Processes and systems for recycling elastane from textiles and its reuse

Abstract

Described herein are methods for recycling and purifying elastane from textile waste of various compositions as well as methods for converting the purified recycled elastane into new ready to use fibers for garment manufacturing or other uses.

Description

PROCESSES AND SYSTEMS FOR RECYCLING ELASTANE FROM TEXTILES ANDITS REUSECROSS-REFERENCE TO RELATED APPLICATION

[0001] This Application claims the benefit of provisional U.S. Application No. 63 / 662,628, filed on June 21, 2024, and entitled “TEXTILE RECYCLING PROCESS AND SYSTEM” which is hereby incorporated by reference in its entirety.

[0002] In cases where the present application conflicts with a document incorporated by reference, the present application controls.FIELD

[0003] The present disclosure relates generally to textile recycling. More specifically, the present disclosure relates to processes for recycling elastane from textile feedstocks and reusing the recycled elastane. These processes may be performed in a modular textile recycling system for processing textiles, including but not limited to post-consumer and post-industrial textiles.BACKGROUND

[0004] Textile waste is a significant waste stream that is currently difficult to abate, and a large percentage of both pre-consumer and post-consumer textile waste (including garments, as well as other sources such as homeware or hospitality) currently ends up in landfills or is incinerated. Textile recycling currently requires collecting and transporting post-consumer and post-industrial textiles to a specialized facility that can recycle these materials for re-use into new fibers and textiles. However, collecting, sorting, and transporting post-consumer and postindustrial textiles to the appropriate centralized recycling facility introduces significant cost into the recycling process, reducing the incentive for businesses and consumers to recycle textiles and thus creating textile waste. There are many challenges in the recycling of textiles, but a key roadblock is the presence of unwanted materials, such as dyes and other non-textile materials, and also the presence of polymers such as elastane (polyurethane elastomers) in the form of fibers or coatings on fibers or textiles which are the target of a recycling process.

[0005] Elastane (also known as “spandex” and marketed under trade names such as “Lycra”) is present in large amounts in textiles both synthetic (polyester, nylon) and natural (cotton, rayon), and often presents problems in recycling processes. Such elastane is present either as elastane fibers or as a coating on the textile material and / or fibers of the textile material. In large amounts, elastane may hinder extrusion with melt based “mechanical” recycling and affect the properties of the resulting fibers. Elastane, being a polyurethane, is also susceptible to glycolysis and hydrolysis reactions similar to those used in so called “chemical” recycling of polyethylene terephthalate (PET) and polyamides, and thus can contaminate the monomer products of these processes with unwanted side products. The presence of dyes is also a hindrance, as it means that either non-specific colored products or only specific single-colored products can be produced, necessitating pre-sorting by color. There are also a wide range of both organic and inorganic potential additives and coatings that could interfere with potential mechanical or chemical recycling techniques. Finally, other synthetic textile fibers such as acrylic can be present in small amounts, especially in blends with other synthetics or natural fibers such as wool, which can also present problems.

[0006] Some processes for the removal of elastane from both synthetic and natural textile materials have been developed. In W02013032408A1, elastane fibers are removed from polyamide textiles through a controlled thermal degradation process in an inert atmosphere, followed by washing with a polar solvent, such as ethanol, followed by subsequent purification of the solvent. W02020130825A1 demonstrates the removal of polyurethane fibers from cellulose-based textiles, where the cellulose-based textile is subjected to a combination of amines, a polar solvent such as DMF, and glycol and heat in order to remove the polyurethane via a degradative mechanism, which may be undesirable. In U.S. Patent 11,085,148, dyes are removed from textiles using a hydrothermal process combined with a sorbent material, in a pressurized reactor. In U.S. Patent 11,001,961, an oxidative method with peroxide, iron water, and acetone mixtures is used to decolor polyester textiles. These existing processes may have various shortcomings still unaddressed by the state of the art.SUMMARY

[0007] A modular textile recycling system is described, as well as various processes for textile recycling including a method for recycling and purifying a target polymer or polymers ina blended textile or mixture of textiles, via dissolution of a non-target polymer(s) and other auxiliary components, to provide a purified target polymer(s) for downstream recycling via various methods. In some embodiments, the non-target polymer(s) are also recovered for further processing and reuse. In accordance with the present disclosure, described herein is a method of treating waste textiles, both synthetic and natural, for recycling that separates target and non- target polymers and removes other auxiliary components, such as dyes and various coatings or additives. The textile can include, for example, polyester and elastane blends, cotton and elastane blends, nylon and elastane blends, polycotton and elastane blends, or other mixtures including polymers such as acrylic, where one or more specific materials or polymers are the intended target and non-target polymer(s) or material(s) for further downstream recycling.

[0008] A purification method according to some embodiments aims to minimize degradation and yield loss of the target polymer in textile waste, by minimizing interaction between the solvent and the target polymers for downstream recycling and keeping conditions as mild as possible. To that end, the process utilizes a set of solvents that dissolves elastane and / or other auxiliary components, whilst having a low boiling point as possible, lower than the melting point of synthetic fibers (i.e., PET), such that the target polymer is not readily dissolvable in the solvent, being selective for only the non-target polymers and auxiliary components. This forms a departure from solvent-based recycling processes, where the target polymer is usually dissolved and regenerated, often under harsh conditions including high temperatures, pressures, or vacuums. In contrast, in accordance with the present disclosure, only the non-target polymers and auxiliary components, including dyes, are dissolved, under mild conditions, leaving the target polymers in the textile undisturbed for further processing, for example, by melt extrusion, after removal of the residual solvent on the textile. Additionally, the non-target polymers such as elastane, once dissolved in the solvent, can be recycled following the removal of the auxiliary components and reused in the production of new textiles. As such this process can also be referred to as a “purification” process for the target and non-target polymers in the textiles prior to recycling, which avoids the need for more energy intensive “chemical” recycling, such as depolymerization. An additional advantage may be provided in that the auxiliary components, such as dyes, and non-target polymers, such as elastane, are removed from the textile materials in separate and distinct steps, as opposed to a single step, with only one kind of chemical required, where previously more complex mixtures of chemicals were needed. The process can also beapplied to mixtures of natural fibers such as cotton mixed with elastane, or wool mixed with acrylic and elastane, or even polycotton blends mixed with elastane, in order to prepare them for downstream mechanical recycling (i.e., opening, carding and yarn spinning) or to prepare cotton as a feedstock for man-made cellulosic fiber (rayon) production, or to recover the elastane for reuse.

[0009] In one aspect of the present disclosure, a method for recycling elastane is provided. The method includes providing a textile feedstock comprising a plurality of polymers and one or more auxiliary components, the plurality of polymers comprising elastane; contacting the textile feedstock with an organic solvent, the organic solvent comprising cyclohexanone, cyclopentanone, or a mixture thereof; at a first temperature, dissolving or suspending at least a portion of the one or more auxiliary components in the organic solvent; separating at least a portion of the organic solvent containing the dissolved or suspended one or more auxiliary components from the textile feedstock to provide a pretreated textile feedstock; and at a second temperature, greater than the first temperature, contacting the pretreated textile feedstock with an additional portion of the organic solvent to dissolve the elastane therein, thereby generating an elastane-containing solution.

[0010] The subject matter disclosed herein is described further below, with references also to the various embodiments and examples provided for further illustration in the detailed description that follows.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate examples of the disclosure and, together with the description that follows, serve to explain the principles of these examples.

[0012] FIG. 1 is a block diagram of a modular textile recycling system according to some embodiments of the present disclosure.

[0013] FIG. 2 is a block diagram of polyester material post processing portion of a modular textile recycling system according to some embodiments of the present disclosure.

[0014] FIG. 3 is a block diagram of a cellulose recovery portion of a modular textile recycling system according to some embodiments of the present disclosure.

[0015] FIG. 4 is a block diagram of another example of a cellulose recovery portion of a modular textile recycling system according to some embodiment of the present disclosure.

[0016] FIG. 5 is a block diagram of another cellulose processing module of the modular textile recycling system according to some embodiments of the present disclosure.

[0017] FIG. 6 is an illustrative rendering, provided for scale, of a modular textile recycling system according to some embodiments of the present disclosure.

[0018] FIG. 7 shows a solvent purification process according to some embodiments of the present disclosure.

[0019] FIG. 8 shows representative experimental conditions illustrating optimized elastane recovery conditions.

[0020] The drawings are not necessarily to scale. In certain instances, details unnecessary for understanding the disclosure or rendering other details difficult to perceive may have been omitted. In the appended drawings, similar components and / or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a letter that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label. The claimed subject matter is not necessarily limited to the particular examples or arrangements illustrated herein.DETAILED DESCRIPTION

[0021] The present disclosure describes a compact modular textile recycling system and associated process for recycling post-consumer and post-industrial textiles into new, ready-to-use fibers for garment manufacturing or other uses. When describing the compact, module recycling plant, the term portion, unit, or module may be used interchangeably to refer to a sub-assembly of the recycling plant, in some cases a single or a set of module units that can be removed and / or interchanged with other unit(s) having a different configuration, and which implement a different process or set of processes, which together form the full textile recycling process from textile waste to new fiber or textile (e.g., fabric, garment, or textile for another use). Inputs to the modular system include textile waste in the form of mixed, unsorted post-consumer and postindustrial textiles. The outputs of the modular system may include synthetic feedstocks, such asdensified polyester pellets or polyurethane (e.g., elastane) spinning solutions, one or more synthetic fibers, such as polyester fiber, and in some cases, a finished (e.g., woven, knitted, etc.) bulk fabric or ready-made textile product (e.g., a particular type of garment or other type of textile product). In accordance with examples of the present disclosure, used, mixed composition post-consumer and post-industrial textiles are taken and turned into new readymade garments, in one compact, modular system and associated processes. In other embodiments, fibers for manufacturing textiles or textile garments are produced in accordance with embodiments of the present disclosure. The term “used” may imply that the mixed textile supply is comprised of post-consumer or post-industrial textiles. It should be understood that post-industrial textiles may include pre-consumer textile waste. The term “mixed” when referring to the textile feedstock or supply herein may refer to the textile feedstock or supply comprised of different types of textile materials which may be interwoven, knitted, or otherwise fixed (e.g., stitched or glued) together to form a mixed material textile and / or to textiles that combine the different types of materials (e.g., polyester such as PET, elastane, dyes, etc.) into the fibers from which a particular textile is made (e.g., knitted or woven). In accordance with examples of the present disclosure, the modular system can accept a wider variety of types of textile waste and is configured, in some cases, to recycle the textiles, from waste to fibers ready for transformation into textiles, into textiles or into finished garments in a single system. The modularity of the system enables reconfiguration of the system for a particular use or customer segment, allowing it to be more easily integrated into the current operations of many different partners in the waste and value chain. Moreover, the modularity of the system enables easy expansion of the system and process embodied therein into additional / different fiber types as needed. However, as textile recycling of multiple different materials may be enabled by the modular system described herein, in some embodiments, the system may be specifically configured to process a used textile input (or supply) primarily comprised of a single type of material (e.g., used polyester fabric, used cotton, viscose or rayon fabric with a polyurethane, such as elastane fiber or coating) and / or to produce an output comprised primarily of a single type of material (e.g., recycled polyester or elastane). That is, in some embodiments, it may be advantageous to configure a portable recycling plant specifically tailored for extracting a single specific material (e.g., polyester or elastane) and producing recycled fibers of that material (e.g., recycled polyester fibers or elastane), without preserving or recycling any other components ofthe mixed textile supply. The system according to some embodiments is designed to have a small footprint (e.g., the size of one or up to a few shipping container sized boxes) and be portable (e.g., substantially fully contained in an enclosure that makes transportation and placement in a desired location easy), such that a fully self-contained automated recycling plant may be co-located with a post-industrial source location (e.g., a garment or other textile product manufacturer or retailer) or other post-consumer textile waste collection point (e.g., Salvation Army, Good Will, or other companies accepting clothing donations, many of which are often unsuitable even for second-hand retail). While described here primarily in the context of clothing recycling, it will be understood that the examples disclosed herein may have application to the recycling of a variety of other textile waste, such as hospital linens, carpets (e.g., remnants or poor quality batches, etc.), and many other types of textile waste.Temperature and Wash Procedure Optimization

