FILAMENT OF RECYCLED POLYPROPYLENE FOR PILE YARN

Abstract

A filament for a pile yarn. The filament is a multi-component filament, comprising a core (10), at least a first sheath (20) at least partly enclosing the core (10) and optionally a second sheath (30) at least partly enclosing the first sheath (20). The core (10) comprises recycled polypropylene, and the first sheath (20) comprises polypropylene and a particulate, opaque additive.

Claims

1. A filament for a pile yarn, wherein the filament is a multi-component filament comprising a core and at least a first sheath at least partly enclosing the core, said core comprising recycled polypropylene, wherein said first sheath comprises polypropylene and a particulate, opaque additive.

2. The filament according to claim 1, wherein the particulate, opaque additive is an inorganic additive, such as titanium dioxide or calcium carbonate; preferably the particulate, opaque additive being titanium dioxide.

3. (canceled)

4. The filament according to claim 1, wherein the first sheath, in addition to the particulate, opaque additive, further comprises a pigment; and/or the core comprises up to 5 wt. % of a particulate, opaque additive, preferably an inorganic particulate, opaque additive, such as titanium dioxide or calcium carbonate, and/or the core comprises a pigment, such as carbon black; and/or wherein the first sheath comprises 5 to 40 wt. %, 5 to 30 wt. %, or 10 to 20 wt. % of the particulate, opaque additive.

5. The filament according to claim 1, wherein the core constitutes at least 40 wt. %, such as 50 to 85 wt. %, of the filament.

6. The filament according to claim 1, wherein the multi-component filament further comprises a second sheath at least partly enclosing the first sheath, said second sheath comprising a polymer, preferably said polymer being polypropylene.

7. The filament according to claim 6, wherein the second sheath comprises a pigment and/or a particulate, opaque additive, preferably an inorganic particulate, opaque additive, such as titanium dioxide or calcium carbonate.

8. (canceled)

9. The filament according to claim 1, wherein: the first sheath constitutes 5 to 30 wt. % or 10 to 25 wt. % of the filament; and/or the first sheath is at least 0.2 m thick or at least 1.0 m thick; and/or the first sheath encloses at least 80%, 90% or 95%, of the circumference of the core; preferably the first sheath encloses the core entirely; and/or the second sheath, if present, constitutes 5 to 30 wt. % or 10 to 25 wt. %, of the filament; and/or the second sheath, if present, is at least 0.2 m thick or at least 1.0 m thick; and/or the second sheath, if present, encloses at least 80%, 90%, or 95%, of the circumference of the first sheath; preferably the second sheath encloses the first sheath entirely; and/or the second sheath, if present, comprises 1 to 20 wt. % of the pigment, and/or 5 to 40 wt. %, 5 to 30 wt. %, or 10 to 20 wt. % of the particulate, opaque additive.

10. The filament according to claim 1, wherein the first sheath comprises virgin polypropylene, or wherein the first sheath comprises recycled polypropylene, the recycled polypropylene in the first sheath being lighter in its color than the recycled polypropylene in the core; and/or wherein the second sheath, if present, comprises virgin polypropylene, or wherein the second sheath comprises recycled polypropylene, the recycled polypropylene in the second sheath being lighter in its color than the recycled polypropylene in the core.

11. A filament for a pile yarn, wherein the filament is a multi-component filament, comprising a core, comprising a polymer, at least a first sheath at least partly enclosing the core, and a second sheath at least partly enclosing the first sheath, wherein said first sheath comprises a polymer and a first particulate, opaque additive, and wherein said second sheath optionally comprises a polymer, a pigment, and/or a second particulate, opaque additive.

12. The filament according to claim 11, wherein the first particulate, opaque additive is an inorganic additive, such as titanium dioxide or calcium carbonate; preferably the additive being titanium dioxide; and wherein the second particulate, opaque additive, if present, is an inorganic additive, such as titanium dioxide or calcium carbonate; preferably the additive being titanium dioxide.

