Method for the production of a yarn, yarn comprising a filament core and a discontinuous fiber sheath and textile article

Description

1 / 28 “METHOD FOR THE PRODUCTION OF A YARN, YARN COMPRISING A FILAMENT CORE AND A STACK FIBER SHEATH AND TEXTILE ARTICLE” Field of the invention

[001] The present invention relates to the field of yarn production. In more detail, the present invention relates to a yarn using short cellulosic fibers, for example, cotton, staple fibers normally obtained from the recycling of yarns and fabrics, and to a process for the production of said yarn. State of the art

[002] Due to the costs and environmental impact of natural fiber production, methods have been developed to recycle natural fibers from textile waste in order to reuse them. A prominent example is the recycling of cotton from textile waste, in particular fabric and yarn waste, in order to obtain recycled cotton fibers.

[003] Known recycling processes for textiles and yarns generally involve the mechanical breakdown of the fabrics into loose fibers that can be used to spin new yarns. In this process, machines are used that break the fabric, for example, by means of rotating drums with metal pins. The mechanical tension on the yarn fibers causes the original fibers to break into shorter fibers.

[004] One problem with recycled cotton fibers is that their short-length fiber content makes them unsuitable or inappropriate for yarn production, particularly on ring spinning machines for the production Petition 870250089179, dated 10 / 01 / 2025, page 14 / 54 2 / 28 of denim. Virgin cotton staple fibers have a greater quantity of long fibers than recycled cotton fibers; for example, the average length L(n) (considering all the fibers in a yarn) of virgin cotton is generally greater than 20 mm, while recycled cotton staple fibers have an average length L(n) that is generally less than 15 mm, usually between 6 and 15 mm, most commonly between 9-12 mm.

[005] Therefore, it is difficult to properly use recycled (short) cotton fibers in the production of yarn by ring spinning.

[006] The short length of cotton fibers results in a yarn with very low strength, resulting in a weak fabric, or it may not even be viable in a yarn due to the combined fiber breaks that occur in yarn manufacturing machines. For this reason, recycled cotton fibers have been blended with virgin cotton fibers to give the final yarn acceptable mechanical properties and physical characteristics, such as bulk and appearance, of yarns containing 100% virgin natural fiber, for example, virgin cotton. The ratio between the amount of virgin cotton (CO) fibers and recycled cotton (RCO) fibers by weight in a yarn depends on the yarn production technique. Typically, open-end yarns can be composed of up to 100% recycled cotton, while in ring-spun yarns the RCO content does not exceed 40% (by weight) and generally the CO / RCO ratio (by weight) is in the range of 70 / 30 to 90 / 10.

[007] It has also been proposed to improve the mechanical properties of yarns containing recycled cotton fibers with Petition 870250089179, dated 10 / 01 / 2025, page 15 / 54 3 / 28 The use of polyester filaments and fibers. In one embodiment, polyester staple fibers are blended with cotton fibers before being spun into a yarn; these yarns have the disadvantage that, due to the presence of polyester, they cannot be easily dyed and have a poor appearance, i.e., an appearance that is not cotton-like. The proposed embodiments in which polyester filaments are provided as filament cores in a recycled cotton sheath have the aforementioned disadvantage of necessarily having a low content of recycled cotton fibers. Furthermore, they also failed to solve the problem, mainly because the recycled cotton fiber sheath breaks easily when stretched or tensioned.

[008] There is therefore a need to solve the problems of the prior art and provide a yarn in which all the cotton fibers are recycled fibers, the yarn is a ring-spun yarn and has a good appearance and good to excellent mechanical characteristics. Summary of the invention

[009] An object of the present invention is therefore to provide a yarn in which all cotton fibers can be recycled, of short length, cotton fibers and having good to excellent mechanical properties and the appearance and aspect of a yarn including virgin cotton fibers.

[0010] Another objective of the invention is to provide a spun yarn with a core containing short-length cotton fibers that is elastic and extensible.

[0011] These objectives are achieved through Petition 870250089179, dated 10 / 01 / 2025, page 16 / 54 4 / 28 present invention relating to a thread and a process according to the independent claims.

[0012] In particular, the present invention relates to a yarn and a relevant production method according to the appended independent claims, while the preferred aspects are cited in the dependent claims.

[0013] According to the invention, a yarn comprises a filament core and a staple fiber sheath, the staple fiber sheath being made entirely of, or comprising at least 95% by weight of, a blend of first staple fibers and second staple fibers, characterized in that the first staple fibers are natural cellulosic fibers and the second staple fibers are regenerated cellulosic fibers. The average length of the sheath fibers is in the range of 10 to 34 mm, preferably from 12 mm to 29 mm; the 5%(n) index of the sheath fibers is between 25 mm and 40 mm, more preferably in the range between 28 and 36 mm, even more preferably between 30 and 34 mm; the short fiber content SFC(n) of the sheath is between 2% and 70%, preferably between 10% and 60%; and the filament core comprises a plurality of polyester filaments.The elongation at break of the polyester filaments in the filament core, measured according to DIN ISO 2062, is in the range of 5% to 15%, more preferably between 10% and 12%.

[0014] The weight ratio of the first discontinuous fibers to the second discontinuous fibers is in the range of 20 / 80 to 80 / 20, preferably in the range of 20 / 80 to 70 / 30 (excluding) Petition 870250089179, dated 10 / 01 / 2025, page 17 / 54 5 / 28

[0015] The average length is the value L(n) measured according to the DIN 53805:1980-06 standard.

[0016] Testing machines that can measure the above-mentioned indices, namely L(n), 5%(n), SFC(n), such as USTER AFIS PRO 2 or Textechno FCS-Fibrotest, are known in the art.