[0022] In some embodiments, the methods disclosed herein involve a two-stage washing process using an organic solvent to remove auxiliary components and elastane from a textile feedstock. As used herein, the term “auxiliary components” refers to non-fibrous materials that are incorporated into or applied onto a textile to impart functional, aesthetic, or processing- related properties, and which are distinct from the fiber- forming polymers that make up the textile’s structural matrix. The auxiliary components may include, but are not limited to, dyes, additives such as UV stabilizers, flame retardants, and antimicrobial agents, coatings such as water-repellent finishes and binders, and surfactants. Examples of organic solvents suitable for this two-stage washing process include, but are not limited to, a cyclic ketone of a general structure (Cth CO, wherein n=4, 5, 6, or 7. In some embodiments, the organic solvent comprises cyclohexanone, cyclopentanone, or a mixture thereof. In some embodiments, the organic solvent is cyclohexanone. In some embodiments, the organic solvent is a mixture of cyclohexanone and cyclopentanone. In some embodiments, the mixture may include cyclopentanone in an amount from about 1 wt% to 50 wt%, for example, about 5 wt%, about 10 wt%, about 15 wt%, about 20 wt%, about 25 wt%, about 30 wt%, about 35 wt%, or about 40 wt%. In some embodiments, an aprotic solvent may be additionally included with the cyclic ketone solvent to further enhance the removal efficacy. In some embodiments, the aprotic solvent may include dimethylsulfoxide, N-methyl-2-pyrrolidone, dimethylacetamide, dimethylformamide, bio-based alkyl esters, such as alkyl lactates (e.g., ethyl lactate), tetrahydrofurfural alcohol, diacetone dialcohol, or isophorone

[0023] A first washing stage is performed to remove the auxiliary components from the textile feedstock, yielding a pretreated textile feedstock for subsequent elastane extraction. The first washing stage is typically carried out at relatively moderate temperatures, ranging from approximately ambient room temperature (~20 °C) up to about 100 °C, preferably from about 90 °C to 95 °C, which experimentation has demonstrated as optimal for removing the auxiliary components including dyes or other non-fibrous materials while simultaneously preserving the integrity and quality of elastane and other polymers present within the textile waste. It has further been experimentally demonstrated that maintaining shortened wash durations of less than 30 minutes, for example, about 10 minutes during this first washing stage provides significantly increased retention of elastane (for instance, elastane retention increasing from approximately 33.3% to approximately 45.9% relative to standard, longer-duration wash conditions of about 30 minutes). Such explicitly optimized wash conditions provide considerable advantages in maintaining elastane quality while still effectively removing the auxiliary components.

[0024] A second washing stage, distinguished by notably higher solvent temperatures greater than 100 °C (for example, between 100 °C and 160 °C, preferably from 120 °C to 130 °C), is subsequently performed to facilitate the selective and substantially complete dissolution and recovery of elastane from the textile substrate. In certain embodiments, solvent conditions may even include superheated solvent (e.g., cyclohexanone) carried out under pressurized conditions to provide maximum elastane extraction performance. In some embodiments, the solvent (e.g., cyclohexanone) is heated to a temperature ranging from 160 °C to 200 °C under a pressure ranging from 2 atm to 10 atm. Agitation by mechanical stirring, ultrasonic, or circulation mixing may be performed to help achieve uniform elastane solubilization. Following dissolution, coarse filtration or mechanical separation (e.g., centrifugation, filtration under vacuum, or mechanical passing through screening filters) may be performed to remove undissolved textile residues (e.g., non-elastane fibers) and other large particulate impurities. The dissolved elastane in the solvent may then be purified by a high-temperature purification process described in detail below.High-Temperature Elastane Purification

[0025] In some embodiments, purification of elastane is carried out at temperatures greater than 80°C, for example, at temperatures at least 100°C, and most preferably above 110°C, ensuring stable elastane solubility throughout. In some embodiments, the purification of elastane is performed at a temperature ranging between 80 °C to 180 °C.Membrane-Based Elastane Purification

[0026] In some embodiments, the elastane-containing solution may be subjected to a membrane-based filtration purification process under maintained elevated temperature conditions. The elastane-containing solution temperature is carefully maintained above approximately 80 °C, preferably above approximately 100 °C, and more preferably above approximately 110 °C throughout the membrane filtration process. Such elevated temperature conditions maintain elastane solubility, prevent undesirable deposition or viscosity increases in the membrane apparatus, and significantly optimize membrane flux.

[0027] In some embodiments, membrane separation may be accomplished using ceramic or polymeric ultrafiltration or nanofiltration membranes compatible with elevated-temperature elastane-containing solutions. Membranes with molecular weight cutoff (MWCO) ranges capable of retaining the elastane while allowing dissolved auxiliary components such as dyes, oligomers, stabilizers, and additives to permeate are selected.

[0028] In some embodiments, because the elastane fraction remains in the retentate, a diafiltration step may be applied to optimize the elastane purity. During diafiltration, fresh and / or purified solvent (e.g., cyclic ketone such as cyclohexanone) may be continuously or periodically introduced into the retentate reservoir simultaneously as permeate fractions containing dissolved auxiliary components are removed. Multiple cycles of diafiltration may be performed to reach the desired elastane purity and reduced concentration of the auxiliary components, each increment of diafiltration clearly improves elastane purity.Adsorption-Based Elastane Purification

[0029] Alternatively or additionally, the elastane-containing solution at elevated temperatures above 80 °C, preferably above 100 °C, and even more preferably above 110 °C may be purified via adsorption techniques. In some embodiments, adsorbents specificallychosen for effectiveness at high operational temperatures, such as activated carbon and polymeric adsorption resins compatible with cyclic ketones such as cyclohexanone at elevated temperature conditions, are utilized. In some embodiments, the elastane-containing solution is purified by adsorbing non-elastane components using active carbon and / or polymeric adsorption resins at temperatures ranging from 80 °C to 150 °C (preferred at temperatures above 110 °C).

[0030] Adsorption purification may be performed by either batchwise adsorption (where the elastane-containing solution is continuously or repeatedly recirculated through a heated adsorption column containing the adsorbent) or via a single-pass adsorption operation for achieving purification in one continuous pass through a high-temperature adsorbent bed.

[0031] In both recirculating and single-pass modes, auxiliary components and impurities, including colorants, degradation products, residual chemical additives, and small-molecule organic impurities, are effectively adsorbed onto the chosen adsorbent material, resulting in measurable improvement of elastane solution purity, particularly color removal. Experimental results confirm that maintenance of high-temperature conditions significantly enhances adsorption performance and elastane solution purity.Precipitation-Based Elastane Purification

[0032] Following high-temperature membrane filtration or adsorption purification, the elastane-containing solution may be subjected to precipitation to recover solid elastane fibers or polymer fractions ready for downstream processing.

[0033] In some embodiments, after removal from the textile, elastane may be purified through precipitation of an elastane-containing solution, initially at temperatures ranging from 80 °C to 150 °C, using one or more of the following methods:(1) Anti-solvent precipitation: Elastane is precipitated by controlled addition of one or more anti-solvents (e.g., water and / or low-solubility organic solvents) to the elastane- containing solution. The anti-solvent substantially reduces elastane solubility and yields elastane precipitate suited for subsequent drying;(2) Temperature-induced precipitation: Lowering the temperature of elastane- containing solution below the elastane solubility threshold (e.g., below 50°C) induces elastane crystallization or precipitation. This technique is useful if solvent recycling via subsequent distillation at low temperatures is desired and solvent retention is prioritized; and(3) Solvent evaporation precipitation: Elastane precipitation via controlled evaporation (thermal or vacuum treatment) of the solvent (e.g., cyclohexanone) to progressively increase elastane concentration, thereby causing elastane to precipitate as the solvent is removed. The removed solvent may be condensed, purified, and reused with considerable environmental and economic benefits.

[0034] Compared to conventional ambient-temperature DMAc / DMF-based elastane dissolution processes, the high temperature elastane purification process disclosed herein, initiated at elevated temperatures of no less than 80 °C, allows the use of safer cyclic ketone solvents such as cyclohexanone. The reduced toxicity significantly enhances worker safety, simplifies material handling, and improves environmental compliance. Advantages of using cyclic ketone solvents such as cyclohexanone include:Industrial- scale adaptability: Cyclohexanone offers superior compatibility with industrial equipment (e.g., seals, pumps, pipelines), substantially improving process sustainability and reducing maintenance expenses;Enhanced elastane quality: The purified elastane achieved herein demonstrates lower coloration and contaminant levels but with improved elastic properties matching or surpassing those of virgin; andImproved sustainability: Solvent reuse following solvent recovery and purification significantly reduces overall solvent consumption.Solvent Reuse and Mechanical Optimization

[0035] The present disclosure also describes specific optimized solvent reuse conditions and mechanical treatment enhancements. In particular embodiments, solvent recovery and reuse are explicitly enabled and optimized by ensuring that reused solvent streams consistently maintain a concentration of impurities (such as dyes, additives, or other textile residues) substantially lower than the impurity concentration within the textile feedstock stream subject to washing treatment. Such impurity concentration-based reuse strategy ensures washing and extraction effectiveness, maximizing both environmental benefits and cost efficiency.Downstream Fiber, Yarn, Textile and Garment Applications

[0036] Elastane recovered explicitly according to the methods disclosed herein is advantageously suitable for downstream applications. Specifically, reclaimed elastane may be directly spun or otherwise processed into fibers suitable for manufacturing yarns with elastic properties matching or comparable to fibers obtained from virgin elastane materials. Such reclaimed elastane fibers may optionally be blended at any desired ratio (1% to approximately 100%) with virgin elastane fiber feedstock, depending on application requirements and desired textile elasticity or other mechanical or aesthetic properties. Subsequently, yarns thus produced are explicitly suitable for downstream textile formation employing weaving, knitting, nonwoven formation, or other appropriate textile-forming techniques. The resulting textiles or fabrics have suitability for multiple end-use purposes, especially the formation of garments including elastic apparel, compression garments (e.g., medical or sportswear applications), elastic industrial textiles (e.g., straps, bands), medical textile products (e.g., bandages, compressive wrappings), athletic garments, and related textile products. These explicit downstream product-by-process embodiments provide considerable strategic advantage in ensuring commercial protection against international trade of items derived from unauthorized use of the recycling methods herein described.

