METHOD FOR PRODUCING FIBERS AND NON-WOVEN FABRICS BY SOLUTION BLOW SPINNING AND NON-WOVEN FABRIC PRODUCED THEREBY

Abstract

The invention refers to the use of a parent solution (A) during a method for producing fibers for a fiber fleece by a so-called solution blow spinning. Water is used as solvent for the parent solution (A). At least one water-soluble polymer and preferably exactly one water-soluble polymer is dissolved in the water of the parent solution (A). The parent solution (A) additionally contains at least one surfactant and optionally plasticizer for the used at least one polymer respectively. By means of a parent solution (A) it is possible to produce fibers (24) by solution blow spinning.

Claims

1. A method for producing fibers and fleece materials (24) by solution blow spinning using a parent solution (A), the method comprising: formulating the parent solution (A) using water as a solvent, dissolving at least one water-soluble polymer in the parent solution (A), adding at least one surfactant to the parent solution (A); and producing at least one of a fiber and a fleece material by solution blow spinning using the parent solution (A).

2. The method according to claim 1, wherein formulating the parent solution (A) includes using water exclusively as the solvent.

3. The method according to claim 1, wherein the at least one water-soluble polymer in the parent solution (A) contains exclusively polymers that are water-soluble.

4. The method according to claim 1, wherein the at least one water-soluble polymer is one or any combination of polyvinyl alcohol, polyvinyl methyl ether, polyethylene oxide, polyvinyl pyrrolidone, polyethylene glycol, polyacrylic acid, and polyacrylamide.

5. The method according to claim 1, wherein the concentration of the water in the parent solution (A) has an amount of 30 wt-% to 99 wt-%.

6. The method according to claim 5, wherein the concentration of the water in the parent solution (A) has an amount of 50 wt-% to 95 wt-%.

7. The method according to claim 6, wherein the concentration of water in the parent solution (A) has an amount of 60 wt-% to 90 wt-%.

8. The method according to claim 1, wherein the concentration of the at least one water-soluble polymer in the parent solution (A) has an amount of 1 wt-% to 70 wt-%.

9. The method according to claim 8, wherein the concentration of the at least one water-soluble polymer in the parent solution (A) has an amount of 5 wt-% to 50 wt-%.

10. The method according to claim 8, wherein the concentration of the at least one water-soluble polymer in the parent solution (A) has an amount of 10 wt-% to 40 wt-%.

11. The method according to claim 1, wherein the concentration of the at least one surfactant in the parent solution (A) has an amount of 0.001 wt-% to 50 wt-%.

12. The method according to claim 11, wherein the concentration of the at least one surfactant in the parent solution (A) has an amount of 0.01 wt-% to 5 wt-%.

13. The method according to claim 12, wherein the concentration of the at least one surfactant in the parent solution (A) has an amount of 0.1 wt-% to 1.5 wt-%.

14. The method according to claim 1, wherein the at least one surfactant has a characteristic to at least partly evaporate during the solution blow spinning.

15. The method according to claim 1, wherein the parent solution comprises solid particles.

16. The method according to claim 1, further comprising: emitting the parent solution (A) from at least one first output nozzle (20), emitting a process gas (G) from at least one second output nozzle (21) that is arranged adjacent to the at least one first output nozzle (20) while concurrently with the emitting the parent solution (A) from the at least one first output nozzle.

17. The method according to claim 16, further comprising producing one or any combination of microfibers, sub-microfibers, nanofibers, and fleece materials formed thereof.

18. The method according to claim 16, further comprising supplying the process gas (G) to the at least one second output nozzle (21) at a pressure of 0.1 to 100 psi.

19. The method according to claim 18, further comprising supplying the process gas (G) to the at least one second output nozzle (21) a pressure of 5 to 80 psi.

20. The method according to claim 19, further comprising supplying the process gas (G) to the at least one second output nozzle (21) a pressure of 10 to 60 psi.

21. The method according to claim 16, further comprising supplying the process gas (G) to the at least one second output nozzle (21), wherein the process gas (G) has a temperature of 0 C. to 100 C.

22. The method according to claim 21, wherein the process gas (G) has a temperature of 10 C. to 90 C.

23. The method according to claim 21, wherein the process gas (G) has a temperature of 20 C. to 80 C.

24. The method according to claim 16, wherein the solvent in the parent solution (A) evaporates at least partly after the parent solution is emitted from the at least one first output nozzle (20).

