HIGH-TENACITY KERATIN FIBERS

Abstract

Disclosed herein are novel keratin fibers, including, for instance, high-tenacity keratin fibers and high-tenacity keratin composite continuous fibers, and methods for the production and use thereof. A method of producing keratin fibers includes one or more of: (1) using a keratin solution having at least about 65% keratin, which may also have one or more anti-plasticizing agents, (2) extruding a keratin solution into a solution bath, (3) drawing one or more keratin fibers through a solution bath (e.g., at a draw ratio of at least about 110%), and/or (4) drawing one or more keratin fibers through one or more heated environments. High-tenacity keratin fibers disclosed herein may have one or more of the following properties: (1) a keratin content of at least about 65%, (2) a thickness of less than about 40 m, (3) a tenacity greater than about 15 cN/tex, and (4) being biocompatible.

Claims

1. A method for producing one or more high-tenacity keratin fibers, the method comprising: extruding a keratin solution into a solution bath, the keratin solution comprising at least 65% keratin by solid weight, thereby forming one or more keratin fibers; drawing the one or more keratin fibers through the solution bath, to produce one or more drawn keratin fibers; and moving the one or more drawn keratin fibers through one or more heated environments, to produce one or more high-tenacity keratin fibers.

2. The method of claim 1, wherein the keratin solution further comprises one or more vinyl polymers and/or one or more anti-plasticizing agents.

3. The method of claim 2, wherein the one or more anti-plasticizing agents are selected from the group consisting of: iodine, lignin, glucarate, and combinations thereof.

4. The method of claim 1, wherein the keratin solution is derived from one or more alpha-keratin sources and/or one or more beta-keratin sources.

5. The method of claim 1, wherein the keratin solution comprises keratin having a molecular weight between about 5 kiloDaltons (kDa) and about 200 kDa.

6. The method of claim 1, wherein the one or more high-tenacity keratin fibers (i) have a thickness of between about 10 m and about 40 m, (ii) have a tenacity between about 15 cN/tex to about 60 cN/tex, and (iii) are biocompatible.

7. The method of claim 1, wherein the solution bath comprises one or more alcohols.

8. The method of claim 1, wherein the one or more keratin fibers form due to solvent-exchange.

9. The method of claim 1, wherein the solution bath comprises a coagulation solution.

10. The method of claim 1, wherein the keratin solution is homogenous before the extruding the keratin solution into the solution bath.

11. The method of claim 1, wherein the drawing the one or more keratin fibers through the solution bath is performed at a draw ratio of between 110% and 2000%.

12. The method of claim 11, wherein the draw ratio is between 300% and 2000%.

13. The method of claim 1, wherein, in the solution bath, the keratin solution coagulates and crosslinks within itself, to produce the one or more keratin fibers.

14. The method of claim 1, wherein the one or more heated environments have a temperature of between about 20 Celsius and about 170 Celsius.

15. The method of claim 1, wherein the keratin solution is disposed over the solution bath such that an air gap exists between the keratin solution and the solution bath.

16. The method of claim 15, wherein the extruding the keratin solution further comprises: passing the keratin solution through the air gap before the keratin solution contacts, and enters, the solution bath.

17. The method of claim 1, wherein the one or more heated environments comprise one or more sources of heated air.

18. The method of claim 1, wherein the one or more heated environments comprise an enclosed space through which the one or more drawn keratin fibers are moved.

19. The method of claim 18, wherein the enclosed space comprises heated oil.

20. The method of claim 1, wherein a pH of the solution bath is not adjusted before the drawing the one or more keratin fibers.

21. An apparatus for producing one or more high-tenacity keratin fibers, the apparatus comprising: a keratin solution container containing keratin solution and comprising an opening from which the keratin solution may be extruded; a solution bath container containing a solution bath, positioned such that the keratin solution extruded from the container enters the solution bath and forms keratin fibers; and one or more rollers for guiding and/or pulling the keratin fibers; wherein the solution bath draws the keratin fibers formed in the solution bath at a draw ratio of greater than 150%; wherein the keratin solution comprises at least 65% keratin by solid weight; and wherein the solution bath comprises one or more vinyl polymers and one or more anti-plasticizing agents.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate exemplary embodiments and, together with the description, further serve to enable a person skilled in the pertinent art to make and use these embodiments and others that will be apparent to those skilled in the art. The invention will be more particularly described in conjunction with the following drawings wherein:

[0019] FIG. 1 shows a method for producing one or more keratin fibers, according to at least one embodiment of the present invention.