[0037] Furthermore, efficacy improvements are explicitly achieved in certain embodiments by introducing mechanical extraction techniques, including squeezing, pressing, screw-pressing, roller pressing, and similar mechanical methods either during the washing stage or after washing steps to mechanically facilitate removal of solvents carrying dissolved impurities. Such mechanical optimization results in substantially improved solvent recovery and enhanced elastane yield.

[0038] The target and non-target recycling and reuse may be carried out in a textile recycling system disclosed herein.

[0039] FIG. 1 shows a block diagram of a compact and modular textile recycling system (or plant) 100 according to embodiments of the present disclosure. The system 100 is modular in that subsystems (also referred to as processing blocks or modules) of the larger recycling system can be removed, interchanged, and / or added to obtain a resulting substantially fully contained recycling plant, with different outputs and / or configured to receive different inputs, all within a similar compact scale envisioned by the present disclosure. Such modularity may enabledifferent configurations of the recycling plant to be co-located with different sources of textile waste, with each specific configuration of the recycling plant uniquely configured for the textile waste at that location. The terms compact and / or portable herein generally imply a size that is sufficiently small to enable transportation (in some cases, in sub-sections of the modular system) and co-location with the source of the textile waste, such as near a textile / clothing store, hospital, or other. As shown in the example in FIG. 1, the system 100 includes a plurality of modules (e.g., Modules A-I), each of which is configured to perform a specific task or collection or related tasks of the textile recycling process, all arranged together into a compact form factor, such that the recycling process proceeds in a substantially automated manner (without human involvement in the recycling process). While the modular recycling system 100 in the example of FIG. 1 is shown as including a certain number of modules, in other embodiments, the modular recycling system (or plant) 100 may include a different number of modules. Stated differently, one or more of the modules, particularly downstream modules such as the elastane recovery unit (Module B), the yam spinning, clothing manufacturing unit (Module H), and / or others may be removed and / or replaced with other modules. The system 100 performs processing on a textile supply (e.g., used mixed textiles) to recycle at least a portion of the supply into at least one type of recycled textile fiber(s), which can then be used for clothing manufacture or other uses.

[0040] The input into the modular system 100 is textile waste in the form of unsorted textiles, mixed textiles or presorted textiles. For example, the unsorted mixed textiles that can be input into the system 100 may include mixed material whole clothing items, single or mixed material postindustrial fabric scraps, single or mixed material rolls or bolts of waste fabric, reject or overproduction material from fiber, yarn, or non-woven textile material production facilities, and / or any other textile fiber waste. In some embodiments, the unsorted mixed textiles may be scraps of fabric of any type (or of different types) which may include impurities, such as synthetics (e.g., elastane, glue, etc.) and non-textile bits such as buttons, zippers, staples, grommets and other metallic or non-metallic components that are frequently added to textiles in a specific application. The output(s) of the system may be one or more different types of fibers (e.g., polyester, such as a polyethylene terephthalate (PET) fiber and / or a polyurethane fiber, e.g., elastane), and in some cases processed (e.g., knitted, woven, etc.) fabric or even a finished garment (e.g., socks, scarves, etc.). In other cases, the output of the system can be feedstock for use in formation of fibers, e.g., spinning of polyurethane (e.g., elastane) fibers. The inputs(textile waste) proceed through the compact recycling system 100 in a substantially fully automated manner and are converted to feedstocks for fiber forming processes, ready-to-use fibers, fabrics or garments, as is described further below. In conventional textile recycling, garments that are not able to be resold for a second use are typically resized or shredded for use in applications such as cloth wipers or stuffing / padding, which is sometimes known as downcycling, turning them into an unrecoverable end of life product. Some fractions of waste, such as good quality cotton and wool free of other polymers or contaminants can also be turned into yarns by “mechanical recycling” methods, but this is limited in scope and typically produces lower quality fibers than their virgin equivalents.

[0041] Referring to the example in FIG. 1, the recycling process begins with a sorting process, shown at block 110, and implemented by a sorting module, referred to herein as Module A. The sorting process (block 110) may involve any combination of sorting, cleaning, shredding and metal removal, as well as any other pre-processing of the textile waste input before it is provided to downstream, chemical processing. The sorting module may be implemented as a mostly electro-mechanical system including one or more mechanical and / or electrical components (e.g., conveyer belt(s), shredder, magnetic demetaler and an eddy current nonferrous ejector, NIR or hyperspectral camera and associated algorithms for object recognition in the sorting process, etc.) operatively arranged to sort, clean (e.g., remove various contaminants), and shred textiles in preparation for solvent processing. Different configurations of the sorting module may be provided in the system 100 of FIG. 1 depending on the source of the waste (e.g., post-consumer mixed material clothing waste vs post-industrial single material fabric waste) expected to be input into the system. As such, and depending on the configuration of the system (e.g., the input fabric waste expected), the NIR or hyperspectral camera and associated sorting algorithm may be differently configured. The sorting process may involve sorting textile components from non-textile components in the textile waste input, and in some cases additionally and optionally sorting the textile waste into different waste processing streams based upon the textile composition (e.g., separating polyester containing textile waste from textile waste that does not contain polyester).

[0042] The sorting module may perform an initial cleaning, for example using CO2 and / or other industrial dry-cleaning techniques when the system is utilized for the recycling of textiles of unknown cleanliness. The mixed textile waste may preliminarily be roughly sorted atthe garment level in embodiments configured to recycle clothing. In other embodiments, an initial sorting based on some other macro-level category of the textile waste may be performed. A combination of an NIR or hyperspectral camera for identification of materials, followed by a mechanical resultant action that sorts the clothing items into major categories may follow the cleaning step to optimize the output of the sorting module for chemical processing by the downstream modules (e.g., modules B, E, and F, which will be further described below). In some embodiments, the sorting process may utilize one or more machine learning models, properly trained to identify, from the images captured by the camera directed to the appropriate portion of the conveyor system, different types of fabrics, fabric compositions and / or contaminants. A batch of materials is then shredded into “confetti”, for example of approximately 1 cmxl cm size. The resultant shredded material (or confetti) may then be sorted by density. Any suitable density sorting technique may be used. For example, the shredded material may be spread appropriately (e.g., lengthwise along the conveyor belt) and may pass across a gap that includes moderate airflow, separating denser materials (e.g., buttons, zippers, “comers”) from the fabric materials. Additionally, or alternatively, a magnetic demetaler and an eddy current non-ferrous ejector unit may be used to remove smaller metal contaminants.

[0043] As noted, the sorting module A may be configured to receive, as input, textile waste in the form of mixed textiles, sorting and pre-processing the textile waste in a manner that separates the textile waste into a predetermined number of waste streams, each optimized for the particular type of downstream processing (e.g., chemical processing). The sorting module A may produce, as output(s), cleaned shredded textile waste, with denser materials (e.g., buttons, textile edges, ferrous and non-ferrous waste etc.) separated out, and with shredded output further sorted by type of material (e.g., polyester, cotton-poly blend, etc.) such that the different types of shredded textile materials can be diverted to a suitable downstream module for further processing. For example, in the embodiment in FIG. 1, the output (e.g., shredded textile waste) is separated into three different categories of textile waste, each of which is coupled to a different downstream processing path and associated processing module(s). That is, in the example in FIG. 1, the single input stream of mixed textile waste provided to Module A is initially processed and sorted into 3 output streams of shredded textile waste, including a first output stream 111-1 or category that contains substantially only (or majority) polyester blends of textiles (e.g., poly / elastane blends or substantially only (or majority) another synthetic such as nylon orpolyamide / elastane blends). A second output stream 111-2 contains substantially only (or majority) pure cellulose-based materials (e.g., 100% cotton, viscose or rayon textiles), optionally with small amounts of another material, such as elastane. A third output stream 111-3 contains substantially only (or majority) a mixture of polyester and cellulose (e.g., cotton) in any proportion, optionally also with small amounts another material, such as elastane. The output stream 111-2, containing cellulose but also polymers such as elastane, can first be optionally treated in module B. The output stream 111-3, containing polyester and cellulose (i.e., polycotton) but also polymers such as elastane, can first be optionally treated in module B. In some embodiments, the majority polycotton stream ( 111-3) may proceed directly to module E and / or the majority cellulose stream ( 113-2) may proceed directly to module F as shown by the dotted process flow lines in FIG. 1. However, as noted above, in some embodiments any of the different output streams may first be passed through a solvent purification process (e.g., module B and / or as further described with reference to FIG. 7) to remove elastane, soluble dyes, soluble organic chemicals and other contaminants before further downstream processing. Passing the different textile waste streams through the purification process may be advantageous since amounts of elastane in low concentrations can be difficult to detect by known techniques.

[0044] In some embodiments, optionally, the polyester blends that include additional man-made materials such as elastane, acrylics, etc. are diverted along one path (e.g., the first processing path 111-1), while polyester blends containing cotton, referred to also as polycotton blends, are diverted along another processing path, shown in FIG. 1 as the third processing path 111-3.

[0045] The polyester-cotton (or polycotton) blends may be processed using different solvents and / or using different sequences of applying the solvents, in the third processing path 111-3 as compared to the first processing path 111-1, e.g., via the cellulose dissolution / polycotton extraction process described herein. As further noted, the polycotton blends may also be treated in Module B (e.g., by a solvent purification process) to remove undesired components (e.g., elastane, dyes, etc.).

[0046] In some embodiments, the first processing path 111-1 is tailored to solve the recycling problem for the polyester material and any polyurethane (e.g., elastane) present by extracting dyes and other undesired materials, e.g., non-textile materials, non-target polymers, such as polyurethanes, e.g., elastane, with minimal or substantially no degradation of thepolyester material, preferably without decomposing the polyester textiles into its building blocks. In contrast, the third processing path 111-3 is tailored to solve for the cellulose material, whereby the polyester output from the processing in path 111-3 would be a secondary output product as opposed to the primary output from path 111-1. This secondary output is then connected to the first stream 111-1 on Module C (block 114). In other embodiments, the portable recycling plant may be specifically configured to process a single waste stream, of unsorted or presorted textiles. In such embodiments, the sorting module may perform one or more of the pre-processing steps described here but rather than diverting one or more portions of the textile waste to different processing paths, all of the sorted and pre-processed textile waste may be supplied to a single downstream processing path optimized for the recycling of the particular type of textile waste expected as input.

