Technical Field

Aspects of the present disclosure relate in general to a process for separating and recovering polymers and/or fibers from solid composite materials or liquid mixtures containing a plurality of polymers and/or fibers. The so id composite materials or liquid mixtures can include or be waste materials. Particular aspects of the present disclosure also pertain to a process for recovering a solvent used in the process for separating polymers, where the recovered solvent can be reused in one or more manners.

Background

Polymers, including fibers, with a high purity that are presently available in the market are mainly produced new. Due to increasing worldwide demand for uses of polymers, there have been sever 1 attempts to provide alternative sources for polymers. One of the alternative sources is polymers recycled from waste materials in many industries. Typically, the waste materials are substantially composed of nylon, spandex, Polyethylene (PE), Polyester, Low Density Polyethylene (LDPE), High Densit Polyethylene (HOPE), Polyethylene Terephthal te (PET), and Polypropylene (PP). However, the waste materials have commonly been land-filled or burned. The polymers in the waste materials can take up to 400 years to degrade, which generates a great environmental liability, while there is demand to use such polymers in many industries.

In general, there have been a few processes disclosed for separa ing polymers or fibers from composite materials, in particular waste materials. Yin, Y., et. al (2014) discloses a method for removal of spandex from nylon-spandex blended fabrics by selective polymer degradation. The method requires a high temperature of 220 degrees Celsius for 2 hours in order to selectively de rade the spandex, while nylon remains undegraded. Then, a solvent (e.g., ethanol) is used to wash off the degraded spandex from the composite materials, and at least some nylon which is still in its original morphology and quality is recovered. The recovered nylon can be recycled. Notwithstanding, such a method undesirably requires a high temperature, and hence, it may not be economically feasible. Furthermore, a heat treatment is part of the method, which serves as a hydrolysis step that basically breaks down the spandex. Therefore, it is difficult to recover spandex using the disclosed method. Moreover, nylon may be degraded as well.

Furthermore, US Patent No. 5,278,282 to E. Bruce Nauman, et al. (hereafter“Nauman”) discloses a method for separating polymers from a physically commingled solid mixture containing a plurality of polymers. Nauman’s method involves dissolving a first one of the polymers in a solvent at a first lower temperature to form a first preferably single phase solution and a remaining solid component. The polymers are then separated from the solution by using a flash evaporation technique or compositional quenching. Nauman’s method can be used for separating polymers from waste materials. However, individuals having ordinary skill in the relevant art will recognize that Nauman’s extraction of the polymers from the solvent by way of flash evaporation or compositional quenching requires high energy consumption. Moreover and quite importantly, evaporated solvent vapor is extremely hazardous to human health. Thus, Nauman’s flash evaporation or compositional quenching should be sealed or isolated from humans the surrounding environment, which results in an undesirably high protection or protective equipment cost. In Nauman’s method, even though the removed solvent can be reused in the next dissolution step or a subsequent solvent-based process, it is not an appropriate method for separating polymers from waste materials on a commercial scale, due to the high energy consumption and high protection cost.

European Patent No. EP 2,596,932 to Heilberg, R, D. (hereafter“Heilberg”) also discloses equipment for recycling nylon contained in fabrics by extraction of elastane. Heilberg’ s equipment utilizes a dissolution step using a solvent, dimethylformamide (DMF), such that textile waste is reused. Nitrogen is also introduced in order to prevent oxidation. Notwithstanding, Heilberg’ s equipment uses a process to extract polymers from solvent by means of a distillation and pressing process. The distillation process generally requires high energy in the form of heat to evaporate the solvent. Although the solvent is recovered for use in the next dissolution step or a subsequent solvent-based process, and the elastane obtained is directed to a new use, it is still not economically feasible, due to its high energy consumption.

In view of the foregoing, there exists a need for a comprehensive method for separating polymers or fibers from waste materials, where solvent used is recovered and reusable, and polymers or fibers obtained have a quality grade or level suitable for reusability. More importantly, the energy consumption of the entire method must be sufficiently low such that it can be effectively used on a commercial scale to turn waste into value.

