| 摘要 |
<p>A method for stretching an assembly, e.g. a sliver or roving, of untwisted staple fibres (12) to reduce their diameter and increase their length employs false twist to provide grip between the fibres to ensure that stretching of the fibres and not drafting of the assembly occurs. The fibres are first plasticized by treatment with a suitable agent in a bath (16) and then passed through apparatus which employs a number of rotatable arrays (24, 25, 29, 32) of driven pulleys (26, 33). The arrays are mounted for rotation between two twist blocking nips (18, 18') and are rotatable about a longitudinal axis corresponding to the direction of travel of the assembly through the apparatus to impart false twist into the assembly. The assembly is stretched between two of the pulley arrays (24 and 25), the pulleys of the downstream array (25) being driven at a higher speed than the pulleys of the upstream array (24). The stretch is then set by steam heating in chamber (17) while the false twist is maintained by further rotatable pulley arrays (29). Post treatment stages (14, 46) may be added to further stabilize the stretched fibres. The fibres are animal hairs, for example wool.</p> |
