METHOD OF MANUFACTURING A COLLAGEN YARN
20220049382 · 2022-02-17
Inventors
Cpc classification
D02G3/10
TEXTILES; PAPER
International classification
Abstract
A method of manufacturing a collagen yarn includes providing collagen fiber. The collagen fiber is spun into a yarn and tanned subsequent to the spinning of the yarn.
Claims
1. A method of manufacturing a collagen yarn, the method comprising steps of: providing collagen fiber; spinning the collagen fiber into a yarn; and tanning the yarn subsequent to the spinning of the collagen fiber into a yarn.
2. The method according to claim 1, wherein the tanning of the yarn is a re-tanning.
3. The method according to claim 1, wherein the collagen fiber is reconstructed fiber staple fibers produced based on a number of mechanically sub-divided or grinded protein fibrils.
4.-22. (canceled)
23. The method according to claim 1, wherein the tanning of the yarn is a continuous process via rolls pulling the yarn through a tanning compound.
24.-26. (canceled)
27. The method according to claim 1, wherein the collagen yarn comprises at least 40% by weight of collagen protein.
28. The method according to claim 1, wherein the collagen yarn comprises non-collagen protein.
29. The method according to claim 1, wherein the collagen yarn comprises 1 to 60% by weight of non-collagen protein.
30.-39. (canceled)
40. The method according to claim 1, wherein the manufacturing consumes less chemicals than in conventional leather tanning.
41. The method according to claim 40, wherein the manufacturing is performed with chemicals reduced by 10% by weight.
42. The method according to claim 40, wherein the manufacturing is performed with chemicals reduced by 25% by weight.
43.-46. (canceled)
47. The method according to claim 1, wherein a fineness of the yarn is within a range of about 10 Tex to 300 Tex.
48. The method according to claim 2, wherein a content of a tanning agent in the collagen fiber is increased during the re-tanning of the yarn with at least 10% by weight of the tanning agent contained in the yarn previous to the re-tanning.
49.-52. (canceled)
53. The method according to claim 1, further comprising dyeing the yarn, wherein the yarn is wound up on a plurality of yarn reels prior to dyeing.
54. The method according to claim 1, wherein the collagen fiber has a tenacity of more than 3 g/denier.
55.-57. (canceled)
58. The method according to claim 1, further comprising forming the yarn into a fabric.
59. (canceled)
60. The method according to claim 1, further comprising subjecting the yarn to tanning agents, wherein the amount of tanning agent is less than 10% by weight.
61. (canceled)
62. A leather shoe comprising: a sole; and an upper part, wherein the upper part is at least partly comprised of leather fabric, and wherein the leather fabric is produced from leather yarn made according to a method of manufacturing a collagen yarn comprising steps of: providing collagen fiber; spinning the collagen fiber into the leather yarn; and tanning the leather yarn subsequent to the spinning of the collagen fiber into the leather yarn.
63. The leather shoe according to claim 62, wherein the leather fabric is applied in the upper part of the shoe.
64. The leather shoe according to claim 62, wherein the leather fabric is applied as a shoe lining or as a part of a shoe lining.
65.-69. (canceled)
70. The method according to claim 58, wherein the leather yarn of the fabric is provided on basis of a suspension of protein fibrils.
Description
THE FIGURES
[0148] The invention will be described in the following with reference to the drawings where,
[0149]
[0150]
[0151]
[0152]
[0153]
[0154]
[0155]
DETAILED DESCRIPTION
[0156] In the description and claims, the percentage values relating to an amount of material are percentages by weight (wt. %) based on the total weight of the filament or the staple fiber in question unless otherwise indicated. The word “comprising” may be used as an open term, but it also includes the closed term “consisting of”.
[0157] As used herein, the singular forms “a”, “an” and “the” include plural referents unless the context clearly dictates otherwise.
[0158] As used herein, “at least one” is intended to mean one or more, i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc.