[0020] FIGS. 2A-2C shows various steps of a method for producing one or more keratin fibers, according to at least one embodiment of the present invention.

DETAILED DESCRIPTION

[0021] The present invention is more fully described below with reference to the accompanying figures. The following description is exemplary in that several embodiments are described (e.g., by use of the terms preferably, for example, or in one embodiment); however, such should not be viewed as limiting or as setting forth the only embodiments of the present invention, as the invention encompasses other embodiments not specifically recited in this description, including alternatives, modifications, and equivalents within the spirit and scope of the invention. Further, the use of the terms invention, present invention, embodiment, and similar terms throughout the description are used broadly and not intended to mean that the invention requires, or is limited to, any particular aspect being described or that such description is the only manner in which the invention may be made or used. Additionally, the invention may be described in the context of specific applications; however, the invention may be used in a variety of applications not specifically described.

[0022] The embodiment(s) described, and references in the specification to one embodiment, an embodiment, an example embodiment, etc., indicate that the embodiment(s) described may include a particular feature, structure, or characteristic. Such phrases are not necessarily referring to the same embodiment. When a particular feature, structure, or characteristic is described in connection with an embodiment, persons skilled in the art may effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0023] In the several figures, like reference numerals may be used for like elements having like functions even in different drawings. The embodiments described, and their detailed construction and elements, are merely provided to assist in a comprehensive understanding of the invention. Thus, it is apparent that the present invention can be carried out in a variety of ways, and does not require any of the specific features described herein. Also, well-known functions or constructions are not described in detail since they would obscure the invention with unnecessary detail. Any signal arrows in the drawings/figures should be considered only as exemplary, and not limiting, unless otherwise specifically noted. Further, the description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.

[0024] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Purely as a non-limiting example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term and/or includes any and all combinations of one or more of the associated listed items. As used herein, at least one of A, B, and C indicates A or B or C or any combination thereof. As used herein, the singular forms a, an, and the are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be noted that, in some alternative implementations, the functions and/or acts noted may occur out of the order as represented in at least one of the several figures. Purely as a non-limiting example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality and/or acts described or depicted.

[0025] As used herein, ranges are used herein in shorthand, so as to avoid having to list and describe each and every value within the range. Any appropriate value within the range can be selected, where appropriate, as the upper value, lower value, or the terminus of the range.

[0026] About means a referenced numeric indication plus or minus 10% of that referenced numeric indication. For example, the term about 4 would include a range of 3.6 to 4.4. All numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification are to be understood as being modified in all instances by the term about. Accordingly, unless indicated to the contrary, the numerical parameters set forth herein are approximations that can vary depending upon the desired properties sought to be obtained. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of any claims, each numerical parameter should be construed in light of the number of significant digits and ordinary rounding approaches.

[0027] The words comprise, comprises, and comprising are to be interpreted inclusively rather than exclusively. Likewise, the terms include, including, and or should all be construed to be inclusive, unless such a construction is clearly prohibited from the context. The terms comprising or including are intended to include embodiments encompassed by the terms consisting essentially of and consisting of. Similarly, the term consisting essentially of is intended to include embodiments encompassed by the term consisting of. Although having distinct meanings, the terms comprising, having, containing, and consisting of may be replaced with one another throughout the description of the invention.

[0028] Conditional language, such as, among others, can, could, might, or may, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain embodiments include, while other embodiments do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, with or without user input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular embodiment.

[0029] Wherever the phrase for example, such as, including and the like are used herein, the phrase and without limitation is understood to follow unless explicitly stated otherwise.

[0030] Typically or optionally means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

[0031] Generally, the present disclosure is directed towards novel high-tenacity keratin fibers, including, for instance, composite fibers, and methods for the production and use thereof.