[0047] Referring back to the example in FIG. 1, the first output stream of shredded textile waste diverted along waste processing path 111-1 is provided next to Module B, shown as block 112, where the textile waste undergoes a process in which a secondary material component of the mixed composition textile waste (e.g., elastane or other polyurethanes, acrylic, cellulose acetate, dyes, additives, coatings, non-polymeric additives and other soluble materials) are separated from one or more primary material components, e.g., at least one target polymer, of the mixed composition textile waste. As used herein, the dyes and non-polymeric additives are referred to as undesired materials. Module B performs a process that separates the secondary materials (e.g., dyes and elastane) without substantially degrading (e.g., without chemically decomposing) the primary material (e.g., target polymer such as polyester) such that the separated primary material (e.g., the polyester) can be repurposed into renewed or recycled fiber (e.g., renewed / recycled polyester fiber) via further downstream processes (e.g., via Modules C and D). In addition, as explained below, Module B is configured to isolate polyurethanes, such as elastane for further downstream processing. In some embodiments, Module B is further configured to separate a second (e.g., cellulose) material from the primary (e.g., polyester) material, and the separated second material (e.g., cellulose) can also be recycled (e.g., into renewed cellulose-based materials such as man-made cellulosic fibers (MMCF) by further downstream processes of the system 100. In some embodiments, Module B is configured to remove undesired materials, such as dyes or other non-polymeric additives, in a first step carried out at a first temperature using a solvent and is configured to remove polyurethane, e.g., elastane,using the same solvent at a second temperature, all while not dissolving polyethylene terephthalate (interchangeably referred to here is as PET or polyester). By not dissolving the PET, further downstream processing is simplified and costs reduced. Thus, the recycling of PET is less energy and carbon intensive than other chemical recycling methods. By recovering the polyurethane (e.g., elastane), further downstream processing can be utilized to reuse the recovered polyurethane (e.g., elastane), thus capturing the benefits of recycling the polyurethane (e.g., elastane). In other embodiments, the same or similar arrangement of Module B (e.g., using continuous stepwise solvent extraction of undesired materials followed by solvent extraction of polyurethane such as elastane) can be configured to purify a different type of textile material and / or remove different “impurities.” For instance, in the example of carpet textiles recycling, Module B may be configured to first remove glue or other impurities from wool, polyester or polyamides or other types of fabric or fiber(s) commonly used in carpets followed by removal of any elastane in the carpet textiles.

[0048] In some embodiments of the invention, and because of the specific mechanical properties of textiles and the way that they shred into porous, non-homogeneous layers of materials, Module B provides a unique mechanical solution to impregnate garments and remove solvents and dissolved elements from garments. This solution can be used to impregnate polyester blends with a suitable solvent to sequentially remove impurities therefrom or it can be tailored for processing different types of fabrics and / or to remove different impurities than the specific examples described in detail herein.

[0049] In some embodiments, the shredded textile materials are conveyed on a permeable screen through a series of varying velocity solvent streams (or “blades”), which may range from gravity flowing rates up to those similar to pressure washers. The path that the permeable screen follows to convey the textile materials through the blades may be substantially straight or it may be circuitous, such as be looping or switching back and forth within a volume that extends vertically to provide a more compact footprint. The increased force of the solvent traveling through the textile materials in the later “blades” aids to carry with it the elements intended to be removed from the textile. The cleanest solvent is used in the final “blade”, and would be preferably recovered from that blade, and used for the previous blade, moving its way in reverse direction with respect to the travel path of the textiles being conveyed through the recycling plant. The “dirtiest” solvent thus would be the first solvent to come in contact with thetextiles, in such embodiments. After being recovered from its first contact with the textiles, the solvent may be provided into a continuous recovery and extraction unit to purify it and return it to the final blade as cleaned solvent, creating a closed loop solvent system with substantially no wasted solvent. In other embodiments, the textiles are treated in a continuous flow submerged screw counterflow solvent immersion process whereby the shredded textile material is mechanically advanced through a solvent bath by means of a rotating screw where the solvent is flowing against the travel direction of the textiles. Various embodiments are described in further detail below with reference to the solvent purification processes illustrated in FIG. 7, including a continuous extraction system based on conveyors and sprayed solvent or solvent immersion, augurs with a counter-flow of solvent, or in a batch-wise fashion in a vessel with horizontal or vertical agitation. Additionally, a soxhlet-type extractor can also be used.

[0050] In some examples, inputs to Module B may include polyester (e.g., PET) fabric, cellulose (e.g., cotton, rayon) fabric, and other fabrics (e.g., wool, nylon, etc.), any of which may contain elastane, acrylic, dyes, and other finishes that are removed during the recycling process. As a result, Module B may output PET, cotton, and / or other fabrics, such as but not limited to wool, nylon or polyamides, which are substantially free of dyes, elastane or other polyurethanes, finishes, soluble chemical compounds and / or any other synthetics. In accordance with embodiments of the present disclosure, Module B may also output a polyurethane (e.g., elastane) rich solution or suspension.

[0051] In the context of an example where impurities are removed from polyester, the solvent is selected such that it does not dissolve polyester in the temperature range where undesired materials are removed or in the elastane dissolution temperature range, and when selected appropriately, can be benign in terms of safety and environmental impact. In embodiments of the present disclosure, the boiling point of the solvent is selected to be close to that of the solvent stripping temperature, thereby saving energy in the solvent recovery step. The solvents are not heated to high temperatures, for example, above 100 °C, and polyester (e.g., PET) is therefore not dissolved. This reduces degradation of the polymer chains due to high temperatures and saves the need to remove traces of solvent from the molten polymer, thereby saving energy. Additives such as TiCE will be preserved, saving further downstream processing cost. As described in more detail below, Module B can also be used to sequentially separate certain dyes and other undesired materials and then separate elastane from PET containingtextiles. Module B can also be used to separate other blended textiles, which include blends with acrylic, other polyurethanes (including adhesives, coatings and membranes) and cellulose acetate. Examples of stepwise solvent purification processes for removing dyes and other undesired materials followed by removal of a non-target polymer B that may be used to implement aspects of Module B are described further below, e.g., with reference to FIG. 7.

[0052] Generally, and continuing with the present example, Module C is configured to use the polyester output of Module B, and prepares it for melt extrusion of pellets or yarn. In some embodiments, the intrinsic viscosity (IV) of the polyester is increased, e.g., by liquid state polycondensation (LSP), by the application of a vacuum. Other suitable processes for increasing the IV of the polyester may be used. Generally, due to degradation in the spinning and consumer lifecycle, a lift in IV may be advantageous to spin good quality fibers in the downstream Module D. In combination with Module B, e.g., by receiving the polyester output of Module B, substantially all of the elastane and contaminants are removed including water, which could otherwise interfere with a liquid-state polycondensation for IV upgrading. By removing the elastane and impurities in Module B, polyester (e.g., PET) can be heated to a high temperature of above 170 °C, under vacuum, in order to pull off excess ethylene glycol and / or water, increasing the molecular weight of PET thereby increasing and upgrading the IV. Moreover, an added technical advantage of achieving polycondensation may be obtained from the same process used to transform “fluffy” textile scraps and waste into a denser form better suited for extrusion, thus combining two steps into one.

[0053] In some examples herein, Module C receives, as inputs, the output(s) of Module B, specifically the polyester (e.g., PET) material free of dyes, elastane, finishes, and the rinsing solvent, and / or output of the polycotton separation Module E as a polyester (e.g., PET) melt. The material input into Module C may undergo compacting / densification. Module C may include, among other things, a screw-type extruder chamber, a chamber to generate a large surface area for the polyester (e.g., PET) melt with vacuum attachment to enable condensation, and may be equipped with online monitoring of IV to control residence times. Additionally, a changeable (or replaceable) filter screen may be used for filtering any solid contaminants out of Module C. Module C may provide pelletized polyester (e.g., PET) as output, and / or a polyester (e.g., PET) melt which may be supplied to Module D for polyester fiber spinning.

[0054] FIG. 2 shows a block diagram 200 of one embodiment of Module C, which may be used to implement block 114 of FIG. 1. In the example in FIG. 2, Module C is configured to increase the intrinsic viscosity (IV) of the polyester material, and may thus be interchangeably referred to as polyester IV upgrade and extrusion module. In other embodiments, a different method may be used, or the polyester material may proceed directly to the PET extrusion / IV uplift stage. The process in FIG. 2 begins at block 210, which may involve size-reducing the output of Module B (polyester, e.g., PET) after removal of the elastane and unwanted material(s) (e.g., dye, and finishes removal) and thereafter densifying the size-reduced output of block 210. In some cases, polyester (e.g., PET) is additionally received from Module E as a result of the polycotton separation process performed therein. Next, the densified polyester textile is subjected to heat (block 216) in order to form a melt state, typically in a form of melt extruder. In the preferred embodiment, the melt-state polyester (e.g., PET) is subjected to a vacuum, as shown in blocks 216 and 218, and optionally an inert atmosphere with agitation to increase the molecular weight via polycondensation. The IV-increased, melt state polyester (e.g., PET) (see block 220) is then suitable for either pelletization, suitable for reprocessing, or to be taken directly to fiber and yam spinning in Module D. In another embodiment, the densified polyester pellets or melt-extruded pellets are subjected to solid-state polycondensation rather than in the melt state, with a combination of heat, and optional inert atmosphere over a specified time period. The polyester (e.g., PET) melt may be received by Module D and form polyester (e.g., PET) filaments (or fibers) and yams. In some embodiments, known and / or commercially available equipment or techniques may be used to implement certain aspects of Module D, such as the fiber and / or yarn spinning.

[0055] Referring back to FIG. 1, the shredded textile waste materials that include substantially only polyester / cotton blends are diverted to the processing path 111-3 and are provided to a polycotton purification / separation unit, referred to as Module E for simplicity, and shown at block 116. The process implemented by Module E is configured to separate cellulose and polyester (e.g., PET) present in polycotton textiles, outputting a dissolved cellulose in solution (a “cellulose dope”), which may be provided directly to the cellulose fiber spinning module G. In other embodiments, a pure cellulose or regenerated cellulose material may be output from Module E. The process may also output polyester (e.g., PET) fabric, free of cellulose, to head to the polyester fiber densification and extmsion module (e.g., blocks 114 and118). Module E may optionally be used for polycotton after its treatment in Module B to remove dyes, finishes, and other polymers such as elastane and acrylic.