25. (canceled)

Description

[0050] Preferred embodiments of the invention result from the dependent claims, the description and the drawings. In the following preferred embodiments of the invention are explained in detail with reference to the attached drawings. The drawings show:

[0051] FIG. 1 a schematic diagram-like illustration of a device for producing fibers by solution blow spinning,

[0052] FIGS. 2 and 3 a schematic principle illustration of different output nozzle arrangements respectively, each having a first output nozzle and at least one assigned second output nozzle in a top view on the output nozzles,

[0053] FIGS. 4 and 5 a schematic principle illustration of different linear output nozzle arrangements of a plurality of first and second output nozzles in a top view onto the output nozzles,

[0054] FIGS. 6 and 7 a schematic cross-section view of an embodiment of an output nozzle arrangement, each having at least one first output nozzle and at least one assigned second output nozzle respectively and

[0055] FIG. 8 a highly schematic illustration of an embodiment of a produced fiber.

[0056] FIG. 1 shows a device 10 for the execution of a solution blow spinning method. The device 10 has a reservoir 11 for providing a parent solution A. A parent solution A is conveyed by a pump device 12 to a solution fluid connection 13 of a spin nozzle device 14.

[0057] Additionally, the spin nozzle device 14 comprises a process gas connection 15 by means of which a pressurized process gas G is supplied to the spin nozzle device 14. The process gas G can be formed by air or pressurized air for example. It can be extracted from a pressure reservoir 16. Alternatively, instead of the pressure reservoir 16 a compressor or the like can be present in order to draw air from the environment and to provide pressurized air as process gas G. The process gas G can also be a different gas, like nitrogen, helium or hydrogen.

[0058] The spin nozzle device 14 has at least one first output nozzle 20. At least one second output nozzle 21 is assigned to each first output nozzle 20. If a plurality of first output nozzles 20 is present, they can have exit or emission directions that are orientated differently, as schematically illustrated in FIG. 1.

[0059] The at least one first output nozzle 20 is fluidically connected with the solution fluid connection 13. The at least one second output nozzle 21 is fluidically connected with the process gas connection 15. Thus, the parent solution A exits through the at least one first output nozzle 20 and the process gas G exits through the at least one second output nozzle 21.

[0060] The process gas G exiting concurrently with the parent solution A carries the parent solution A and conveys it from the spin nozzle device 14 away in direction toward a collector 22. Due to the high velocity of the process gas G, one or more liquid jets 23 of the parent solution A are formed above the mouth of the respective first output nozzle 20. During the further path toward the collector 22, a solvent contained in the parent solution A and where applicable additional liquid components of the parent solution A evaporate, such that solid fibers 24 are formed that are collected at the collector 22.

[0061] The collector 22 can have moveable parts, e.g. a moving conveyor that is moved via drive rolls 25. In a modification compared with the illustrated embodiment, the collector 22 can also be formed immovably, statically.

[0062] The collector 22 is preferably gas permeable and can be formed, for example, by a grid or mesh-shaped carrier like a fine-meshed net. At the side opposite the spin nozzle device 14 of the collector 22 a suction device 26 can be present. The suction device 26 can be configured to move the fibers 24 forming between the spin nozzle device 14 and the collector 22 toward the collector 22 by drawing of an air stream.

[0063] The nozzle collector distance z between the at least one first output nozzle 20 and the collector 22 and/or between the at least one second output nozzle 21 and the collector 22 has an amount of 20 cm or 25 cm. In the illustrated embodiment the nozzle collector distance z can have an amount of about 30 to 70 cm. Preferably the nozzle collector distance z is smaller than 200 cm and further preferably smaller than 100 cm.

[0064] In FIGS. 2 to 7 different embodiments of an output nozzle arrangement 30 of the spin nozzle device 14 are schematically illustrated as an example respectively. The spin nozzle device 14 can comprise one or more of the illustrated output nozzle arrangements 30. These can be arranged or orientated parallel or inclined with each other at the spin nozzle device 14. Each output nozzle arrangement 30 comprises at least one and, for example, exactly one first output nozzle 20 for the parent solution A and at least one assigned second output nozzle 21 for the process gas G.

[0065] In the embodiment illustrated in FIG. 2 the nozzle arrangement 30 contains exactly one first output nozzle 20 and exactly one assigned second output nozzle 21. The first output nozzle 20 is arranged in the center of a completely ring-shaped second output nozzle 21 that surrounds the first output nozzle 20 coaxially completely in the embodiment.

