Method for producing cellulose ester fibers from pre-consumer textile waste

Abstract

Dissolving pulp comprising pre-consumer textile waste is used to produce cellulose esters and corresponding fibers. According to the process, the cellulose content in waste materials generated during textile manufacturing is utilized, and the waste materials comprise cotton linters, bottom combing materials, fabric scraps, cattle feed waste materials, combing machine protruding materials, broken-end cotton suction device waste materials, soft regenerated wool waste materials, yarn waste materials, production waste materials, cutting machine scraps, twisting waste materials or mixtures of the cotton linters, the bottom combing materials, the fabric scraps, the cattle feed waste materials, the combing machine protruding materials, the broken-end cotton suction device waste materials and the soft regenerated wool waste materials.

Description

Background Art 1. Technical Field

[0001] The present application generally relates to the use of dissolving pulp derived from waste textiles in the production of cellulose esters.

[0002] 2. Description of related technologies

[0003] Dissolving grade wood pulp raw materials are commonly used to make the cellulose fibers used in consumer textiles. While there are sustainably managed forests from which to obtain at least some of the required wood pulp supply, the situation is not ideal. Additionally, the global textile industry generates large amounts of waste textiles each year, which end up in landfills or are incinerated. Technologies are needed to reduce landfill and polluting incineration processes while reducing wood pulp use. Summary of the invention

[0004] In one embodiment, the present disclosure provides a method comprising reacting an esterifying agent with cellulose to form a cellulose ester. At least a portion of the cellulose is derived from pre-consumer textile waste.

[0005] In another embodiment, the present disclosure provides a method for producing cellulose ester fibers. The method includes breaking a coil and / or sheet of a dissolving pulp comprising recycled pre-consumer textile waste containing cellulose into smaller pieces. The cellulose is reacted with an esterifying agent to form a cellulose ester. A spinning solution containing the cellulose ester is spun through a spinneret to produce one or more cellulose ester fibers.

[0006] The present disclosure also provides a cellulose ester fiber made by one of the above methods. In another embodiment, the present disclosure provides an article including the cellulose ester fiber. DETAILED DESCRIPTION

[0007] The present application generally relates to a process for preparing cellulose esters using pre-consumer textile waste. In one embodiment, the disclosed process includes reacting an esterifying agent with a cellulose pulp derived from pre-consumer textile waste to form a cellulose ester.

[0008] Pre-consumer textile waste can be waste generated by the commercial textile industry during processing of cotton-based fibers, such as during the manufacture of clothing, fabrics and / or yarns. Pre-consumer textile waste can include any unclassified (off-class) materials from any step in the manufacturing process: from combing until the final manufacturing step of a specific process. The commercial textile industry generates waste during the start-up and / or shutdown of the manufacturing process and / or during the conversion to new materials. Pre-consumer textile waste can be distinguished from post-consumer textile waste because the latter includes clothing that is made and delivered to consumers and / or used by consumers. Pre-consumer textile waste can include, be essentially composed of or consist of one or more of the following items: cotton linters, undercard, fabric scraps, cattle feed waste, comber knoll, pneumafil waste, soft recycled wool waste, yarn waste, production waste, cutter scraps, twisting waste or its mixture.

[0009] Ginning leaves short cellulose fibers on the seeds after the raw cotton has been removed by ginning or other separation methods. These fibers are called cotton linters, and cotton linters are pre-consumer textile waste that can be used as dissolving pulp, as described in this disclosure.

[0010] In the cotton textile spinning process, short fibers, seed waste and stalks are removed before the spinning process. The opening and combing equipment used for this process has a filtration extraction system to remove and collect these particles. In the process of separating the high-quality fibers from foreign particles, some fibers are usually still captured. The bottom comb material includes such fibers and is a pre-consumer textile waste that can be used to prepare cellulose esters as described herein.

[0011] Each textile cutting operation has a pattern cut from a standard width of fabric, leaving behind fabric scraps that will not become part of the final garment and are likely to be discarded as waste. Many of these fabrics are originally formed from cellulosic materials. Fabric scraps such as these are pre-consumer textile waste that can be used to prepare cellulose esters as described herein. T-shirt scraps are an example of fabric scraps that are suitable for use as pre-consumer textile waste.

[0012] Cattle feed waste includes heavy seed and stalk cotton that is less useful than bottom combing. Comber stubs include fine cotton but have short fibers 1 / 2 inch (1.27 cm) or shorter. Downcomb waste includes fibers that are collected during drawing or spinning during processing.

[0013] Soft recycled wool waste includes reprocessed fabrics that have been cut into smaller pieces and torn into fibers again. Yarn waste includes waste generated by substandard (e.g., abnormal or uncommon) or cut packages. Twisting waste includes that captured during multi-end twisting and / or final package winding.

[0014] Production scraps include material that is substandard (e.g., faded, wrong fabric weight, broken needle runs, etc.) Cutter scraps include material from cutting patterns that is not used to make garments.

[0015] In one embodiment, the pre-consumer textile waste can be in the form of a dissolving pulp. The dissolving pulp can be provided as a roll or sheet, and the roll or sheet can contain cellulose from more than one source of pre-consumer textile waste and / or cellulose from sources other than pre-consumer textile waste, such as bamboo, switchgrass, hemp, juice industry waste (such as waste left over from the pulping process), sugarcane bagasse, or mixtures thereof.

[0016] In one embodiment or in combination with any of the other mentioned embodiments, at least 1 wt%, at least 20 wt%, at least 50 wt%, at least 70 wt%, at least 85 wt%, at least 90 wt% or at least 100 wt% of the cellulose in the dissolving pulp will come from pre-consumer textile waste sources.

[0017] The rolls or sheets of dissolving pulp may be mechanically conditioned prior to acetylation. Mechanical conditioning may include breaking the roll or sheet into smaller pieces (e.g., shredding, chopping). Additionally, multiple rolls or sheets of the same or different types (e.g., having cellulose from different sources, as described above) may be mechanically conditioned to form smaller pieces and combined with the smaller pieces obtained from pre-consumer textile waste dissolving pulp.

[0018] In one embodiment or in combination with any of the other mentioned embodiments, the pre-consumer textile waste dissolving pulp will contain no more than 3 wt%, no more than 2 wt%, no more than 1 wt%, no more than 0.5 wt%, no more than 0.1 wt% or no more than 0 wt% surfactant molecules (charged or uncharged), based on the total weight of the pre-consumer textile waste dissolving pulp.

[0019] In one embodiment or in combination with any of the other mentioned embodiments, the pre-consumer textile waste dissolving pulp will contain no more than 3 wt%, no more than 2 wt%, no more than 1 wt%, no more than 0.5 wt%, no more than 0.1 wt% or no more than 0 wt% silicon atoms, based on the total weight of the pre-consumer textile waste dissolving pulp.

[0020] In one embodiment, the pre-consumer textile waste dissolving pulp will contain no more than 3 wt%, no more than 2 wt%, no more than 1 wt%, no more than 0.5 wt%, no more than 0.1 wt% or no more than 0 wt% of combined silicon atoms and surfactant molecules based on the total weight of the pre-consumer textile waste dissolving pulp.

[0021] In one embodiment or in combination with any of the other mentioned embodiments, the pre-consumer textile waste dissolving pulp will have one, two, three, four, five, six, seven, eight, nine, ten, eleven or twelve properties of Table A in any combination. In one embodiment or in combination with any of the other mentioned embodiments, the pre-consumer textile waste dissolving pulp will have all thirteen properties of Table A.

[0022] Table A

[0023]

[0024] Regardless of the source of pre-consumer textile waste, cellulose esters can be produced by any method known in the art. The dissolving pulp can be soaked, such as by dissolving the pulp in water, acetic acid and / or glacial acetic acid, so that the fibers swell, which can increase chemical reactivity. If mechanical conditioning is performed, soaking can be performed after the mechanical conditioning. In one embodiment, soaking can be performed at a temperature of at least 15°C, at least 17°C, at least 20°C, at least 23°C, at least 25°C, at least 27°C, or at least 30°C and / or no more than 65°C, no more than 63°C, no more than 60°C, no more than 57°C, no more than 55°C, no more than 53°C, or no more than 50°C. In one embodiment or in combination with any other mentioned embodiment, soaking can be performed for 30 minutes to 90 minutes, or 50 minutes to 70 minutes. In embodiments where the pulp is dissolved in water, dehydration can be performed prior to esterification.

[0025] Suitable esterification agents may include acetylating agents such as acetic anhydride.In one embodiment or in combination with any of the other mentioned embodiments, a catalyst (eg, sulfuric acid), an organic acid (eg, acetic acid), or both a catalyst and acetic acid will be present during acetylation.

[0026] In one embodiment or in combination with any of the other mentioned embodiments, the acetylation may be performed at a temperature of at least 5° C., at least 7° C., at least 10° C., at least 13° C., at least 15° C., at least 20° C., or at least 25° C. and / or no more than 95° C., no more than 93° C., no more than 90° C., no more than 85° C., no more than 80° C., no more than 75° C., or no more than 70° C. In one embodiment or in combination with any of the other mentioned embodiments, the acetylation may be performed for 10 minutes to 3 hours, or 15 minutes to 2 hours.