[0056] Module E (block 116), which may also be referred to as polycotton separation module, may be implemented using a number of different approaches. For example, in one embodiment, as shown in the block diagram 300 in FIG. 3, the polycotton separation is done by dissolution of cellulose from the input textile waste. In this approach, at block 316 the cellulose is dissolved by means of a cellulose solvent, such as an aqueous or organic electrolyte solution, or an ionic liquid. This approach could be adapted to use the Module B (block 112) solvent stripping apparatus to impregnate the polycotton and dissolve the cellulose component of polycotton. After the cellulose is removed, the polyester (e.g., PET)-containing fabric is rinsed and dried at block 320 and carried to Module C (block 114) for further processing. In one embodiment, the cellulose is precipitated from the solution (regenerated at block 330) by means of a water-based anti-solvent at block 319, and the solvent is recovered in a solvent recovery unit. The form of the regenerated cellulose may vary, but can be a powder, film, or mixed with another material as a composite. In another embodiment, the cellulose in solution is brought directly to the MMCF spinning module (e.g., Module G, shown at block 122) for wet-spinning of a regenerated (or man-made) cellulosic fiber. Embodiments of a polycotton separation process by means of dissolving the cellulose-portion of the blend with organic and aqueous solutions are described with reference to FIG. 4 and also further below, e.g., with reference to the cellulose extraction / recycling process illustrated in FIG. 5.

[0057] Referring back to the block diagram 300 in the example in FIG. 4, the polycotton textile, having any soluble dyes and elastane removed, is brought into the polycotton separation process, as shown at block 410. In an alternative embodiment, Module B can also be connected at the end of Module E. Prior to dissolution, a dilute acid or enzymatic hydrolysis process (block 312) reduces the molecular weight of the cellulose in cotton in Module F (block 120) or the pretreatment module (block 120). This stage may optionally be before the dye and elastane removal stage in Module B (block 112). After removing any residual acid (block 314), and the polycotton textile is both free of soluble dyes and elastane, a cellulose-dissolving solvent mixture is introduced (block 316). This cellulose dissolving solvent is an aqueous or organic electrolyte solution in some embodiments. The cellulosic component of the polycotton textile is dissolved in the solvent, e.g., in atmospheric conditions, or in other embodiments, with the addition ofheat. The residual polyester fabric (blocks 320), free of cellulose, is separated from the cellulose solution (blocks 330), with a method such as, but not limited to, filtration, mechanical action, with or without the assistance of an additional solvent.

[0058] Any solvent is removed from the polyester fabric by a method such as evaporation, preferably at a temperature sufficient to minimize degradation of the polymer chains. The polyester fabric is free of any cellulose, dye and elastane (see block 318) and is forwarded to Modules C (block 114) and D (block 118) for densification, melt extrusion and filtration, and if required, filament spinning. The cellulose-containing solution can then be processed in two ways. In one route, a solvent (the “anti-solvent”) is added (with or without additional additives, such as salts and acids) to the cellulose-containing solution such that the solubility is lowered, causing the cellulose to precipitate out of solution (also known as regeneration). The regenerated cellulose is then separated by filtration or another separation method. The regenerated cellulose is washed with a combination of solvents and / or water and is optionally dried. The solvent and “anti-solvent” mixture is recovered by a method such as distillation, phase-separation or filtration (block 417), with the anti-solvent being removed (block 419) to a level where the solvent is capable of dissolving cellulose and the anti-solvent is separated from the cellulose solvent for use again. In an alternative pathway, the cellulose- containing solution is sent directly to the wet fiber- spinning Module G for direct spinning of a cellulose fiber.

[0059] In another embodiment, the separation of cellulose may be done by glycolysis or partial-glycolysis of polyester (e.g., PET), an example flow diagram 400 of which is shown in FIG. 4. In this approach, ethylene glycol is used to partially glycolyse the PET. The glycolysate can then be separated from cotton via filtration. This can be re-polymerized in Module C in the vacuum LSP chamber, or polymerized in a separate chamber and combined upstream in Module C, forming one flow of PET melt to the extrusion modules. Excess ethylene glycol is removed from the cotton, and then dried, and sent to Module F for further processing. The example in FIG. 4 shows an example Module E configured to perform polycotton separation by density and surfactant-aided bubbles. Separating target polymer(s), e.g., PET, and undesired materials of a textile feedstock in accordance with embodiments of the present disclosure can produce feedstocks for other recycling processes that enable their operations, such as the cellulose process described above.

[0060] In yet another embodiment, the separation of cellulose may be done by density. In this approach, after a hydrolysis pretreatment and fine shredding / grinding, cellulose and polyester are separated by density. This can be achieved through the use of a bubbling action with a surfactant, thereby separating the textiles into a polyester rich and cellulose rich fraction, which can be sent to either Module B or F for further processing.

[0061] Referring to FIG. 1, the recycling system 100 may include a cellulose pretreatment Module, labeled for simplicity as Module F, and which defines, in part, a textile waste processing path 111-2 of the recycling plant for processing substantially pure cellulose-based materials or additionally cellulose-containing materials, such as polycotton blended textiles. Module F receives as input the shredded textile waste sorted to contain substantially only cellulose based materials (e.g., 100% cotton, viscose, or rayon) as output from the sorting Module A and / or cellulose-containing material from the processing path 111-3, e.g., polycotton blends. Both streams may optionally have been processed through module B (block 112) to remove elastane, dyes and other materials. This pre-treatment module may additionally receive polycotton blended materials (stream 111-3) before Module E (block 116), to pre-treat the material before polycotton separation. In another embodiment, module F can also be reconfigured as a post treatment module, taking cellulose or regenerated cellulose material after separation in module E.

[0062] The cellulose pre-treatment process in module F (block 120) may include one or more of the following cellulose pre-treatment steps, in any suitable order:

[0063] Molecular Weight Reduction, which may include any combination of the following, in any suitable order: dilute acid hydrolysis with a mineral or organic acid (such as succinic acid or formic acid), enzymatic hydrolysis, ozone treatment, electron beam or plasma (high energy) treatment, and ripening in sodium hydroxide. Formic acid can dissolve non-target polymers, e.g., nylon, hydrolyze acid, and possibly dissolve metals. Removing dissolved metals and non-target polymers from the textile materials being processed produces cleaner feedstocks, making the feedstocks and processes used to produce such feedstocks more valuable.

[0064] Bleaching by any suitable method, with any combination of the following, in any suitable order: ozone treatment, with or without additives, reductive bleaching treatment, with sulphur based reagents such as thiourea, thiosulphate, sodium borohydride, sodium hydrosulphiteand others, oxidative bleaching treatment, such as, but not exclusively, sodium hypochlorite or other chlorine based bleaches or peroxide based bleaches;

[0065] Swelling pretreatment with any combination of the following: sodium hydroxide, ionic liquids, organic or aqueous electrolyte solutions, and amines; and

[0066] Residual metal removal using any suitable combination of acids including carboxylic acids, and / or EDTA or other chelating agents.

[0067] Referring to FIG. 1, the recycling system 100 may include a man-made cellulosic fiber spinning module (block 122), labeled for simplicity as Module G. In one embodiment, this module receives dissolved cellulose in solution (known as “cellulose dope”) from the polycotton separation Module E (block 116) and is used to spin man-made cellulosic fibers directly. In this embodiment, the cellulose is optionally pre-treated in Module F (block 120) before the polycotton separation process. In another embodiment, the module can also receive pure (not dissolved) cellulose or regenerated cellulose from the polycotton separation process.

[0068] In some embodiments, Module G (block 122) receives substantially pure cellulose, i.e., a cotton textile received from directly sorting module A (block 110) and after pretreatment in Module F (block 120), alternatively also after treatment in purification module B (block 112) to remove elastane, dyes and other contaminants.

[0069] In some embodiments, the solvent used in module B to remove elastane and other contaminants may become part of the cellulose solvent (i.e., the molecular co-solvent), in combination with certain ionic additives as explained further below with reference to the “Cellulose Recycling Process”. In such embodiments, the process constitutes a novel direct dissolution solvent system for wet fiber spinning of cellulose. Pre-treatment of the cellulose in Module F (block 120) can take place before purification in Module B (block 112) or after.

[0070] Alternatively, in other embodiments the MMCF (man-made cellulosic fiber) spinning process in Module G (block 122) may be other known methods including viscose xanthogentation (viscose fiber spinning), dissolution in NMMO (lyocell fiber spinning) or dissolution in other solvents, such as pure ionic liquids.

[0071] FIG. 5 shows a block diagram of one embodiment of the cellulose pre or posttreatment process 500 that may be implemented by Module F and Module G together (e.g., block 120 of FIG. 1). The process 500 may be used to prepare the cellulose output from Module B and E as well as incoming pure cotton or rayon garments, for a subsequent cellulose dissolution andfiber spinning process. The process 500 may receive as inputs cotton and rayon textile optionally with soluble dyes, elastane, other finishes removed and may output dye free, molecular weight reduced, pre-treated cellulose. In the specific example shown in FIG. 5, Module F is configured to receive a reactive-dyed cotton input (block 510) where a viscose fiber spinning line is provided as Module G (at block 520).

[0072] In the specific example in FIG. 5, the process 500 includes a molecular weight reduction step (block 512), which is in this example is performed using H2SO4, a bleaching step (block 514), which in this example is performed by ozone treatment, a swelling pretreatment step (block 516), in this example using sodium hydroxide, and a residual metal removal step (block 518). In other examples, the process 500 may be performed using any other suitable combination of steps.

[0073] A finishing module, shown as block 124 and also referred to as Module H, may be configured to produce a finished ready to use fiber, fabric or garment. In some embodiments, this module may be configured to spin one or more manmade fiber(s) output from upstream components of the system. In some embodiments, the finishing module may alternatively or additionally be configured to produce fabric such as by knitting or weaving the manmade fibers. In yet further embodiments, the finishing Module may alternatively or additionally be configured to produce ready to wear garments such as by knitting or the manmade fibers. The function of Module H is to transform raw fiber into yarn to be used in clothing. The yarn can then be used to knit fabric, or even be knit directly into final products like seamless clothing such as socks, leggings, shirts, scarves, or other accessories. This small scale production of end use consumer goods is not in and of itself a key invention, and would use equipment currently commercially available.