[0066] In the embodiment shown in FIG. 3 the output nozzle group 30 comprises exactly one first output nozzle 20 and a plurality of assigned second output nozzles 21 arranged adjacent thereto, e.g. four second output nozzles 21. The number of the second output nozzles 21 can vary, wherein at least two second output nozzles 21 are present. The second output nozzles 21 are preferably uniformly distributed in the peripheral direction around the first output nozzle 20. The second output nozzles can also have a curved slit form and partly surround the first output nozzle 20 in its peripheral direction.

[0067] In general a cross-section form of the output nozzles 20, 21 can be selected arbitrarily. According to the embodiment, circular or circular ring-shaped cross-sections are illustrated respectively. Also other polygonal or slit-like straight or curved cross-section contours can be provided, particularly for the at least one second output nozzle 21 of each output nozzle group 30.

[0068] FIGS. 4 and 5 show only by way of example that the output nozzles 20, 21 can be arranged in one or more rows side-by-side in a linear arrangement.

[0069] FIGS. 6 and 7 illustrate that the dashed dotted illustrated center length axis of the output nozzles 20, 21 of one output nozzle group 30 can be orientated parallel with each other (FIG. 6) or alternatively can be orientated inclined with regard to each other (FIG. 7). In the embodiment that is schematically shown in FIG. 7, the exit direction for the process gas G of the at least one second output nozzle 21 is inclined compared with the exit direction of the parent solution A, according to the example, such that the process gas G is orientated obliquely to the center length axis or the exit direction of the first output nozzle 20 at several circumferential locations.

[0070] The mouth of the at least one first output nozzle 20 is arranged with distance and preferably downstream of the process gas stream from the mouth of the at least one assigned second output nozzle 21. The distance can have an amount of, e.g. 0.5 to 20 mm or 1 to 10 mm or 1 to 5 mm or 2 to 3 mm.

[0071] The orientations of the exit directions according to FIGS. 6 and 7 can be provided for the output nozzle group 30 of FIG. 2 as well as for the output nozzle group 30 of FIG. 3.

[0072] For formation of the parent solution A at least one and preferably exactly one water-soluble polymer from which the fibers 24 shall be formed, is dissolved in a solvent and according to the example in water. The parent solution additionally contains at least one surfactant. Also for the at least one polymer of the parent solution A a plasticizer can be contained in the parent solution A. The polymer can be dissolved in solid form, e.g. as powder, in form of small balls or pellets or the like in the water of the parent solution A that serves as solvent.

[0073] The concentration of the at least one water-soluble polymer in the parent solution A can have an amount of 1 wt-% to 70 wt-%, preferably 5 wt-% to 50 wt-%, further preferably 10 wt-% to 40 wt-%. If a plasticizer is used for the at least one polymer, the values of the concentration refer to the total sum of the at least one polymer including the plasticizer.

[0074] In preferred embodiments the concentration of the water and the parent solution has an amount of 30 wt-% to 99 wt-%, preferably 50 wt-% to 95 wt-% and further preferably 60 wt-% to 90 wt-%.

[0075] In the embodiment the concentration of the surfactant in the parent solution A has an amount of 0.001 wt-% to 50 wt-%, preferably 0.01% to 5 wt-% and further preferably 0.1 wt-% to 1.5 wt-%.

[0076] The process gas G can be supplied at the process gas connection 13 with a pressure of up to 1000 psi, preferably with a pressure of 5 to 80 psi. If air is used as process gas G, the pressure can be in the range of 10 to 60 psi. The process gas G has a temperature in the range of 0 C. to 100 C., preferably 10 C. to 90 C. and further preferably of 20 C. to 80 C. when supplied to the spin nozzle device 14. According to the example, the process gas temperature of the process gas G during supply to the spin nozzle device 14 is higher than the environment temperature, e.g. a room temperature, and can be in the range of 35 C. to 70 C.

[0077] The fibers 24 formed by polymer chains are obtained in the method, because the solvent, here water, and/or the at least one surfactant evaporates completely or at least partly on the way between the spin nozzle device 14 and the collector 22. That is the solvent and/or the surfactant evaporate by at least 85% or at least by 90% or at least by 95% or at least by 99%.

[0078] During the method by use of the device 10, the fibers 24 are formed. A fiber fleece of fibers 24 is created on the collector 22, wherein preferably the fiber diameter is in the micrometer range, in the sub-micrometer range or in the nanometer range. The fibers 24 consist substantially of the polymer present in the parent solution A optionally additionally of the plasticizer used for the at least one polymer.

[0079] The created fibers 24 have preferably a ratio of a length L to a mean thickness D of at least 100:1, preferably at least 500:1, further preferably at least 1000:1 and yet further preferably at least 10000:1. Preferably the fibers 24 have a length L of at least 1 mm, preferably of at least 3 mm and further preferably of at least 5 mm.