[0032] In at least one embodiment of the disclosure, a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers) is disclosed. The method comprises using a homogenous keratin solution to generate one or more keratin-vinyl polymer fibers. In at least one example, the keratin solution contains at least 65% keratin by solid weight, one or more vinyl polymers (e.g., polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyethylene, polyvinyl chloride, polypropylene, and the like), and optionally one or more anti-plasticizing agents (e.g., iodine, lignin, glucarate, and the like). The one or more keratin-vinyl polymer fibers that are produced contain at least 65% keratin with a high tenacity (e.g., a minimum of about 15 cN/tex, such as, for instance, between about 15 cN/tex to about 60 cN/tex, preferable between about 30 cN/tex to about 60 cN/tex) and/or a low thickness (e.g., more than about 10 m and less than about 40 m).

[0033] In at least one example, the one or more keratin-vinyl polymer fibers are processed (e.g., drawn to create thin fibers). The one or more anti-plasticizing agents may lower the gel melting temperature of the one or more vinyl polymers (e.g., to about 10 Celsius to about 30 Celsius), and/or can allow for enhanced drawability of the fibers. At least as used herein, the term drawability means the ability to reduce the fiber diameter by drawing. If a fiber has enhanced drawability, a mass of the fiber can be drawn to a greater length relative to a control (e.g., a fiber without the one or more anti-plasticizing agents). In at least one example, a fiber has enhanced drawability if there is at least a 10% increase in drawability relative to a control.

[0034] In at least one embodiment, a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers) comprises extruding keratin solution (e.g., any keratin solution disclosed herein) into a solution bath to create one or more keratin fibers. In at least one example, the fiber forms due to solvent-exchange and/or the solution bath does not require any pH adjustment. The solution bath may be a coagulation solution bath containing one or more alcohols and/or saturated salts (e.g., NaCl, KCl, CaCl.sub.2), LiCl, LiBr, etc.). Such a solution bath is therefore different than, for instance, baths containing, e.g., sodium sulfate or ammonium sulfate solution. The one or more alcohols may provide various benefits, such as, for instance, re-usability, increased ease of processability (as defined by for instance, only requiring one bath or not requiring the fiber(s) to be processed through more than one bath, including baths having different solutions), and not requiring any pH adjustment. In at least another example, the solution bath is reused and/or recycled for further rounds of production of the one or more keratin fibers (e.g., a minimum of 1 kg of liquid dope per 8 liters of coagulation bath before replacement and/or recycling).

[0035] In at least one embodiment, a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers) comprises drawing one or more keratin fibers through a solution bath (e.g., any solution bath disclosed herein) at a draw ratio of between about 110% to about 2,000%, between about 150% to about 2,000%, or between about 300% to about 2,000%. In at least one example, the draw ratio is defined as the ratio of the velocity the one or more fibers exits the solution bath to the extrusion velocity.

[0036] In at least one embodiment, the one or more keratin fibers are not subject to a secondary oxidation solution bath, reducing overall toxicity.

[0037] In at least one embodiment, the one or more keratin fibers are drawn one or more times (e.g., through heated environments (e.g., heated air, a heated roller, a heated oil bath such as, for instance, a heated oil bath or a heated silicone oil bath) having a temperature lower than about 170 Celsius, but above room temperature (e.g., about 20 Celsius). Such temperatures are lower than known methods, which use, for instance, temperatures of at least 195 Celsius. Temperatures lower than about 170 Celsius may result in various benefits, such as, for example, allowing the keratin material to maintain its structure without denaturing, improving the strength of the resulting fibers, and the like. In at least one example, the heated environments comprise one or more of: a heated tube, and a heated oil bath.

[0038] In at least one embodiment, the high-tenacity keratin fibers produced by any of the methods described herein contain at least 65% keratin. Such keratin may be derived from, for instance, alpha-keratin sources and/or beta-keratin sources (e.g., feathers, wool, hairs, horns, hooves, etc.). The keratin may also be derived from, for example, one or more waste materials. The keratin in the keratin solution (e.g., any keratin solution disclosed herein) may be of either low molecular weight or high molecular weight; that is, between about 5 kiloDaltons (kDa) and about 200 kDa.