[0027] The above process will produce a cellulose triester (e.g., cellulose triacetate). In embodiments where a secondary ester (e.g., cellulose diacetate) is desired, the reaction solution may be subjected to a partial hydrolysis reaction, which converts the cellulose triacetate to cellulose diacetate. This process may include adding water to the triacetate solution and heating to at least 40°C, at least 45°C, at least 50°C, at least 55°C, at least 60°C, or at least 65°C and / or no more than 100°C, no more than 95°C, no more than 90°C, no more than 85°C, no more than 80°C, or no more than 75°C. In one embodiment or in combination with any of the other mentioned embodiments, the hydrolysis may be carried out for 4 hours to 25 hours, or 5 hours to 20 hours. In one embodiment or in combination with any of the other mentioned embodiments, the hydrolysis may be carried out in the presence of an acid catalyst (e.g., sulfuric acid).

[0028] Cellulose esters formed as described herein generally comprise repeating units of the following structure:

[0029]

[0030] Where R 1 , R 2 and R 3 Independently selected from hydrogen or a straight chain alkanoyl group having 2 to 10 carbon atoms. Exemplary alkanoyl groups include acetyl, propionyl and / or butyryl.

[0031] For cellulose esters, the level of substitution is often expressed in terms of the degree of substitution ("DS"), which is the average number of non-OH substituents per anhydroglucose unit ("AGU"). In general, conventional cellulose contains three hydroxyl groups per AGU unit that can be substituted; therefore, the value of DS can be between zero and three. However, low molecular weight cellulose esters can have a total degree of substitution slightly higher than 3 due to end group contributions. Since DS is a statistical average, a value of 1 does not guarantee that each AGU has a single substituent. In some cases, there may be unsubstituted AGUs, some with two substituents and some with three substituents. "Total DS" is defined as the average number of all substituents per AGU, and typically, the value is a non-integer. The degree of substitution per AGU can also refer to a specific substituent, such as, for example, hydroxyl, acetyl, butyryl, or propionyl.

[0032] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester comprises the following DS 乙酰基: at least 1.5, at least 1.55, at least 1.6, at least 1.65, at least 1.7, at least 1.75, at least 1.8, at least 1.85, at least 1.9, at least 1.95, at least 2.0, at least 2.05, at least 2.1, at least 2.15, at least 2.2, at least 2.25, at least 2.3, at least 2.35, or at least 2.38 and / or no more than 2.95, no more than 2.9, no more than 2.8, no more than 2.7, no more than 2.6, no more than 2.55, no more than 2.5, or no more than 2.45. In certain embodiments, the cellulose ester may comprise a DS within the range of 乙酰基 : 2.7 to 2.95, 1.5 to 2.6, 1.6 to 2.6, 1.7 to 2.6, 1.8 to 2.6, 1.9 to 2.6, 2.0 to 2.6, 2.05 to 2.6, 2.1 to 2.6, 2.15 to 2.6, 2.2 to 2.6, 2.25 to 2.55, 2.3 to 2.5 or 2.38 to 2.45.

[0033] Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester comprises the following DS OH : at least 0.05, at least 0.1, at least 0.2, at least 0.3, at least 0.4, or at least 0.5 and / or no more than 1.5, no more than 1.4, no more than 1.3, no more than 1.2, no more than 1.1, or no more than 1.0. In certain embodiments, the cellulose ester comprises a DS in the range of OH : 0.05 to 1.5, 0.1 to 1.5, 0.2 to 1.4, 0.3 to 1.2, 0.4 to 1.1 or 0.5 to 1.0.

[0034] Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester comprises the following DS 丁酰基 : at least 0.1, at least 0.2 or at least 0.3 and / or no more than 1.5, no more than 1.4, no more than 1.3, no more than 1.2, no more than 1.1, no more than 1.0, no more than 0.9, no more than 0.8, no more than 0.7, no more than 0.6, no more than 0.5 or no more than 0.4. In certain embodiments, the cellulose ester comprises a DS in the range of 丁酰基 : 0.1 to 1.5, 0.1 to 1.2, 0.1 to 0.8, 0.1 to 0.4, 0.2 to 1.5, 0.2 to 1.2, 0.2 to 0.8, 0.2 to 0.4, 0.3 to 1.5, 0.3 to 1.2, 0.3 to 0.8 or 0.3 to 0.6.

[0035] Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester comprises the following DS 丙酰基: at least 0.1, at least 0.2 or at least 0.3 and / or no more than 1.5, no more than 1.4, no more than 1.3, no more than 1.2, no more than 1.1, no more than 1.0, no more than 0.9, no more than 0.8, no more than 0.7, no more than 0.6, no more than 0.5 or no more than 0.4. In certain embodiments, the cellulose ester comprises a DS in the range of 丙酰基 : 0.1 to 1.5, 0.1 to 1.2, 0.1 to 0.8, 0.1 to 0.4, 0.2 to 1.5, 0.2 to 1.2, 0.2 to 0.8, 0.2 to 0.4, 0.3 to 1.5, 0.3 to 1.2, 0.3 to 0.8 or 0.3 to 0.6.

[0036] Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester comprises a total DS of at least 1.5, at least 1.55, at least 1.6, at least 1.65, at least 1.7, at least 1.75, at least 1.8, at least 1.85, at least 1.9, at least 1.95, at least 2.0, at least 2.05, at least 2.1, at least 2.15, at least 2.2, at least 2.25, at least 2.3, at least 2.35 or at least 2.38 and / or no more than 2.95, no more than 2.9, no more than 2.85, no more than 2.8, no more than 2.75, no more than 2.7, no more than 2.65, no more than 2.6, no more than 2.55, no more than 2.5 or no more than 2.45. In certain embodiments, the cellulose ester may comprise a total DS in the range of 1.5 to 2.95, 1.6 to 2.85, 1.7 to 2.8, 1.8 to 2.75, 1.9 to 2.7, 2.0 to 2.65, 2.05 to 2.6, 2.1 to 2.6, 2.15 to 2.6, 2.2 to 2.6, 2.25 to 2.55, 2.3 to 2.5, or 2.38 to 2.45.

[0037] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester may be cellulose diacetate and / or cellulose triacetate. Alternatively, in certain embodiments, the cellulose ester may include mixed cellulose esters, such as cellulose acetate butyrate or cellulose acetate propionate.

[0038] In one embodiment or in combination with any of the other mentioned embodiments, the degree of acetylation of the cellulose ester may be at least 30 wt%, at least 35 wt%, or at least 40 wt%, and / or no more than 62.5 wt%, no more than 60 wt%, no more than 55 wt%, no more than 50 wt%, or no more than 45 wt%. In certain embodiments, the degree of acetylation of the cellulose ester may be in the range of 30 wt% to 62.55 wt%, 35 wt% to 55 wt%, 35 wt% to 50 wt%, 35 wt% to 45 wt%, 40 wt% to 62.55 wt%, 40 wt% to 60 wt%, 40 wt% to 55 wt%, 40 wt% to 50 wt%, or 40 wt% to 45 wt%.

[0039] Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester may have a hydroxyl content of at least 0.3 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 3 wt%, or at least 4 wt%, and / or no more than 20 wt%, no more than 15 wt%, no more than 10 wt%, or no more than 5 wt%. In certain embodiments, the cellulose ester may have a hydroxyl content in the range of 0.3 wt% to 20 wt%, 0.5 wt% to 20 wt%, 2 wt% to 15 wt%, 3 wt% to 10 wt%, or 4 wt% to 5 wt%.

[0040] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester can have a number average degree of polymerization of at least 100, at least 110, at least 120, at least 130, at least 140, at least 150, at least 160, at least 170, at least 180, at least 190, at least 200, at least 210, at least 220, at least 230, at least 240, at least 250, at least 260, or at least 265. Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester may have a number average degree of polymerization of no more than 1,000, no more than 900, no more than 800, no more than 700, no more than 600, no more than 500, no more than 400, no more than 350, no more than 325, no more than 300, no more than 290, no more than 280, no more than 270, no more than 260, no more than 250, no more than 240, no more than 230, no more than 220, no more than 210, no more than 200, no more than 190, no more than 180, no more than 170, no more than 160, no more than 150, no more than 149, no more than 150 8. Not more than 147, not more than 146, not more than 145, not more than 144, not more than 143, not more than 142, not more than 141, not more than 140, not more than 139, not more than 138, not more than 137, not more than 136, not more than 135, not more than 134, not more than 133, not more than 132, not more than 131, not more than 130, not more than 129, not more than 128, not more than 127, not more than 126, not more than 125, not more than 124, not more than 123, not more than 122, not more than 121, not more than 120, not more than 119, not more than 118, not more than 117, not more than 116 or not more than 115. In certain embodiments, the number average degree of polymerization of the cellulose ester may be in the range of 100 to 1,000, 100 to 500, 100 to 400, 100 to 300, 100 to 250, 100 to 200, 100 to 150, 100 to 135, 100 to 200, 100 to 150, 100 to 135, 100 to 180, 100 to 150, 100 to 145, 100 to 140, 100 to 135, or 100 to 130.