[0080] Subsequently, examples 1 to 4 are indicated that describe a possible composition of a parent solution A and features of the device 10.

EXAMPLE 1

[0081] For producing the polymer solution 10 wt-% of polyvinyl alcohol powder (with a molecular weight of 130000 u) are dissolved in distilled water (88 wt-%) and 2 wt-% of the surfactant polyoxyethylen(23)lauryl ether (known under the trade name Brij-35) are added. From the polymer solution fine fibers 24 are produced by the solution blow spinning method. The method is executed by using pressurized air as process gas G that is supplied with a pressure of 10 psi to the at least one second output nozzle 21. The at least one first output nozzle 20 has a diameter of 0.6 mm (at the exit opening). The distance between the at least one first output nozzle 20 and the collector 22 has an amount of 65 cm. The fibers produced with this method have a fiber diameter with a diameter in the range of 50 to 400 nm. The mean value of the diameter of the created fibers 24 is at 200 nm.

EXAMPLE 2

[0082] The polymer solution is produced of 12 wt-% polyvinyl alcohol (molecular weight 130000 u) that is dissolved in distilled water that is present in the parent solution A with 87 wt-%. The parent solution A comprises 1 wt-% isopropanol. The method is executed under use of pressurized air as process gas G that is supplied to the at least one second output nozzle 21 under a pressure of 20 psi. The at least one first output nozzle 20 has a diameter of 0.6 mm (at the exit opening). The distance between the at least one first output nozzle 20 and the collector 22 has an amount of 65 cm. The fibers 24 produced with this method have a fiber diameter with a range of 100 to 450 nm. The mean value of the diameter of the created fibers 24 is at 240 nm.

EXAMPLE 3

[0083] 10 wt-% polyvinyl alcohol (molecular weight 130000 u) and 2 wt-% polyvinyl methyl ether are dissolved in 87 wt-% water. The parent solution A also contains 1 wt-% isopropanol. The method is executed under use of pressurized air as process gas G that is supplied with a pressure of 20 psi to the at least one second output nozzle 21. The at least one first output nozzle 20 has a diameter of 0.8 mm (at the exit opening). The distance between the at least one first output nozzle 20 and the collector 22 has an amount of 65 cm. The fibers 24 produced with this method have a fiber diameter in the range of 100 to 500 nm. The mean value of the diameter of the created fibers 24 is at 250 nm.

EXAMPLE 4

[0084] 3 wt-% of polyethylene oxide (molecular weight 600.000 u) are dissolved in 96 wt-% of distilled water. The parent solution A also contains 2 wt-% isopropanol. The method is executed under use of pressurized air as process gas G that is supplied under a pressure of 40 psi to the at least one second output nozzle 21. The at least one first output nozzle has a diameter of 0.6 mm. The distance between the at least one first output nozzle 20 and the collector 22 has an amount of 65 cm. The fibers 24 produced with this method have a fiber diameter in the range of 100 to 500 nm. The mean value of the diameter of the created fibers 24 is at 250 nm.

[0085] The four examples above or in general the spinning method according to the invention can be further optimized by the use of additional and/or alternative surfactants. For example, each surfactant and/or polymer can be used that is contained in the tables indicated at the beginning of the description.

[0086] Further specific examples result particularly from the selection of the composition of the components of the parent solution A in the ranges, as indicated in the description.

[0087] The features of the device 10 indicated in the examples 1 to 4 can also be used for other compositions of the parent solution A respectively.

[0088] The invention refers to the use of a parent solution A during a method for producing fibers for a fiber fleece by a so-called solution blow spinning. Water is used as solvent for the parent solution A. At least one water-soluble polymer and preferably exactly one water-soluble polymer is dissolved in the water of the parent solution A. The parent solution A additionally contains at least one surfactant and optionally plasticizer for the used at least one polymer respectively. By means of a parent solution A it is possible to produce fibers 24 by solution blow spinning environmental friendly.

REFERENCE LIST

[0089] 10 device [0090] 11 reservoir [0091] 12 pump device [0092] 13 solution fluid connection [0093] 14 spin nozzle device [0094] 15 process gas connection [0095] 16 pressure reservoir [0096] 20 first output nozzle [0097] 21 second output nozzle [0098] 22 collector [0099] 23 liquid jet [0100] 24 fiber [0101] 25 drive roll [0102] 26 suction device [0103] 30 output nozzle group [0104] A parent solution [0105] D thickness of the fiber [0106] G process gas [0107] L length of the fiber [0108] z nozzle collector distance