[0159] The term “collagen” refers to any one of the known collagen types of the at least 28 distinct collagen types, each serving different functions in animals. The major component of skin is type I collagen although other types of collagen may also be used to form leather. Collagens are proteins, i.e. they are made up of amino acids. They can be separated into alpha-amino acids and beta-amino acids. Each one features a terminal amino group and a terminal carboxyl group, which become involved in the peptide link and a sidechain attached to the methylene group in the center of the molecule. When the amino acids are linked together to form proteins, they create an axis or ‘backbone’ to the polymer, from which the sidechains extend. It is the content and distribution of the sidechains that determine most of the properties of any protein.
[0160] The term “collagen fibrils” refers to nanofibers composed of triple helices of collagen molecules (tropocollagen). The fibrils may have diameters ranging from 10-100 nanometers and are usually not found alone but rather a part of greater hierarchical structures. Each fibril may be interlocked with its neighboring fibrils to form a collagen fiber. Collagen fibrils may originate from shavings, leather pulp and/or tanned hides including the waste material from tanning process, non-finished and finished leather scraps. The collagen fibrils may originate from different sources but typically skin.
[0161] The term “collagen fiber” refers to tightly packed collagen fibrils that exhibit a high degree of alignment in the direction of the fiber and is often longer than it is wide. Variations of organization or crosslinking of fibrils and fibers may provide strength to the material. Collagen fiber may comprise staple fibers or filaments. The fiber may be a reconstructed fiber and may comprise other material than collagen.
[0162] The term “staple fiber” refers to fibers of discrete length and may be of any composition. Staple fiber may e.g. be provided by division of a collagen-based filament into discrete staple fibers of a certain length. The length may vary dependent on the application. In the present context, the length should be chosen to allow subsequent spinning of the staple fibers into a yarn. The staple fibers may be further processes to provide an item, such as a yarn or non-woven material.
[0163] The term “reconstructed” fiber refers to staple fibers produced on the basis of a number of mechanically sub-divided protein fibrils. The reconstructed fiber may be formed from a protein suspension directed through a nozzle onto a surface for drying. The suspension is dried to remove water and solvent from the suspension and thereby the reconstrued fiber is formed e.g. on a belt or a cylinder surface.
[0164] Such a manufacturing method of reconstructing fibers on the basis of protein fibrils is e.g. illustrated in WO 2018/149950 or WO 2018/149949 for the use in connection with collagen.
[0165] Other starting materials may of course be added to the collagen, there facilitating reconstructed fibers based on a mixture of fibrils derived from collagen material such as leather and fibrils derived from e.g. cellulose sources.
[0166] The term “wool” refers to a fluffy material of staple fibers or fibers or reconstructed natural based fiber. The term wool may also be used as natural fiber based wool or staple fiber wool.
[0167] The term “manufacturing process” as used herein, may be the process where fibers forms an inhomogeneous network of natural fiber based raw wool and processes through carding preparations and carding, where carding includes fiber cleaning, opening, mass reduction, mixing, homogenization and structuring that disentangles and intermixes fibers to produce a continuous web or sliver suitable for subsequent processing such as spinning.
[0168] The term “sliver” as used herein, is a long bundle of fiber or rope-like strand of fibers that is generally used to spin yarn and created by carding or combining the fibers, which is then drawn into long strips where the fibers are parallel. A sliver may be slightly twisted and considered as a loose and soft robe-like textile fiber.
[0169] Spinning is the twisting together of drawn-out strands of fibers to form yarn and can be processed with ring spinning or other systems could include air-jet, open-end and vortex spinning. Ring spinning is the most common method of spinning fibers to make a yarn by a continuous process where the roving is first attenuated by using drawing rollers, then spun and wound around a rotating spindle which in its turn is contained within an independently rotating ring flyer. The term roving refers to a long and narrow bundle of fiber and are produced during the process of making spun yarn from fibers. Their main use is as fibers prepared for spinning, but they may also be used for specialized kinds of knitting or other manufacturing processes.
