Yarn spinning from fibre sub-assemblies with variation of their

Details Yarn spinning from fibre sub-assemblies with variation of their Yarn spinning from fibre sub-assemblies with variation of their

1996-07-29

2000-01-11

Stryjewski, William

Textiles: spinning, twisting, and twining

Apparatus and processes

With drafting

19237, 19243, 19258, 19287, 19288, 57 2, 57317, 57319, 57326, D01H 528

Patent

active

060122773

DESCRIPTION:

BRIEF SUMMARY
FIELD OF THE INVENTION

This invention relates generally to the processing of fibre assemblies. A particularly useful application is to the spinning of yarns, especially though not exclusively staple yarns, and in preferred aspects the invention provides a weavable or low pilling yarn from single or double rovings or slubbings.


BACKGROUND ART

Two-strand yarns may be produced by spinning or twisting together two strands in which the fibre tails have been wrapped by an air-jet (eg Plyfil) or in which the alternating strand twist is trapped during the operation (eg Sirospun). Such yarns have enhanced strength and abrasion resistance relative to singles yarns but in worsted processing have an average cross-section of around 80 or more fibres. It would be very useful to produce a weavable singles yarn of a structure which may be of significantly smaller cross-section, with say around 50-60 fibres or less. However, singles yarns of such size to date have tended to have inadequate strength and abrasion resistance for weaving and knitting applications.
It was recognized by Peirce [Peirce, F. T.; Textile Research Journal, 1947, 17, p123], Morton and Yen [Morton, W. E. and Yen, K. C. J.; Journal of the Textile Institute, 1952, 22, T.463], and Morton [Morton, W. E.; Annales Scientifiques Textiles Belges, 1956, p29], that fibre migration, or entanglement, must occur during twist insertion to give the resulting yarn strength and abrasion resistance. In relation to the fibre strand emerging from the front roller nip, Morton stated in part that " . . . since the length of the fibre path increases from the core to the surface, so also must the tension in the fibres. At any given instant, those forming the outer layer of the yarn follow the longest path and are conseqently highly stressed; and furthermore the curvature of their path is also the largest" It has been shown by the above authors that these highly stressed fibres will tend to migrate toward the axis of the yarn in order to achieve a lower tension condition. However, " . . . as soon as the trailing end of the fibre emerges from the nip of the front rollers, tension in the fibre must drop to zero. It is then in no condition to do other than suffer expulsion to the surface, where it will appear as (a) projecting fibre." In his concluding remarks, Morton states, "A further practical outcome is that, since wild, or wildish fibres, (we must recognise that there are degrees of wildness) are unlikely to contribute their fair share to the strength of the yarn, the width of the ribbon of drawn-out roving should be limited as much as possible".
International patent publication WO94/01604 (PCT/NZ93/00055) by Wool Research Organization of New Zealand discloses a number of practical techniques for applying the above concepts to a single drafted assembly or strand of fibres as the strand is spun from a drafting system. In one of these techniques, a guide oscillates the strand laterally so as to cyclically vary the tension in the fibres of the strand. By varying the tension in this way, the fibres are caused to migrate cyclically between the core and the surface of the resultant yarn. In another arrangement, the drafted strand is passed through an additional pair of nip rollers located immediately downstream of the front drafting rollers. The nip rollers are driven at a lower speed than the delivery speed of the front drafting rollers, a negative draft which induces an "overfeed" zone in which the fibres are found to randomly alter their positions at the nip. There is thus a random migration of the fibres between the core and the surface of the yarn. In a third arrangement, the drafted strand is allowed to spread sufficiently laterally for "sub-groupings" to form in which the fibres are false twisted to form separate sub-strands that are then twisted together in a recombined yarn.
The proposal in WO94/01604 for guide oscillation has some similarities to various proposals for forming two-strand yarns from a pair of separate strands, disclosed or discussed eg in U.S. Pat. No.

REFERENCES:
patent: 2358656 (1944-09-01), Nutter et al.
patent: 2925628 (1960-02-01), Boer
patent: 3105997 (1963-10-01), Mackie
patent: 3599416 (1971-08-01), Reuter et al.
patent: 3851698 (1974-12-01), Leach et al.
patent: 4418523 (1983-12-01), Lemaire
patent: 4662164 (1987-05-01), Morrison
patent: 5084941 (1992-02-01), Brockmanns et al.
patent: 5090192 (1992-02-01), Stahlecker
patent: 5228281 (1993-07-01), Stahlecker
patent: 5431005 (1995-07-01), Fehrer
Effect of Volume Fraction of Each Fleece . . . Spun Yarn, vol. 43, No. 11 (1990) pp. T98-T104.
Structural Effects of Spun Yarns on Wear Resistance, vol. 41, No. 12 (1988) pp. T177-T183.
Geometrical Principles Applicable . . . Functional Fabrics, vol. XVII, No. 3, Mar, 1947, pp. 123-147.
The Arrangement of Fibres in Fibro Yarns, pp. T60-T66.
The Arrangement of Fibers in Single Yarns, vol. XXVI, No. 5, May 1956, pp. 325-331.
An Alternative Approach to Two-Fold . . . Surface Fibres, vol. 73, No. 3, May/Jun. 1982, pp. 99, 106.
An Alternate Approach to Two-Fold . . . Yarns, J. Text Inst., 1983, No. 6, pp. 320-328.
Influence Exerted by the Spinning . . . Fiber Yarns, Melliand Textilberichte, Aug. 1985, pp. 605-610.

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