[0017] The average fiber length in the numerical sense Ln can be calculated using the following formula: . _ ΣηίΐίLn“ Σ». where: Ln is the average fiber length in numerical terms, η± is the number of fibers with length li, and li is the length of fiber i.

[0018] In the sheath, the 5% (n) index (as before, measured with DIN 53805:1980-06) of the fibers is at least 25 mm, preferably between 25 mm and 40 mm, more preferably between 28 and 38 mm, and characterized in that the short fiber content SFC(n) (measured with DIN 53805:1980-06) of the sheath is between 30% and 70%, characterized in that the preferred values ​​are greater than 35%, more preferably above 40%, i.e., between 40 and 70%.

[0019] The claimed elongation at break is the elongation of all core filaments, tested together.

[0020] In particular, it has been found that if the core elongation is low (i.e., less than 15%, as discussed above), yarn production and weaving processes are facilitated. In particular, in these Petition 870250089179, dated 10 / 01 / 2025, page 18 / 54 6 / 28 realizations, the elongation of the core is generally similar to the elongation of cotton fibers.

[0021] In fact, if the end yarn is tensioned, a high-elongation polyester core (i.e., more than 15% or more than 20%) can cause the core sheath to slip and / or can cause a break in the discontinuous fiber sheath.

[0022] The use of low-stretch polyester filament(s) in the core helps to avoid the problems mentioned above.

[0023] Low-stretch polyester filaments are known in the art and are commercially available. They can be obtained in different ways. One possible solution may be to provide a draft during a texturing step of POY polyester filaments. This draft is preferably between 1.7 and 2.5, more preferably between 1.8 and 2.1.

[0024] Polyester filaments are in fact preferably textured and, as mentioned, drafting can be applied during the texturing process, usually also heating the filaments during the drafting stage in the texturing process.

[0025] According to one aspect, the amount of polyester filaments in the core is between 10% and 35% of the yarn weight, more preferably between 15% and 25%, even more preferably around 20%. The percentage above refers to the total count of polyester filaments, i.e., the total sum of the filament count.

[0026] According to one aspect, the total count of polyester filaments is between 50 and 150 den, more Petition 870250089179, dated 10 / 01 / 2025, page 19 / 54 7 / 28 preferably between 60 and 120 den, even more preferably between 75 and 100 den.

[0027] The use of low-stretch polyester is beneficial as it promotes the mechanical properties of the final yarn, while also preventing problems such as core slippage during yarn production. This applies particularly to realizations with high percentages of cotton. However, it has been found that low-stretch polyester helps prevent core slippage even in realizations with lower percentages of cotton.

[0028] One aspect of the invention also relates to a yarn comprising a filament core and a staple fiber sheath, the staple fiber sheath being, or comprising at least 95% by weight of, a blend of first staple fibers and second staple fibers, characterized in that the first staple fibers are natural cellulosic fibers and the second staple fibers are regenerated cellulosic fibers.The weight ratio of the first discontinuous fibers to the second discontinuous fibers is in the range of 20 / 80 (inclusive) to 80 / 20 (inclusive), preferably 20 / 80 (inclusive) to 70 / 30 (exclusive); the average length of the sheath fibers is in the range of 13 to 34 mm, preferably 15 mm to 29 mm; the 5%(n) index of the sheath fibers is between 25 mm and 40 mm, more preferably in the range between 28 and 36 mm, even more preferably between 30 and 34 mm; the short fiber content SFC(n) of the sheath is between 2% and 61%, preferably between 10% and 51%; and the filament core comprises a plurality of polyester filaments. Petition 870250089179, dated 10 / 01 / 2025, page 20 / 54 8 / 28 elongation at break of the polyester filament core, measured in accordance with DIN ISO 2062, is less than the range of 5% to 15%, more preferably between 10% and 12%.

[0029] It was found, through testing of several yarns, that the L(n) index increases as a function of the increase in the percentage of first fiber in the blend, while the SFC(n) index decreases as a function of the increase in the percentage of first fiber in the blend. As discussed further below, the relationship between the percentage of cotton in the blend and the L(n) and SFC(n) indices is almost linear, with the best approximation being a parabolic curve with a very low quadratic coefficient.

[0030] Conversely, in the 20 / 80 - 70 / 30 range of the ratio between the first and second fibers, it was found that the 5% index (n) remains substantially constant.

[0031] As a result, the preferred values ​​for the L(n) and SFC(n) indices of the mixture are discussed below.

[0032] One aspect of the invention relates to the weight ratio of the first discontinuous fibers to the second discontinuous fibers in the range of 20 / 80 (included) to 30 / 70 (excluded), the average length of the sheath fibers in the range of 19 to 34 mm, preferably 21 mm to 29 mm, while the short fiber content SFC (n) of the sheath is between 2% and 41%, preferably between 10% and 31%,

[0033] One aspect of the invention relates to the weight ratio of the first discontinuous fibers to the second discontinuous fibers in the range of 30 / 70 (included) to 40 / 60 (excluded), the average length of the sheath fibers in Petition 870250089179, dated 10 / 01 / 2025, p. 21 / 54 9 / 28 range of 18 to 33 mm, preferably 20 mm to 28 mm, while the short fiber content SFC (n) of the sheath is between 3% and 43%, preferably between 13% and 33%,

[0034] One aspect of the invention relates to the weight ratio of the first discontinuous fibers to the second discontinuous fibers in the range of 40 / 60 (included) to 50 / 50 (excluded), the average length of the sheath fibers in the range of 16 to 31 mm, preferably 18 mm to 26 mm, while the short fiber content SFC(n) of the sheath is between 8% and 48%, preferably between 18% and 38%,

[0035] One aspect of the invention relates to the weight ratio of the first discontinuous fibers to the second discontinuous fibers in the range of 50 / 50 (included) to 60 / 40 (excluded), the average length of the sheath fibers in the range of 15 to 30 mm, preferably 17 mm to 25 mm, while the short fiber content SFC(n) of the sheath is between 14% and 54%, preferably between 24% and 44%.

