Table of Contents:
Abstract............................................................................................................................................ 3
1.1Introduction................................................................................................................................. 3
2.1Objective…………………………………………………………………………………………3
3.1Experimental................................................................................................................................. 4
3.2Material……………………………………………………………………….………………4
3.3Equipment………………..…………………………………………………….……………..4
4.1 Methodology:................................................................................................................................ 4
5.1Result and disscussion:................................................................................................................... 5
6.1Conclusion: ..................................................................................................................................... 5
References:............................................................................................................................................ 5
Lab #3
To find out the Mechanical draft of roving frame.
Abstract:
In this lab, it was determined that the roving frame rollers' main draft and break draft were measured.
The main draft was multiplied by the break draft to determine mechanical draft. Also noted was the
surface speed of the front and back rollers.
1.1Introduction:
It is an intermediate process in which fibers are converted into low twist lea called roving. The
sliver which is taken from draw frame is thicker so it is not suitable for manufacturing of yarn. Its
purpose is to prepare input package for next process. It is an intermediate process in which fibers are
converted into low twist lea called roving. The sliver which is taken from draw frame is thicker so it is
not suitable for manufacturing of yarn. Its purpose is to prepare input package for next process. The
roving sliver is thick and untwisted. Because of it hairiness and fly are created. So the draft is needed
to reduce the linear density of sliver. The ring drafting arrangement is not capable that it may process
the roving sliver to make the yarn.
Drafting system for roving frame (figure a)
2.1Objective:
Attenuation- Drafting the draw frame sliver into roving.
Twisting-To inserts the twist into the roving.
Winding-Winding the twisting roving on the bobbin.
package building
2.2Drafting:
In roving frame, two drafting frame are used:
In 4 over 4 drafting system, a total draft should be 13 and in 3 over 3 drafting system, the total
draft should not be more than 11.
3 over 3 drafting system is better in that case when there is good fiber length
2.3Winding:
For the winding purpose, we used builder motion. An important task of the winding are:-
Shift the cone belt corresponding to increase in the bobbin diameter
Reverse the direction of movement of bobbin rail at the upper and lower ends of the lift
stroke.
2.4Twisting:
It is a very important factor which produces strength in the roving and twist is inserted with the
help of flyer. When flyer rotates, the twist is produced in the sliver. Twist level depends upon flyer
speed and delivery speed.
3.1Factors Affecting Roving:
Critical factors affecting roving strength are given below:-
The amount of twist and compactness of the roving.
Linear density and uniformity of the twist.
CV% of roving.
4.1Experimental:
Material:
Carded sliver
Equipment:
Roving frame
5.1Methodology:
Firstly draft between the rollers was measured.
The draft b/w front and middle pair of rollers is called main or major draft. The draft b/w
middle and back pair of rollers is known as break draft. The draft b/w front and back pairs of
rollers is called mechanical draft.
Main draft was calculated by using formula:
D1=Surface Speed of front rollers/Surface Speed of middle rollers
Then back draft was also be measured by using formula:
D2=Surface Speed of middle rollers/Surface Speed of back rollers.
Mechanical draft was also being measured by using this relation
Draft=D1×D2
Mechanical Draft =Surface speed of Front Roller /Surface Speed of Back Roller
6.1Results and discussion:
Rollers N(rpm) Diameter Surface speed Mechanical draft
Front 56 32.78 5764.03 5.604
Middle 12 32.78 1235.15 5.604
Back 10 32.78 1029.29 5.604
This table can be shown that the draft of front roller was always larger than the middle or back rollers.
7.1Conclusion:
It has been determined that front rollers move at a higher pace than middle or back rollers.
In comparison to middle or back rollers, front rollers also rotate at a fast speed. Middle rollers rotate
at an intermediate pace. Therefore, the roving frame's mechanical draught was 5.88.
Reference:
[1] A.R. Grade, V.A. Wakankar, S.N. Bhaduri, "Role of Roving process in spinning," Fiber Configuration
in Sliver and Roving and its Effect on Yarn Quality, vol. 31, no. 12, pp. 1026-1036.
[2] M Muthuvelan, "Indian Textile Journal," Spinning and Weaving, April 2012. [Accessed
24/01/2023]
[3] Frey, M. Recycling of spinning waste and influence on yarn quality. [Accessed 24/01/2023]
[4] The Reiter Manual of Spinning, Volume 2, Waste Management, Page 81, Retrieved :[Accessed
24/01/2023].