[0041] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester can comprise a number average absolute molecular weight of at least 5,000 Daltons, at least 10,000 Daltons, at least 15,000 Daltons, at least 20,000 Daltons, or at least 25,000 Daltons and / or no more than 75,000 Daltons, no more than 70,000 Daltons, no more than 65,000 Daltons, no more than 60,000 Daltons, no more than 55,000 Daltons, no more than 50,000 Daltons, no more than 45,000 Daltons, no more than 40,000 Daltons, no more than 35,000 Daltons, or no more than 30,000 Daltons as measured by gel permeation chromatography ("GPC") according to ASTM D6474. In certain embodiments, the cellulose ester may comprise a number average absolute molecular weight as measured by GPC according to ASTM D6474 within the following ranges: 5,000 Daltons to 75,000 Daltons, 10,000 Daltons to 65,000 Daltons, or 15,000 Daltons to 35,000 Daltons.

[0042] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester can comprise a weight average absolute molecular weight as measured by GPC according to ASTM D6474 of at least 50,000 Daltons, at least 55,000 Daltons, at least 60,000 Daltons, at least 65,000 Daltons, at least 70,000 Daltons, at least 75,000 Daltons, at least 80,000 Daltons, or at least 85,000 Daltons and / or no more than 150,000 Daltons, no more than 140,000 Daltons, no more than 130,000 Daltons, no more than 120,000 Daltons, no more than 110,000 Daltons, no more than 100,000 Daltons, or no more than 95,000 Daltons. In certain embodiments, the cellulose ester may comprise a weight average absolute molecular weight as measured by GPC according to ASTM D6474 in the following ranges: 50,000 Daltons to 150,000 Daltons, 70,000 Daltons to 120,000 Daltons, or 80,000 Daltons to 95,000 Daltons.

[0043] In one embodiment or in combination with any other mentioned embodiment, the cellulose ester may comprise the following crystallinity measured according to ASTM F2625: at least 1%, at least 2%, at least 5%, at least 10%, at least 15%, or at least 20%. Additionally or alternatively, in one embodiment or in combination with any other mentioned embodiment, the cellulose ester may comprise the following crystallinity measured according to ASTM F2625: no more than 25%, no more than 20%, no more than 15%, no more than 10%, no more than 9%, no more than 8%, no more than 7%, no more than 6%, no more than 5%, no more than 4%, no more than 3%, no more than 2%, or no more than 1%. In certain embodiments, the cellulose ester may comprise the following crystallinity measured according to ASTM F2625: 1% to 99%, 1% to 50%, 1% to 30%, 1% to 20%, or 1% to 15%.

[0044] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester can exhibit a glass transition temperature of at least 120°C, at least 125°C, at least 130°C, at least 135°C, at least 140°C, at least 145°C, at least 150°C, at least 155°C, at least 160°C, at least 165°C, at least 170°C or at least 175°C and / or no more than 250°C, no more than 245°C, no more than 240°C, no more than 235°C, no more than 230°C, no more than 225°C, no more than 220°C, no more than 215°C, no more than 210°C, no more than 205°C, no more than 200°C, no more than 195°C, no more than 190°C or no more than 185°C.

[0045] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester may comprise a hemicellulose content of at least 0.1 wt%, at least 0.25 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 3 wt%, at least 4 wt%, at least 5 wt%, at least 6 wt%, or at least 7 wt%. Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester may comprise a hemicellulose content of no more than 10 wt%, no more than 9 wt%, no more than 8 wt%, no more than 7 wt%, no more than 6 wt%, no more than 5 wt%, no more than 4 wt%, no more than 3 wt%, no more than 2 wt%, or no more than 1 wt%.

[0046] Whether cellulose triacetate or cellulose diacetate is the desired end product, cellulose ester flakes may be precipitated from solution, washed and dried.

[0047] In one embodiment or in combination with any of the other mentioned embodiments, at least 20%, at least 40%, at least 60%, at least 80%, or at least 100% by weight of the cellulose in the flakes may come from pre-consumer textile waste sources.

[0048] The cellulose ester can then be dissolved in a suitable solvent to form a spinning solution to be wet spun or dry spun through a spinneret to form one or more spun fibers. In one embodiment, a cellulose ester (eg, cellulose triacetate) can be melt spun through a spinneret to form one or more spun fibers.

[0049] In one embodiment, the cellulose ester (I) prepared from pre-consumer waste textiles as described above can be the only cellulose ester added to the spinning solution or melt-spun. In another embodiment, the cellulose ester (I) can be mixed or blended with a different cellulose ester flake (II) to form a blend of at least two different cellulose esters.

[0050] As an alternative to precipitation and dissolution in wet or dry spinning embodiments, the cellulose ester can be retained in an acid-based solution (i.e., an acidic spinning solution) and used directly in a downstream fiber wet or dry spinning process. In one embodiment, the acidic spinning solution can be derived solely from pre-consumer textile waste. In another embodiment, an acidic spinning solution from one or more other cellulose sources can be blended with an acidic spinning solution derived from pre-consumer textile waste.

[0051] In one embodiment or in combination with any of the other mentioned embodiments, the different cellulose esters (II) are not formed from cellulose derived from pre-consumer textile waste. The cellulose ester sheet (II) may be formed from a cellulosic material selected from wood pulp and / or other plant-based cellulose sources. Examples of other plant-based cellulose sources may include bamboo, switchgrass, hemp, juice industry waste (such as waste left over from the pulping process), bagasse, agricultural residues, or mixtures thereof.

[0052] In one embodiment or in combination with any of the other mentioned embodiments, at least 20 weight %, at least 40 weight %, at least 60 weight %, at least 80 weight % or at least 100 weight % of the cellulose in the combination of cellulose ester (I) and cellulose ester (II) may come from pre-consumer textile waste sources.

[0053] In one embodiment or in combination with any of the other mentioned embodiments, if the pre-consumer textile waste comprises cotton linters, the blend of cellulose ester (I) and cellulose ester (II) comprises no more than 95 wt.%, no more than 90 wt.%, no more than 85 wt.%, no more than 80 wt.%, no more than 75 wt.%, no more than 70 wt.%, no more than 65 wt.%, or no more than 60 wt.% of cellulose ester formed from cellulose derived from cotton linters, based on the total weight of the flake blend.

[0054] In one embodiment or in combination with any of the other mentioned embodiments, cellulose ester can be added to the spinning solution so that the spinning solution comprises at least 5 wt%, at least 8 wt%, at least 10 wt%, at least 12 wt%, at least 15 wt%, at least 18 wt%, at least 20 wt%, or at least 22 wt% of cellulose ester, and / or no more than 35 wt%, no more than 33 wt%, no more than 30 wt%, no more than 29 wt%, no more than 25 wt%, no more than 22 wt%, or no more than 20 wt% of cellulose ester, based on the total weight of the spinning solution. In certain embodiments, the cellulose ester spinning solution comprises from 5 wt% to 35 wt%, from 10 wt% to 35 wt%, from 12 wt% to 35 wt%, from 15 wt% to 35 wt%, or from 25 wt% to 35 wt% of cellulose ester, based on the total weight of the spinning solution.

[0055] Sufficient dissolving solvent should be added so as to effectively dissolve the cellulose ester, thereby forming a cellulose ester spinning solution. In one embodiment or in combination with any other mentioned embodiments, the cellulose ester spinning solution may contain at least 65 wt %, at least 70 wt %, at least 75 wt %, at least 80 wt %, at least 85 wt %, at least 90 wt % or at least 95 wt %, or 99 wt % and / or no more than 99 wt %, no more than 95 wt %, no more than 90 wt % or no more than 85 wt % of one or more dissolving solvents, based on the total weight of the spinning solution. In certain embodiments, the cellulose ester spinning solution contains 65 wt % to 99 wt %, 70 wt % to 95 wt %, 75 wt % to 95 wt %, 80 wt % to 95 wt % or 90 wt % to 99 wt % of one or more dissolving solvents, based on the total weight of the spinning solution.

[0056] The dissolving solvent may be any solvent in which the particular cellulose ester is readily soluble. Examples of suitable dissolving solvents for cellulose diacetate include those selected from acetone, methylene chloride, alcohols (e.g., methanol, ethanol), tetrahydrofuran, dimethylformamide, dimethylacetamide, formamide, N-formylmorpholine, N-methyl-2-pyrrolidone, N-methylformamide, N-vinylacetamide or N-vinylpyrrolidone, methyl ethyl ketone, cyclohexanone, diacetone alcohol, ethylene glycol diacetate, or mixtures thereof. Examples of suitable dissolving solvents for cellulose triacetate include those selected from chloroform, methylene chloride, alcohols (e.g., methanol, ethanol), dimethylacetamide, dimethylformamide, formamide, N-formylmorpholine, N-methyl-2-pyrrolidone, N-methylformamide, N-vinylacetamide or N-vinylpyrrolidone, or mixtures thereof.

