All these doublings of the sliver and re-drawing are for the purpose of getting each fibre to lie parallel and to make the sliver of an equal weight over every yard of its length.
It is easy to see that a certain amount of draft, or drawing out of the sliver, is necessary, otherwise the various doublings would cause the sliver to emerge thicker and thicker from each machine.
The doublings play a very important part in the appearance of the ultimate rove and yarn, for the chief reason for doubling threads or slivers is to minimize irregularities of thickness and of colour in the material.
In an ordinary case, the total doublings in jute from the breaker card to the end of the second drawing is ninety-six: 12 X 4 X 2 = 96; and if the slivers were made thinner and more of them used the ultimate result would naturally be improved.
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