[0074] Referring to the rendering in FIG. 6, and for the appreciation of scale, a modular recycling plant 600 according to the present disclosure may be implemented within a box or enclosure roughly about the size of a shipping container. In some embodiments, and depending on the desired output, the modular recycling plant may be as large as the size of two or three shipping containers. The ultimate footprint of the modular recycling plant, whether sized to fit in a single or a plurality of shipping containers would be orders of magnitude smaller than an industrial facility built for the recycling of textile waste and thus would facilitate wide distribution of these compact modular recycling plant to any source of waste textile, where theycan be co-located with the source removing the need for transportation of the waste materials to a centralized recycling facility.Solvent Purification Process

[0075] FIG. 7 shows a flow chart of a solvent purification process 700, which may be used, in some embodiments, for removing non-target polymer material(s), such as polyurethane (e.g., elastane), from desired target polymer material(s), such as polyester (e.g., PET), to prepare the desired target polymer material for downstream recycling processes. The process 700 may be used to implement Module B (block 112) of the system shown and described above with reference to FIG. 1. It will be understood that in some embodiments, this solvent purification process 700 may be used entirely separately (or independently) from any downstream recycling processes or in combination with various other recycling process different from the ones described herein.

[0076] As shown in block 710, the process 700 starts by providing a feedstock of materials. The feedstock is a blended textile or mixture of textile materials containing a target polymer or mixture of target polymer(s) A (e.g., for use in further recycling), together with one or more non-target polymers B and materials, such as non-target textile fiber polymer(s) and one or more undesired materials or contaminants. The target polymer(s) A may include, but is not limited to, a polyester such as PET and others, a polyamide such as nylon 6 and nylon 6,6 and others, cellulose such as cotton, rayon, wool, etc., and others. The non-target polymer(s) B may include, but are not limited to, elastane and other polyurethanes, acrylic, cellulose acetate, or others. The undesired material(s) may include, without limitation, soluble dyes, including disperse dyes, as well as other organic and inorganic coatings, additives, and other auxiliary chemicals. In some embodiments of the process, the material is a polyester-elastane, polycotton- elastane, or cotton-elastane blended textile (in streams 111-1, 111-2, 111-3) of the wider recycling system, as received from Module A (block 110) after sorting. In some embodiments of the process, the material can also be a nylon-elastane blended textile of the wider recycling system, as received from Module A (block 110) after sorting, which would be fed into a separate downstream module homologous to modules C and D, but configured for polyamides or nylon instead. In some embodiments, the target polymer is a polyester such as PET and the non-target polymer is a polyurethane such as elastane. 1

[0077] An organic solvent (block 714) is provided to initiate the solvent purification process (see block 712) which may be carried out in Module B of FIG. 1. In some embodiments, the organic solvent preferably has a boiling point below the melting point of the target polymer(s) A and selectively dissolves the non-target polymer(s), referred to as B, and undesired materials, in the same temperature range. In some embodiments, the organic solvent dissolves or is able to suspend the undesired materials at a first temperature that is below a second temperature at which the non-target polymer(s) are dissolved or suspended in the organic solvent. Organic solvents suitable for this process may include, but not limited to, cyclic ketones of a general structure (CH2)»CO where n=4, 5, 6, or 7), such as cyclopentanone and cyclohexanone. In some embodiments, additional solvents, for example, aprotic solvents including dimethylsulfoxide, N-methyl-2-pyrrolidone, dimethylacetamide, dimethyl formamide, bio-based alkyl esters, such as alkyl lactates (ethyl lactate), tetrahydrofurfural alcohol, diacetone dialcohol and isophorone, may be used along with the cyclic ketone to further enhance the removal efficacy. In some embodiments, the organic solvent comprises cyclohexanone, cyclopentanone, or a mixture thereof.

[0078] In block 712, the solvent is contacted with the blended textile or mixture of textile materials at a first temperature effective to cause a portion or all of one or more undesired materials in the blended textile or mixture of textile materials, e.g., dyes, to dissolve or become suspended in the organic solvent. In some embodiments, the first temperature is below a temperature at which polyurethanes (e.g., elastane) in the textile materials dissolve or suspend in the organic solvent. In some embodiments, the first temperature is below a temperature at which a majority (greater than 50 percent by weight) of polyurethanes (e.g., elastane) in the textile materials dissolve or suspend in the organic solvent. In other embodiments, the first temperature is below a temperature at which greater than 10 percent by weight of polyurethanes (e.g., elastane) in the textile materials dissolve or suspend in the organic solvent. In other embodiments, the first temperature is below a temperature at which greater than 20 percent by weight of polyurethanes (e.g., elastane) in the textile materials dissolve or suspend in the organic solvent. In other embodiments, the first temperature is below a temperature at which greater than 30 percent by weight of polyurethanes (e.g., elastane) in the textile materials dissolve or suspend in the organic solvent. In other embodiments, the first temperature is below a temperature at which greater than 40 percent by weight of polyurethanes (e.g., elastane) in thetextile materials dissolve or suspend in the organic solvent. In some embodiments, the first temperature is below 100° C. In some embodiments, at such first temperature, the target desired polymer(s) A and the non-target polymer(s) B are not dissolved or do not become suspended in the organic solvent. In other embodiments, at such first temperature, the target desired polymer(s) A are not dissolved or do not become suspended in the organic solvent and more than 50 percent by weight, more than 60 percent by weight, more than 70 percent by weight, more than 80 percent by weight or more than 90 percent by weight of the non-target polymer(s) B are not dissolved or do not become suspended in the organic solvent. The solvent contacting can be performed in a batch- wise fashion, with specific residence times. For example, the organic solvent may be contacted to one or more batches of the feedstock, and be in contact for a period of time sufficient to allow the undesired materials to dissolve or become suspended in the organic solvent as described above, while the target polymer(s) A is not dissolved or suspended in the organic solvent as described above and the non-target polymer(s) B are dissolved or suspended in the organic solvent as described above. Typically, such period of time is not more than 1 hour, and in some embodiments is less than 30 minutes per batch. In some embodiments, the period of time is sufficient to cause 95% or more of the undesired materials(s) to be dissolved or suspended in the organic solvent. In some embodiments, the contacting may be in a continuous flow-through fashion until 95% or more of the undesired materials dissolve or become suspended in the organic solvent while the target polymer(s) A and the non-target polymer(s) B are not dissolved or suspended in the organic solvent as described above. The first temperature and the length of time the textile materials are in contact with the organic solvent at the first temperature in the continuous flow process can be the same as the contact times and first temperature for the batch process. In some examples, the organic solvent is sprayed onto the textile material, in some cases in a continuous fashion as the textile is advanced on a conveyor through a recycling system module. The contaminated solvent may then be collected and recycled as further described below. In some examples, the textile material (i.e., the feedstock) is submerged in a vat, optionally in batches. In some examples, the conveyor moving the feedstock through the module may submerge the feedstock into the vat containing the organic solvent. The undesired materials are dissolved or suspended in the organic solvent (block 716) forming a contaminated solvent solution containing the organic solvent and the dissolved or suspended undesired material(s) (and dissolved or suspended non-target polymer(s) B if any),which can then be removed from the textile to separate the undesired components (and dissolved or suspended non-target polymer(s) B if any) from the target polymer(s) A and the non-target polymer(s) B of the textile material(s) which have not been dissolved or suspended by the organic solvent. In some embodiments, the contacting and consequently the separation may involve supporting the textile on a screen (or filter) while contacting, such that the contaminated solvent solution passes through the textile feedstock and screen and is collected, optionally for recycling. In some embodiments, force may additionally be applied to the wetted textile to press the solvent solution out of the wetted textile and collected optionally for recycling into the purification process. In some embodiments, force may additionally be applied to the wetted textile to accelerate the removal of undesired components from the waste textile within a given wash cycle. The textile material separated from the organic solvent containing the undesired materials (and dissolved or suspended non-target polymer(s) B if any) moves from block 712 to block 722. Various processes for separating the contaminated solvent with the dissolved or suspended undesired materials (and dissolved or suspended non-target polymer(s) B if any) from the textile material (at block 716) may be used, at different stages. In some embodiments, the ratio of textile mass to solvent mass can be altered to control the degree of undesired material extraction within a given wash cycle. This ratio is typically in excess of 5:1 (solvent:textile), with the minimum amount being an amount of solvent required to effect conveyance of the textile “slurry”. Increasing the amount of solvent above this ratio can accelerate the removal of undesired materials from the textile waste. In some embodiments, this ratio can be 7.5 times the textile mass to 10 times the textile mass. In some embodiments, mechanical agitation is used to accelerate the removal of undesired components from the textile waste.

[0079] In some embodiments, at least a portion of the organic solvent may be recovered (block 720) and optionally preferably recycled into the solvent purification process (block 712). The organic solvent may be recovered from the dissolved undesired materials (and dissolved or suspended non-target polymer(s) B if any) by a suitable recovery method, for example distillation. The recovered solvent from block 720 may be provided back into purification step (at block 712), which may involve heating the organic solvent recovered at block 720. In some embodiments, additionally or alternatively, the organic solvent may be recovered at block 720 by one or more other suitable processes including, but not limited to, filtration. At block 718, the undesired materials may be recovered as a solid, dry waste stream which can be treated, forexample via incineration with energy recovery. In some embodiments, the undesired materials can, additionally or alternatively, be recovered from the waste stream by an additional downstream recovery step.

[0080] In accordance with embodiments of the present disclosure, organic solvent (e.g., from block 714) is provided to initiate a second solvent purification process of the textile materials (from block 722) at block 723, to remove non-target polymer(s) (B) from the textile material(s). This second solvent purification can be carried out in Module B of FIG. 1. In some embodiments, the organic solvent preferably has a boiling point below the melting point of the target polymer(s) A and selectively dissolves the non-target polymer(s), referred to as B and undesired materials, in the same temperature range. In some embodiments, the non-target polymer B is dissolved or suspended in the organic solvent when the organic solvent is at a second temperature above the first temperature. The second temperature is below the temperature at which the target polymer A dissolves or suspends in the organic solvent. Organic solvents suitable for this process may include, but not limited to, cyclic ketones of a general structure (CFDnCO where n=4, 5, 6, or 7), such as cyclopentanone or cyclohexanone. In some embodiments, additional solvents, for example, aprotic solvents including dimethylsulfoxide, N- Methyl-2-pyrrolidone, dimethylacetamide, dimethyl formamide, bio-based alkyl esters, such as alkyl lactates (ethyl lactate), tetrahydrofurfural alcohol, diacetone dialcohol and isophorone, may be used along with the cyclic ketone to enhance the removal efficacy.