[0057] The water or moisture content of the spinning solution can be kept relatively low. In one embodiment or in combination with any of the other mentioned embodiments, the moisture content of the cellulose ester spinning solution is no more than 4 wt%, no more than 3.5 wt%, no more than 3 wt%, no more than 2.5 wt%, no more than 2 wt%, no more than 1.5 wt%, no more than 1.4 wt%, no more than 1.3 wt%, no more than 1.2 wt%, no more than 1.1 wt%, no more than 1 wt%, no more than 0.9 wt%, no more than 0.8 wt%, no more than 0.7 wt% or no more than 0.6 wt%, based on the total weight of the cellulose ester spinning solution.

[0058] The cellulose spinning solution may exhibit a desired operating viscosity due to the type of cellulose ester and dissolving solvent used. In one embodiment or in combination with any other mentioned embodiments, the cellulose ester spinning solution may exhibit the following viscosity when measured at the spinning temperature for making the fiber: at least 10 poise, at least 20 poise, at least 30 poise, at least 40 poise, at least 50 poise, at least 60 poise, at least 70 poise, at least 80 poise, at least 90 poise or at least 100 poise and / or no more than 3,000 poise, no more than 2,000 poise, no more than 1,500 poise, no more than 1,000 poise, no more than 950 poise, no more than 900 poise, no more than 850 poise, no more than 800 poise, no more than 750 poise, no more than 700 poise, no more than 650 poise, no more than 600 poise, no more than 550 poise or no more than 500 poise. This spinning temperature is nominally the temperature of the spinning solution as it passes through and enters the spinneret. The viscosity defined herein is the "zero" shear viscosity obtained by extrapolation to very low shear rates when the viscosity is plotted against shear rate, or alternatively by using a Brookfield viscometer with a low spindle RPM. Thus, the "when measured" threshold does not in any way reflect actual cellulose ester spinning dope usage or practice.

[0059] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester spinning solution may exhibit a viscosity of at least 10 poise, at least 20 poise, at least 30 poise, at least 40 poise, at least 50 poise, at least 60 poise, at least 70 poise, at least 80 poise, at least 90 poise or at least 100 poise and / or no more than 5,000 poise, no more than 4,000 poise, no more than 3,000 poise, no more than 2,000 poise, no more than 1,500 poise, no more than 1,000 poise, no more than 950 poise, no more than 900 poise, no more than 850 poise, no more than 800 poise, no more than 750 poise, no more than 700 poise, no more than 650 poise, no more than 600 poise, no more than 550 poise or no more than 500 poise when measured at 25°C, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C or 110°C. It should be noted that this "when measured" standard does not require that cellulose ester spinning dope be utilized only at this specified temperature; rather, this temperature standard merely provides a temperature threshold for measuring the viscosity of the cellulose ester spinning dope. Thus, the "when measured" threshold does not in any way reflect actual cellulose ester spinning dope usage or practice. Viscosity can be measured using a Brookfield viscometer at low spindle RPM.

[0060] In one embodiment or in combination with any other mentioned embodiment, the cellulose ester spinning solution may contain some additives or no additives in addition to the cellulose ester. Such additives may include, but are not limited to, plasticizers, antioxidants, heat stabilizers, pro-oxidants, inorganic substances, pigments, colorants, or combinations thereof.

[0061] In one embodiment or in combination with any of the other mentioned embodiments, the spinning solution comprises no more than 10 wt.%, no more than 5 wt.%, no more than 3 wt.%, no more than 2 wt.%, no more than 1 wt.%, or 0 wt.% of a polymer that is not a cellulose ester, based on the total solids in the spinning solution.

[0062] In one embodiment or in combination with any other mentioned embodiment, the spinning solution comprises no more than 10 wt %, no more than 5 wt %, no more than 3 wt %, no more than 2 wt %, no more than 1 wt % or 0 wt % additives based on the total solids in the spinning solution. Examples of such additives include metal oxides, matting agents, plasticizers, water, biodegradation enhancers and / or fiber lubricants. Depending on the embodiment, when the total weight of one, two, three, four, five or all of the metal oxides, matting agents, plasticizers, water, biodegradation enhancers and / or fiber lubricants is combined in the spinning solution, the spinning solution comprises any one or more of the aforementioned weight % ranges.

[0063] In one embodiment or in combination with any of the other mentioned embodiments, the spinning solution comprises no more than 10 wt%, no more than 5 wt%, no more than 3 wt%, no more than 2 wt%, no more than 1 wt%, or 0 wt% of a combination of additives and polymers that are not cellulose esters, based on the total solids in the spinning solution.

[0064] In one embodiment or in combination with any other mentioned embodiment, the spinning solution is prepared by mixing the cellulose ester, the solvent and any other components at a relatively low temperature. In certain embodiments, this mixing is performed by mixing at a temperature of at least 45°C, at least 46°C, at least 47°C, at least 48°C, at least 49°C, at least 50°C, at least 51°C, at least 52°C, at least 53°C, at least 54°C, at least 55°C, at least 56°C, at least 57°C, at least 58°C, at least 59°C or at least 60°C and / or no more than 140°C, no more than 130°C, no more than 120°C, no more than 110°C, no more than 105°C, no more than 104°C, no more than 103°C, no more than 102°C, no more than 101°C, no more than 100°C, no more than 99°C, no more than 98°C, no more than 97°C, no more than 96°C or no more than 95°C. In certain embodiments, this temperature is between 45°C and 140°C, between 45°C and 105°C, between 47°C and 103°C, or between 50°C and 100°C.

[0065] In one embodiment or in combination with any other mentioned embodiment, this mixing is carried out for at least 5 minutes, at least 6 minutes, at least 8 minutes, at least 10 minutes, at least 12 minutes, at least 14 minutes or at least 15 minutes and / or no more than 48 hours, no more than 36 hours, no more than 24 hours, no more than 20 hours, no more than 16 hours, no more than 12 hours or no more than 8 hours. In certain embodiments, this time is 5 minutes to 48 hours, 5 minutes to 36 hours, 5 minutes to 24 hours or 5 minutes to 8 hours.

[0066] After the cellulose ester spinning solution is formed, it can be sent to an optional spinning solution holding tank for temporary storage and / or degassing. The spinning solution holding tank can include any conventional storage tank known in the art that can store cellulose ester spinning solution. When stored in the holding tank, the cellulose ester spinning solution can be subjected to conditions that are conducive to maintaining the physical properties of the spinning solution and / or removing bubbles introduced during the mixing step. The temperature and pressure of the holding tank and / or the degassing tank can be optimized as needed to enhance and maintain the quality of the cellulose ester spinning solution.

[0067] Then, the cellulose ester spinning solution can be pumped out from the spinning solution storage tank into a filter, which can remove any large and undesirable particles and gels from the cellulose ester spinning solution before spinning. The filter can include any conventional filter device and filter type known in the art. After filtering, the filtered cellulose ester spinning solution can be pumped to a spinneret positioned near or in an evaporation chamber or evaporation bin for dry spinning, or pumped to a coagulation bath for wet spinning.

[0068] The cellulose ester spinning solution can be metered through a spinneret to form one or more fibers. The shape and size of the one or more holes in the spinneret help determine the cross-section of the fiber. The number of holes in the spinneret surface determines the number of fibers that are formed simultaneously when the spinning solution is metered into the spinneret. When the spinning solution passes through the holes in the spinneret surface, a single fiber is formed.

[0069] More particularly, in one embodiment or in combination with any other mentioned embodiment, the cellulose ester spinning solution can be spun at a rate of 10 to 1000 m / min through a spinneret having a design known in the art (e.g., a hole area having a circular diameter equal to 20 to 200 microns). In one embodiment or in combination with any other mentioned embodiment, the spinneret can be maintained at a temperature of at least 50°C, at least 55°C, at least 60°C, at least 65°C, at least 70°C, or at least 75°C and / or no more than 175°C, no more than 170°C, no more than 165°C, no more than 160°C, no more than 155°C, or no more than 150°C. In certain embodiments, the head of the spinneret can be maintained at a temperature in the following range: 50°C to 175°C, 75°C to 175°C, 85°C to 165°C, 95°C to 160°C, or 100°C to 150°C.

[0070] At the spinneret, the cellulose ester spinning solution can be extruded through a plurality of holes to form a continuous cellulose ester fiber. At the spinneret, the fiber can be stretched to form a plurality of independent fibers, or hundreds of independent fibers, or even a bundle of one thousand independent fibers. Each of these bundles may include at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, at least 100, at least 150, at least 200, at least 250, at least 300, at least 350 or at least 400 and / or be no more than 1,000, no more than 900, no more than 800, no more than 700 or no more than 600 fibers. The spinneret can be suitable for any speed operation to produce independent filament fibers, and then these fibers are assembled into a bundle with desired size and shape. As used herein, the term "independent filament fibers" refers to the continuous filaments initially produced by each hole in the surface of the spinneret.

