LYOCELL FIBER TOW, ITS MANUFACTURE AND USE

Abstract

This invention relates to a crimped lyocell tow for use in stretch breaking, worsted or semi worsted spinning, its manufacture and use.

Claims

1. A lyocell tow for use in stretch breaking or worsted or semi worsted spinning, wherein each individual filament is crimped and has a filament titer in the range of between 0.8 and 1.4 dtex, and that wherein the lyocell tow has a tow titer of between 60 and 160 ktex and a length of between 1,000 and 10,000 m.

2. The lyocell tow according to claim 1, wherein the lyocell tow comprises a finish suitable for stretch break and onward worsted and semi worsted processing.

3. The lyocell tow according to claim 1, wherein fibers in the lyocell tow have a crosslinked surface.

4. A method for the manufacture of a lyocell tow for use in stretch breaking or worsted or semi worsted spinning, comprising: a. splitting a coagulated, washed, and dried lyocell full tow band into (m+1) primary sub tows by m primary guides; b. jointly passing the primary sub tows through a crimper when the primary sub tows can be jointly crimped; and c. cutting at least m primary sub tows to lengths of between 1,000 and 10,000 m and subsequently plaiting into one or more containers.

5. The method according to claim 4, wherein m is 1, wherein the primary sub tows are plaited into one container, and wherein a residual tow is further cut into short staple fibers having a length of between 20 and 60 mm.

6. The method according to claim 5, wherein the primary sub tows have a tow titer of between 60 and 160 ktex and the residual tow has a tow titer of more than 300 ktex.

7. The method according to claim 4, wherein m is greater than 1, between step a. and step b., all primary sub tows are split into (n+1) secondary sub tows by n secondary guides, and wherein the secondary sub-tows are plaited into containers.

8. The method according to claim 7, wherein each of the primary sub-tows is divided into 3 or more, optionally up to 6 secondary sub tows, optionally into 4 secondary sub tows.

9. The method according to claim 7, wherein all secondary sub tows originating from one of the primary sub tows are jointly plaited into one container.

10. The method according to claim 9, wherein in a subsequent step, all secondary sub tows originating from one primary sub tow are jointly pulled out of the one container, and are separated and collected in individual containers.

11. The method according to claim 7, wherein the primary sub tows have a tow titer of between 180 and 600 ktex, the secondary sub tows have a tow titer of between 60 and 160 ktex.

12. A method for the manufacture of blended yarns using the lyocell tow according to claim 1, comprising: blending the lyocell tow with one or more fiber types comprising wool, animal hairs other than wool, silk, linen, acrylic, polyester, nylon, or polypropylene.

13. A method for the manufacture of circular- and flatbed knitted fabrics for sweaters, t-shirts, tops, woven shirts and blouses, ladies and men's outerwear for fine suits, dresses, and skirts, using the blended yarns according to claim 12.

14. A. worsted yarn comprising a lyocell fiber having a fiber titer of between 0.8 and 1.4 dtex and a mean staple length of more than 70 mm.

Description

DESCRIPTION OF THE DRAWINGS

[0067] FIG. 1 shows the split-crimp-section of embodiment 1; m=1.

[0068] FIG. 2 shows the split-crimp-section of embodiment 2; the figure shows an embodiment with 2 primary guides and 11 secondary guides; m=2 and n=11.

[0069] FIG. 3 shows a possible separating mechanism comprising of two finger guide devices to separate and split off the smaller tow bundle(s) from larger tow.

[0070] FIG. 4 shows a finger guide device as foreseen in FIG. 3; the guides can be individually moved into a splitting position. Left drawing: View into machine direction; right drawing: Side view.

LEGEND

[0071] 1 Full tow band before splitting

[0072] 2 Primary guide

[0073] 3, 3′ Primary sub tow

[0074] 4 Secondary guide

[0075] 5, 5′ Secondary sub tow

[0076] 6 Residual tow

[0077] 7 Crimper

[0078] 8 Residual, crimped tow

[0079] 9 Crimped secondary sub tow of embodiment 1

[0080] 10 Collection of crimped secondary sub tows of embodiment 2, originating from one primary sub tow