Summary

In accordance with various embodiments of the present disclosure, a process for separating polymers from waste materials or mixtures includes: (1) dissolving the waste materials or mixtures in a solvent to form a solution and a remaining solid component; (2) separating the solution from the remaining solid component; and (3) separating the soluble polymer from the solution, where the solution is cooled to solidify the soluble polymer by way of heat exchanging and/or naturally cooling in an environment, and the soluble polymer in solid form is separated from the solution by way of a centrifugation process, e.g., involving the use of a centrifugal separator.

It has been found that such a process in accordance with the present disclosure does not require the introduction of nitrogen into the dissolution step. Furthermore, in various embodiments the polymer is extracted from the solvent by way of the centrifugation process, e.g., typically or preferably by way of a centrifugal separator, which significantly reduces energy consumption compared to that of conventional processes. Therefore, a process in accordance with an embodiment of the present disclosure is scalable and economically feasible on a commercial scale for turning or converting waste into value, e.g., economically valuable material(s). In accordance with multiple embodiments of the present disclosure, the solvent is also recoverable for use in a subsequent or next process or process portion, such as a next dissolution step, or essentially any solvent-based processes). The polymers obtained or recovered by way of processes in accordance with embodiments of the present disclosure have a high purity, and are suitable for use or reuse in many manufacturing industries or processes, such as textiles or textile manufacturing processes, respectively.

In accordance with a first aspect of the present disclosure, a process for separating polymers from waste materials or a solid mixture includes: (1) dissolving the solid mixture in a solvent to form a solution and a remaining solid component, where the solid mixture contains at least one soluble polymer in the solvent; (2) separating the solution from the remaining solid component, where the solution contains a soluble polymer in the solvent and the solvent, and the remaining solid component contains an insoluble polymer in the solvent; and (3) separating the soluble polymer from the solution, where the solution is cooled to solidify the soluble polymer by way of heat exchanging and/or naturally cooling in an environment and the soluble polymer in solid form is separated from the solution by way of a centrifugation process, e.g., typically through the use of centrifugal separator. Both the insoluble polymer and soluble polymer are readily used for recycling or manufacturing processes in many industries.

In various embodiments, the process in accordance with the present disclosure further includes recycling the solvent obtained after the centrifugation process, e.g., typically by way of a centrifugal separator. The solvent can be recycled for use in a next dissolution step, or any other solvent-based process(es).

In multiple embodiments of the present disclosure, a ratio of insoluble polymers to soluble polymers in the solid mixture is between 99: 1 and 80:20. The solid mixture can contain at least two polymers of or selected from Polyamide (PA) including nylon or nylon 6,6, Polyether- Polyurea copolymer including, corresponding to, or formed of elastane or spandex type material(s), Polyethylene (PE), Polyester, Low Density Polyethylene (LDPE), High Density Polyethylene (HOPE), Polyethylene Terephthalate (PET), Polypropylene (PP) and Polyurethane (PU). A ratio of the solvent to the solid mixture used in accordance with embodiments of the present disclosure is typically between 10: 1 and 50: 1. Furthermore, the solvent can include or be selected from the group consisting or essentially consisting of Dimethylformamide (DMF), Dimethyl sulfoxide (DMSO), Toluene, Xylene, Dimethylacetamide (DMAC) and combinations thereof. A range of temperature and time used in embodiments of the present disclosure for dissolving the solid mixture in the solvent can be between 50— 160 degrees Celsius and between 10 - 60 minutes, respectively.