[0071] For dry spinning, the fibers are extruded through a spinneret into a vertical spinning chamber, which may have walls nominally between 150°C and 240°C, and may contain a gas nominally between 200°C and 500°C inside the chamber, in which the solvent is flashed or evaporated. In certain embodiments, evaporation comprises exposing the spun fibers to a temperature of at least 100°C, at least 110°C, at least 120°C, at least 130°C, at least 140°C, at least 145°C, at least 150°C, at least 153°C, at least 155°C, at least 160°C, at least 165°C, at least 170°C, at least 175°C, at least 180°C, at least 185°C, or at least 189°C and / or no more than 500°C, no more than 400°C, no more than 375°C, no more than 350°C, no more than 325°C, no more than 300°C, no more than 275°C, no more than 250°C, no more than 240°C, no more than 230°C, or no more than 220°C. In certain embodiments, this temperature is from 100°C to 500°C, 110°C to 400°C, 120°C to 375°C, 130°C to 350°C, 140°C to 300°C, or 150°C to 250°C.

[0072] For wet spinning, the fibers may be drawn through a coagulation bath comprising a coagulation solvent formed from water or a blend of water and an additional solvent.

[0073] It should be noted that the cellulose ester fibers formed can be in the form of monocomponent fibers formed from only one material (e.g., cellulose ester) or a uniformly blended composition, and therefore, are not considered "bicomponent" or "multicomponent fibers" that are characterized by internal phases or boundaries of different compositions within the outer surface of the fiber. In one embodiment or in combination with any of the other mentioned embodiments, the resulting cellulose ester fibers can contain at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or at least 99.9% by weight of cellulose ester, based on the total weight of the fiber. In certain embodiments, the cellulose ester fibers can be formed entirely of cellulose ester.

[0074] The individual cellulose ester fibers discharged from the spinneret may have any suitable cross-sectional shape. Exemplary cross-sectional shapes include, but are not limited to, circular or shapes other than circular (non-circular). In one embodiment or in combination with any other mentioned embodiments, the individual fibers discharged from the spinneret may have a substantially circular cross-sectional shape. As used herein, the term "cross section" generally refers to the cross section of the fiber measured in a direction perpendicular to the direction of elongation of the fiber. Quantitative image analysis ("QIA") can be used to determine and measure the cross section of the fiber.

[0075] The cross-sectional shape of an individual fiber may also be characterized according to its deviation from a circular cross-sectional shape. In some cases, this deviation may be characterized by the shape factor of the fiber, which is determined by the following formula: Shape Factor = Perimeter / (4π x Cross-sectional Area) 1 / 2 In some embodiments, the shape factor of individual cellulose ester fibers may be from 1 to 2, 1 to 1.8, 1 to 1.7, 1 to 1.5, 1 to 1.4, 1 to 1.25, 1 to 1.15, or 1 to 1.1. A fiber having a perfectly circular cross-sectional shape has a shape factor of 1. The shape factor can be calculated from the cross-sectional area of ​​the fiber, which can be measured using a QIA.

[0076] Furthermore, in certain embodiments, the cellulose ester fibers may be in the form of solid fibers (fibers having a solid cross-sectional shape without the presence of pores therein) rather than hollow fibers.

[0077] In one embodiment or in combination with any of the other mentioned embodiments, at least 20 weight percent, at least 40 weight percent, at least 60 weight percent, at least 80 weight percent, or at least 100 weight percent of the cellulose in the fibers may come from pre-consumer textile waste sources.

[0078] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers and / or yarns produced therefrom may exhibit the following tenacity measured according to ASTM D22556: at least 0.2 g / den, at least 0.3 g / den, at least 0.4 g / den, at least 0.5 g / den, at least 0.6 g / den, at least 0.7 g / den, at least 0.8 g / den, at least 0.9 g / den, at least 1 g / den, at least 1.1 g / den, at least 1.2 g / den, at least 1.3 g / den, at least 1.4 g / den, at least 1.5 g / den, at least 1.6 g / den, at least 1.7 g / den, at least 1.8 g / den, at least 1.9 g / den or at least 2 g / den and / or no more than 3.0, or no more than 2.5, no more than 2.3, no more than 2.1, no more than 2 or no more than 1.9 g / den.

[0079] Elongation, also known as elongation at break, is expressed as a percentage that indicates how much a yarn or filament will be able to stretch before it breaks. In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers and / or yarns produced therefrom may exhibit an elongation at break measured according to ASTM D22556 of at least 10%, at least 15%, at least 16%, at least 17%, at least 18%, at least 19%, at least 20%, at least 21%, at least 22%, at least 23%, at least 24%, at least 25%, at least 26%, at least 27%, at least 28%, at least 29%, or at least 30%.

[0080] The Silk Factor (SF) is an empirically determined relationship between tenacity and elongation that is used to predict the failure envelope of a given fiber. The Silk Factor can be used to characterize the suitability of a yarn or fiber for a given process and is calculated based on the following formula:

[0081]

[0082] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers and / or yarns produced therefrom may exhibit a Silk Factor of at least 5.0, at least 6.0, at least 7.0, or at least 7.6, wherein elongation is defined as a percentage and tenacity is measured in grams per denier.

[0083] In one embodiment or in combination with any other mentioned embodiments, cellulose ester fibers and / or yarns formed therefrom can be biodegradable. As used herein, the term "biodegradable" generally refers to the tendency of a material to chemically decompose under specific environmental conditions. The degree of degradation can be characterized by the weight loss of a sample in a given period of time exposed to specific environmental conditions. In some cases, cellulose ester fibers and / or yarns formed therefrom can show at least 5%, at least 10%, at least 15% or at least 20% weight loss after being buried in soil for 60 days, and / or at least 15%, at least 20%, at least 25%, at least 30% or at least 35% weight loss after being exposed in a composter for 15 days. However, the degradation rate can vary according to the specific end use of the fiber. Exemplary test conditions are provided in U.S. Patent Nos. 5,870,988 and 6,571,802, which are incorporated herein by reference.

[0084] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers and / or yarns formed therefrom can be compostable. In order to be considered "compostable," a material must meet the following four criteria: (1) the material must be biodegradable; (2) the material must be disintegrable; (3) the material must not contain more than a maximum amount of heavy metals; and (4) the material must not be ecotoxic. The term "disintegrable" refers to the tendency of a material to physically break down into smaller fragments when exposed to specific conditions. Disintegration depends on both the material itself and the physical size and construction of the article being tested. Ecotoxicity measures the effect of a material on plant life and is determined according to procedures specified in standard test methods.

[0085] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers and / or yarns formed therefrom can be industrially compostable, home compostable, or both. In such embodiments, the cellulose ester fibers can meet four criteria: (1) biodegradable, in that at least 90% of the carbon content is converted within 180 days; (2) disintegrable, in that at least 90% of the material disintegrates within 12 weeks; (3) does not contain heavy metals exceeding the threshold value determined under the EN12423 standard; and (4) the disintegrated contents serve as humus to support future plant growth; wherein each of these four conditions is tested in accordance with ASTM D6400, ISO 17088, or EN 13432 methods.

[0086] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers and / or yarns formed therefrom may exhibit at least 70% biodegradation within a period of no more than 50 days when tested under aerobic composting conditions according to ISO 14855-1 (2012) at ambient temperature (28°C ± 2°C). In some cases, the cellulose ester fibers and / or yarns formed therefrom may exhibit at least 70% biodegradation within a period of no more than 49, no more than 48, no more than 47, no more than 46, no more than 45, no more than 44, no more than 43, no more than 42, no more than 41, no more than 40, no more than 39, no more than 38, or no more than 37 days when tested under these conditions (also referred to as "home composting conditions"). These conditions may not be aqueous or anaerobic.

[0087] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers and / or yarns formed therefrom may exhibit at least 60% biodegradation within a period not exceeding 45 days when tested under aerobic composting conditions at a temperature of 58° C. (± 2° C.) according to ISO 14855-1 (2012). In some cases, they may exhibit at least 60% biodegradation within a period not exceeding 44 days when tested under these conditions (also referred to as “industrial composting conditions”). These conditions may not be aqueous or anaerobic conditions.

[0088] The newly formed fiber can be accumulated on a core or tube at a winder after evaporation or solvent flashing and can be sent to an optional downstream process. The fiber can be wound on a take-up roll, which provides tension and pulls the fiber into the downstream steps of the process, which can include, for example, one or more annealing sections, a winder, a crimper, a cutter, or a combination thereof.

[0089] The formed cellulose ester fibers can be gathered into bundles, bands or yarns. Bundles, bands or yarns can include a plurality of cellulose ester fibers. Each of these bundles, bands or yarns can include at least 15, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, at least 100, at least 150, at least 200, at least 250, at least 300, at least 350 or at least 400 and / or no more than 70,000, no more than 60,000, no more than 50,000, no more than 40,000, no more than 30,000, no more than 20,000, no more than 15,000, no more than 10,000, no more than 5,000, no more than 1,000, no more than 900, no more than 800, no more than 700 or no more than 600 individual fibers.