[0170] Yarn is a long continuous length of interlocked fibers suitable for use in the production of fabric. Yarn may be spun from a variety of materials, including variants of collagen fiber, but the yarn may also include amounts of natural fibers and synthetic fibers within the scope of the invention. The direction in which the yarn is spun is called twist and is characterized as S-twist or Z-twist according to the direction of spinning. Tightness of twist is measured in TPI (twists per inch or turns per inch). Two or more spun yarns may be twisted together or plied to form a thicker yarn. The term plies refer to a process used to create strong balanced yarn and is done by taking two or more strands of yarn that each have a twist to them and putting them together. Filament yarn may be long continuous fibers twisted or grouped together. Multiple filament yarns may be combined into a yarn with different textures. Spun yarn may contain a single type of fiber or be a blend of various types of yarn and possible combining yarn of natural fibers with yarn of synthetic fibers.
[0171] The yarn may further be used for a manufactured fabric by weaving, a method of material production where two distinct sets of yarns are interlaced at right angles to form a fabric. The longitudinal yarns are called the warp and the lateral yarns are the weft or filling. The method in which these threads are inter-woven affects the characteristics of the fabric and the three basic weaves are plain, twill and satin but can also be special weaves such as pile, Jacquard, dobby and leno that requires special loom attachments for their construction.
[0172] The yarn may also be used for a manufactured fabric by knitting, a method that creates multiple loops of yarn called stitches in a line or tube. Knitting has multiple active stitches and knitted fabric consists of a number of consecutive rows of intermeshing of loops. Different types of yarn (fiber type, texture and twist), needle sizes, and stitch types may be used to active knitted fabrics with different properties such as texture, weight, look, heat retention, color, water resistance, integrity, conductivity and other possible properties.
[0173] The yarn may also be subjected to any other manufacturing processes including, but not excluded to, crocheting, braiding and/or knotting.
[0174] Tanning is used as the conventional ways of treating leather and may be applied to the invention. Depending on the compounds, the color and texture of the fabric may change. The technical definition of tanning is well known in the art, but briefly, according to Anthony D. Covington “Tanning Chemistry” chapter 10, the only strict definition of tanning is the conversion of a putrescible organic material into a stable material capable of resisting biochemical attack. Tanning involves a number of steps and reactions depending on the initial material and the final product.
[0175] In the case of collagen, it is the sidechains that largely define its reactivity and its ability to be modified by the stabilizing reactions of tanning when leather is made. In addition, the chemistry of the backbone, defined by the peptide links, offers different reaction sites that can be exploited in some tanning processes. During the tanning process, modification of collagen by the chemistry of the tanning agent(s) affects the different features of the properties of the material; The hydrophilic-hydrophobic balance of the leather may be markedly affected by the chemistry of the tanning agent by changing the relationship between the leather and the solvent, which in turn could affect the equilibrium of any reagent between the solvent and the substrate. Also, the site of reaction between the reagent and the collagen may affect the isoelectric point of the collagen and consequently there could be a different relationship between pH and charge on the leather. The lower the isoelectric point, the more anionic or less cationic the charge on the pelt may be at any pH value: the higher the isoelectric point, the more cationic or less anionic the charge on the pelt will be at any pH value. Further, the relative reactions at the sidechains and the backbone of the protein could possible determine the type of reaction and hence the degree of stability of the tannage: the fastness of the reagent may be influenced by the interaction between reagents and the substrate.
[0176] Hydrothermal stability as used herein could possibly be measured through the shrinkage temperature (Ts) of a hide. This is the temperature at which the energy input (heat) exceeds the energy bound in existing hydrogen bonding of the collagen structure resulting in the decomposition of the helical structure. The shrinkage temperature for untanned hides is generally around 65 degrees Celsius. The Ts may be increased through the process of tanning.
[0177] Decitex (dtex) as used herein is the unit of the linear density of a continuous filament or yarn, equal to 1/10 of a tex.
[0178] Referring to
[0179] Further embodiments are illustrated in
[0180] Returning to
[0181] Applicable collagen fiber materials applicable as a basis for the inventive yarn, fabrics and end-items thereof include yarn based on collagen fibers made on the basis of e.g. natural collagen fibers, staple fibers of such or staple fibers of reconstructed filaments or reconstructed filaments, biologically grown collagen fibers and synthesized collagen fibers.