[0036] One aspect of the invention relates to the weight ratio of the first discontinuous fibers to the second discontinuous fibers in the range of 60 / 40 (included) to 70 / 30 (excluded), the average length of the sheath fibers in the range of 13 to 28 mm, preferably 15 mm to 23 mm, while the short fiber content SFC(n) of the sheath is between 21% and 61%, preferably between 31% and 51%.

[0037] One aspect of the invention relates to the weight ratio of the first discontinuous fibers to the second discontinuous fibers in the range of 70 / 30 (inclusive) to 80 / 20 (inclusive), preferably about 75 / 25, with the average length of the sheath fibers in the range of 10 to 25 mm, preferably from 12 mm to 20 mm, while the content Petition 870250089179, dated 10 / 01 / 2025, page 22 / 54 10 / 28 short fiber SFC(n) of the sheath is between 30% and 70%, preferably between 40% and 60%.

[0038] The expression “fiber blend” in the present description is used to identify a mixture of different fibers that is suitable for use in a ring spinning process to provide the sheath of a spun core yarn. Single fibers in the yarn sheath of the invention can be identified and, if necessary, physically removed from the blend that forms the sheath.

[0039] For the present invention, the term “regenerated cellulosic fiber” or “synthetic fiber” indicates any type of cellulose-based staple fiber that is industrially produced. This term includes all types of regenerated cellulosic fibers, such as lyocell, viscose, modal, bamboo (commercially available bamboo fiber is generally a regenerated cellulosic fiber produced from bamboo, i.e., a synthetic rayon made from cellulose extracted from bamboo), polynosic fiber, cupro, acetate, etc. These synthetic staple fibers have a substantially constant length, so that the length of these fibers falls within a very small range, i.e., they have a low CV value (i.e., coefficient of variation). For the present invention, the average length of these fibers, measured according to DIN 53805:1980-06, is in the range of 25 mm to 38 mm, preferably from 29 mm to 35 mm.The preferred count of regenerated fibers suitable for the invention is in the range of 1 dtex to 3 dtex, preferably about 1.2 dtex. The preferred regenerated cellulosic fibers for the present invention are sustainable cellulosic fibers. Petition 870250089179, dated 10 / 01 / 2025, page 23 / 54 11 / 28 like FSC-certified regenerated cellulosic fibers.

[0040] For the present invention, the term “virgin fiber” indicates cotton staple fibers derived from cotton that has not been worked into yarns and fabrics and that therefore has a high average fiber length.

[0041] For the present invention, the term “natural cellulosic fibers” means fibers obtained from the body of plants or animals. Preferred natural cellulosic fibers are those obtained or obtainable from the recycling process of fabrics and fibers from plants such as cotton, hemp, flax, and so forth. Typically, the natural cellulosic fibers used in the invention are recycled fibers, with counts close to each other, and are generally within the count range of regenerated cellulosic fibers.

[0042] In the following description, the term “recycled cotton fibers” designates discontinuous cotton fibers resulting from mechanical treatments, for example, opening and sorting, of yarns and fabrics; one possible way to identify these fibers is by measuring their average fiber length. In the embodiments, the average fiber length L(n), measured with DIN 53805:1980-06, is in the range of 6 to 16 mm. Tow falls within the definition of recycled cotton fibers. As is known, tow is short fibers that are produced as waste in yarn production, normally removed from the yarn during the combing process.

[0043] In the final blend of the sheath, the high index of 5% (n) is mainly due to the presence of fibers. Petition 870250089179, dated 10 / 01 / 2025, page 24 / 54 12 / 28 longer regenerated cellulosic fibers, while the high SFC(n) value is mainly due to the presence of the first short discontinuous fibers, for example, recycled cotton fibers with a high percentage of short fibers.

[0044] According to the invention, the yarn is a core spun yarn comprising or consisting of polyester filaments. The linear density of the polyester filaments is in the range of 20 to 300 denier. The number of filaments is in the range of 6 to 288, while the total count for the final yarn is in the range of 5 / 1 to 60 / 1 Ne. In preferred embodiments, the weight ratio of the polyester filaments to the total weight of the yarn is in the range of 10 to 35%.

[0045] According to one aspect of the invention, a yarn comprises a filament core and a staple fiber sheath. The fiber sheath is made of first and second staple fibers. The first staple fibers are natural cellulosic fibers, preferably recycled cotton staple fibers with an average length in the range of 6 to 16 mm, even more preferably about 10 mm.

[0046] The second staple fibers are synthetic fibers, for example, regenerated staple fibers, preferably viscose, with an average length greater than the average length of the first staple fibers, preferably between 25 mm and 40 mm, more preferably between 28 mm and 36 mm. High-quality yarns have been achieved, in particular, with secondary staple fibers around 32 mm, as well as between 30 and 34 mm. Petition 870250089179, dated 10 / 01 / 2025, page 25 / 54 13 / 28

[0047] At least 95% of the sheath fibers are the first and second discontinuous fibers mentioned above, characterized by the fact that the weight ratio of the first fiber to the second discontinuous fibers is between 20 / 80 and 70 / 30 (excluding).

[0048] In other words, the preferred embodiments have a hem comprising (for at least 95% of its weight) a blend made of 20% to 70% first staple fibers, i.e., recycled cotton fibers, while the remaining 80% to 30% by weight of the blend is made of second staple fibers, i.e., viscose.