In some embodiments, the solution is separated from the remaining solid component by way of a filtration process, e.g., using a metal mesh filter, and/or other process(es) which can separate the solid from liquid, and the solvent present in the insoluble polymer of the remaining solid component is removed by way of tumble drying, e.g., by having hot air at a temperature of at least 50 degrees Celsius introduced or blown into a vessel carrying the remaining solid component while the vessel tumbles. In another embodiment, a process in accordance with the present disclosure further includes a reprocessing sequence for dissolving or further dissolving at least some polymer that is still present in the remaining solid component and which is soluble in the selected solvent to form a second solution and a second remaining solid component; and separating the second solution from the second remaining solid component, where the second remaining solid component contains the insoluble polymer. The reprocessing sequence can be performed in multiple cycles. A range of temper ture and time, and/or a ratio of the solvent to the solid mixture or remaining solid component used in some or each of the multiple cycles can be different, e.g., from one cycle to another. The insoluble polymer obtained is more purified by way of the reprocessing sequence. Furthermore, more soluble polymer in the solvent i s obtained by way of the reprocessing sequence.

In view of the foregoing, in accordance with the first aspect of the present disclosure, a process for separating polymers from a solid mixture containing two or more polymers includes: (a) dissolving the so id mixture in a solvent to form a solution and a remaining solid component, wherein the solid mixture contains a first set of polymers soluble in the solvent, and the remaining solid component contains a second set of polymers insoluble in the solvent; (b) separating the solution from the remaining solid component, wherein the solution contains the solvent and the first set of polymers soluble in the solvent; and (c) separating the first set of polymers soluble in the solvent from the solution, wherein the solution is cooled to solidify the first set of polymers to produce the first set of polymers in solid form, and the first set of polymers in solid form is separated from the solution by way of a centrifugation process. A ratio of the second set of polymers to the first set of polymers in the solid mixture can be between 99: 1 and 80:20.

In accordance with a second aspect of the present disclosure, a process for separating a polymer or fiber from a solvent in a liquid mixture, where the polymer or fiber is soluble in the solvent, includes steps of: (1) cooling the liquid mixture to solidify the polymer or fiber by way of heat exchanging and/or naturally cooling in an environment; and (2) separating the polymer or fiber in solid form from the liquid mixture by way of a centrifugation process, e.g., involving the use of centrifugal separator. The solvent can include or be selected from the group consisting or consisting essentially of Dimethylformamide (DMF), Dimethyl sulfoxide (DMSO), Toluene, Xylene, Dimethylacetamide (DMAC) and combinations thereof. The solvent remaining in the liquid mixture after the centrifugation process can be recycled for use in any solvent-based process, and the polymer or fiber obtained after the centrifugation process, e.g., which involves the use of a centrifugal separator, is readily usable or used for recycling or manufacturing processes in many industries.

Brief Description of the Figures

Figure 1 is a flowchart of a process for separating and recovering polymers or fibers from waste materials or solid composite materials or solid mixture according to an embodiment of the disclosure;

Figure 2 is a flowchart of a process for separating a remaining solvent from a remaining solid component, containing the insoluble polymer, according to an embodiment of the disclosure; and

Figure 3 is a flowchart of a process for separating and recovering a polymer or fiber from a solvent in a liquid mixture, where the polymer or fiber is soluble in the solvent, according to an embodiment of the disclosure.

Detailed Description

The description and associated flowcharts set forth particular non-limiting represen ative processes for separ ing polymers or fibers in accordance with certain embodiments of the present disclosure. It i s to be understood that different or other embodiments are also encompassed within the scope of the present disclosure, which provide the same, equivalent, or similar functional, technical, and/or structural features as those described herein. As used herein, the phrase“in embodiments” means in at least some embodiments, but not necessarily in all embodiments.