13. (canceled)

14. The filament according to claim 11, wherein: the core constitutes at least 40 wt. %, such as 50 to 85 wt. %, of the filament; and/or the first sheath constitutes 5 to 30 wt. % or 10 to 25 wt. % of the filament; and/or the second sheath constitutes 5 to 30 wt. % or 10 to 25 wt. % of the filament.

15. The filament according to claim 11, wherein: the first sheath is at least 0.2 m thick or at least 1.0 m thick; and/or the first sheath encloses at least 80%, 90%, or 95% of the circumference of the core; preferably the first sheath encloses the core entirely; and/or the second sheath is at least 0.2 m thick or at least 1.0 m thick; and/or the second sheath encloses at least 80%, 90%, or 95% of the circumference of the first sheath; preferably the second sheath encloses the first sheath entirely; and/or the first sheath comprises 5 to 40 wt. %, 5 to 30 wt. %, or 10 to 20 wt. % of the particulate, opaque additive; and/or the second sheath comprises 1 to 20 wt. % of the pigment, and/or 5 to 30 wt. %, 5 to 30 wt. %, or 10 to 20 wt. % of the particulate, opaque additive.

16. The filament according to claim 11, wherein: the polymer in the core is recycled polyolefin, recycled aliphatic polyamide, or recycled polyester, such as recycled semi-aromatic polyester; preferably the polymer in the core being recycled polypropylene; and/or the polymer in the first sheath is polyolefin, aliphatic polyamide, or polyester, such as semi-aromatic polyester; preferably the polymer in the first sheath being polypropylene; and/or the polymer in the second sheath is polyolefin, aliphatic polyamide, or polyester, such as semi-aromatic polyester; preferably the polymer in the second sheath being polypropylene.

17. The filament according to claim 1, wherein the cross-section of the multi-component filament has at least two lobes, preferably the cross-section being bi-lobal, tri-lobal or quad-lobal; more preferably the waist of the bi-lobal cross-section being concave and the sides of the tri-lobal and/or the quad-lobal cross-section being concave.

18. The filament to claim 1, wherein the linear mass density of the filament is 1 dtex to 20 dtex.

19. A filament for a pile yarn, wherein the filament is a multi-component filament, comprising a core, the core comprising a polymer, at least a first sheath at least partly enclosing the core, and a second sheath at least partly enclosing the first sheath, wherein said first sheath comprises a polymer and optionally a first additive, and wherein said second sheath comprises a polymer and a second additive, said second additive being distinct from the first additive.

20-29. (cancelled)

30. A yarn comprising at least two filaments according to claim 1.

31. A staple fiber, wherein the staple fiber is obtainable by cutting the filament according to claim 1 into staple fibers; preferably the staple fibers being 20 to 100 mm long, or 30 to 70 mm long.

32. A carpet or a rug comprising the yarn according claim 30.

33. A method of producing a filament according to claim 1, wherein the method comprises the steps of: extruding a first melt comprising recycled polypropylene to form a core, a second melt comprising polypropylene and optionally a particulate, opaque additive to form a sheath at least partly enclosing the core, and optionally a third melt comprising a polymer, preferably polypropylene, to form a second sheath at least partly enclosing the first sheath; drawing and solidifying the filament; and optionally texturing and/or stretching the filaments.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0045] These and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which:

[0046] FIG. 1a shows a cross-section of filaments with a first sheath according to an embodiment;

[0047] FIG. 1b shows a cross-section of filaments with a first sheath and a second sheath according to an embodiment;

DETAILED DESCRIPTION

[0048] In FIG. 1a, a number of cross-section of filaments according to an embodiment is shown. The filament is a bi-component filament with a first sheath 20 enclosing a core 10. The filament's cross-section is tri-lobal. As can be seen, the thickness if the first sheath 20 varies slightly over the circumference of the filament.

