Splittable multicomponent fiber with high temperature, corrosion resistant polymer

Abstract

The present invention provides a splittable, multicomponent fiber or filament comprising a first polymer that has a high melting point and does not degrade in a corrosive environment, and a second polymer that has a high melting point but that is degradable in a corrosive environment. The multicomponent fiber or filament is particularly useful in filtration media.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

In order to assist the understanding of embodiments of the invention, reference will now be made to the appended drawings, which are not necessarily drawn to scale. The drawings are exemplary only, and should not be construed as limiting the invention in any way.

FIGS. 1A-1F provide cross-sectional views of exemplary embodiments of multicomponent fibers according to the present invention;

FIGS. 2A-2B provide cross-sectional and longitudinal views, respectively, of an exemplary fiber according to one embodiment of the invention, wherein the fiber has been mechanically dissociated;

FIG. 3 provides a flow diagram illustrating a fabric formation process according to one embodiment of the invention; and

FIG. 4 schematically illustrates one fabric formation process of the invention.

Claims

1. A splittable, multicomponent fiber having an outer surface, said fiber comprising: a first fiber component comprising a polymer having a melting point of at least about 200° C. and that does not degrade in a corrosive environment, said first fiber component being dimensioned to form a microfilament; anda second fiber component comprising a polymer having a melting point of at least about 200° C. and that is degradable in a corrosive environment;wherein each of said fiber components forms a portion of the outer surface of said fiber and form distinct, unocclusive cross-sectional segments along the length of the fiber.

2. The multicomponent fiber according to claim 1, wherein said first fiber component comprises a polymer selected from the group consisting of polyphenylene sulfide, fluoropolymers, chlorofluoropolymers, epoxies, silicones, polymethylpentene, mixtures thereof, copolymers thereof, and terpolymers thereof.

3. The multicomponent fiber according to claim 1, wherein said second fiber component comprises a polymer selected from the group consisting of polyesters and polyamides.

4. The multicomponent fiber according to claim 3, wherein said second fiber component comprises a polymer selected from the group consisting of polycyclohexylene dimethyl terephthalate, polyethylene terephthalate, polybutylene terephthalate, poly(trimethylene) terephthalate, polyethylene naphthalate, nylon 6, nylon 6,6, mixtures thereof, copolymers thereof, and terpolymers thereof.

5. The multicomponent fiber according to claim 1, wherein said first fiber component comprises polyphenylene sulfide and said second fiber component comprises polyethylene terephthalate.

6. The multicomponent fiber according to claim 1, wherein said fiber is selected from the group consisting of pie/wedge fibers, hollow pie/wedge fibers, segmented round fibers, segmented oval fibers, segmented rectangular fibers, segmented cross fibers, and segmented multilobal fibers.

7. The multicomponent fiber according to claim 1, wherein said fiber is selected from the group consisting of continuous filaments, staple fibers, spunbond fibers, and meltblown fibers.

8. The multicomponent fiber according to claim 1, wherein said first fiber component comprises at least about 50% by weight of said multicomponent fiber.

9. The multicomponent fiber according to claim 1, wherein said first fiber component comprises at least about 75% by weight of said multicomponent fiber.

10. The multicomponent fiber according to claim 1, wherein said fiber is capable of being mechanically dissociated.

11. The multicomponent fiber according to claim 10, wherein said mechanical dissociation comprises a method selected from the group consisting of carding, crimping, drawing, and high pressure water jet impinging.

12. The multicomponent fiber according to claim 1, wherein said fiber is capable of being chemically dissociated.

13. A fabric comprising a multicomponent fiber according to claim 1.

14. The fabric of claim 13, wherein the fabric is selected from the group consisting of nonwoven fabrics, woven fabrics, and knit fabrics.

15. A filtration media comprising a multicomponent fiber according to claim 1.

16. The filtration media according to claim 15, wherein said filtration media further comprises one or more non-splittable fiber comprising a polymer having a melting point of at least about 200° C. and that does not degrade in a corrosive environment

17. A method for preparing a microfilament filter at a point of use, said method comprising: a. providing a filtration media comprising a splittable, multicomponent fiber having an outer surface, said fiber comprising: i. a first fiber component comprising a polymer having a melting point of at least about 200° C. and that does not degrade in a corrosive environment; andii. a second fiber component comprising a polymer having a melting point of at least about 200° C. and that does degrade in a corrosive environment;wherein each of said fiber components forms a portion of the outer surface of said fiber and form distinct, unocclusive cross-sectional segments along the length of the fiber;b. installing said filtration media at said point of use; andc. flowing a stream for filtration through said filtration media under high temperature, corrosive conditions such that said second fiber component degrades and said first fiber component remains intact as microfilaments having a fineness of less than or equal to about 1 denier per filament.

18. The method according to claim 17, wherein said filtration media further comprises one or more non-splittable fibers comprising a polymer having a melting point of at least about 200° C. and that does not degrade in a corrosive environment.

19. The method according to claim 17, wherein said microfilament filter prepared according to said method has a filtration performance of greater than or equal to about 99%, said filtration performance being measured as the percentage of particles having a diameter of 1 micron or greater that are retained by said microfilament filter.

20. The method according to claim 17, further comprising removing said degraded second fiber component from said microfilament filter.

21. The method according to claim 20, wherein said removing step comprises entraining the degraded second fiber component in the filtered stream exiting the filtration media such that the degraded second fiber component is carried away by said filtered stream.

22. The method according to claim 20, wherein said removing step comprises mechanical cleaning of said microfilament filter.

23. The method according to claim 17, wherein said stream comprises a gas.

24. The method according to claim 17, wherein said multicomponent fiber is selected from the group consisting of continuous filaments, staple fibers, spunbond fibers, and meltblown fibers.

25. The method according to claim 17, wherein said filtration media comprises a fabric selected from the group consisting of nonwoven fabrics, woven fabrics, and knit fabrics.

26. The method according to claim 17, wherein said point of use comprises a baghouse filter.

27. A microfilament filter prepared according to the method of claim 17.

28. A filter comprising polyphenylene sulfide microfilaments having a fineness of less than or equal to about 1 denier per filament, wherein said filter has a filtration performance of greater than or equal to about 95%, said filtration performance being measured as the percentage of particles having a diameter of 1 micron or greater that are retained by said filter.

29. The filter according to claim 28, wherein said filter has a filtration performance of greater than or equal to about 99%.