In the present disclosure, depiction of a given element or consideration or use of a particular element number in a particular figure or a reference thereto in corresponding descriptive material can encompass the same, an equivalent, or an analogous element or element number identified in another figure or descriptive material associated therewith. Unless explicitly stated otherwise, in the description herein, the recitation of particular numerical values or value ranges is taken to be a recitation of particular approximate numerical values or approximate value ranges. For instance, a given numerical value or value range provided below should be interpreted or defined as an approximate numerical value or value range, e.g., to within +/- 20%, +/- 15%, +/- 10%, +/- 5%, +/- 2.5%, or +/- 0%. For instance, a temperature of 90 degrees Celsius should be interpreted as approximately or about 90 degrees Celsius, within a percentage such as indicated above. As used herein, the term“set” corresponds to or is defined as a non-empty finite organization of elements that mathematically exhibits a cardinality of at least 1 (i.e., a set as defined herein can correspond to a unit, singlet, or single element set, or a multiple element set), in accordance with known mat ematical definitions (for instance, in a manner corresponding to that described in An Introduction to Mathematical Reasoning: Numbers, Sets, and Functions , "Chapter 1 1 : Properties of Finite Sets" (e.g., as indicated on p. 140), by Peter J. Eccles, Cambridge University Press (1998)). Thus, a set in ludes at least one element. For instance, in the context of the present dis losure, an element of a set can include or be one or more portions of a process; a substance, material, or composition; a physical parameter; or a value, depending upon the type of set under considera ion.

As used herein, the terms“waste material,” "waste materials,"“solid composite material,”“solid composite materials,”“solid mixture,”“solid mixtures,”“liquid mixture,” and“liquid mixtures” refer to any materials and/or mixtures, e.g., obtained from post-industrial or post-consumer sources or processes, containing various portions of polymers and/or fibers based upon, corresponding to, or formed of one or more of Polyamide (PA) including nylon or nylon 6,6; Polyether-Polyurea copolymer including, corresponding to, or formed of elastane or elastane based materials, e.g., spandex or Lycra ^® ; Polyethylene (PE); Polyester; Low Density Polyethylene (LDPE); High Density Polyethylene (HOPE); Polyethylene Terephthalate (PET); Polypropylene (PP); Polyurethane (PU); and various portions of other synthetic polymers and/or fibers. In the context of the present disclosure, reference to Polyether-Polyurea copolymer encompasses or includes reference to spandex, Lycra ^® , and other elastane based materials unless otherwise explicitly stated.

As used herein, the term“filtration” corresponds to any mechanical, physical, and/or biological process(es) or operation(s) that separate(s) solids from liquids by the inclusion, presence, or addition of a medium or structure through which only a fluid, or a fluid carrying or containing substances or particles smaller than a predetermined size, can pass. The medium can include a filter. In various embodiments, filtration involves the use of a metal mesh filter having a particular mesh size, e.g., selected based on or in accordance with a particle size of a type of insoluble polymer under consideration, in a manner readily understood by individuals having ordinary skill in the relevant art. The term“centrifugation” refers to any technique which involves the application of centrifugal force(s) to separate particles from a solution according to their size, shape, density, viscosity of the medium and rotor speed. In several embodiments, centrifugation involves introducing or pumping a liquid mixture into an approximately or generally conical or conical vessel to create a vortex. The generated vortex produces or exerts centrifugal force on the liquid mixture, where higher density suspended polymers are pushed to the side and ejected from the system. In various embodiments, centrifugation involves the use or occurs by way of a centrifugal separator.

A first aspect of the present disclosure relates to a process for separating polymer(s) and/or fiber(s) (hereafter“polymers” or“polymer” for purpose of brevity, simplicity, and clarity) from waste materials, solid composite materials, and/or a solid mixture (collectively referred to hereafter “solid mixture” for purpose of brevity, simplicity, and clarity), where the process includes: (1) dissolving the solid mixture in a solvent to form a solution and a remaining solid component; (2) separating the solution from the remaining solid component; and (3) separating soluble polymer(s) from the solution by way of a centrifugation process. In multiple embodiments, the centrifugation process involves the use of a centrifugal separator. Both the insoluble polymer(s) and soluble polymer(s) are readily (re)usable or (re)used for recycling or manufacturing processes in many industries, such as textiles. In various embodiments, the process further includes recycling the solvent obtained after the centrifugation process, e.g., after centrifugation by way of a centrifugal separator. The solvent can be recycled for use in a subsequent or next dissolution step, or essentially any other solvent-based process(es).

In another or further aspect of the present disclosure, a process for separating a polymer or fiber from a solvent in a liquid mixture, where the polymer or fiber is soluble in the solvent, includes: (1) cooling the liquid mixture to solidify the polymer or fiber by way of heat exchanging and/or naturally cooling in an environment; and (2) separating the polymer or fiber in solid form from the liquid mixture by way of a centrifugation process, e.g., using a centrifugal separator.