[0090] In one embodiment or in combination with any of the other mentioned embodiments, cellulose ester fibers and / or cellulose ester bundles, ribbons or yarns may be passed through a crimping zone wherein a patterned wavy shape may be imparted to at least a portion or substantially all of the individual fibers. When used, the crimping zone includes at least one crimping device for mechanically crimping the fibers. Generally speaking, the cellulose ester fibers are preferably not crimped by thermal or chemical means (e.g., a hot water bath, steam, air jets or chemical coatings), but rather mechanically crimped using a suitable crimping machine. An example of a suitable type of mechanical crimping machine is a "stuffing box" or "stuffing box" crimping machine, which utilizes multiple rollers to create friction, which causes the fibers to bend and form crimps. Other types of crimping machines may also be suitable. Examples of equipment suitable for imparting crimped fibers are described, for example, in U.S. Patent Nos. 9,179,709; 2,346,258; 3,353,239; 3,571,870; 3,813,740; 4,004,330; 4,095,318; 5,025,538; 7,152,288; and 7,585,442, each of which is incorporated herein by reference to the extent not inconsistent with the present disclosure.

[0091] In one embodiment or in combination with any of the other mentioned embodiments, the crimping can be performed so that the cellulose ester fiber has the following crimp frequency measured according to ASTM D3937-12: at least 5, at least 7, at least 10, at least 12, at least 13, at least 15, or at least 17 and / or at most 30, at most 27, at most 25, at most 23, at most 20, or at most 19 crimps / inch ("CPI") . In certain embodiments, the average CPI of fibers used to make cellulose ester tow, tape or yarn and / or various downstream products may be in the range of 7 to 30 CPI, 10 to 30 CPI, 10 to 27 CPI, 10 to 25 CPI, 10 to 23 CPI, 10 to 20 CPI, 12 to 30 CPI, 12 to 27 CPI, 12 to 25 CPI, 12 to 23 CPI, 12 to CPI, 15 to 30 CPI, 15 to 27 CPI, 15 to 23 CPI, 15 to 20 CPI or 15 to 19 CPI.

[0092] In one embodiment or in combination with any of the other mentioned embodiments, when curled, the fiber may have a curl amplitude that varies and may, for example, be at least 0.85, 0.90, 0.93, 0.96, 0.98, 1.00, or 1.04 mm. Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the fiber may have a curl amplitude that is at most 1.75, at most 1.70, at most 1.65, at most 1.55, at most 1.35, at most 1.28, at most 1.24, at most 1.15, at most 1.10, at most 1.03, or at most 0.98 mm.

[0093] Additionally, in one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester fibers, cellulose ester tows, tapes or yarns, and / or staple fibers produced therefrom may have a crimp ratio of at least 1:1. As used herein, "crimp" refers to the ratio of the length of a non-crimped tow to the length of a crimped tow. In certain embodiments, the cellulose ester fibers, cellulose ester yarns, and / or staple fibers produced therefrom may have a crimp ratio of at least 1:1, at least 1.1:1, at least 1.125:1, at least 1.15:1, or at least 1.2:1.

[0094] Curl amplitude and curl rate were measured according to the procedures outlined in U.S. Patent Application Publication No. 2020 / 0299822, which is incorporated herein by reference to the extent not inconsistent with the present disclosure.

[0095] Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, one or more types of surface finishes may be applied to the cellulose ester fibers and / or bundles, ribbons, or yarns formed therefrom. The application method is not limited and may include the use of spraying, wick application, dipping, or the use of squeeze rollers, lick rollers, or kiss rollers. The location where the finish is applied to the fibers may vary depending on the function of the finish. For example, a lubricant finish may be applied after spinning and before crimping, or before the fibers are gathered into bundles. A cutting lubricant and / or an antistatic lubricant may be applied before or after crimping and before drying. Suitable amounts of all finishes on the cellulose ester fibers, whether lubricants, cutting lubricants, antistatic finishes or other finishes, may be at least 0.01%, at least 0.02%, at least 0.05%, at least 0.10%, at least 0.15%, at least 0.20%, at least 0.25%, at least 0.30%, at least 0.35%, at least 0.40%, at least 0.45%, at least 0.50%, at least 0.55%, or at least 0.60% yarn finish ("FOY") relative to the weight of the dry cellulose ester fibers. Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the cumulative amount of finish may be present in an amount of no more than 2.5%, no more than 2.0%, no more than 1.5%, no more than 1.2%, no more than 1.0%, no more than 0.9%, no more than 0.8%, or no more than 0.7% FOY, based on the total weight of the dry fibers. The amount of finish on the fibers (expressed as a weight percent) may be determined by solvent extraction. As used herein, "FOY" or "yarn finish" refers to the amount of finish on the fiber or yarn minus any added water.

[0096] In one embodiment or in combination with any other mentioned embodiment, the cellulose ester fiber may contain at least one plasticizer, or in the alternative, no plasticizer. Based on the total weight of the cellulose ester fiber, the cellulose ester fiber may contain less than 30% by weight, less than 12% by weight, less than 10% by weight, less than 9% by weight, less than 8% by weight, less than 7% by weight, less than 6% by weight, less than 5% by weight, less than 4% by weight, less than 3% by weight, less than 2% by weight, less than 1% by weight, less than 0.5% by weight of at least one plasticizer. When a plasticizer is present, the plasticizer may be incorporated into the fiber itself by spinning a spinning solution containing the plasticizer (contained in a sheet used to make the spinning solution), and / or the plasticizer may be applied to the surface of the fiber or filament by any method used to apply a finish. If desired, the plasticizer may be included in the finish formulation.

[0097] The resulting cellulose ester fibers can be used to produce a variety of intermediate fiber products, such as towbands, staple fibers, filaments, bundles, slivers, bobbins, rovings, yarns and / or bales, as well as final products, such as fabrics, textiles, woven articles (e.g., woven fabrics or textiles), nonwoven articles (e.g., nonwoven webs, fabrics or textiles), knitted textiles, tobacco filters and / or heat-not-burn tobacco products.

[0098] In one embodiment or in combination with any other mentioned embodiments, the cellulose ester fibers and / or cellulose ester yarns described above can be cut into staple fibers. Any suitable type of cutting device can be used, and the cutting device can cut the fibers into desired lengths without excessively damaging the fibers. The example of the cutting device may include, but is not limited to, a rotary cutter, a paper cutter, a pull-off device, a reciprocating blade, or a combination thereof. Once cut, the cellulose ester staple fibers can be packaged or otherwise bagged or packaged for subsequent transportation, storage, and / or use. In one embodiment or in combination with any other mentioned embodiments, the d50 length of the staple fibers may be at least 10, at least 20, at least 30, at least 40, or at least 50 mm and / or be no more than 450, no more than 400, no more than 350, no more than 300, no more than 250, no more than 200, no more than 150, no more than 115, no more than 110, no more than 105, no more than 100, or no more than 95 mm.

[0099] Additionally or alternatively, in one embodiment or in combination with any other mentioned embodiment, the denier per filament (weight in grams for 9000 m of fiber length) or "DPF" of cellulose ester fibers (whether cellulose ester staple fibers or cellulose ester continuous fibers) may be in the range of 0.5 to less than 30, or 0.5 to less than 20. The specific method of measurement is not limited, and includes the ASTM 1577-07 method using the FAVIMAT vibrator procedure (if filaments from which staple fibers are cut are available), microbalance weight measurement of samples with known lengths, or width analysis using any convenient optical microscope or analyzer. DPF may also be related to the maximum width of the fiber.

[0100] In one embodiment or in combination with any of the other mentioned embodiments, the staple fibers may be formed into cellulose ester spun yarns. Spun yarns are continuous strands comprising staple fibers that are mechanically entangled by a staple yarn spinning process. The staple yarn spinning process may be, but is not limited to, ring spinning, open end spinning, air jet spinning, compact spinning, siro spinning, vortex spinning, worsted spinning, semi-worsted spinning, woolen spinning, and flax wet spinning.

[0101] In one embodiment or in combination with any other mentioned embodiments, the cellulose ester fibers can be formed into nonwoven articles, such as nonwoven textiles. Exemplary nonwoven articles can include wet-laid nonwoven articles, air-laid nonwoven articles, carded articles, and / or dry-laid nonwoven articles.

[0102] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester yarn can be formed into a woven article, such as a woven textile. The woven textile can be formed by interlacing at least two yarns (warp yarns and weft yarns) on a loom, wherein the warp yarn strands are oriented in parallel, and the weft yarns are interlaced in an alternating pattern over and under the warp yarns at an angle to the warp yarn orientation.

[0103] In one embodiment or in combination with any of the other mentioned embodiments, the cellulose ester yarn can be formed into a knitted article, such as a knitted textile. Such a knitted textile can be formed from interlocking loops of yarn.