[0182] Examples of applicable natural collagen fibers may e.g. be provided according to the loosening method described in EP 1 736 577B or alternatively be manufactured as fibers according to e.g. WO 2018/149950, WO 2018/149949 or U.S. Pat. No. 3,556,969, or WO 2017/142896 or 2007/225631 A1. According to the latter, the collagen fiber should be loosened from the provided non-woven-structure.
[0183] The collagen fiber in the present context is generally understood as a fiber comprising collagen protein in an amount of at least 20% by weight of the fiber, such as at least 40% by weight of the fiber, such as at least 60% by weight of the fiber, such as at least 80% by weight of the fiber.
[0184] The collagen fiber in the present context has several benefits for use in the present invention, e.g. by providing stretch to a final fabric made according to the provisions of the invention.
[0185] Yarn is here understood as a kind of minimum structure of bundled collagen fibers extending in the direction of length. The extension of the bundled structure can in principle be infinite, although this is of course not a real-world application.
[0186] In the present embodiment of
[0187] The spinning process is the twisting together of drawn-out strands or slivers of fibers to form yarn and can be processed with ring spinning or other systems could include air-jet, open-end and vortex spinning. Ring spinning is the method of spinning fibers to make a yarn by a continuous process where the roving is first attenuated by using drawing rollers, then spun and wound around a rotating spindle which in its turn is contained within an independently rotating ring flyer. The direction in which the yarn may be as S-twist or Z-twist according to the direction of spinning and spun yarn may contain a single type of fiber or be a blend of various types of yarn and possible combining yarn of natural fibers with yarn of synthetic fibers.
[0188] The tanning (TE) equipment in the present context is provided to perform at least a chemical modification of the collagen protein of the yarn (Y). The tanning process as such is well-known to the skilled person and may be performed in numerous ways as long as a wet-tanning process step is involved and where a chemical reaction is obtained between a tanning agent and the collagen protein of the yarn.
[0189] The illustrated tanning step may in principle cover a tanning process design and executed on a yarn, where the collagen proteins of the cord has not previously been tanned. It is a however preferred to regard the tanning step as a re-tanning step in the sense that the collagen fiber subjected to the tanning step has previously be subjected to some kind of tanning agent.
[0190] It is however noted that the preferred tanning operation is best described as a so-called post-tanning, involving at least one wet processing step involving a single chemical process or a combination of chemical processes.
[0191] Post-processing may be any processes of the yarn comprising but not limited to the process of making fabric including knitting, weaving etc. and further processes such dyeing, impregnating, functionalizing and stabilizing the product.
[0192] It should be noted that the illustrated embodiment of
[0193] Yarn is here understood as a kind of minimum structure of bundled collagen fibers extending in the direction of length. The extension of the bundled structure can in principle be infinite, although this is of course not a real-world application.
[0194] Referring to
[0195] Spun yarn may contain a single type of fiber or be a blend of various types of yarn and possible combining yarn of natural fibers with yarn of synthetic fibers.
[0196] In the present embodiment of
[0197] After the cord (CO) has been provided, the cord is processed with tanning equipment (TE) in a tanning step.
[0198] The tanning (TE) equipment in the present context is provided to perform at least a chemical modification of the collagen protein of the cord (CO). The tanning process as such is well-known to the skilled person and may be performed in numerous ways as long as a wet-tanning process step is involved and where a chemical reaction is obtained between a tanning agent and the collagen protein of the yarn/cord.
[0199] The illustrated tanning step may in principle cover a tanning process design and executed on a cord/yarn, where the collagen proteins of the yarn/cord has not previously been tanned. It is a however preferred to regard the tanning step as a re-tanning step in the sense that the collagen fiber subjected to the tanning step has previously be subjected to some kind of tanning agent.
[0200] It is however noted that the preferred tanning operation is best described as a so-called post-tanning, e.g. involving at least one wet processing step involving a single chemical process or a combination of chemical processes.
[0201] Post-processing may be any processes of the yarn or cord (CO) comprising but not limited to the process of making fabric including knitting, weaving etc. and further processes such dyeing, impregnating, functionalizing and stabilizing the product.