Representative aspects of a polymer or fiber separation process from a solid or liquid mixture Figure 1 shows a flowchart of a process 100 for separating polymers or fibers from waste materials, solid composite materials, and/or a solid mixture (collectively referred to as“solid mixture,” as above) according to an embodiment of the present disclosure. In a first process portion 1 10, at least one solid mixture is provided or obtained. In a number of non-limiting representative example embodiments, a solid mixture includes at least polymers of one or more of Polyamide (PA), Polyether-Polyurea copolymer (where as indicated above, use of the term Polyether-Polyurea copolymer encompasses elastane or spandex type materials), Polyethylene (PE), Polyester, Low Density Polyethylene (LDPE), High Density Polyethylene (HOPE), Polyethylene Terephthalate (PET), Polypropylene (PP) and Polyurethane (PU). In a non-limiting representative embodiment provided for purpose of aiding understanding, the solid mixture includes Polyamide (PA) and Polyether-Polyurea copolymer. More specifically, a ratio of these two polymers in the solid mixture can be between 99: 1 and 80:20.

In a second process portion 120, the solid mixture is dissolved in a selected solvent or solvent mixture (hereafter“solvent” for purpose of simplicity and clarity) to form a solution and a remaining solid component. In various embodiments, the solvent includes or is selected from Dimethylformamid (DMF), Dimethyl sulfoxide (DMSO), Toluene, Xylene, Dimethylacetamide (DMAC), and combinations thereof. For instance, the solvent can be selected from the group consisting or consisting essentially of DMF, DMSO, Toluene, Xylene, DMAC, and combinations thereof. In a representative embodiment, the selected solvent is DMF. A typical ratio of solvent to solid mixture is between 10: 1 and 50:1. The two or more polymers in the solid mixture generally have different solubilities in the selected solvent. A typical range of temperature and time used in the second process portion 120 is between 50 - 160 degrees Celsius and between 10 - 60 minutes, respectively. However, in some embodiments, the second process portion 120 can be performed without heating (e.g., at ambient or room temperature), or with low or minimal heating (e.g., at a temperature below 50 degrees Celsius). After dissolving the solid mixture containing Polyamide (PA) and Polyether-Polyurea copolymer with the DMF, the solution contains the Polyether- Polyurea copolymer which is soluble in the DMF, and the remaining solid mixture contains the Polyamide (PA) which is insoluble in the DMF.

In a third process portion 130, the solution containing the Polyether-Polyurea copolymer obtained from the second process portion 120 is separated from the remaining solid component containing the Polyamide (PA) by way of a filtration process. In various embodiments, the filtration process includes or occurs by way of filtration using a metal mesh filter. However, individuals having ordinary skill in the relevant art will understand that the filtration process can occur by way of another type of filter, and/or essentially any process or process sequence that can separate solids from liquids.

In a fourth process portion 140, the solution without the remaining solid component from the third process portion 130 is cooled to solidify the Polyether-Polyurea copolymer by way of heat exchanging and/or naturally cooling in an environment. In a fifth process portion 150, the Polyether-Polyurea copolymer in solid form is then separated from the solution by way of a centrifuga ion process, or any process that involves the application of centrifugal force to separate solids from a solution, e.g., by way of a centrifug tion system. In various embodiments, the fifth process potion 150 utilizes a centrifugal separator, which pumps liquid mixture into a conical vessel to create a vor ex. The generated vortex produces or exerts centrifugal force on the liquid mixture, such that higher density suspended polymers re pushed outward or to the side and collected or ejected from the centrifugation system. Typically, a rate, speed, or frequency of centrifugation is at least 600 RPM. The Polyether-Polyurea copolymer obtained in association with the fifth process portion 150 is readily usable or used for recycling or manufacturing in many industries.