[0081] In block 723, the organic solvent from block 714 is at the second temperature or is heated to the second temperature when it is in contact with the textile materials from block 722 which have had the undesired materials removed at block 712. When the organic solvent is at the second temperature and contacts the textile material at block 723, the remaining non-target polymers B (e.g., elastane or other polyurethanes) dissolves or become suspended in the organic solvent, while the target polymers A do not dissolve or become suspended in the organic solvent. In some embodiments, the second temperature is above the first temperature at which the undesired materials (and possibly a portion of the non-target polymer(s) B in the textile material) are dissolved or suspended in the organic solvent at block 712. In some embodiments, the second temperature is below the boiling point of the solvent and above 100° C. When the organic solvent at such second temperature is contacted with the non-target polymer(s) B, the non-target polymers B dissolve or become suspended in the organic solvent, while the targetpolymer(s) A do not dissolve or become suspended in the organic solvent. The solvent contacting at block 723 can be performed in a batch-wise fashion, with specific residence times. For example, the organic solvent may be contacted with one or more batches of the textile materials from block 722, and be in contact for a period of time sufficient to allow the non-target polymer(s) B to dissolve or become suspended in the organic solvent. Typically, such periods of time is not more than 1 hour, and in some embodiments is less than 30 minutes per batch. In some embodiments the period of time is sufficient to cause 95% or more of the non-target polymer(s) B in the textile materials at block 723 to be dissolved or suspended in the organic solvent. In some embodiments, the contacting may be in a continuous flow-through fashion until 95% or more of the non-target polymer(s) B at block 723 to dissolve or become suspended in the organic solvent. The second temperature and the length of time the textile materials are in contact with the organic solvent at the second temperature in the continuous flow process can be the same as the contact times and second temperature for the batch process. In some examples, the organic solvent is sprayed onto the textile material, in some cases in a continuous fashion as the textile is advanced on a conveyor through a recycling system module. The contaminated solvent may then be collected and recycled as further described below. In some examples, the textile material (i.e., the feedstock) is submerged in a vat, optionally in batches. In some examples, the conveyor moving the feedstock through the module may submerge the feedstock into the vat containing the organic solvent. The non-target polymer(s) B are dissolved or suspended in the organic solvent (block 725) forming a contaminated solvent solution containing the organic solvent and the dissolved or suspended non-target polymer(s) B, which can then be removed from the textile material containing target polymer(s) A. In some embodiments, the contacting and consequently the separation may involve supporting the textile on a screen (or filter) while contacting, such that the contaminated solvent solution passes through the textile feedstock and screen and is collected, optionally for recycling. In some embodiments, force may additionally be applied to the wetted textile to press the solvent solution out of the wetted textile and collected optionally for recycling into the purification process. The separated textile material containing target polymer A is delivered to a downstream recycling process represented by block 726. Various processes for separating the contaminated solvent with the dissolved or suspended non-target polymer(s) B from the textile material (at block 725) may be used, at different stages. Recovered non-target polymer B at block 727 may be subjected to furtherprocessing at block 729. For example, the recovered non-target polymer B can be dried and formed into pellets or other forms for use as a feedstock in subsequent processes. Alternatively, the organic solvent containing the non-target polymer B can be provided as a feedstock to an onsite process for forming fibers of non-target polymer B, e.g., a solvent spinning process.

[0082] In some embodiments, at least a portion of the organic solvent from block 725 may be recovered (at block 731) and optionally recycled into the second solvent purification process (block 723) via solvent recovery 731. The organic solvent may be recovered from the dissolved non-target polymer(s) B by a suitable recovery method, for example distillation. The recovered solvent from block 731 may be provided back into the first purification step (at block 712) or delivered to second purification process at block 723, both of which may involve heating of the recovered solvent. In some embodiments, additionally or alternatively, the organic solvent may be recovered from target polymer A of the solid textile material at block 733 by one or more other suitable processes including, but not limited to, filtration. At block 727, the non-target polymer(s) B may be recovered as a polymer in solution or may be recovered as a solid, dry material. The recovered non-target polymer(s) B in solution may be subjected to further processing at 729, for example, spinning of fibers from the solution of non-target polymer(s) B or melt extrusion of fibers using dry recovered non-target polymer(s) B as a feedstock.

[0083] After separation of the bulk of the contaminated organic solvent (e.g., containing the non-target polymer(s) B or the undesired materials dissolved in the solvent), the targeted polymer(s) A now exist in a solid textile form as shown at block 733, with no or minimal degradation of the targeted polymer(s) A, minus the extracted non-target polymer(s) B and extracted undesired materials. Residual organic solvent may remain in the textile material after separation of the bulk of the solvent from the textile material, which may be removed via any suitable method or combination of methods. In some embodiment, a physical removal method, such as via a pressing or centrifugal force, may be used first to remove remaining solvent. Various mechanical ways for removing solvent, either at step 733 or at steps 712, 716, or 725 may include the use of a graduated augur press, a screw press, a roller press, a hydraulic or pneumatic filter press, or centrifuge, which are operatively arranged to apply a force on the purified textile for the removal, and optional collection / recovery of the solvent (see also block 724). The physical removal step may be followed by 1) evaporation of any remaining solvent from the textile, in some cases optionally in combination with the application of heat, airflow,and / or vacuum, and / or 2) a solvent exchange with a solvent having a lower boiling point than the organic solvent used for the purification step. Examples of such solvents include, but not limited to, methanol, ethanol, and acetone.

[0084] Following step 733, the desired (or target) polymer(s) A may now be in substantially dry, textile form, ready for downstream recycling processes (as shown in blocks 726-732) if the process 700 is used in combination with further recycling. For example, for synthetic fibers, including polyesters (such as PET) and polyamides, such downstream recycling processes may include one or more melt extrusion recycling processes (see block 732), whereby the textile polymers are melted under controlled conditions and re-spun into synthetic fibers or, alternatively, extruded into polymer pellets. For natural fibers such as cotton, such downstream recycling processes may include one or more mechanical recycling processes (see block 728), whereby the fibers are opened, carded, and re-spun into yarn. Additionally, or alternatively, one or more further chemical processes (see block 730) may be used, such as where the cotton is subjected to a pre-treatment and used as cellulose source for regenerated cellulose, including man-made cellulosic (rayon) fibers. Other natural fibers such as wool can thereafter be mechanically recycled in a similar fashion to cotton.

[0085] In some embodiments of the process 700, the material is a polyester-elastane, polycotton-elastane, or cotton-elastane blended textile (in streams 111-1, 111-2, 111-3) of the wider modular recycling system, as received from Module A (block 110) after sorting. In some such embodiments, the “downstream recycling process” includes, for example, the module C and D for elastane-synthetic blended textiles, module F and E for polycotton-elastane blended textiles, and module F and G for cotton-elastane textiles. In some embodiments of the process 700, the material can also be a nylon-elastane blended textile of the wider modular recycling system, as received from Module A (block 110) after sorting, which would be fed into a separate downstream module homologous to modules C and D, but configured for polyamides or nylon instead.EXAMPLETwo STEP REMOVAL OF DYE AND ELASTANE FROM POLYESTER-ELASTANE BLENDS WITH CYCLOHEXANONE

[0086] In this example, a process for removing auxiliary components, e.g., dye, from a textile containing polyester, elastane, and the auxiliary components prior to removing elastane from the textile material (containing polyester and elastane) which has been processed to remove the auxiliary components, follow by further recycling (e.g., via melt extrusion) is described. In this example, a solvent purification process according to the present disclosure is used to first extract the auxiliary components from a polyester and elastane blended textile containing the auxiliary components. The resulting pre-treated textile material containing polyester and elastane is then treated with a solvent to remove elastane and prepare the polyester for a downstream melt recycling process. The process starts by providing a fabric for purification. In one example, the fabric (or textile) waste may include a mixture of dispersed-dyed polyester (polyethylene terephthalate or PET) and elastane blended textile. The fabric is prepared for the purification process by shredding it to provide the fabric (or textile) feedstock. An organic solvent is heated to a target temperature and contacted with the fabric for up to one hour to substantially dissolve soluble dyes and other soluble organic and inorganic extractives, while suppressing dissolution of the elastane. A variety of organic solvents may be used as described herein. In one specific embodiment, the solvent is cyclohexanone, which is heated to a target temperature of about 95° C. In other embodiments, cyclopentanone may be used. The resulting pre-treated textile feedstock comprising a blend of polyester and elastane is subjected to a second solvent treatment with cyclohexanone to remove elastane from the pre-treated textile feedstock. The pre-treated textile feedstock is contacted with cyclohexanone at a second temperature above the first temperature at which the blend of polyester and elastane was contacted with cyclohexanone. In this example the second temperature was 140° C. The solvent was contacted with the pre-treated textile feedstock for one hour to dissolve and / or suspend the elastane in the solvent. This second extraction process produces a purified elastane free from dyes and other additives contained in the textile and polyester which is substantially free of elastane, dyes and other additives that were removed in the first and second extraction steps.

[0087] The contacting of the textile feedstock comprising a blend of polyester, elastane, dyes and other additives with the solvent in the dye / additive extraction step and the contacting ofthe pre-treated textile feedstock comprising a blend of polyester and elastane with the solvent in the elastane extraction step can be performed in various ways in a scale application. For example, the contacting can be performed in a continuous fashion, such as by spraying or soaking the textile feedstock as the textile feedstock is advancing (e.g., on a conveyor) through the recycling system. In some embodiments, the feedstock may be portioned into batches, and each batch may be contacted with solvent (e.g., by immersion of the textile into the solvent) at least one time, and in some embodiments multiple (e.g., 2 or 3) times. In some such embodiments, each subsequent contacting step with a given batch may produce a progressively more dilute solution of elastane, dyes and contaminants in the solvent. Such more dilute solutions of the solvent from later contacting steps may be re-used in earlier contacting steps of the same or another batch, in some cases without first purifying the solvent. Reusing contaminated solvent in this manner may reduce the total volume of solvent utilized by the process. In some embodiments, the solvent may first be purified to remove the contaminants (e.g., dyes or other additives) before re-using it for textile purification at any step in the process. The step(s) of contacting the organic solvent with the textile to extract auxiliary components may also be interchangeably referred to herein as “extraction” or “rinsing” steps, which may further involve the collection of contaminated solvent following the contact of the solvent with the textile, also referred to herein as “separation” of the solvent from the solid form textile. Each immersion may be for a time of about 10 minutes to about 30 minutes or 10 minutes to 60 minutes. In some embodiments, the textile is contacted with the solvent multiple times, including an initial, larger volume rinse step, followed by one or more (e.g., 2 or 3) additional smaller volume rinse steps. In some embodiments, the full batch of textile waste processed during the initial rinse step is rinsed, as a single batch, in the subsequent rinse steps, in some cases optionally with a smaller volume of solvent than in the initial rinse step. In other embodiments, the batch is further portioned into smaller sub-batches for the subsequent rinse steps, whereby a smaller volume of solvent may be used in the subsequent rinse steps than in the initial rinse step. The batch sizes may be determined such that the total usage of solvent, including the main extraction (or rinse) step, is not more than 15 times the mass of the dry textile, and preferably not more than 10 times the mass of the dry textile. In some embodiments, the subsequent rinse steps may take place using heated solvent (e.g., at the target temperature) orrelatively cooler solvent (e.g., any temperature ranging from the target temperature to room temperature).