[0049] As discussed previously, the blending of the fiber sheath, as well as the presence of one or more polyester filaments in the core, allows the claimed fibers and filament to be worked into a yarn which is, in turn, workable into a fabric that has excellent market properties. In particular, the resulting yarn can be ring spun, i.e., a process that was previously not possible to perform on yarns with a high percentage of short fibers, such as recycled cotton fibers.

[0050] The elongation at break of the polyester filaments of the filament core is less than 15%, preferably between 5% and 15%, more preferably between 8% and 12%, even more preferably between 10% and 12%, when tested with DIN ISO 2062.

[0051] As mentioned, the second discontinuous fibers of the sheath have a greater average length than the average length of the first discontinuous fibers. Petition 870250089179, dated 10 / 01 / 2025, page 26 / 54 14 / 28

[0052] Fiber length can be measured using suitable machines, such as the Uster Afis Pro 2 or TexTechno FCS-Fibro test, with methods known in the art, such as AFIS (Advanced Fiber Information System) according to DIN 53805:1980-06 or ASTM D1447.

[0053] In order to measure the fiber nature and fiber length (i.e., the L(n), SFC(n) and 5%(n) values) of the sheath of a finished yarn, the sheath must first be separated from the core. This can be done by opposite twisting the yarn (i.e., applying a twist opposite to that of the yarns, such as S-twisting a Z-twisted yarn). This can be done manually or by a twisting machine.

[0054] The fibers obtained can then be tested to determine their nature, that is, to determine the presence of natural cellulosic fibers and regenerated cellulosic fibers. Possible known methods are AATCC 20 and 20A, or ISO 1833.

[0055] Subsequently, the fiber length can be tested, for example, via DIN 53805 or ASTM D1447, using a USTER AFIS PRO 2 or a Textechno FCS-Fibrotest.

[0056] Preferably, in order to provide better interaction between the first discontinuous fibers and the second discontinuous fibers of the sheath, the length of the second discontinuous fibers is not much greater than the length of the first discontinuous fibers. A preferred ratio between the average length L(n) of the second discontinuous fibers versus the average length L(n) of the first discontinuous fibers is between 1.5 and 3.8, more preferably between 2 and 3.5. The best Petition 870250089179, dated 10 / 01 / 2025, page 27 / 54 15 out of 28 results occurred when the ratio discussed above was between 2.5 and 3.3.

[0057] The yarn, according to one or more of the preceding aspects, can be used to produce a fabric, in particular a woven fabric (preferably denim) and a garment comprising that woven fabric. It is particularly possible to produce a fabric characterized in that the yarns according to the invention are used in both the warp and weft directions.

[0058] It has been found that a fabric of this type, and in particular a garment made from this fabric, can be manufactured without virgin (i.e., conventional) cotton, although it has similar wearability (hand, softness, etc.) and optical properties (brightness, dyeing, etc.) to a fabric made from conventional cotton yarns. Furthermore, compared to fabrics made from conventional cotton yarns, the fabric according to the present invention exhibits similar mechanical properties, such as similar tensile strength, as well as better abrasion properties.

[0059] As an example, the abrasion of fabrics can be tested using the BS EN ISO 12947-2 method and the test, for which 25,000 to 30,000 cycles are performed.

[0060] If the test is continued even after this number of cycles, until the fabric breaks, a fabric according to the present invention has greater resistance (i.e., breaks after a greater number of cycles) compared to a standard cotton yarn fabric or a fabric made with recycled cotton yarns.

[0061] It has been tested that if three identical garments Petition 870250089179, dated 10 / 01 / 2025, page 28 / 54 16 / 28 are tested, the only difference between the garments is a first garment made with virgin cotton yarns, the second garment with recycled cotton yarns, the third garment made according to the present invention, with recycled cotton fibers as the first staple fibers, if the abrasion test is continued until the tested garment breaks, the third garment will last 2 to 3 times the duration of the first garment and 3 to 4 times the duration of the second garment.

[0062] The core may consist of a plurality of polyester filaments, or it may also comprise elastomeric filaments, such as elastane. Typically, in this case, the core consists of both polyester and elastomeric filaments.

[0063] Elastomeric filaments are generally in the range of 40 to 140 den, which usually undergo at least 2.0 draws, more preferably about 3 draws before sheath application, so that their count on the yarn would be lower (with a 3.0 draw it would be between about 13 and 47 den).

[0064] The present invention also relates to a method of producing a yarn comprising the steps of: a) Selecting a filament core comprising a plurality of polyester filaments; b) Selecting first staple fibers that are natural cellulosic fibers; c) Selecting second staple fibers that are regenerated cellulosic fibers; d) Providing a staple fiber sheath comprising at least 95% by weight of a blend of said first staple fibers and said second staple fibers, Petition 870250089179, dated 10 / 01 / 2025, page 29 / 54 17 / 28 characterized in that the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 20 / 80 to 70 / 30, characterized in that the sheath fibers have an average length between 10 and 34 mm, preferably between 12 and 29 mm, characterized in that the 5% index (n) of the sheath fibers is between 25 mm and 40 mm, preferably between 28 and 38 mm, and characterized in that the short fiber content SFC(n) of the sheath is between 2% and 70%, more preferably between 10% and 60%; combining said filament core and said discontinuous fiber sheath by means of ring spinning.