In various embodiments, the process 100 further includes a sixth process portion 160 in which the solvent obtained in association with fifth process portion 150 is recycled for use in the second process portion 120, or essentially any other solvent-based process(es).

In some embodiments of the present disclosure, the process 100 further includes a seventh process portion 170, in which the remaining solid component obtained in association with third process portion 130 is reprocessed. Individuals having ordinary skill in the relevant art will understand that the remaining solid component obtained in association with the third process portion 130 can still contain at least some polymer(s) that are soluble in the selected solvent, but which were not or were not completely dissolved during their original or previous exposure to the selected solvent. Thus, the remaining solid component obtained in association with the third process portion 130 can be reprocessed or subjected to a reprocessing sequence to further remove such soluble polymer(s) therefrom, e.g., which further extracts the soluble polymer(s) and which further purifies this solid component. More particularly, in the seventh process portion 170, the remaining solid component obtained in association with the third process portion 130 is exposed again to a selected solvent to form a second solution and a second remaining solid component. The selected solvent used in the seventh process portion 170 can be the same solvent used in the previous process portion 130, or another different solvent, e.g., selected from the group consisting or consisting essentially of Dimethyl sulfoxide (DMSO), Toluene, Xylene, and combinations thereof. In a nonlimiting represent tive embodiment, the second solution contains at least some Polyether-Pol urea dissolved in the selected solvent, and the remaining solid component contains Polyamide (PA). Furthermore, the seventh process portion 170 can be performed in multiple cycles, and depending upon embodiment details, a range of temperature and time, and/or a ratio of the solvent to the solid mixture or remaining solid component used in some or each of the multiple cycles can be identical or different. A polymer obtained in association with the seventh process portion 170, for example the Polyamide (PA), can be more purified. Furthermore, more soluble polymer in the solvent, for example, the Poiyether-Polyurea copolymer, is extracted or obtained by way of such reprocessing. In some embodiments, solvent present in the remaining solid component obtained in association with the third process portion 130 of the process 100 can be removed by way of a drying procedure, e.g., tumble drying, prior to the seventh process portion 170. Figure 2 shows a flowchart of a process 200 for separating or removing solvent present in the remaining solid component, containing the insoluble polymer, according to an embodiment of the present disclosure. In a first process portion 210, the remaining solid component obtained in association with the third process portion 130 of the process 100 is spun to dry or spin dried by way of tumble drying, typically involving heated or hot air at a temperature of at least 50 degree Celsius blown into a vessel carrying the aforementioned remaining solid component while the vessel tumbles. In a second process portion 220, the solvent is evaporated from the remaining so id component in association with or by way of such spin drying. The insoluble polymer, for example the Polyamide (PA), is dried and ready for industrial (re)use.

In accordance with another or a further embodiment of the present disclosure, Figure 3 shows a flowchart of a process 300 for separating and recovering a polymer or fiber from a solvent in a liquid mixture, where the polymer or fiber is soluble in the solvent. In a first process portion 310, at least one liquid mixture, containing a solvent and a polymer or fiber, is provided or obtained. In various embodiments, representative examples of a liquid mixture include polymers or fibers of at least one of Polyamide (PA), Polyether-Polyurea copolymer, Polyethylene (PE), Polyester, Low Density Polyethylene (LDPE), High Density Polyethylene (HOPE), Polyethylene Terephthalate (PET), Polypropylene (PP), and Polyurethane (PU), in a solvent that includes or which is selected from the group consisting or consisting essentially of Dimethylformamide (DMF), Dimethyl sulfoxide (DMSO), Toluene, Xylene, Dimethylacetamide (DMAC) and combinations thereof. In a non-limiting representative embodiment provided to aid understanding, the liquid mixture includes Polyether-Polyurea copolymer in DMF solvent, where the Polyether-Polyurea copolymer is soluble in the DMF.