[0202] It should be noted that the illustrated embodiment of
[0203] In other words, the inventive post-tanning may be performed on e.g. a yarn or a further processed yarn, such as a cord, or e.g. on a fabric.
[0204] Finally, the yarn or cord may typically be post-processed into a fabric (F) and referring to
[0205] The fabric (F) within the scope of the invention may comprise different fibers and/or yarns such as but limited to wool, cellulose, polyester, silver, elastic etc.
[0206] The fabric may be tanned subsequently to the ended process of making the fabric or it may not be subjected to a further tanning process if the yarn has been post-tanned before the manufacture of the fabric, but after manufacture of the yarn
[0207] It should be noted that the illustrated embodiment of
[0208] It should also generally be noted that the term post-tanning when applied, may be referring to a conventional understanding of post-tanning, including a re-tanning, i.e. a tanning process within the understanding of conventional re-tanning in terms of the applied chemical products, process temperatures, process pH values, etc. In other words, the inventive tanning process would thus typically within the scope of the invention involve at least a conventional re-tanning applied to the yarn or fabric in question if the collagen fiber has been somewhat chemically modified in an earlier tanning process. It should here be noted that “conventional” in no way indicates that re-tanning has previously be applied to yarn according to the provisions of the invention. It merely means that the skilled person may find relevant guidance in conventional re-tanning processes when designing the inventive tanning process.
[0209]
[0210] According to the illustrated process flow collagen fibers (CF) are spun into a yarn (Y) by a yarn spinning process (YSP). After this, the yarn (Y) may either be tanned, typically in a re-tanning/tanning process (TP) into a tanned yarn (TY).
[0211] Alternatively, the produced yarn (Y) may instead by processed into a fabric (F) based on the collagen yarn (Y) in a fabric manufacturing process (FMP) subsequently be processed in a tanning process (TP) into a tanned fabric (TF).
[0212] Technically, it would also be possible to do tanning after both the provision if the yarn (Y) and then add a further tanning step (not shown) when the already tanned yarn (TY) has been processing into a fabric in a fabric manufacturing process (not shown). This may be possible, but not necessarily desirable, as one tanning step should typically enough.
[0213] The spinning process (YSP) is the twisting together of drawn-out strands or slivers of fibers to form yarn and can be processed with ring spinning or other systems could include air-jet, open-end and vortex spinning. Ring spinning is the method of spinning fibers to make a yarn by a continuous process where the roving is first attenuated by using drawing rollers, then spun and wound around a rotating spindle which in its turn is contained within an independently rotating ring flyer. The direction in which the yarn may be as S-twist or Z-twist according to the direction of spinning and spun yarn may contain a single type of fiber or be a blend of various types of yarn and possible combining yarn of natural fibers with yarn of synthetic fibers.
[0214] The illustrated tanning step may in principle cover a tanning process design and executed on a cord/yarn, where the collagen proteins of the yarn/cord has not previously been tanned. It is a however preferred to regard the tanning step as a re-tanning step if the collagen fiber subjected to the tanning step has previously be subjected to some kind of tanning agent.
[0215] It is however noted that the preferred tanning operation is best described as a so-called post-tanning, e.g. involving at least one wet processing step involving a single chemical process or a combination of chemical processes.
[0216] It should be noted that the illustrated embodiments of
[0217]
[0218] The upper part (UP) may be formed completely in fabric made according to the provisions of the invention. The upper part (UP), may also include a shoe lining (SL).
[0219] The shoe lining (SL) is the material inside the shoe that in some applications comes in contact with the entire foot: the sides, top and heels, or at least some of these parts of the foot. A purpose of the lining is to cover the inside seams of the shoe and lengthen the shoe's lifespan. Shoe lining (SL) made according to the present invention may cushion and comfort the foot or draw out moisture.