[0049] In FIG. 1b, a number of cross-section of filaments according to an embodiment is shown. The filament is a tri-component filament with a first sheath 20, enclosing a core 10, and a second sheath 30, enclosing the first sheath 20. The filament's cross-section is tri-lobal. As can be seen, the thickness of the first sheath 20 and the second sheath 30, respectively, varies slightly over the circumference of the filament.

EXPERIMENTAL

Filament Spinning and Yarn Drawing

[0050] The present sheath-core fibers may be spun using conventional fiber-forming equipment. Thus, for example, separate melt flows of the virgin sheath polypropylene and re-cycled core polypropylene may be fed to a conventional sheath-core spinneret pack (examples are given inter alia in U.S. Pat. Nos. 5,162,074, 5,125,818, 5,344,297 and 5,445,884) where the melt flows are combined to form extruded multi-lobal (e.g., tri-, tetra-, penta- or hexalobal) filaments having sheath and core structures. In embodiments including two sheaths, an additional melt flow is fed to the spinneret pack.

[0051] After the extrusion, the extruded filaments are quenched, for example with air, in order to solidify the filaments. The filaments may then be treated with a finish comprising a lubricating oil or mixture of oils and antistatic agents. The thus formed filaments are then combined to form a yarn bundle.

[0052] In a subsequent step, the yarn may be drawn and texturized to form a bulked continuous fiber (BCF) yarn suitable for e.g. tufting into carpets. Further, the spinning and the drawing may be combined in a single process. A one-step method of making BCF is generally known in the art as spin-draw-texturing (SDT).

Example 1

[0053] A first flat yarn (cf. FIG. 1a) of core sheath-core filaments with recycled polypropylene in the core 10 were provided with the following specification: [0054] Weight ratio core/sheath: 60/40 [0055] Polymer in the core 10: recycled polypropylene from A.D. Compound S.p.a. (MFI at 230 C./2.16 kg according to ISO 1133: 26.4 g/10 min; density at 23 C. 0.964 g/cm.sup.3) [0056] Additives in the core 10: TiO.sub.2 (5 wt. %) and carbon black (3 wt. %) [0057] Polymer in the sheath 20: virgin polypropylene (Metocene MF650Y) from LyondellBasell (MFI at 230 C./2.16 kg according to ISO 1133: 18 g/10 min) [0058] Additives in the sheath 20: TiO.sub.2 (35 wt. %) and red pigment (2 wt. %) [0059] Linear density filament: 12 denier per filament (dpf) [0060] Linear density yarn: 1700 dtex

[0061] The yarn was reddish brown had a tenacity of 2.16 and an elongation of 106%

Example 2

[0062] A second flat yarn (cf. FIG. 1b) of sheath-sheath-core filaments with recycled polypropylene in the core 10 were provided with the following specification: [0063] Weight ratio core/sheath/sheath: 60/30/10 [0064] Polymer in the core 10: recycled polypropylene MFI at 230 C./2.16 kg according to ISO 1133: 26.4 g/10 min; density at 23 C. 0.964 g/cm.sup.3) [0065] Additives in the core 10: carbon black (3 wt. %) [0066] Polymer in the first sheath 20: virgin polypropylene (Metocene MF650Y) from LyondellBasell (MFI at 230 C./2.16 kg according to ISO 1133: 18 g/10 min) [0067] Additives in the first sheath 20: TiO.sub.2 (15 wt. %) [0068] Polymer in the second sheath 30: virgin polypropylene (Metocene MF650Y) from LyondellBasell (MFI at 230 C./2.16 kg according to ISO 1133: 18 g/10 min) [0069] Additives in the second sheath 30: TiO.sub.2 (10 wt. %) and yellow pigment (2 wt. %) [0070] Linear density filament: 12 denier per filament (dpf) [0071] Linear density yarn: 1800 dtex

[0072] The yarn was greenish and had a tenacity of 2.08 and an elongation of 98%