[0039] In at least one embodiment, the keratin solution (e.g., any keratin solution disclosed herein) is extruded into a solution bath containing one or more alcohols and/or one or more other solvents, and/or saturated salts. In at least one example, the solution bath allows the keratin solution to coagulate and crosslink within itself, forming one or more fibers. In at least one example, a draw ratio of at least 300% is used to stress the one or more fibers as the fibers are forming and to induce solvent extraction from the fibers.

[0040] In at least one embodiment, the keratin solution (e.g., any keratin solution disclosed herein) used to produce the high-tenacity keratin fibers is homogenous before extrusion into the solution bath (e.g., any solution bath disclosed herein).

[0041] In at least one embodiment, a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers) utilizes wet-spinning. Wet-spinning can be much more scalable than other spinning methods (e.g., electro-spinning). For instance, electrospinning results in the direction of the fibers or nanofibers being generally uncontrolled and/or uncontrollable. By contrast, wet-spinning maintains control of the direction and/or orientation of the fibers, thereby allowing the fibers to be used more efficiently and/or effectively to produce high-tenacity fibers.

[0042] In at least one embodiment, a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers) utilizes only one solution bath. In at least one example, the single solution bath may be a coagulation solution bath containing one or more alcohols. Utilizing a single bath, instead of, for instance, multiple oxidation baths, can result in an easier manufacturing process and/or less waste.

[0043] In at least one embodiment, a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers) does not include oxidation of the fibers, thereby reducing the amount of toxic chemicals required.

[0044] In at least one embodiment, a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers) does not utilize any ionic liquids. Ionic liquids may be difficult to use at large scales, presenting difficulties for manufacturing.

[0045] In at least one embodiment, the high-tenacity keratin fibers produced by any of the methods described herein have one or more of the following properties: (1) a thickness of greater than about 10 m but less than about 40 m, (2) a tenacity greater than about 15 cN/tex (e.g., about 15 cN/tex to about 60 cN/tex, preferable about 30 cN/tex to about 60 cN/tex), and (3) are biocompatible. The term biocompatible, at least as used herein, refers to a material (e.g., one or more keratin fibers as described herein) the chemical components of which are compatible with one or more biological tissues and/or biological systems of one or more living organisms. Such compatibility is due to, for instance, being non-toxic, non-injurious, and/or not causing immunological reactions.

[0046] Turning now to FIG. 1, a method 100 is shown for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers). The method comprises, at block 102, obtaining a keratin solution comprising at least about 65% keratin by solid weight. In at least one example, the keratin solution may also comprise one or more vinyl polymers and/or one or more anti-plasticizing agents. Non-limiting examples of such anti-plasticizing agents include, for instance, iodine, lignin, glucarate, and the like. In at least one example, the keratin in the keratin solution may be derived from, for instance, alpha-keratin sources and/or beta-keratin sources (e.g., feathers, wool, hairs, horns, hooves, etc.) found in one or more waste materials.

[0047] The method further comprises, at block 104, extruding the keratin solution into a solution bath and drawing one or more high-tenacity keratin fibers through the solution bath. In at least one example, the fiber forms due to solvent-exchange. In at least one example, the solution bath is not pH adjusted and/or does not require any pH adjustment. The solution bath may be a coagulation solution bath containing one or more alcohols and/or one or more other solvents. In at least one example, the solution bath allows the keratin solution to coagulate and crosslink within itself, forming one or more fibers. In at least one example, the keratin solution is homogenous before extrusion into the solution bath. In at least one example, there is a single solution bath.

[0048] The aforementioned drawing one or more high-tenacity keratin fibers through the solution bath may occur at, for instance, a draw ratio of at least about 110% (but less than about 2,000%), at least about 150% (but less than about 2,000%), or at least about 300% (but less than about 2,000%). In at least one example, a draw ratio of at least 300%, but less than about 2,000%, is used to stress the one or more fibers as the fibers are forming and to induce solvent extraction from the fibers.

[0049] The method further comprises, at block 106, drawing the one or more high-tenacity keratin fibers through one or more heated environments having a temperature lower than about 170 Celsius.

