Question 27 (Textile Engineering & Fibre Science)
The delivery rate of a roving machine is 20 m/min. Assuming the flyer speed as 1000 rpm, inner diameter of the flyer top as 1 cm, diameter of roving as 2.5 mm, and the slippage between the flyer top and roving as 50%, the false twist (turns/m) in the roving above the flyer is ___________________
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Given in the question-
Delivery rate of roving machine(FRD)=20 m/min
Flyer speed=1000 rpm
Inner dia of the flyer top=1 cm
Dia of roving=2.5 mm
=0.25 cm
Slippage between flyer top and roving=50%
False twist(turns/m) in the roving above the flyer=?
Calculations-
We know-
Surface speed of bobbin=Surface speed of flyer
Speed of bobbin=4000 rpm
Now,
False twist=200 turms/meter
Becuase there is 50% slippage beween flyer top and roving,then remaing 50% will not slip,so-
False twist=200 x 50% turns/meter
False twist=200 x 50/100 turns/meter
False twist=100 turns/m (Ans)