[0088] In some embodiments (e.g., when immersing the textile), the extraction may take place in a heated vessel, with horizontal or vertical agitation. In some embodiments, the solvent contacting is performed with a continuous flow of heated solvent, at a specific residence time and flow rate, until the depletion of the elastane. During the application of the heated solvent, the textile feedstock may be stationary, mobile, or a combination thereof (e.g., initially stationary and then advanced through the system as the contaminates are depleted, or the reverse whereby the feedstock is initially mobile and may be slowed down or stopped upon determination of slower than expected depletion of contaminants). The depletion of contaminants (e.g., dyes, additives etc.) from the textile may, for example, be detected in the solvent effluent, e.g., by spectroscopy, viscometry, or any other suitable method. The contaminant concentration in the solvent effluent may be provided to controller that controls the movement of the feedstock and / or the flow rate of the solvent at any stage of the path of the feedstock. In some embodiments, an augur-based counter-current extraction device may be used, whereby solvent moves counter to the fabric, at a specific residence time until the elastane is depleted. In other embodiments, the textile is carried on a conveyor belt with spray of solvent, falling through a coarse filter on the conveyor based with gravity, at a specific speed and residence time until the elastane is depleted, by detection in the effluent with the above methods. In a variation of this embodiment, the conveyor belt system moves the fabric through the solvent whilst continuously immersing or partially immersing the fabric in the solvent. The textile may additionally be contained on the conveyor in specific cells or baskets which are permeable to the solvent. In some embodiments, the containment cells or baskets include a permeable cover to contain the textile therein, such as during immersion steps.

[0089] In some embodiments, the dissolved elastane, dyes and other soluble auxiliary components are separated from the textile material in a solid-liquid separation process, for example via a course filter built into an extraction device, such that the majority of the elastane, dye and contaminants in solution drain and fall through the mass of textiles under gravity. Optionally, vacuum or compressive forces may be used to aid in solid-liquid separation. After removal of the elastane and other components, the polyester is left undisturbed, still in solid textile form, which is also referred to herein as substantially non-degraded. The polyester textilemay typically include a small amount (e.g., less than 5-10% of the applied solvent) of residual solvent soaked into the textile. The solvent effluent from the dye / additive extraction process and the elastane extraction process contains dissolved elastane, dyes and other soluble materials, and can be processed for recovery of at least a portion of the organic dissolution solvent. The solvent may be recovered via any suitable means, for example by distillation, leaving a solid waste containing elastane and dyes. This solid waste can be used for energy recovery by incineration.

[0090] In some embodiments, further recovery of additional solvent occurs through recovery of the residual solvent on the polyester textile. For example, residual solvent is first removed by a physical pressing action using, e.g., compressive, vacuum, or centrifugal forces. This physical pressing removes substantially all remaining excess solvent from the shredded textile material. Various types of equipment can be used for the pressing, such as, but not limited to, a graduated augur press, a screw press, a roller press, a hydraulic or pneumatic filter press, or centrifuge. Any remaining residual solvent is removed from the textile by the application of heat, optionally aided by either vacuum or a positive airflow over the material. The textile may be heated to promote solvent evaporation after which textile, dry and free of solvent, may be provided to downstream recycling processes. In other embodiments, cyclopentanone may be used. The residual solvent collected may be recycled into the system. After solvent removal, the polyester textile (e.g., PET) material can optionally be subjected to a solid or liquid-state polymerization process to increase its molecular weight and intrinsic viscosity. The resulting polyester in solid or melt form can then be processed into polyester filament yam, such as via melt-extrusion to a filament or staple yam, or into polymer pellets, which can then be processed into yams in downstream facilities. It is understood that individual process steps may be operated as separate process steps or combined into process steps as needed, depending on the specific process equipment. In a further embodiment, the PET and elastane blend can instead be a polyamide and elastane blend under the same conditions. In a further embodiment, the PET and elastane blend can instead be a PET, cotton and elastane blend, where the temperature is not more than 150° C.

[0091] Optimized wash conditions were evaluated. Textile samples were systematically subjected to cyclohexanone solvent washes in a two-step wash process at varying temperatures (80 °C - 130 °C) and durations for three times, and results are summarized in FIG. 8. As shown in FIG. 8, optimal dye removal activity coupled with elastane preservation is consistentlyobserved within a temperature range of about 90 °C to about 95 °C. Significantly greater mass loss occurs above 100 °C, indicating the effective elastane removal at these higher temperatures. Additionally, it was observed that significantly enhanced elastane preservation is achieved in washes maintained around approximately 10 minutes duration compared to longer wash times (approximately 30 minutes).

[0092] The foregoing description has broad application. The discussion of any embodiment is meant only to be explanatory and is not intended to suggest that the scope of the disclosure, including the claims, is limited to these examples. In other words, while illustrative embodiments of the disclosure have been described in detail herein, the inventive concepts may be otherwise variously embodied and employed, and the appended claims are intended to be construed to include such variations, except as limited by the prior art.

[0093] The foregoing discussion has been presented for purposes of illustration and description and is not intended to limit the disclosure to the form or forms disclosed herein. For example, various features of the disclosure are grouped together in one or more aspects, embodiments, or configurations for the purpose of streamlining the disclosure. However, various features of the certain aspects, embodiments, or configurations of the disclosure may be combined in alternate aspects, embodiments, or configurations. Moreover, the following claims are hereby incorporated into this Detailed Description by this reference, with each claim standing on its own as a separate embodiment of the present disclosure.

[0094] All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, back, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are only used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and may include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other. Identification references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to connote importance or priority, but are used to distinguish one feature from another. The drawings are for purposes of illustration only andthe dimensions, positions, order and relative sizes reflected in the drawings attached hereto may vary.

Claims

CLAIMS1. A method comprising: a) providing a textile feedstock comprising a plurality of polymers and one or more auxiliary components, the plurality of polymers comprising elastane; b) contacting the textile feedstock with an organic solvent, the organic solvent comprising cyclohexanone, cyclopentanone, or a mixture thereof; c) at a first temperature, dissolving or suspending at least a portion of the one or more auxiliary components in the organic solvent; c) separating at least a portion of the organic solvent containing the dissolved or suspended one or more auxiliary components from the textile feedstock to provide a pretreated textile feedstock; and d) at a second temperature, greater than the first temperature, contacting the pretreated textile feedstock with an additional portion of the organic solvent to dissolve the elastane therein, thereby generating an elastane-containing solution.

2. The method of claim 1, wherein the first temperature is lower than a temperature at which greater than 50% by weight elastane dissolves or suspends.

3. The method of any one of claims 1-2, wherein the first temperature is no less than 100° C.

4. The method of claim 3, wherein the first temperature ranges from 90 °C to 95 °C.

5. The method of any one of claims 1-4, wherein a duration of contacting the textile feedstock with the organic solvent at the first temperature is about 10 minutes.

6. The method of any one of claims 2-5, wherein the second temperature is above the temperature sufficient to dissolve or suspend greater than 50% by weight of elastane in the organic solvent.

7. The method of claim 6, wherein the second temperature is greater than 100 °C.

8. The method of claim 6, wherein the second temperature ranges from about 110 °C to about 160 °C.

9. The method of any one of claims 1-8, wherein the plurality of polymers further comprises polyester, polyamide, cotton, or a combination thereof.

10. The method of any one of claims 1-9, wherein the one or more auxiliary components comprise a dye.

11. The method of claim 10, wherein the one or more auxiliary components further comprise an additive.

12. The method of any one of claims 1-11, wherein the organic solvent is cyclohexanone or a mixture of cyclohexanone and cyclopentanone.

13. The method of any one of claims 1-12, further comprising: purifying the elastane-containing solution by performing one or more purification processes using membrane filtration and adsorption purification to produce a purified elastane solution, wherein the elastane-containing solution is maintained at a temperature greater than about 80°C during purification; and precipitating the purified elastane from the purified elastane solution.

14. The method of claim 13, wherein the elastane-containing solution is maintained at a temperature greater than about 100 °C during the purification.

15. The method of any one of claim 14, wherein the elastane-containing solution is maintained at a temperature greater than about 110 °C during the purification.

16. The method of any one of claims 13-15, wherein purifying the elastane - containing solution comprises passing the elastane-containing solution through one or more filtration membranes having molecular weight cutoffs (MWCO) selected to retain the elastane in a retentate fraction.

17. The method of claim 16, further comprising subjecting the elastane-containing solution to diafiltration during membrane filtration, wherein additional cyclohexanone is added to the retentate fraction to further improve elastane purity and remove impurities.

18. The method of any one of claims 13-15, wherein purifying the elastane- containing solution comprises contacting the elastane-containing solution with one or more adsorbents to remove impurities.

19. The method of claim 18, wherein the one or more absorbents comprise active carbon, a polymeric resin, or a combination thereof.

20. The method of any one of claims 18-19, wherein purifying the elastane- containing solution comprises circulating the elastane-containing solution multiple times or passing the elastane-containing solution once through the one or more absorbents.

21. The method of any one of claims 13-20, wherein precipitating the purified elastane from the purified elastane solution comprises performing one or more operations selected from: i) adding one or more anti-solvents to precipitate the elastane; ii) reducing the temperature of the purified elastane solution below an elastane solubility limit to precipitate the elastane; and iii) evaporating the organic solvent from the purified elastane solution to precipitate the elastane.

22. The method of claim 21, wherein the one or more anti-solvents comprise water, an organic solvent having lower elastane solubility, or a mixture thereof.

23. The method of claim 22, wherein precipitating the purified elastane comprises cooling the purified elastane solution to a temperature below about 50°C.

24. The method of any one of claims 13-23, wherein the purified elastane has improved purity relative to elastane produced using solutions of dimethyl acetamide (DMAc) or dimethyl formamide (DMF) at ambient temperatures.

25. The method of claim 24, wherein the improved purity comprises reduced coloration, reduced organic impurities, reduced oligomer content, improved whiteness, improved uniformity, or combinations thereof.

26. The method of any one of claims 13-25, further comprising converting the purified elastane into fibers.

27. The method of claim 26, further comprising converting the fibers into yams.

28. The method of claim 27, further comprising forming textiles from the yams.

29. The method of claim 28, further comprising forming garments, medical textiles or industrial textiles from the textiles.

30. The method of any one of claims 1-29, further comprising recycling the organic solvent and reusing the recycled organic solvent at any contacting step of (b) or (d), wherein a concentration of the one or more auxiliary components in the recycled organic solvent is lower than that of the original textile feedstock.

31. The method of any one of claims 1-30, further comprising performing mechanical squeezing during or after any contacting step of (b) or (d).

32. A fiber comprising the elastane recovered from the textile feedstock according to the method of any one of claims 1 to 31.

33. The fiber of claim 32, wherein the fiber comprises from about 1% to about 99% by weight of the purified elastane and from about 99% to about 1% by weight of elastane fiberforming materials.

34. A yarn comprising the fiber of any one of claims 32-33.

35. A textile comprising the yam of claim 34.

36. A garment, medical textile, or industrial textile article comprising the textile of claim 35.

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