Speed Frame:
Calculation of Speed Frame or Simplex is an important process in ring spinning. In this process, fibers are converted into low twist lea called roving. So it is also called a roving frame. The main function of the roving frame is the attenuation of the sliver. To draft the sliver to reduce weight per unit length. The sliver which is taken from the draw frame is thicker so it is not suitable for manufacturing yarn. By speed, frame slivers are converted to roving. Which is appropriate for the next process. Speed frame is used for the carded and combed yarn process but for the rotor spinning system, this process can be eliminated.
Calculation of Speed Frame or Simplex
Simplex Production Calculation:
Problem: 1
Calculate the TPI (twist per inch) produced on a simplex with a diameter of front roller 28 mm and its rpm be 30. The rpm of the flyer is 1000.
Solution:
Here,
Dia of front roller = 28 mm = 2.8 cm = 1.1024 inch
rpm of front roller = 30
rpm of flyer = 1000
TPI = ?
We know,
Surface speed of front roller = π x Dia of front roller x rpm of front roller
= π x 1.1024 x 30
= 103.9 inch/min
………………………Flyer speed or Spindle speed (rpm)
Twist or TPI = ……………………………………………………….
……………………………Delivery speed (inches/min)
…….1000
= ……………
…….103.9
= 9.63 (Ans)
Problem: 2
Calculate the TPI on simplex if the diameter of the back roller is 15/16’’, rpm of B.R is 10, rpm of the flyer is 1000 and draft is 6.
Solution:
Here,
Dia of B.R. = 15/16 = 0.9375 inch
Draft = 6
rpm of F.R. = 30
rpm of B.R = 10
rpm of flyer = 1000
TPI = ?
We know,
Surface speed of B.R. = π x Dia of B.R. x rpm of B.R
= π x 0.9375 x 10
= 29.45 inch/min
……………………Surface speed of F.R.
Total draft = …………………………………
……………………Surface speed of B.R.
=> Surface speed of F.R.= 6 x 29.45 = 176.7 inch/min
………………………Flyer speed or Spindle speed (rpm)
Twist or TPI = ……………………………………………………….
…………………………….Delivery speed (inches/min)
……1000
= …………..
……176.7
= 5.66 (Ans)
Problem: 3
If Spindle speed = 1600 rpm, Roving count = 90 Ne, TM (Twist Multiplier) = 4.2, Efficiency = 85% then calculate the production of a speed frame in lb/hr.
Solution:
We know,
……………………Spindle speed
Production = ………………………
……………………………..TPI
TPI = TM√(Roving count)
Efficiency = 85% = 85/100 = 0.85
Now,
…………………..Spindle speed
Production = …………………….
……………………………TPI
…..1600 x 60 x 1 x 0.85 x 120
= ………………………………………..
……4.2√.90 x 36 x 840 x 0.90
= 90.297 (Ans)
Author of this Article, Rofiquzzaman Raju Fabric Technologist, B.J.Group, Mawna, Gazipur Chittagong Textile Engineering College Facebook: https://www.facebook.com/ERZRAZU