This document provides examples of math problems for calculating production rates and drafts for combing machines. It includes problems calculating production constants, production per shift, ribbon lap hanks, actual drafts given mechanical drafts and waste percentages, DCP from various combing machine parameters, total production given nip rate, head number, feed rate, efficiency and noil percentage, number of machines needed to produce a daily production amount, and finding drafts or DCPs given sliver hanks or required outputs. Solutions are provided for each example problem.

1. MATH PROBLEM OF
COMBING MACHINE
MD. ABUL SHAHID SHOJOL
2013-01-01-017
BUTEX

2. Mathmatical law:
• Production = πDN inch / min
• Production = Nip/min X Feed/Nip X No. of head X Waste% X Eff.%
• Production per day,
100-Noil%
= Nip/min X Feed/nip X No. of head X Feed lap weight X Efficiency X …..…………. X 60 X 24
100
• Mechanical draft =
draft constant
𝐷𝐶𝑃
Feed sliver weight
• Actual draft = ………………………… X Doubling
Delivered sliver weight
•
Actual draft = (Mechanical draft X 100) / (100 –Waste%)
• Production constant = Circumference speed of coiler calendar roller / 36

3. 1. In a combing machine coiler calendar roller speed
is 118 rpm, radius 1”, Delivered sliver weight per yd is
46.6 grain. Calculate the production constant. If
efficiency is 90% then also calculate the production
per shift.
Ans : Production constant = 20.58
Production/shift= 59.20 lb/shift

4. 2. Ribbon/feed lap weight per yd 580 grain. 6 laps
are feeded in a combing machine .
If delivered sliver weight per yds is 46.60 grain,
then what will be the ribbon lap hank and draft?
Ans: Ribbon lap hank= 0.0144
Actual draft= 74.68

5. 3. If in a combing machine draft constant is 2780 and
DCP is 46, then what will be the mechanical draft of
the machine?
If waste is 18%, then what will be the actual draft?
Ans: 60.43
73.70

6. 4. Calculate the DCP of a combing machine from
these parameters. Feed lap hank = 64 KTex,
Delivered single sliver hank = 3.40 KTex,
Doubling = 6,Waste = 15%, and draft constant =
1696.The machine is giving twine sliver delivery.
Ans: 35T

7. 5. Calculate the production for 8 hrs of a combing
machine from the following data –
Feed/Nip = 6.7 mm
Waste = 16%
Nip/min = 120
Efficiency = 90%
No. of head = 6 Feed
lap hank = 68 Ktex
A ns: 119.04 kg/8hrs

8. 6. Calculate the production per day of a combing
machine when,
Nip/min = 220
No. of head = 8
Feed/nip = 7mm
Lap weight = 1000 grains/yd
Efficiency = 90% & Noil = 15%
Ans: 2113.31 lbs

9. 7. If the hank = 60 ktex,
sliver hank = 5 ktex,
a six head comber used
what is the draft or actual draft ?
Ans: 72

10. 8. For a comber machine, which is
6 head comber
Sliver delivered in cans = 1
The linear density = 68 ktex
Sliver hank = 3.54
What is the actual draft ?
Ans: 57.7

11. 9. If the data in comber is:
Feed/nip = 6.7 mm
Sliver nip = 324 mm
Then what is the mechanical draft
?
Ans: 48.5

12. 10. if for a six head comber m/c , twin slivers of 3.4 ktex
is required,
Head is six head comber
Feed lap = 64 ktex
Draft constant = 1696
Waste extraction = 15%
Dcp = ?
Ans: 36

13. 11.The sliver delivered by a comber is of 3.4
ktex & the dcp is 35
What is the dcp if the required output sliver
had to be 3 ktex ?
Ans: 31

14. 12. Find out the no of comber m/c to produce 10000 lb/day of
40 count semi combed [50:50] yarns when:
Nips/min = 380
Feed/nip = 5 mm
Lap wt = 1000 grains/yd
No of head/ frame = 8
Noil % = 15 %
Efficiency = 90 %
Ans: 4

15. 13. Find out production if nips/min & feed/nips
are
360 & 5.5 mm
Assume the parameters .

16. 14. Find out the production/shift/comber machine
in kgs
( assume necessary parameter)
15. Find out the total draft required to produce a
comber lap ( assume necessary parameter)

17. Thank you