What is the meaning of the head-and-tail effect of fibre slivers?
This effect is particularly evident on combing machine slivers, where almost all fibres composing a single tuft are aligned in the head position relative to the outgoing direction, while fibres in the tail terminate in different places according to their length. Overlapping of different tufts makes up a sliver whose weight is proportional to the overlapping length adopted, but with minimum fibre spacing. At the can-emptying passage, the tails become heads; thus, alternating the draft sense during subsequent operations causes fibre spacing. Should the head-tail reversal not take place and slivers be fed directly to the jar-emptying machine, draft would take out fibre agglomerates as if the fibres were all of the same length without causing spacing.