In a second process portion 320 of the process 300, the liquid mixture from the first process portion 310 is cooled to solidify the polymer, for example Polyether-Polyurea copolymer, by way of heat exchanging and/or naturally cooling in an environment. In a third process portion 330, the polymer in solid form is then separated from the liquid mixture by way of a centrifugation process, e.g., essentially any process that involves the application of centrifugal force to separate solids from a liquid. The third process portion 330 typically utilizes a centrifugation system such as a centrifugal separator, which pumps liquid mixture into a conical vessel to create a vortex. The generated vortex produces or exerts centrifugal force on the liquid mixture, such that higher density suspended polymers are pushed outward or to the side and collected or ejected from the system. Typically, a rate, speed, or frequency of centrifugation is at least 600 RPM. The polymer and solvent obtained in association with the third process portion 330 is readily used for recycling or manufacturing in many industries or any other solvent-based process(es).

The following representative examples detail experiments describing particular aspects of a process for separating polymers or fibers from a solid or liquid mixture in accordance with an embodiment of the present disclosure. An individual having ordinary skill in the relevant art will understand that the scope of the present disclosure is not limited by the following representative examples.

Example One

Experiments described in example one were conducted to illustrate a process for separating Polyamide (PA) and Polyether-Polyurea copolymer, especially spandex, from a solid mixture, and a process for separating and recovering Polyether-Polyurea copolymer, especially spandex, from the solvent DMF in a liquid mixture, where the polymer or fiber is soluble in the solvent, according to an embodiment of the present disclosure.

The process for separating Polyamide (PA) and Polyether-Polyurea copolymer, especially spandex, from a solid mixture includes: (1) dissolving the solid mixture in the DMF to form a solution and a remaining solid component, where the solid mixture contains Polyamide (PA) and Polyether-Polyurea copolymer, especially spandex, having a different solubility in the DMF; (2) separating the solution from the remaining solid component by way of a metal mesh filter, where the solution contains Polyether-Polyurea copolymer, especially spandex, which is soluble in the DMF, and the remaining solid component contains Polyamide (PA) which is insoluble in the DMF; and (3) separating the Polyether-Polyurea copolymer, especially spandex, from the solution, where the solution is cooled to solidify the Polyether-Polyurea copolymer by way of a water bath and the Polyether-Polyurea copolymer, especially spandex, in solid form is separated from the solution by way of using a centrifugal separator at a centrifuga ion rate, speed, or frequency of 2000 RPM.

A ratio of Polyamide (PA) to Polyether-Polyurea copolymer, especially spandex, in the solid mixture is 80:20 and a ratio of the DMF to solid mixture used in the experiment is between 10: 1 and 50: 1. The volume and temperature of the solid mixture is 50 milliliters and 20 degree Celsius, respectively. In addition, a range of temperature and time used in the experiment for dissolving the solid mixture in the DMF is set to between 50 - 90 degree Celsius and between 10 - 60 minutes, respectively.

Furthermore, Polyamide (PA) obtained from the process is spun to dry or spin dried by way of tumble drying at a tumble drying temperature and a tumble drying cycle rate, speed, or frequency of 90 degree Celsius and 300 RPM, respectively. The DMF is then evaporated from the Polya ide (PA). Such DMF can be recovered for subsequent use.

Hence, in example one, both Polyamide (PA) and Polyether -Polyurea copolymer obtained are readily used for recycling or manufacturing in many industries, and/or the DMF is recovered for use in any other solvent-based process(es).

Example Two

Experiments described in example two were conducted to illustrate a process for separating Polyamide (PA) and Polypropylene (PP) from a solid mixture and a process for separating and recovering Polypropylene (PP) from a solvent Xylene in a liquid mixture, where the polymer or fiber is soluble in the solvent, according to an embodiment of the present disclosure. In example two, the process for sepa ating Polyamide (PA) and Polypropylene (PP) from a solid mixture includes: (1) dissolving the solid mixture in the Xylene to form a solution and a remaining solid component, where the solid mixture contains Polyamide (PA) and Polypropylene (PP) having a different solubility in the Xylene; (2) separating the solution from the remaining solid component by way of a metal mesh filter, where the solution contains Polypropylene (PP) which is soluble in the Xylene, and the remaining solid component contains Polyamide (PA) which is insoluble in the Xylene; and (3) separating the Polypropylene (PP) from the solution, where the solution is cooled to solidify the Polypropylene (PP) by way of using a water bath and the Polypropylene (PP) in solid form is separated from the solution by way of a centrifugal separator at a centrifugation rate, speed, or frequency of 2000 RPM.