[0220] Thus, the leather fabric lining feels soft on the skin and will conform to the shape of the foot over time. It's also durable and allows air flow, letting moisture evaporate. Although leather is the highest quality material for lining, certain shoes, particularly athletic shoes, don't use leather lining because the leather adds extra weight. The present invention facilitates such use as the leather fabric may provide all or many of the advantages of conventional leather but also be present in a light weight, thereby increasing to application to e.g. athletic shoes, but also by realizing that the incorporated dye may be matched very well to fabric e.g. in terms of amount contrary to conventional leather where such a process is extremely time consuming and difficult to control in terms of desired end-color.
[0221] Overall it is noted that the leather fabric provided according to the present in invention is very breathable and that a shoe provided according to the present invention may not only be relatively color-durable but also be used both as out and optional inner layer of a shoe thereby providing a shoe having an upper part which very breathable compared to conventional shoe fabric.
[0222] The upper part (UP) may be formed wholly or partly of single layered inventive leather fabric, it may be multilayered including a layer of inventive leather fabric and further optionally comprise a lining (SL).
[0223] The single layer of inventive leather fabric may e.g. form part of a vamp, quarter or a tongue of the upper part (UP).
[0224] The inventive leather fabric may be oriented towards the outside of the shoe and/or the inside.
[0225] If multilayered, the multilayer structure of the upper part may comprise one or more layers of the inventive leather fabric and at least one layer, e.g. a reinforcing layer, comprised of another material.
[0226] The multilayered fabric may be laminated together.
[0227] If laminated, the multilayered fabric of the upper part (UP) may comprise adhesive bonding a reinforcing fabric to the inventive leather fabric.
[0228] The reinforcing fabric may provide strength to the laminate, allowing the leather layer to be thin and the overall laminate to be flexible. The reinforcing fabric is therefore relatively thin and has high tensile strength, high tear strength and low elongation at break.
[0229] Suitably, the basis weight for the reinforcing fabric is below 150 g/m.sup.2, typically below 100 g/m.sup.2, more typically below 75 g/m.sup.2, and most typically below 60 g/m.sup.2.
[0230] A suitable method for measuring the basis weight of the reinforcing fabric is ASTM D3776.
[0231] Suitably, the ultimate tensile strength (breaking strength) of the reinforcing fabric is above 5 kN/m, more typically above 10 kN/m, or even above 15 kN/m.
[0232] The ultimate tensile strength expressed in kN/m is the pulling force required to break a 1 m wide sample of the material. A suitable test for measuring the ultimate tensile strength of the reinforcing fabric is ISO 3376:2011. An alternative test specifically adapted for testing tensile properties of polymer matrix composites which could be used is ASTM D3039.
[0233] Suitably, the elongation at break of the reinforcing material (i.e. the elongation of the fabric when stretched to its breaking point) is less than 5%, typically less than 4%, or even less than 3%.
[0234] A suitable test for measuring the elongation at break is ISO3376:2011. An alternative test specifically adapted for testing the elongation properties of polymer matrix composites which could be used is ASTM D3039.
[0235] Suitably, the tear strength of the reinforcing material is above 25 N, typically above 50 N, or even above 75 N.
[0236] A suitable method for measuring the tear strength of the reinforcing material is ISO 3377-1:2011. An alternative test specifically adapted for testing the tear strength of polymer matrix composites which could be used is Mil-C-21189 10.2.4.
[0237] It will be clear from the above characteristics that the reinforcing fabric is very low basis weight (and hence typically very thin) yet typically has very high tensile strength and tear strength. Suitable materials that fulfil these requirements include fabrics which include at least one layer comprising high strength fibres.
[0238] By “high strength fibre” is meant a fibre having an ultimate tensile strength of above 1500 MPa. A suitable test for measuring the ultimate tensile strength of the fibre is ASTM D3822.
[0239] Typical high strength fibres include carbon fibres or high tensile strength polymeric fibres, with suitable high tensile strength polymeric fibres including polyethylene (particularly UHMWPE), polyaramid, polybenzoxazole, and polyaromatic esters.
[0240] Suitable high strength fibres that can be used in the reinforcing fabric therefore include carbon fibre, UHMWPE fibres such as Dyneema® available from DSM or Spectra® available from Honeywell; polyaramid fibres such as Kevlar® available from DuPont; polybenzoxazole fibres such as Zylon® available from Toyobo; and polyaromatic esters such as Vectran® available from Kuararay, Inc.
