Jute Draw Frame
Functions of Drawing
1. Drafting the finisher card sliver to a count suitable for feeding the spinning frames.
2. Reduction of weight irregularities by doubling.
3. Straightening the fibers & laying them along the sliver axis so that when they come to be spun on the spinning frame they will be evenly drafted & twisted to form an acceptable yarn.
Types of Draw Frame
1. According to the Faller bar mechanism-
a) Push bar type drawing frame.
b) Spiral drawing frame.
2. On the basis of yarn count-
a) For Hessian warp and weft & sacking warp yarns of 7 lbs/spindle & above,
i. First drawing frame(Push bar type).
ii. Second drawing frame(Spiral type).
iii. Third drawing frame(Spiral type).
b) For sacking weft yarn 20 lbs/spindle & over,
i. First drawing frame
ii. Second drawing frame.
Definition terms
Reach: The distance from the centre point of the retraining r/r to the bite of the pressing & drawing r/r is known as reach.
Nip: The distance between the foremost gill where the pins leave the sliver & the bite of the pressing & drawing r/r is known as nip.
Pitch of Faller: The distance between the one row of pins of one faller bar to pins of next faller bar is called pitch of faller.
Lead%: The difference in the surface speed of fallers over the surface speed of retaining r/r to give sufficient tension to the sliver is known as lead%.
Surface speed of faller – surface speed of retaining r/r
Faller bar Lead% = --------------------------------------------------× 100
Surface Speed of Retaining r/r
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