Process for the preparation of a fiber, a fiber and a yarn made from such a fiber

1. A process for the preparation of a fiber comprising polyethylene-2,5-furan-dicarboxylate, by melt spinning, wherein a molten composition comprising polyethylene-2,5-furan-dicarboxylate having an intrinsic viscosity of at least 0.55 dl/g, determined in dichloroacetic acid at 25° C., is passed through one or more spinning openings to yield molten threads;

wherein the molten threads are cooled to below the melting temperature of the composition to yield spun fibers;

wherein the spun fibers are drawn to a linear density in the range of 0.05 to 2.0 tex per fiber;

wherein the molten composition further comprises at least one polymer different from polyethylene-2,5-furan-dicarboxylate; and

wherein the molten composition further comprises polyethylene terephthalate or polyethylene naphthalate.

2. The process according to claim 1 , wherein the molten composition comprises from 75 to 100% wt polyethylene-2,5-furan-dicarboxylate, based on the weight of the molten composition.

3. The process according to claim 1 , wherein the at least one polymer different from polyethylene-2,5-furan-dicarboxylate has been selected from polyolefins, polyamides, polyesters and combinations thereof.

4. The process according to claim 1 , wherein the at least one polymer different from polyethylene-2,5-furan-dicarboxylate is present in an amount of 99 to 75% wt or 1 to 25% wt, based on the weight of the at least one polymer different from polyethylene-2,5-furan-dicarboxylate and polyethylene-2,5-furan-dicarboxylate.

5. The process according to claim 1 , wherein the spun fibers are drawn in a secondary drawing step at a draw ratio of 1:1.4 to 1:6.0.

6. The process according to claim 1 , wherein the spun fibers are combined to a multifilament yarn before or after being drawn.

7. The process according to claim 1 , wherein the molten composition is kept at a temperature of 20 to 70° C. above the melting temperature of the molten composition.

8. The process according to claim 1 , wherein the spun fibers are drawn at a temperature of between glass transition temperature and the melting temperature of the polymer composition.

9. The process according to claim 1 , wherein the polyethylene-2,5-furan-dicarboxylate has an intrinsic viscosity in the range of 0.55 to 1.55 dl/g, determined in dichloroacetic acid at 25° C.

10. The process according to claim 1 , wherein the spun fibers are textured.

11. The process according to claim 1 , wherein the fibers after drawing are subjected to a spin finishing step by treating the fibers with a liquid.

12. The process according to claim 1 , wherein the fibers after drawing are subjected to a dyeing technique.

13. The process according to claim 1 , wherein the polyethylene-2,5-furan-dicarboxylate has been modified by the introduction of a third monomer to facilitate dyeing, which third monomer contains functionalized groups or disturbs the regularity of the chain of the polyethylene-2,5-furan-dicarboxylate.

14. A fiber comprising polyethylene-2,5-furan-dicarboxylate having a linear density of 0.05 to 2.0 tex, wherein the polyethylene-2,5-furan-dicarboxylate has an intrinsic viscosity of at least 0.45 dl/g, determined in dichloroacetic acid at 25° C.,

wherein the fiber further comprises at least one polymer different from polyethylene-2,5-furan-dicarboxylate, and

wherein the fiber further comprises polyethylene terephthalate or polyethylene naphthalate.

15. The fiber according to claim 14 , having a linear density of 0.05 to 0.5 tex.

16. The fiber according to claim 14 , which has a tenacity of 200 to 1,000 mN/tex.

17. The fiber according to claim 14 , wherein the polyethylene-2,5-furan-dicarboxylate has an intrinsic viscosity in the range of 0.45 to 0.85 dl/g, determined in dichloroacetic acid at 25° C.

18. The fiber according to claim 14 , wherein the fiber has a birefringence in the range of 0.01 to 0.4.

19. The fiber according to claim 14 , wherein the fiber has a crystallinity of at least 5 J/g as determined by Differential Scanning calorimetry (DSC).

20. The fiber according to claim 14 , wherein the fiber has been obtained by drawing an undrawn spun fiber at a draw ratio of 1:1.4 and 1:6.0 in a secondary drawing step.

21. The fiber according to claim 14 , which has been dyed by a dyeing technique.

22. A yarn, comprising a plurality of fibers according to claim 14 .

23. A knit, woven or non-woven article, comprising a yarn according to claim 22 .

24. The article according to claim 23 , which is selected from a textile, a carpet and a tire cord.

25. The process according to claim 1 , wherein the molten composition further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 85% wt, based on the total composition.

26. The process according to claim 12 , wherein the fibers after drawing are subjected to a dyeing technique selected from the group consisting of carrier or carrier free dyeing, high temperature and high pressure (HTHP) dyeing, thermosol dyeing, plasma techniques, solvent free, supercritical CO 2 -based dyeing, dyeing using swelling agents and combinations thereof.

27. The fiber according to claim 19 , wherein the fiber has a crystallinity of at least 30 J/g, as determined by Differential Scanning calorimetry (DSC).

28. The fiber according to claim 24 , wherein the fiber further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 85% wt, based on the total fiber.

29. The fiber according to claim 21 , which has been dyed by a dyeing technique selected from the group consisting of carrier or carrier free dyeing, high temperature and high pressure (HTHP) dyeing, thermosol dyeing, plasma techniques, solvent free, supercritical CO 2 -based dyeing, dyeing using swelling agents and combinations thereof.

30. The process according to claim 25 , wherein the molten composition further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 90% wt, based on the total composition.

31. The fiber according to claim 28 , wherein the fiber further comprises polyethylene terephthalate or polyethylene naphthalate in an amount of 99 to 90% wt, based on the total fiber.