[0241] In this context, UHMWPE is “ultra-high molecular weight polyethylene”, which is sometimes also referred to as high-modulus polyethylene (HMPE) or high-performance polyethylene (HPPE). UHMWPE is typically characterized by having an intrinsic velocity of at least 4 dl/g, desirably at least 8 dl/g. Generally, the intrinsic viscosity is less than 50 dl/g, typically less than 40 dl/g.
[0242] A suitable methodology for measuring intrinsic viscosity is ASTM D1601-2004 (at 135° C. in decalin, dissolution time 16 hours, with DBPC as an anti-oxidant in an amount of 2 g/l solution, by extrapolating the viscosity as measured at different concentrations to zero concentration).
[0243] The at least one layer in the reinforcing fabric comprising the high strength fibres may be woven or nonwoven. However, in order to benefit from the strength properties of the fibres, typically the at least one layer will contain the high strength fibres in an oriented fashion, such as woven (including uniweave), monodirectional or multidirectional fabrics.
[0244] Typically, the reinforcing fabric will comprise at least one layer having parallel high strength fibres. Said parallel high strength fibres may optionally be embedded in a resin matrix.
[0245] The multilayered fabric including the inventive leather fabric may e.g. form part of a vamp, quarter or a tongue of the upper part (UP).
[0246] The inventive leather fabric may be oriented towards the outside of the shoe and/or the inside.
[0247]
[0248]
[0249] With reference to the drawing, a collagen fiber (CF) is initially subjected to an acidification (ACI) as mentioned above. The collagen fiber (CF) is then subjected to a tanning process/re-tanning (TP) and subsequently subjected to a basification (BAS). The collagen fiber is then subject to a dyeing step (D) resulting in a dyed collagen fiber which is then spun into a yarn (Y) by a yarn spinning process (YSP). The dyed collagen based yarn may then subsequently be processed into a fabric (F).
[0250] The present embodiment the illustrates that collagen fibers may be subjected to a tanning process (TP), wherein the collagen fibers are first subjected to acidification and application of tanning agents. This could be a re-tanning and even a first tanning is possible. After application of tanning agents, the collagen fibers are subjected to basification and then to dye, wherein the details related to dyeing are described elsewhere in the description. The dyed fibers are subjected to yarn spinning and possibly manufacturing into fabric. Other processes may be applied in the process, such as i.e. fatliquoring and optional further tanning is possible.
[0251] Different variants of the process will be described below. It is however noted that the principle difference in terms of process, not necessarily in terms of the obtained end-product, are referring to the same process steps, just organized in different logic sequences. Only the differences will be highlighted below.
[0252]
[0253]
[0254]
[0255] The latter embodiment is generally considered a very advantageous embodiment of the invention as the semi-finalized yarn may be manufactured in a durable and distributable state, e.g. in a standard color which is relatively neutral or just a color being a natural result of the tanning agents applied. The standard colored dyed yarn, which is now considered a leather yarn, may then be dyed subsequently, e.g. after manufacturing of the fabric (F). The basic point is that such process has never been attractive in relation to conventional leather not produced by leather yarn, as dyeing is a very complex and demanding step which should typically be performed at the tannery or at least at some kind to the manufacturer, e.g. a shoe manufacturer, requiring the leather in a certain color. This means at the very least that a lot of dyestuff are applied to hides or parts of hides and thereby restricting the use of the applied hide/leather.
[0256] The present invention basically facilitates in some embodiments that all yarn may of course be produced in a certain color or produced in one or few color appearances which may subsequently be subject to dyeing into the desired end-color. In other words. The applied dye is applied and fixed for the intended purpose at a very late stage of the process, thereby reducing risks of waste or the manufacturing for storage of leather materials which may be irrelevant at the time they are to be used.