[0104] In one embodiment or in combination with any of the other mentioned embodiments, the final products described herein (including staple fibers, yarns, nonwoven articles, knitted articles, and woven articles) can comprise, consist essentially of, or consist of cellulose ester fibers. The final products described herein, including staple fibers, yarns, nonwoven articles, knitted articles, and woven articles, can contain at least 0.25%, at least 0.5%, at least 0.75%, at least 1%, at least 2%, at least 3%, at least 4%, at least 5%, at least 6%, at least 7%, at least 8%, at least 9%, at least 10%, at least 12%, at least 15%, at least 18%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 45%, at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 99%, or at least 99.9% by weight of one or more cellulose ester fibers, based on the total weight of the article. Additionally or alternatively, in one embodiment or in combination with any of the other mentioned embodiments, the final products described herein (including staple fibers, yarns, nonwovens, knitted articles, and woven articles) may contain no more than 99 weight percent, no more than 95 weight percent, no more than 90 weight percent, no more than 85 weight percent, no more than 80 weight percent, no more than 75 weight percent, no more than 70 weight percent, no more than 65 weight percent, no more than 60 weight percent, no more than 55 weight percent, no more than 50 weight percent, no more than 45 weight percent, no more than 40 weight percent, no more than 35 weight percent, no more than 30 weight percent, no more than 25 weight percent, no more than 20 weight percent, no more than 15 weight percent, no more than 10 weight percent, no more than 9 weight percent, no more than 8 weight percent, no more than 7 weight percent, no more than 6 weight percent, or no more than 5 weight percent of one or more cellulose ester fibers, based on the total weight of the article. In certain embodiments, the final product may be formed entirely from cellulose ester fibers, or contain one or more cellulose ester fibers in a range of 0.25% to 50%, 1% to 99%, 1% to 50%, 50% to 99%, 1% to 20%, or 0.25% to 5% by weight, based on the total weight of the article.

[0105] In one embodiment or in combination with any other mentioned embodiments, the final product described herein may have one, two, three or four properties in any combination of Table B. In one embodiment or in combination with any other mentioned embodiments, the final product will have all five properties of Table B.

[0106] Table B*

[0107]

[0108] *Determined as described in Example 3.

[0109] Each document of Table C is incorporated by reference in its entirety into this specification, to the extent that they do not contradict the statements made herein. In addition, any one or more embodiments disclosed in any one or more documents of Table C may be used in combination with each other and / or with one or more embodiments disclosed herein, to the extent that such combination does not contradict the statements made herein.

[0110] Table C

[0111]

[0112]

[0113] After reviewing the disclosure of this article and the following working examples, the additional advantages of various embodiments will be apparent to those skilled in the art. It should be understood that, unless otherwise specified herein, the various embodiments described herein are not necessarily mutually exclusive. For example, a feature described or depicted in one embodiment may also be included in other embodiments but not necessarily included. Therefore, the present disclosure encompasses various combinations and / or integrations of the specific embodiments described herein.

[0114] definition

[0115] It should be understood that the following is not intended to be an exhaustive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, where context accompanies the use of a defined term.

[0116] As used herein, the terms "a," "an," and "the" mean one or more.

[0117] As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items may be employed alone, or any combination of two or more of the listed items may be employed. For example, if a composition is described as containing components A, B, and / or C, the composition may contain only A; only B; only C; a combination of A and B; a combination of A and C, a combination of B and C; or a combination of A, B, and C.

[0118] As used herein, the terms "comprising," "comprises," "comprise," "contain," "containing," and "contains" are open transition words that are used to transition from the subject matter recited before the term to one or more elements recited after the term, wherein the one or more elements listed after the transition word are not necessarily the only elements making up the subject matter.

[0119] As used herein, the terms "having," "has," and "have" have the same open-ended meaning as "comprising," "comprises," and "comprise" provided above.

[0120] As used herein, the terms "including," "include," and "included" have the same open-ended meaning as "comprising," "comprises," and "comprise" provided above.

[0121] Numerical range

[0122] This specification uses numerical ranges to quantify certain parameters related to the present invention. It should be understood that when numerical ranges are provided, these ranges should be interpreted as providing literal support for claim limitations that only recite the lower limit of the range and claim limitations that only recite the upper limit of the range. For example, the disclosed numerical range of 10 to 100 provides literal support for claims that recite "greater than 10" (no upper limit) and claims that recite "less than 100" (no lower limit).

[0123] In addition, it should be understood that the listing of values ​​following descriptors such as "at least" and "not more than" provides literal support for ranges based on all of the values ​​following the descriptor. For example, a statement specifying "at least 2, 5, or 10 and / or not more than 100, 50, or 25" would provide literal support for ranges of "at least 25," "not more than 50," and "at least 10 and not more than 25."

[0124] Example

[0125] The following examples illustrate the methods according to the present disclosure. However, it should be understood that these examples are provided by way of illustration only, and nothing therein should be construed as limiting the overall scope.

[0126] Example 1

[0127] Thin film preparation and characterization

[0128] 1. Thin Slice Preparation

[0129] Pulp rolls containing cotton linters, which are pre-consumer textile waste, were shredded and the shreds were soaked in glacial acetic acid. After soaking, the cellulose present in the shreds was acetylated with acetic anhydride, followed by partial hydrolysis in the presence of sulfuric acid. Cellulose diacetate flakes were recovered from the solution, washed and dried. This process was repeated three times to generate four cellulose diacetate samples whose cellulose was derived entirely from cotton linters.

[0130] 2. Acetyl content and inherent viscosity of flakes

[0131] The samples were analyzed for acetyl content and intrinsic viscosity ("IV") and compared to a control, which was cellulose diacetate made by the same process except that 100% wood pulp was used.

[0132] To determine the acetyl content, each flake sample was dissolved in acetone by stirring. After dissolution, the sample solution was injected into a liquid chromatography system, where the polymers were separated based on the degree of substitution by reversed phase liquid chromatography. Quantification was performed using an evaporative light scattering detector. The calculation used was as follows:

[0133] Acetyl percentage

[0134] Acetyl weight % = mx CT + b

[0135] in:

[0136] Acetyl weight % = acetyl weight percentage

[0137] m = calibration slope in acetyl weight % min-1

[0138] CT = Peak centroid time in minutes of the polymer sample

[0139] b = y-intercept of the calibration line in acetyl weight %

[0140] Relative acetyl diffusion

[0141]

[0142] in:

[0143] RAS = relative acetyl diffusion

[0144] WDs = time width of the sample peak at one-tenth of its height

[0145] WDc = time width of the reference sample peak at one-tenth the height

[0146] The intrinsic viscosity was determined by first heating the flakes in an MF-50 moisture analyzer at 130°C for about 5 minutes, followed by drying the flakes by heating in an oven at 105°C for 30 minutes. The dried flakes were dissolved in acetone at a concentration of 0.75 g / dL. The samples were injected individually into a relative viscometer, where one capillary measured the pressure of HPLC grade acetone and the other capillary measured the pressure of the cellulose acetate and acetone sample solutions. The ratio of the values ​​was used to determine the relative viscosity. The calculation is as follows:

[0147]

[0148] (relative to the viscosity of the solvent)

[0149] η 比 =η 2相对 -1

[0150] (Specific viscosity)

[0151]

[0152] (Solomon-Gatesman equation for intrinsic viscosity)

[0153] In the above formula, "c" is the viscometer constant, which is defined by the ratio of the two capillaries under baseline conditions, where the system has solvent flowing in both capillaries at a steady pressure.

[0154] Table 1 lists these results.

[0155] Table 1.

[0156]

[0157]

[0158] A Drying was performed in a rotary cone vacuum dryer at 82°C until the moisture content was less than 2%.

[0159] A blend of 67 wt% of Sample #1 flakes (100% wood pulp) and 33 wt% of Sample #8 flakes (100% cotton linters) was prepared and analyzed for acetyl content and inherent viscosity. These results are shown in Table 2.

[0160] Table 2.

[0161] sample %-Acetyl IV (dL / g) Sample #8 remeasured (100% CLP) 39.63 1.69 Sample #9 (Blend - 67% #1: 33% #8) 39.88 1.72

[0162] The foregoing demonstrates that using a flake made from recycled cellulosic material in combination with flake made from conventional wood pulp results in substantially similar flake properties when compared to flakes made entirely from wood pulp and / or flakes made entirely from cotton linter pulp.

[0163] 3. Polymer evaluation

[0164] The corresponding molecular weights and polydispersity index ("PDI") of the cellulose diacetate of samples 2-5 and 8 were determined. The molecular weight was determined by GPC according to ASTM D6474. The molecular weight measurements were used to calculate the PDI, which is defined as Mw / Mn.

[0165] Table 3 presents these results.

[0166] Table 3.

