How to Calculate NRE% and Noil% of the Comber Machine

Posted by Default on December 27, 2018 in

Introduction: 
Neps Removal Efficiency is expressed as NRE%. The amount of neps are determined by AFIS. In the combing, neps removal efficiency is less than 50% then it is considered that there is problem in m/c setting. So it should be more than 50%. In carding, neps removal efficiency should be more than 50%. 

Noil percentage is the ratio of Noil weight to the total wt of sliver and noil. 
                                           Noil weight
Noil percentage = ────────────────────── x 100
                               Sliver weight + Noil weight 

Objectives:

1. To estimate the NRE% of comber.
2. To calculate the noil% of comber.
3. To know about the performance of comber machine.

Theory: 
Neps removal efficiency is the percentage ratio of the difference between Neps/gm in comber lap & Neps /gm in comber sliver to Neps/gm in comber lap. Neps removal efficiency is expressed as NRE%. 

                Neps/gm in comber lap --- Neps /gm in comber sliver
NRE% = ───────────────────────────────────── ×100
                                       Neps/gm in comber lap 

Noil percentage is the ratio of Noil weight to the total wt of sliver & noil. 

                                         Noil weight
Noil percentage = ────────────────────────── x 100
                              Sliver weight + Noil weight 

Required apparatus:

1. Comber machine
2. Combed sliver

Fig: Comber machine

Experimental procedure:

1. At first, we determined the neps/gm in comber lap.
2. Then the neps/gm in comber sliver was also determined.
3. The NRE% has been measured by using these values in formula.
4. To find out the Noil%, Noil weight and sliver weight has been determined at first.
5. By using the value of them in formula of noil%, it has been determined easily.

Experimental data: 

Table 1: Measurement of NRE% 

Table 2: Measurement of Noil% 

Results: 
Average neps removal efficiency is 56% & Noil% is 17%. 

Conclusion: 
In this experiment, neps removal efficiency & noil percentage has been calculated which is very important for knowing the performance about comber machine. We have acquired proper knowledge about how to calculate NRE% & Noil% of a comber machine after this experiment which will be very helpful in our future industrial life.

Author of this article: 
Abeed Hasan 
Dept. of Textile Engineering, 
Khulna University of Engineering & Technology 
Email: 1521033abeed@gmail.com