Production of micro- and nano-fibers by continuous microlayer coextrusion

Patent metadata

Field	Value
Publication number	US-10077509-B2
Application number	US-201314394234-A
Country	US
Kind code	B2
Filing date	Apr 15, 2013
Priority date	Apr 13, 2012
Publication date	Sep 18, 2018
Grant date	Sep 18, 2018

Abstract

A multilayered polymer composite film includes a first polymer material forming a polymer matrix and a second polymer material coextruded with the first polymer material. The second polymer material forms a plurality of fibers embedded within the polymer matrix. The fibers have a rectangular cross-section.

First claim

Having described the invention, the following is claimed:

1. A multilayered polymer composite film comprising:
a first polymer material forming a polymer matrix; and
a second polymer material coextruded with the first polymer material and forming a plurality of fibers embedded within the polymer matrix, the fibers having a rectangular cross-section and extending the entire length of the multilayered polymer composite film, a planar layer interface being defined between each fiber and the polymer matrix; and
a pair of polymer skin layers provided on opposite sides of the fibers and the polymer matrix such that the layer interfaces are positioned between the pair of polymer skin layers.

2. The multilayered polymer composite film of claim 1 , wherein the first polymer material comprises polycaprolactone and the second polymer material comprises polyethylene oxide.

3. The multilayered polymer composite film of claim 1 , wherein the fibers have a Young's Modulus from about 300 MPa to about 3.2 GPa.

4. The multilayered polymer composite film of claim 1 further comprising a third polymer material coextruded with the first polymer material and the second polymer material and forming a second plurality of fibers embedded within the polymer matrix, the second plurality of fibers having a rectangular cross-section and extending the entire length of the multilayered polymer composite film.

5. The multilayered polymer composite film of claim 4 , wherein the first polymer material comprises polystyrene, the second polymer material comprises polyamide 6, and the third polymer material comprises poly(ethylene terephthalate).

6. The multilayered polymer composite film of claim 1 , wherein the fibers are axially oriented within the polymer matrix.

7. The multilayered polymer composite film of claim 1 , wherein the first polymer material and the second polymer material are substantially immiscible.

8. The multilayered polymer composite film of claim 1 , wherein each of the plurality of fibers has the same rectangular cross-section.

9. The multilayered polymer composite film of claim 1 , wherein the cross-section of each fiber is the same along the entire length of the fiber.

10. The multilayered polymer composite film of claim 1 , wherein the first polymer material and the second polymer material both have rectangular cross-sections prior to coextrusion.

11. The multilayered polymer composite film of claim 1 , wherein each planar interface extends over the entire thickness of the matrix.

12. A method for producing polymer fibers comprising:
coextruding a first polymer material with a second polymer material to form a coextruded polymer film having discrete overlapping layers of polymeric material that each extend the entire length of the coextruded polymer film;
multiplying the overlapping layers by dividing the coextruded polymer film into portions and stacking the portions to form a multilayered composite film; and
separating the first polymer material from the second polymer material to form a plurality of first polymer material fibers having a rectangular cross-section.

13. The method of claim 12 , wherein separating the first polymer material from the second polymer material comprises immersing the multilayered composite film in a solvent to dissolve one of the first polymer material or the second polymer material.

14. The method of claim 12 , wherein solvent comprises water, the first polymer material being water soluble and the second polymer material being water insoluble.

15. The method of claim 12 , wherein the first polymer material comprises polycaprolactone and the second polymer material comprises polyethylene oxide.

16. The method of claim 12 , wherein separating the first polymer material from the second polymer material comprises applying pressurized water to the multilayered composite film.

17. The method of claim 12 further comprising axially orienting the multilayered composite film in at least one direction.

18. The method of claim 12 , wherein the first polymer material and the second polymer material are substantially immiscible.

19. The method of claim 12 , wherein separating the first polymer material from the second polymer material forms a plurality of first polymer material fibers having the same rectangular cross-section.

20. The method of claim 12 , wherein separating the first polymer material from the second polymer material forms a plurality of first polymer material fibers that each has a cross-section that is the same along the entire length of the fiber.

21. The method of claim 12 , wherein the first polymer material and the second polymer material both have rectangular cross-sections coextruded to form the coextruded polymer film.

22. A method for producing polymer fibers comprising:
coextruding a first polymer material with a second polymer material to form a coextruded polymer film having discrete overlapping layers of polymeric material that each extends the entire length of the coextruded polymer film;
multiplying the overlapping layers to form a multilayered composite film;
separating the first polymer material from the second polymer material to form a plurality of first polymer material fibers having a rectangular cross-section; and
coextruding a third polymer material with the first polymer material and the second polymer material and separating the third polymer material from the first and second polymer materials to form a second plurality of fibers having a rectangular cross-section.

23. The method of claim 22 , wherein the first polymer material comprises polystyrene, the second polymer material comprises polyamide 6, and the third polymer material comprises poly(ethylene terephthalate).

24. A fiber produced from a composite stream comprised of discrete overlapping layers of polymeric material, a pair of such discrete overlapping layers define a generally planar layer interface therebetween which lies generally in an x-y plane of an x-y-z coordinate system, wherein the y-axis extends in the general direction of flow of the first composite stream, the x-axis extends transversely of the first composite stream and defines a transverse dimension of the layer interface, and the z-axis extends perpendicularly away from the planar layer interface in the thickness direction of the pair of discrete overlapping layers, the fiber comprising:
a polymeric material extending longitudinally along the y-axis and having a rectangular cross-section of about 0.1 μm to about 0.4 μm along the z-axis and about 0.3 μm to about 2.4 μm along the x-axis, the cross-section of the polymeric material being the same along its entire length.

25. The fiber recited in claim 24 , wherein the polymeric material comprises one of PCL, PEO, PA6, and PET.

26. The fiber recited in claim 24 , wherein the polymeric material has a Young's Modulus from about 300 Mpa to about 3.2 Gpa.

27. The fiber recited in claim 24 , wherein the polymeric material has the same cross-section along its entire length.

Assignees

• Univ Case Western Reserve

Inventors

• Baer Eric
• Langhe Deepak
• Wang Jia

Classifications

• B32B2367/00

  Polyesters, e.g. PET, i.e. polyethylene terephthalate · CPC title

• D01F8/00

  Conjugated, i.e. bi- or multicomponent, artificial filaments or the like; Manufacture thereof · CPC title

• B29C48/307

  specially adapted for bringing together components, e.g. melts within the die · CPC title

• D10B2509/00

  Medical; Hygiene · CPC title

• D01D5/253

  with a non-circular cross section; Spinnerette packs therefor (D01D5/38 takes precedence) · CPC title