[0167] Sample #2 Sample #3 Sample #4 Sample #5 Sample #8 Mn 50989 45535 48923 44644 43637 M 134078 114945 118888 116502 107451 Mz 259703 216704 225080 223292 202944 PDI 2.63 2.52 2.43 2.61 2.46

[0168] Example 2

[0169] Yarn preparation and characterization

[0170] 1. Yarn Preparation

[0171] Sheets Sample 1 (100% wood pulp), Sample 8 (100% cotton linters), and Sample 9 (blend) from Example 1 were individually dry spun into yarns according to the procedure previously described.

[0172] 2. Polymer Evaluation

[0173] The corresponding molecular weight and PDI of the cellulose diacetate for the yarns formed from Samples 1, 8 and 9 were determined as described in Example 1. Table 4 gives these results.

[0174] Table 4.

[0175] Sample #1 Yarn Sample #8 Yarn Sample #9 Yarn Mn 27547 28528 31551 M 95987 95035 90681 Mz 271412 258648 184139 PDI 3.48 3.33 2.87

[0176] 3. Chip whiteness

[0177] The yarns of samples 1, 8 and 9 were analyzed for chip whiteness. Pressed chips were prepared from washed, dried, ground and pressed acetate fibers. The sample chips were presented and measured using a spectrophotometer in the wavelength range of 380-700 nm. Whiteness results were generated using a whiteness index based on the CIE Ganz82 formula.

[0178] The results are shown in Table 5.

[0179] Table 5.

[0180] sample Slice whiteness Sample #1 Yarn 79.3 Sample #8 Yarn 82.9 Sample #9 Yarn 83.3

[0181] The chip brightness should be 73 or higher, indicating that the use of recycled content as a cellulose source does not adversely affect the yarn.

[0182] 4. Tensile strength

[0183] The yarns of Samples 1, 8 and 9 were analyzed for tensile strength and elongation as described in ASTM D22556. The results are shown in Table 6.

[0184] Table 6.

[0185] sample Elongation at break (%) Toughness (gf / den) Sample #1 Yarn 18.5 1.25 Sample #8 Yarn 19.5 1.25 Sample #9 Yarn 19.9 1.28

[0186] Example 3

[0187] Fabric preparation and dye absorption analysis

[0188] 1. Fabric Preparation

[0189] Yarns from Sample 1 (100% wood pulp), Sample 8 (100% cotton linters), and Sample 9 (blend) as described in Example 2 were individually knitted into 100-GSM (±10) single knit jersey using a 9" diameter 28gg Vanguard knitting machine. The knitted fabrics were heat set in preparation for wet processing. Each pair of samples being compared was moved together through the wet processing sequence in the same dyeing container. Thus, the two samples being compared experienced the same knitting, heat setting, and wet processing conditions. To determine if there were any wet processing differences in the color shade change, four colors were dyed: ivory, harvest gold, gray, and black. The dyed fabrics were dried and conditioned for dye absorption analysis.

[0190] 2. Fabric color comparison

[0191] Paired samples in each dyeing container are measured against each other, with the control sample used as a standard and the experimental sample used as a batch. Both the control sample and the experimental sample are folded to produce eight layers so that no light is transmitted through the fabric. The color coordinates ΔL, Δa, Δb and ΔE CMC are recorded for each measurement. ΔL is a measure of the lightness difference, Δa is a measure of the red / green difference, and Δb is a measure of the yellow / blue difference. ΔE CMC is the total color difference between the two samples measured. Repeat this process for fabrics folded in different ways, still producing eight layers, to take into account any differences caused by the fabric being oriented differently.

[0192] This procedure is used to compare the hue impact of using different pulp sources. The three different comparisons are: 100% wood-based (0% cotton linter) pulp compared to 100% cotton linter pulp; 100% wood-based pulp compared to 33% cotton linter blended pulp; and 33% cotton linter blended pulp compared to 100% cotton linter pulp. The modification to the procedure for this study is that the control sample and the experimental samples were dyed by using two wet processing methods. The two different conditions are: including a control sample and two experimental samples in the same dyeing container, or including a control sample and only one experimental sample in the same dyeing container. The hue data are recorded in Tables 7 to 9, where the different methods are labeled "Two-way comparison" or "Three-way comparison". In most cases, the two-way comparison produces better results than the three-way comparison.

[0193] The results are shown in Tables 7 to 9. In each of these tables, if a standard and batch are designated as "statistically equivalent", this means:

[0194] The ivory data point is below a ΔE CMC of 0.65;

[0195] Harvest Gold data points below a ΔE CMC of 1.25:

[0196] Black data points below ΔE CMC of 0.45:

[0197] The grey data points are all below a ΔE CMC of 0.90; and

[0198] The average ΔE CMC of all grey data points is close to 0.31.

[0199] Based on the data in Tables 7-9, pulp source has a statistically significant effect on dye absorption, especially as the cotton linter pulp content increases.

[0200]

[0201]

[0202]

[0203]

[0204]

[0205] The claims are not limited to the disclosed embodiments

[0206] The preferred forms of the present invention described above are intended to be used as examples only and should not be used in a limiting sense to interpret the scope of the present invention. The exemplary embodiments set forth above may be easily modified by those skilled in the art without departing from the spirit of the present invention.

[0207] The inventors hereby declare that it is their intention to determine and assess the fair and equitable scope of the present invention under the doctrine of equivalents as it relates to any device that does not materially depart from the literal scope of the present invention as set forth in the following claims.

Claims

1. A method comprising reacting an esterifying agent with cellulose to form a cellulose ester, wherein at least a portion of the cellulose is derived from pre-consumer textile waste.

2. The method according to claim 1, wherein the pre-consumer textile waste is selected from cotton linters, bottom combing materials, fabric scraps, cattle feed waste, comber protrusions, end-break suction device waste, soft recycled wool waste, yarn waste, production waste, cutter scraps, twisting waste or a mixture thereof.

3. The method according to any one of the preceding claims, further comprising mechanically conditioning a dissolving pulp prior to said reacting, wherein said dissolving pulp comprises said cellulose.

4. The method of claim 3, wherein the dissolving pulp is in the form of a sheet or a coil and the mechanical conditioning comprises forming the sheet or coil into smaller pieces.

5. The method according to any one of the preceding claims, further comprising soaking the dissolving pulp in acetic acid and / or water prior to the reacting.

6. A method according to any one of the preceding claims, wherein the esterification agent comprises an acetylating agent.

7. The process according to any one of the preceding claims, wherein the reaction is carried out in the presence of acetic acid, a catalyst, or both acetic acid and a catalyst.

8. The method of any one of the preceding claims, wherein the cellulose ester comprises cellulose triacetate, and the method further comprises hydrolyzing the cellulose triacetate to form cellulose diacetate.

9. The method according to any one of the preceding claims, further comprising forming the cellulose ester into a cellulose ester sheet (I).

10. The method of claim 9, further comprising mixing the cellulose ester flakes (I) with cellulose ester flakes (II) to form a flake blend, wherein the cellulose ester flakes (II) are not formed from cellulose derived from pre-consumer textile waste.

11. The method of claim 10, wherein if the pre-consumer textile waste comprises cotton linters, the flake blend comprises no more than 95 wt%, no more than 90 wt%, no more than 85 wt%, no more than 80 wt%, no more than 75 wt%, no more than 70 wt%, no more than 65 wt%, or no more than 60 wt% of cellulose esters formed from cellulose derived from cotton linters, based on the total weight of the flake blend.

12. The method of any one of the preceding claims, further comprising spinning a cellulose ester spinning solution comprising the cellulose ester through a spinneret to produce one or more spun fibers.

13. The method according to claim 1, further comprising at least one of the following: evaporating the solvent from the one or more spun fibers; or The one or more fibers are drawn through a coagulation bath.

14. A method for producing cellulose ester fibers, the method comprising: Breaking coils and / or sheets of dissolving pulp into smaller pieces, the dissolving pulp comprising Recycled pre-consumer textile waste containing cellulose; The cellulose is reacted with an esterifying agent to form Cellulose ester: and a spinning solution containing the cellulose ester The fibers are spun through a spinneret to produce one or more cellulose ester fibers.

15. The method according to claim 14, wherein the pre-consumer textile waste is selected from cotton linters, bottom combing material, fabric scraps, cattle feed waste, comber protrusions, end-break suction device waste, soft recycled wool waste, yarn waste, production waste, cutter scraps, twisting waste or mixtures thereof.

16. The method according to claim 14, further comprising forming the cellulose ester into a cellulose ester sheet (I).

17. The method of claim 14, further comprising mixing the cellulose ester flakes (I) with cellulose ester flakes (II) to form a flake blend, wherein the cellulose ester flakes (II) are not formed from cellulose derived from pre-consumer textile waste.

18. The method of claim 14, wherein if the pre-consumer textile waste comprises cotton linters, the flake blend comprises no more than 95%, no more than 90%, no more than 85%, no more than 80%, no more than 75%, no more than 70%, no more than 65%, or no more than 60% by weight of cellulose esters formed from cellulose derived from cotton linters.

19. A cellulose ester fiber formed according to any one of the preceding claims.

20. An article comprising cellulose ester fibers formed according to any one of claims 1 to 19.

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