[0065] The present invention also relates to a method of producing a yarn comprising the steps of: a) Selecting a filament core comprising a plurality of polyester filaments; b) Selecting a staple fiber sheath characterized in that at least 95% of the sheath is made of first staple fibers and second staple fibers, the first staple fibers being natural cellulosic fibers, preferably with an average length between 6 and 16 mm, said second staple fibers being regenerated cellulosic fibers, preferably with an average length greater than the first fiber and preferably greater than 25 mm, more preferably greater than 30 mm, said first staple fibers being recycled cotton fibers, said second staple fibers being regenerated cellulosic fibers, the weight ratio of said first staple fibers to said second staple fibers Petition 870250089179, dated 10 / 01 / 2025, page 30 / 54 18 / 28 is in the range of 20 / 80 to 70 / 30 (excluding), c) combine said filament core and said discontinuous fiber sheath, preferably by ring spinning.

[0066] As mentioned, recycled materials are preferentially used, so the first staple fibers of the hem are recycled cotton fibers and / or the polyester filaments are made of recycled polyester. Detailed description of the invention

[0067] Exemplary and non-limiting achievements will now be discussed with reference to the attached non-limiting figures, where: - Fig. 1 is a histogram of recycled cotton fibers, - Fig. 2a is a histogram of a fiber blend from a yarn sheath according to the invention, characterized in that the blend (by weight percent) is 20% recycled cotton and 80% viscose; - Fig. 2b is a histogram of a fiber blend from a yarn sheath according to the invention, characterized in that the blend (by weight percent) is 50% recycled cotton and 50% viscose; - Figures 3a and 3b are a comparison of a test performed on fibers of the same yarns made according to the invention, taken from a fabric (Fig. 3a) and before being woven into plain weave (Fig. 3b); Figures 4 and 5 show the preferred ranges of L(n) and SFC(n) as a function of the percentage of natural cellulosic fibers.

[0068] To facilitate the discussion, in the general discussion Petition 870250089179, dated 10 / 01 / 2025, page 31 / 54 19 / 28 below, reference will be made to: - Recycled cotton fibers as the first staple fibers of the hem. However, unless otherwise specified, the following description applies to other natural cellulosic fibers as the first staple fibers of the hem; - Viscose fibers as the second staple fibers of the sheath. However, unless otherwise specified, the following description applies to other regenerated cellulosic fibers as second staple fibers of the sheath; - Elastane filaments possibly present in the core as one or more elastomeric filaments. However, unless specified, the following description applies to cores comprising a single elastane filament as well as one or more different elastomeric filaments.

[0069] In preferred embodiments, a yarn comprises a core provided with polyester filaments and possibly also elastane filaments; the sheath is made of staple fibers comprising recycled cotton fibers and viscose fibers.

[0070] Polyester filaments typically make up between 10% and 35% of the total yarn weight, usually around 20% of the yarn. The total polyester filament count is typically between 20 and 300 den, while more preferred embodiments use a total polyester count between 75 and 100 den.

[0071] The elongation at break of the polyester filaments (i.e., of the polyester core component) is less than 15%, more preferably between 8% and 12%, even more preferably between 10% and 12%. The test for Petition 870250089179, dated 10 / 01 / 2025, page 32 / 54 20 / 28 elongation at break measurement is DIN ISO 2062.

[0072] By comparison, a traditional polyester yarn, initially produced using the same method but without the claimed draw, will be heavier (i.e., having a higher count) and have a higher elongation at break when tested with the same test, above 15%, generally in the range of about 17% - 25%.

[0073] Elastane, if present, generally undergoes high drawing processes (with a draw greater than 2.0, usually around 3.0) and is present in a low weight quantity in the yarn and therefore generally around 5 to 15% of the total yarn weight.

[0074] According to one aspect, the polyester filaments and the elastane filaments are combined at least at a plurality of connection points, in a known manner, and preferably by means of tangle, twisting or mechanical co-extrusion. As mentioned, the elastane filaments preferably undergo drawing before being combined with the polyester filaments.

[0075] According to one aspect, the continuous core fibers and the elastomeric filament(s) are connected to each other in a continuous or substantially continuous manner by “mechanical co-extrusion of the filaments, preferably in a tensioned condition. During this co-extrusion, also known as co-feeding, two (or more) fiber bundles (in a tensioned state) are forced (fed together) through a restriction in which the fibers join together to such an extent that they remain locked even after exiting the restriction.

[0076] The sheath is composed of discontinuous fibers. By Petition 870250089179, dated 10 / 01 / 2025, page 33 / 54 21 / 28 minus 95% of the staple fibers in the hem are a blend of recycled cotton fibers and regenerated cellulosic fibers, preferably viscose fibers.

[0077] Preferred realizations have 20% to 80% by weight (more preferably between 20% and 70%) recycled cotton fibers and the remainder of the blend is viscose fibers.

[0078] The average length of recycled cotton fibers is typically between 6 and 16 mm.

[0079] Typically, more than 90% (by number) of recycled cotton fibers are below 30 mm. Achievements are possible where at least 50% of the fibers are below 15 mm.

[0080] Viscose fibers are longer than recycled cotton fibers in order to provide hem strength. However, as mentioned, it is preferable that they are not much longer than recycled cotton fibers in order to promote the coupling and blending of the hem fibers.

[0081] Viscose fibers have an average length greater than 25 mm, preferably greater than 30 mm, generally between 28 mm and 36 mm. In particular, it has been observed that very long viscose fibers can decrease the quality of the final yarn. In view of this, the most preferred embodiments use viscose fibers around 32 mm, such as between 30 mm and 34 mm. Typically, regenerated cellulosic staple fibers, such as viscose staple fibers, have uniform length, being produced by cutting viscose filaments.

[0082] Viscose filaments are preferably Petition 870250089179, dated 10 / 01 / 2025, page 34 / 54 22 / 28 selected so that their average length is between 1.5 and 3.8 times the average length of recycled cotton fibers, preferably between 2 and 3.5 times, and even more preferably between 2.5 and 3.3 times the average length of recycled cotton fibers.

