A 46 mm diameter rotor is spinning 60 tex yarn at 100 m/min. The trash level in feed sliver is 0.2%. The opening roller can clean the sliver to the extent of 70%. The self cleaning effect of the yarn arm within the rotor is 50%
Question 79 (Textile Engineering & Fibre Science)
If an interruption in spinning is expected once the deposition attains 0.2 mg/cm in the rotor groove, number of end breaks expected in 8 hours is
| (A) | 260 |
| (B) | 290 |
| (C) | 299 |
| (D) | 312 |
[Show Answer]
Option C is correct.
Rotor dia=46mm
Yarn count=60 tex
Rotor speed=100 m/min
Trash level in feed sliver=0.2%
Cleaning % of opening roller=70%
Self cleaning effect of the yarn within the rotor=50%
Deposition attains once=0.2 mg/cm in rotor groove
Number of ends breaks expected in 8 hrs=?
Calculation-
Rotor circumference=0.1444 m
Rotor circumference=14.44 cm
Now,
By definition of tex-
By unitary rule-
1000 meter length have..=60 gm weight
1 m have……………………………=60/1000
Similarily,
100 m length have…………….=60 x 100/1000
Weight of yarn=6 gm
Weight of output yarn=6 x (Trash level% in feed sliver) x (1-Cleaning % of opening roller) x (1-Self cleaning effect %of the yarn within the rotor)
Weight of output yarn=6 x (0.2%) x (1-70%) x (1-50%)
Weight of output yarn=6 x (0.002) x (1-0.70) x (1-0.50)
Weight of output yarn=6 x 0.002 x 0.30 x 0.50
Weight of output yarn=0.0018 gm
Weight of output yarn=1.8 mg
Trash deposition (mg/cm of rotor circumference) =Weight of output yarn/Rotor circumference
Trash deposition (mg/cm of rotor circumference) =1.8/14.44
Trash deposition (mg/cm of rotor circumference) =0.1245
Now,
Number of ends breaks expected in 8 hrs=Trash deposition (mg/cm of rotor circumference) x 60 x 8/Deposition attains once in rotor groove.
Number of ends breaks expected in 8 hrs=0.1245 x 60 x 8/0.2
Number of ends breaks expected in 8 hrs=59.76/0.2
Number of ends breaks expected in 8 hrs=298.8
=299 (Ans)