[0050] FIGS. 2A-2C shows various steps of a method for producing high-tenacity keratin fibers (e.g., high-tenacity keratin composite continuous fibers), such as, for instance, method 100. As shown in FIG. 2A, pressure 202 is applied to a keratin solution 204, which may be any of the keratin solutions described herein, extruding it out of a container and dropping it into a bath 206 below. The fibers may generally be guided and/or pulled by one or more rollers 216 (which may be, for instance, heated rollers). The keratin solution 204 is disposed over a solution bath 206, which may be, as described above herein, a coagulation bath containing one or more alcohols and/or one or more solvents. One or more keratin fibers 208 are then drawn through the solution bath 206. In at least one example, there is an air gap 210 above the solution bath 206 (e.g., the air gap being 0 to about 10 mm) such that the keratin solution 204 passes through the air gap 210 before contacting, and entering, the solution bath 206. However, in at least another example, there is no air gap 210 and the keratin solution 204 is extruded directly into the solution bath 206. As in FIG. 2A, the fibers may generally be guided and/or pulled by one or more rollers 216 (which may be, for instance, heated rollers).

[0051] FIGS. 2B and 2C show keratin fiber 208 being drawn through heated environments 212 and 214. Such heated environments may be as described above herein. As shown in FIG. 2B, the heated environment 212 may be open or partially open, for example here the fiber is drawn above a source of hot air. As shown in FIG. 2C, the heated environment 214 may be a closed or enclosed space, e.g., here a container of heated oil through which the fiber is drawn. In at least another example, a heated roller may be used. As described above herein, when the fiber is in contact with a heated material (e.g., a heated roller, a heated oil bath, etc.), the temperature may range from about 25 Celsius to about 90 Celsius. When the fiber is in contact with air (e.g., heated air), the temperature may range from about 25 Celsius to about 170 Celsius. The length of time the fiber is in contact with the heated material (e.g., a heated roller, a heated oil bath, etc.) may be about 4-30 seconds. The length of time the fiber is in contact with air (e.g., heated air) may be about 4-120 seconds.

[0052] The one or more high-tenacity keratin fibers produced by the methods described herein have various properties, including, for instance, (1) at least about 65% keratin, (2) a thickness of less than about 40 m, (3) a tenacity greater than about 15 cN/tex, and/or (4) biocompatibility.

[0053] Thus, a skilled artisan will appreciate that embodiments of the disclosure herein have at least one or more of the following improvements over currently-available keratin fibers and methods of producing such fibers.

[0054] Known keratin fibers contain relatively low amounts of keratin (e.g., about 15% or lower), have a relatively low tenacity (e.g., about 8 cN/tex or lower), have a relatively high thickness (e.g., about 110 m or more), and/or cannot be processed or drawn.

[0055] Known methods for producing keratin fibers use solution baths that require one or more pH adjustments and contain, e.g., sodium sulfate or ammonium sulfate solution.

[0056] Known methods for producing keratin fibers can also use more than one oxidation bath, which results in higher cost and the production of large amounts of waste and/or toxic chemicals.

[0057] Known methods for producing keratin fibers use temperatures of at least 195 Celsius, which can result in denaturing, weakening the strength of the fibers, and the like.

[0058] Known methods for producing keratin fibers are difficult to scale up and/or use in the context of large-scale manufacturing due to, for instance, (1) the use of multiple oxidation baths, (2) the use of ionic liquids, and/or (3) the use of electro-spinning.

[0059] These and other objectives and features of the invention are apparent in the disclosure, which includes the above and ongoing written specification.

[0060] The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the invention with which that terminology is associated.

[0061] The invention is not limited to the particular embodiments illustrated in the drawings and described above in detail. Those skilled in the art will recognize that other arrangements could be devised. The invention encompasses every possible combination of the various features of each embodiment disclosed. One or more of the elements described herein with respect to various embodiments can be implemented in a more separated or integrated manner than explicitly described, or even removed or rendered as inoperable in certain cases, as is useful in accordance with a particular application. While the invention has been described with reference to specific illustrative embodiments, modifications and variations of the invention may be constructed without departing from the spirit and scope of the invention as set forth in the following claims.