sliver is produced Roving is the production of complex Raw material of Roving is Sliver .Sliver and Roving count is determined as number of hanks of 840 yds present in 1 lb.

Sliver Hank = Length of hanks of 840 yds / weight in 1 lbs

Object:

• To determine the hank of Sliver
• To determine the hank of Roving                                    
• To know the sliver and Roving sample thickness
• To determine the relation between count and weight of Sliver and Roving

Working principle: Determine the count of Sliver and Roving is componed between beam and wrap block. Generally the beam has 1 lb length of Sliver or Roving. So that the revolution to beam it will pass 1yds of Sliver or Roving.

Machine Description: There is a block Roller of the Front side of the m/c. The top side the tension is arranged .There is a count meter behind the machine. The Sliver or Roving is passed between block roller and tension roller.

Apparatus:

1. Wrap block
2. Electric balance
3. Sliver or Roving

Wrap Block

Working procedure:

1. At first we fixed the count zero
2. Then the sliver is passed through the block roller
3. Take yds of sliver and weight it and then determine the sliver hank
4. Let’s take 5 time for average hank
5. We also measure the standard deviation and co-efficient of variable.
6. Similarly measure roving hank length 6 yds also determine CV%

Calculation: 

From table 1 Roving hank

We know that, Hank=(sample Lenght÷ Length  unit ) × (Weight unit × sample lweight)

So ,

Hank1 = (6yds ÷840yds ) × ( 1lb÷4.13gm )

           =( 6yds ÷840yds ) × (453.46 ÷4.13gm )= 0.784

Hank2 =( 6yds ÷840yds ) × (453.46 ÷4.20gm )= 0.771

Hank3 =( 6yds ÷840yds ) × (453.46 ÷4.07gm )= 0.796

Hank4 =( 6yds ÷840yds ) × (453.46 ÷4.13gm )= 0.773

Hank5 =( 6yds ÷840yds ) × (453.46 ÷4.18gm )= 0.78

Average Hank: = 0.78

From table 2:-

SD = 0.000098

CV% = 0.013

CL = 0.78

UCL = 3.43

LCL = 1.87

UWAL =  2.55

LWAL = 0.99

Table 01:- Table for roving

Obs no	Sample length(yds)	Length unit(yds)	Sample weight(gm)	Weight count	Hank	Average Hank
1	6yds	840yds	4.13	1lb	0.784	0.7806
2	6yds	840yds	4.20	1lb	0.771
3	6yds	840yds	4.07	1lb	0.796
4	6yds	840yds	4.17	1lb	0.777
5	6yds	840yds	4.18	1lb	0.775

Table 2:-Table for efficient of variation

Obs no	hank	Average Hank	(Xi-X)2	SD	CV%
1	0.784	0.7806	0.000016	0.000098	0.013
2	0.771		o.000081
3	0.796		0.00026
4	0.777		0.000007
5	0.775		0.000025

Table 3:- table for controlling Value

UCL	UWAL	CL	LWAL	LCL
3.43	2.55	0.78	0.99	1.87

Result: For roving the count of cotton Roving 0.78 and CV% is 0.013

Remarks: By this experiment we get the clean concept about Sliver and Roving count of Yds . It is very import experiment for counting yarn>