In example two, a ratio of Polyamide (PA) to Polypropylene (PP) in the solid mixture is 90: 10 and a ratio of the Xylene to solid mixture is between 10:1 - 50:1. The volume and temperature of the solid mixture is 50 milliliters and 20 degree Celsius, respectively. In addition, a range of temperature and time used in the experiment for dissolving the solid mixture in the Xylene is between 100 - 130 degree Celsius and between 10 - 60 minutes, respectively.

Furthermore, Polyamide (PA) obtained from the process is spun to dry or spin dried by way of tumble drying, at a tumble drying temperature and a tumble drying cycle rate, speed, or frequency of 90 degrees Celsius and 300 RPM, respectively. The Xylene is then evaporated from the Polyamide (PA), e.g., such that it be recovered for subsequent use.

Hence, in example two, both Polyamide (PA) and Polypropylene (PP) obtained are readily used for recycling or manufacturing in many industries, and/or the Xylene is recovered for use in any other solvent-based process(es).

Example Three

Experiments described in example three were conducted to illustrate the process for separating Polyamide (PA) and Polyethylene terephthalate (PET) from a solid mixture and the process for separating and recovering Polyethylene terephthalate (PET) from a solvent DMSO in a liquid mixture, where the polymer or fiber is soluble in the DMSO solvent, according to an embodiment of the present disclosure. In example three, the process for separating Polyamide (PA) and Polyethylene terephthalate (PET) from a solid mixture includes: (1) dissolving the solid mixture in the DMSO to form a solution and a remaining solid component, where the solid mixture contains Polyamide (PA) and Polyethylene terephthalate (PET) having a different solubility in the DMSO; (2) separ ting the solution from the remaining solid component by way of a metal mesh filter, where the solution contains Polyethylene terephthalate (PET) which is soluble in the DMSO, and the remaining solid component contains Polyamide (PA) which is insoluble in the DMSO; and (3) separating the Polyethylene terephthalate (PET) from the solution, where the solution is cooled to solidify the Polyethylene terephthalate (PET) by way of a water bath and the Polyethylene terephthalate (PET) in solid form is separated from the solution by way of a centrifugal separator at a centrifugation rate, speed, or frequency of 2000 RPM.

In example three, a ratio of Polyamide (PA) to Polyethylene terephthal e (PET) in the solid mixture is 90: 10 and a ratio of the DMSO to solid mixture is between 10: 1 - 50: 1. The volume and temperature of the solid mixture is 50 milliliters and 20 degree Celsius, respectively. In addition, a range of temperature and time used in the experiment for dissolving the solid mixture in the DMSO is between 120 - 160 degrees Celsius and between 10 - 60 minutes, respectively.

Furthermore, Polyamide (PA) obtained from the process is spun to dry or spin dried by way of tumble drying, at tumble drying temperature and tumble drying cycle rate, speed, or frequency of 120 degrees Celsius and 300 RPM, respectively. The DMSO is then evaporated from the Polyamide (PA), e.g., such that it can be captured or recovered.

Hence, in example three, both Polyamide (PA) and Polyethylene terephthalate (PET) obtained are readily used for recycling or manufacturing in many industries, and/or the DMSO is recovered for use in any other solvent-based process(es).

Particular embodiments in accordance with the present disclosure are described above for addressing at least one of the previously indicated disadvantages, problems, or needs. While advantages of certain embodiments have been described, other embodiments may exhibit such advantages, and not all embodiments need to exhibit such advantages to fall within the scope of the disclosure. The above-disclosed aspects of the present disclosure, as well as presently unforeseen or unanticipated altem tives, variations or improvements thereto that may be subsequently made by an individual having ordinary skill in the relevant art, are encompassed by the following claims.