Determine the count of lap, sliver, roving and yarn

 

Title:

          Determine the counts of Lap and Sliver, Roving and Yarn

Abstract:

                Our goal is to calculate the count of lap, sliver, roving and yarn. The count of the lap, sliver, roving and yarn was obtained by weighing 1 yard, 6 yards, 15 yards and 120 yards respectively. The count controls the variation in fineness. The count of lap   calculated was 0.0014, for sliver was 0.371, for roving was 0.31 and for yarn was 29.39. The count of lap, sliver, roving and yarn was calculated by wrapping reel for yarn, wrapping drum for sliver and roving and template of measuring of lap for weight balance.

Objectives:

·       To calculate average count of lap, sliver, roving and yarn in English system.

·       To calculate standard deviation and finally percentage of coefficient of variation.

Equipment and Tools:

Ø wooden Template for preparing the sample of lap

Ø Wrapping drum

Ø Wrapping reel

Ø Weight balance

These equipments was used for the calculation of the count of the yarn.

Introduction

                    i.            Template of measuring lap

                                                             This template was used for measurement of lap to find its weight. Its one side is 36 inches and 2^nd is 40 inches. It was put on the lap and lap was cut of according to its length and width.

                 ii.            Wrapping reel

                                          This was used to get the samples of yarn and length of each yarn was 120 yards. Yarn was fixed to one end at right angle and it was rotated while the needle of yard watch came back by rotating zero to zero.

              iii.            Wrapping drum

                                           This drum was used to get the 6 yard and 15 yard of sliver and roving respectively. Sliver and roving was wrapped on the drum by a fixed sign. The diameter of this drum was 1 yard.

Theory:

·       Count:

                    Count is another measure of linear density by indirect method. Defined as, the number of hanks in one pound. Count is another measure of linear density that equals number hanks in one pound. In this system, higher the number, finer the count will be.

Ne= 8.33*length in yards/weight in grains

Terms and definitions:

Ø Lap:

It is the output of blow room. Lap is a sheet of cleaned cotton fibers that are pressed together to keep them in proper shape for later use.

Ø Sliver:

It is the output of card machine and its input is lap. Sliver is the first output in the spinning department that resembles to yarn in terms of its appearance.

Ø Roving:

It was finer than sliver that is slightly twisted.

Ø Yarn

It was the final form of fibers twisted to get the desired length and count

Procedure:

                   Five samples of Lap were taken exactly to be one yard which was separated with the help of wooden template. Similarly, five samples of Sliver were also taken of six yards and separated with the help of warping drum. Five samples of roving was also taken by wrapping drum. Five samples of yarn was also taken by wrapping it on wrapping reel. Samples of Lap, Sliver, Roving and Yarn were weighed on a digital balance in ounces for lap and in grams for sliver, Roving and Yarn. Grams and ounces were converted to grains to get value of each sample in grains per yard. 

Count was calculated for lap, sliver, roving and yarn samples by using the formula.

Ne= 8.33*length in yards/weight in grains

Observations and calculation:

Lap calculations:

Serial No.	Weight in ounces	Weight in grains
1	13.5	5906.25
2	13.25	5796.875
3	13.75	5988.125
4	13.5	5906.25
5	13.25	5796.875
		Average= 5878.875

 

Count of Lap

Ne= 8.33*length in yards/weight in grains

Ne=8.33*1/5878.875

                    Ne  =  0.0014

Sliver calculations:

 

Serial No.	Weight in grams	Weight in grains
1	25.47	131.30
2	25.43	131.00
3	25.61	139.33
4	25.40	132.62
5	24.99	131.92
		Average = 133.234

Sliver calculations:

 

 

                  

Ne of sliver=8.33× 6/133.234

                          Ne of sliver  = 0.375

Roving calculations:

 

Serial No.	Weight in grams	Weight in grains
1	8.51	393.0029
2	8.49	392.38
3	9.03	395.16
4	8.60	391.92
5	8,55	385.59
		Average=391.61

Count of Roving:

                 

       Ne of Sliver= 8.33*15/391.61

                          Ne of sliver  = 0.31

Yarn calculations:

                      

Serial No.	Weight in grams	Weight in grains
1	2.18	33.63
2	2.22	34.25
3	2.10	32.40
4	2.12	32.71
5	2.02	37.03
		Average = 34.004

Yarn count:

               Ne of Yarn= 8.33*120/34.004   

                          Ne of Yarn  = 29.39

 

Result:

The results of this practical are given below

Ø Count of lap 0.0014

Ø Count of sliver is 0.375

Ø The count of roving is 0.31

Ø The count of yarn is 29.39

 

Discussion:

                   As in direct system increase in number means that decrease in fineness and in indirect system increase in number means that increase in fineness. Here we are talking about Count (Indirect system) so the count of lap, sliver, roving and yarn control the fineness of yarn. If they have more count this mean the yarn is finer and vice versa.

Count of sliver is greater than that of lap, so sliver is finer than lap. The count of Yarn is greater than roving, so it is finer than roving. The count gives us the quality and fineness. By varying count we can achieve the required fineness and quality.

Conclusion:

                    The basic point is to calculate the count of different samples taken from lap, sliver, roving and yarn. By taking the five samples of each we can get the average weight and finally we can calculate the count of yarn. The count of lap, sliver, roving and yarn is 0.0014, 0.375, 0.31, 29.39.

Safety measures:

Ø Make the samples of sliver, roving and yarn by Warping drum and wrapping reel using carefully.

Ø Measure the count.

Ø Separate the lap sheet with Wooden Template carefully.

Ø Weight balance should be free from errors.