[0083] Viscose fibers and recycled cotton fibers are blended to form a blend that is at least 95% by weight of hem fibers. As discussed, the ratio (by weight) between viscose fibers and recycled cotton fibers is between 20 / 80 and 80 / 20, preferably 20 / 80 to 70 / 30.

[0084] The average length L(n) of the sheath fibers is between 10 and 34 mm, preferably between 12 and 29 mm, while the 5%(n) index of the sheath fibers is at least 25 mm, preferably between 25 mm and 40 mm, more preferably between 28 and 38 mm. The short fiber content SFC(n) of the sheath is between 2% and 70%.

[0085] As mentioned, the L(n) and 5%(n) indices are a function of the percentage of cotton (i.e., the cotton / viscose weight ratio) in the blend.

[0086] It was found that the L(n) index decreases if the percentage of cotton increases. The relationship can be loosely approximated as inversely proportional. A better approximation is a negative parabolic relationship, with a very small quadratic component. Similarly, it was found that the 5% (n) index increases if the percentage of cotton increases. The relationship can be loosely approximated as proportional. A better approximation is a parabolic relationship, with a very small quadratic component. A possible trend of Petition 870250089179, dated 10 / 01 / 2025, page 35 / 54 23 / 28 L(n) and SFC(n) indices in exemplary realizations as a function of cotton percentage is visible in fig. 4.

[0087] In view of the above, the preferred embodiments have narrower ranges for the L(n) and SFC(n) indices as a function of the percentage of cotton in the cotton / viscose blend.

[0088] In particular, in embodiments where the ratio between first discontinuous fibers and second discontinuous fibers is in the range between 20 / 80 (included) and 30 / 70 (excluded), the average fiber length of the sheath is in the range between 19 and 34 mm, preferably 21 mm to 29 mm, while the content of short SFC(n) fibers of the sheath is between 2% and 41%, preferably between 10% and 31%,

[0089] In embodiments where the weight ratio of the first discontinuous fibers to the second discontinuous fibers is in the range of 30 / 70 (included) to 40 / 60 (excluded), the average fiber length of the sheath is in the range of 18 to 33 mm, preferably 20 mm to 28 mm, while the short fiber content SFC(n) of the sheath is between 3% and 43%, preferably between 13% and 33%,

[0090] In embodiments where the weight ratio of the first discontinuous fibers to the second discontinuous fibers is in the range of 40 / 60 (included) to 50 / 50 (excluded), the average fiber length of the sheath is in the range of 16 to 31 mm, preferably 18 mm to 26 mm, while the short fiber content SFC(n) of the sheath is between 8% and 48%, preferably between 18% and 38%,

[0091] In embodiments where the weight ratio of the first discontinuous fibers and the second discontinuous fibers is in the range of 50 / 50 (inclusive) to 60 / 40 Petition 870250089179, dated 10 / 01 / 2025, page 36 / 54 24 / 28 (excluding), the average fiber length of the sheath is in the range of 15 to 30 mm, preferably 17 mm to 25 mm, while the short fiber content SFC(n) of the sheath is between 14% and 54%, preferably between 24% and 44%.

[0092] In embodiments where the weight ratio of the first discontinuous fibers to the second discontinuous fibers is in the range of 60 / 40 (inclusive) to 70 / 30 (exclusive), the average fiber length of the sheath is in the range of 13 to 28 mm, preferably 15 mm to 23 mm, while the short fiber content SFC(n) of the sheath is between 21% and 61%, preferably between 31% and 51%,

[0093] In embodiments where the weight ratio of the first discontinuous fibers to the second discontinuous fibers is in the range of 70 / 30 (inclusive) to 80 / 20 (inclusive), preferably about 75 / 25, the average fiber length of the sheath is in the range of 10 to 25 mm, preferably 12 mm to 20 mm, while the short fiber content SFC(n) of the sheath is between 30% and 70%, preferably between 40% and 60%.

[0094] In all the above embodiments, the 5%(n) index of the sheath fibers is between 25 mm and 40 mm, more preferably in the range between 28 and 36 mm, even more preferably between 30 and 34 mm.

[0095] Apparatus for producing yarns is known in the art and is not discussed in detail here.

[0096] The yarn production method according to the present invention comprises providing a core, drawing polyester filaments and possibly combining them with elastane filaments.

[0097] The core is then combined with the sheath, which Petition 870250089179, dated 10 / 01 / 2025, page 37 / 54 25 / 28 is usually supplied in the form of one or more strands of discontinuous fiber.

[0098] The resulting product is then spun into yarn, preferably by ring spinning.

[0099] The yarn obtained can be used in a textile article and, in particular, a plurality of yarns according to the invention can be used in a fabric. In particular, they can be used as warp and / or weft yarns of the fabric.

[00100] In particular, the object of the invention is a fabric, preferably a denim fabric, characterized in that all warp and weft yarns are yarns according to the invention.

[00101] Warp yarns can be dyed, for example, dyed indigo, while weft yarns can be left undyed (although dyeing is possible).

[00102] As mentioned, a fabric obtained with the yarns according to the present invention is provided with better abrasion performance compared to fabrics made with standard cotton yarns and recycled cotton yarns.

[00103] An exemplary comparison is proposed below.

[00104] Fabric 1 is a fabric made with standard cotton yarns, while Fabric 2 is a fabric made with warp and weft yarns according to the invention.