[0257]
[0258] With reference to the drawing, a collagen-based yarn (Y) subjected to a tanning process T. This tanning process may e.g. include or be associated with a dye normalization step e.g. a pre-dyeing (PD)
[0259] After the tanning and optional color normalization process, the yarn is wound on reels (SP), or similar suitable constructions for keeping yarn.
[0260] Thereafter the yarn reels SP may be picked for subsequent dying into the desired end colors e.g. red (RE), blue (BL) or yellow (YE).
[0261] The step of pre-dyeing or normalizing the color of the yarn is an optional step, however, a highly advantageous step wherein the color of the yarn achieves the same neutral base color and thereby optimizing the dyeing (D) process and promotes predictability in relation to the final dyeing process. This is a new a very interesting aspect of the invention as collagen-based products to be dyed, e.g. leather requires complex dyeing, and the results are typically obtained by trial and error, while the present embodiment of the invention makes it possible to perform a much more predictable dyeing, independent of the eventual color of the yarn.
[0262] Normalization of the color of the yarn in the present context is generally understood as a process to obtain yarn with the same neutral base color. That may be a discoloring, pre-dying, bleach or other relevant process to obtain a similar neutral base color. In other words, the pre-dyeing may not necessarily include the process of adding dye as bleaching or other chemical processing may be enough to provide the desired neutral base color.
[0263] According to an advantageous embodiment of the invention, a so-called neutral base-color may include a color which is able to be dyed into different relevant colors, such as black, white, yellow, red and blue, with basically the same dyeing process, just with colors of dye.
[0264] The collagen-based yarn may origin from several sources, e.g. hide such as e.g. bovine, other animals, leather waste or other sources of collagen and the basis color might be different. Different treatments or processes of the hide, waste products etc. may change the color of the products and thereby also the initial color of the collagen-based yarn. Further, the hide may have been treated with tanning agents e.g. chrome tanning, that may provide a blue or grey color of the yarn. Hide treated with vegetable tanning agents may have a more white or yellow appearance. Applying the same amount of dye to yarns with different base colors may become irregular and aesthetic difficult to handle in the final products without applying extra dyeing, dependent on which color the final yarn is intended to have.
[0265] It should thus be noted that the present, although very advantageous, providing of a neutral base is extremely attractive both for the purpose of avoiding final leather/collagen-based yarn manufactured in an undesired color. Such a problem is often associated to conventional leather manufacturing. It, on the other hand, also makes it possible to re-user such waste products for the purpose of re-constructing collagen-based fibers, staple fibers, collagen-based yarn even if the waste product starting material has been dyed already or at least partially present in e.g. a bluish color due to an already performed chrome-tanning. In other words, the collagen material applied as the basis for the manufacture of staple fibers/filament/yarn in the present invention, may due to different origin, be inherit very diverse. The term “spool” in this context means a physical object suitable for rolling up yarn for storage or further processes. It may also be a cone, reel or any other suitable object for rolling up yarn. The processing of rolling/winding up the yarn may also simply be performed as to provide a ball of yarn with no physical object onto which the yarn has be wound.
[0266] It is noted that the tanning process performed prior to the providing of the yarn on the reels facilitate both subsequent dyeing into a desired end color/use-color but also makes it possible to apply a general yarn material featuring leather properties, which may be utilized and benefitted from in a subsequently produced fabric.
[0267] Another advantageous aspect is that the yarn, when reeled up, already is possessing the desired tenacity, strength or elasticity properties required of the produced yarn. In other words, the manufacture of the yarn into a fabric may benefit of the fact that the tanning has already been performed and that the yarn is therefore less susceptible to breakage or that the yarn is at least easier to handle without risking breaking or weakening the yarn during manufacture of the fabric.
FIGURE REFERENCES
[0268] CF. Collagen fiber [0269] Y. Yarn [0270] TY. Tanned yarn [0271] CO. Cord [0272] TE. Tanning equipment [0273] YSP. Yarn spinning process [0274] S. Shoe [0275] UP. Upper part [0276] SO. Sole [0277] SL. Shoe lining [0278] F. Fabric [0279] TP. Tanning process [0280] TF. Tanned fabric [0281] FMP. Fabric manufacturing process.