[00105] Fabric 1 is made according to the following parameters: - Warp yarn composition: 100% cotton - warp thread count: 10 / 1 Ne - Composition of the weft yarns: 94% cotton / 6% Petition 870250089179, dated 10 / 01 / 2025, page 38 / 54 26 / 28 elastane - Weft thread count: 16 / 1 Ne - Fabric weave: 3 / 1 denim fabric, - Fabric composition: 98% cotton / 2% elastane.

[00106] Fabric 2 is made according to the following parameters: - Composition of the warp yarns: 61% recycled cotton / 20% viscose / 19% recycled polyester - Warp thread count: 10 / 1 Ne (same as Fabric 1) - Composition of the weft yarns: 60% recycled cotton / 20% viscose / 14% recycled polyester / 6% elastane - Weft thread count: 16 / 1 Ne (same as fabric 1) - Fabric weave: 3 / 1 denim fabric (same as fabric 1), - Fabric composition: 60% cotton / 20% viscose / 18% recycled polyester / 2% elastane.

[00107] The two fabrics were tested as follows: Table 1 Tear resistance in grams Raw After 5 domestic washes After 10 domestic washes Fabric 1 weft 3068 2832 2650 warp 7577 7070 7030 Fabric 2 weft 2982 3400 2832 warp 8450 8304 7679

[00108] The tear test is performed in accordance with ISO 13937-1, 5 and 10 domestic washes are carried out at 40°C, normal procedure, followed by machine drying. In each Petition 870250089179, dated 10 / 01 / 2025, page 39 / 54 27 / 28 cell, the top line shows the value in the weft direction, the bottom line shows the value in the warp direction. Table 2 Tensile strength in kg (raw) After 5 domestic washes After 10 domestic washes Fabric 1 weft 57.4 171.4 48.48 171.1 54.07 173.04 warp Fabric 2 weft 58.8 167.5 47.97 172.38 53.24 174.48 warp

[00109] The tensile strength test is performed according to ISO 1393-1, 5 and 10 domestic washes are carried out at 40°C, normal procedure, followed by machine drying. In each cell, the top line shows the value in the weft direction, the bottom line shows the value in the warp direction. Table 3 Abrasion resistance: Number of cycles required to break the fabric. Fabric 1: 93,000. Fabric 2: 186,000.

[00110] The abrasion test is carried out in accordance with ISO 12947-2 and continues until the tested fabric breaks.

[00111] As can be seen from the tests above, a fabric according to the invention has similar tensile strength and slightly improved tear resistance compared to a standard virgin cotton fabric. As a result, a fabric according to the invention has Petition 870250089179, dated 10 / 01 / 2025, pages 40 / 54 28 / 28 similar usability, maintaining similar optical properties, in relation to a standard virgin cotton fabric.

[00112] In addition, the fabric of the invention exhibits improved abrasion resistance, thus improving the fabric's lifespan.

[00113] The composition and length of the fiber can be tested according to the methods discussed above.

[00114] They can be tested before being woven into a fabric and after being woven into a fabric, by removing them from a fabric, with similar results. In this sense, Figures 1 and 2 are tested on fibers that are not being woven into a fabric. Figures 3a and 3b show the comparison between fibers from the same yarn set according to the invention, characterized by the fact that the test fibers in Fig. 3a come from a yarn removed from a fabric, while the test fibers in Fig. 3b come from a yarn after yarn production, before being woven into a fabric. As visible, the fiber length distribution is substantially the same. Petition 870250089179, dated 10 / 01 / 2025, pp. 41 / 54

Claims

1 / 7 CLAIMS 1) Method for producing a yarn, characterized in that it comprises the steps of: a. Selecting a filament core, comprising a plurality of polyester filaments, characterized in that the elongation at break of the polyester filaments of the filament core is in the range of 5% to 15%, more preferably between 10% and 12%, when tested with DIN ISO 2062; b. Selecting a staple fiber sheath, characterized in that at least 95% by weight of the sheath is made of first staple fibers and second staple fibers, said first staple fibers being recycled cotton fibers, the second staple fibers being regenerated cellulosic fibers; c. combining said filament core and said staple fiber sheath by means of ring spinning. 2) Method according to claim 1, characterized in that the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 20 / 80 to 70 / 30 (excluding). 3) A method according to any one of claims 1 or 2, characterized in that the recycled cotton fibers have an average length L(n) between 6 and 16 mm, and / or characterized in that the regenerated cellulosic fibers have an average length L(n) between 25 mm and 40 mm, preferably between 28 mm and 36 mm. 4) Method for the production of a yarn, characterized in that it comprises the following steps: Petition 870250089179, dated 01 / 10 / 2025, page 42 / 54 2 / 7 a. Selecting a filament core, comprising a plurality of polyester filaments, characterized in that the elongation at break of the polyester filaments of the filament core is in the range of 5% to 15%, more preferably between 10% and 12%, when tested with DIN ISO 2062; b. Selecting the first staple fibers which are natural cellulosic fibers; c. Selecting the second staple fibers which are regenerated cellulosic fibers; d.To provide a staple fiber sheath comprising at least 95% by weight of a blend of said first staple fibers and said second staple fibers, characterized in that the weight ratio of said first staple fibers to said second staple fibers is in the range of 20 / 80 to 70 / 30 (excluding), characterized in that the fibers of the sheath have an average length between 10 and 34 mm, preferably between 12 and 29 mm, characterized in that the 5% index (n) of the fibers of the sheath is between 25 mm and 40 mm, preferably between 28 and 38 mm, and characterized in that the short fiber content SFC(n) of the sheath is between 2% and 70%, more preferably between 10% and 60%; and to combine said filament core and said staple fiber sheath by means of ring spinning; 5) Method, according to any one of claims 1 to 4, characterized in that the polyester filament of the core is made of recycled polyester. Petition 870250089179, dated 10 / 01 / 2025, p. 43 / 54 3 / 7 6) Method, according to any one of claims 1 to 5, characterized in that: a. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 20 / 80 (included) to 30 / 70 (excluded) and i. the average fiber length of the sheath is in the range of 19 to 34 mm, preferably 21 mm to 29 mm; ii. the short fiber content SFC(n) of the sheath is between 2% and 41%, preferably between 10% and 31%, or b. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 30 / 70 (included) to 40 / 60 (excluded) and i. the average fiber length of the sheath is in the range of 18 to 33 mm, preferably 20 mm to 28 mm; ii. the short fiber content SFC(n) of the sheath is between 3% and 43%, preferably between 13% and 33%, or c.the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 40 / 60 (included) to 50 / 50 (excluded) and i. the average fiber length of the sheath is in the range of 16 to 31 mm, preferably 18 mm to 26 mm; ii. the short fiber content SFC(n) of the sheath is between 8% and 48%, preferably between 18% and 38%, or d. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 50 / 50 (included) to 60 / 40 (excluded) and i. the average fiber length of the sheath is in the range Petition 870250089179, dated 01 / 10 / 2025, page. 44 / 54 4 / 7 from 15 to 30 mm, preferably 17 mm to 25 mm; ii. the short fiber content SFC(n) of the sheath is between 14% and 54%, preferably between 24% and 44%, or e. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 60 / 40 (included) to 70 / 30 (excluded) and i.The average fiber length of the sheath is in the range of 13 to 28 mm, preferably from 15 mm to 23 mm; ii. The short fiber content SFC(n) of the sheath is between 21% and 61%, preferably between 31% and 51%. 7) Yarn comprising a filament core and a staple fiber sheath, said staple fiber sheath being made of, or comprising at least 95% by weight of, a blend of first staple fibers and second staple fibers, characterized in that the first staple fibers are natural cellulosic fibers and the second staple fibers are regenerated cellulosic fibers, characterized in that: the weight ratio of said first staple fibers to said second staple fibers is in the range of 20 / 80 to 70 / 30 (excluding); the average length of the sheath fibers is in the range of 10 to 34 mm, preferably from 12 mm to 29 mm; the 5%(n) index of the sheath fibers is between 25 mm and 40 mm, more preferably in the range between 28 and 36 mm, even more preferably between 30 and 34 mm; the short fiber content SFC(n) of the sheath is between 2% and 70%, preferably between 10% and 60%;and the said filament core comprises a plurality of polyester filaments; the elongation at break of the polyester filaments of the filament core, measured in accordance with DIN ISO 2062, is in the range of 5% to 15%, more preferably between 10% and 12%. 8) Yarn, according to claim 7, characterized in that: a. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 20 / 80 (included) to 30 / 70 (excluded) and i. the average length of the sheath fibers is in the range of 19 to 34 mm, preferably 21 mm to 29 mm; ii. the short fiber content SFC(n) of the sheath is between 2% and 41%, preferably between 10% and 31%, or b. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 30 / 70 (included) to 40 / 60 (excluded) and i. the average length of the sheath fibers is in the range of 18 to 33 mm, preferably 20 mm to 28 mm; ii. the short fiber content SFC(n) of the sheath is between 3% and 43%, preferably between 13% and 33%, or c.the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 40 / 60 (included) to 50 / 50 (excluded) and i. the average fiber length of the sheath is in the range of 16 to 31 mm, preferably 18 mm to 26 mm; ii. the short fiber content SFC(n) of the sheath is between 8% and 48%, preferably between 18% and 38%, Petition 870250089179, dated 10 / 01 / 2025, page 46 / 54 6 / 7 or d. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 50 / 50 (included) to 60 / 40 (excluded) and i. the average fiber length of the sheath is in the range of 15 to 30 mm, preferably 17 mm to 25 mm; ii. the short fiber content SFC(n) of the sheath is between 14% and 54%, preferably between 24% and 44%, or e. the weight ratio of said first discontinuous fibers to said second discontinuous fibers is in the range of 60 / 40 (included) to 70 / 30 (excluded) and i.i. the average fiber length of the sheath is in the range of 13 to 28 mm, preferably from 15 mm to 23 mm; ii. the short fiber content SFC(n) of the sheath is between 21% and 61%, preferably between 31% and 51%. 9) Yarn, according to claim 7 or 8, characterized in that the ratio between the average length of the regenerated cellulosic fibers and the average length of the first discontinuous fibers is in a range between 1.5 and 3.8, preferably between 2 and 3.5, more preferably between 2.5 and 3.

3. 10) Yarn, according to any one of claims 7 to 9, characterized in that the core comprises one or more elastomeric filaments, preferably with a draw of 2.0 to 4.0, more preferably of at least 2.5, preferably of about 3.

0. 11) Yarn, according to any one of claims 7 to 10, characterized in that the polyester filaments have a draw length between 1.5 and 2.5, preferably between 1.8 and 2.

2. 12) Yarn, according to any one of claims 7 to 11, characterized in that the polyester filaments are textured filaments. 13) Yarn, according to any one of claims 7 to 12, characterized in that the amount of polyester filaments in the core is in the range of 10% to 30% of the yarn's weight, preferably between 15% and 25% by weight, more preferably about 20% by weight. 14) Yarn, according to any one of claims 7 to 13, characterized in that the total count of polyester filaments is between 50 and 150 den, preferably between 60 and 120 den, more preferably between 75 and 100 den. 15) Textile article, preferably a denim fabric or garment, characterized in that it comprises a yarn according to one or more of claims 7 to 14 above. Petition 870250089179, dated 10 / 01 / 2025, pp. 48 / 54

Images