WO2025222239A1 - Method of and system for separating waste - Google Patents

Abstract

Described is a method of and system for separating a mixture of non-entangled particles/short fibres of two or more individual components, such as formed from a blended fabric or entangled mixture of solid material, comprising an optional cutting step and dispersing, separating, and filtering steps.

Description

METHOD OF AND SYSTEM FOR SEPARATING WASTE

Related Applications

[001 ] The present application claims priority to Australian provisional patent application AU 2024901127 filed on 22 April 2024, the entire contents of which are incorporated herein by crossreference.

Technical Field

[002] The disclosure herein relates to a method of separating textiles and mixed wastes via formation of non-entangled particles/short fibres by physical separation and to a system therefor. More particularly, the method comprises physical separation of, for example, polyester and cotton from textiles and mixed wastes, although it will be appreciated that the method and systems herein are not limited to this particular textile and mixed waste composition.

Background of Invention

[003] A reference herein to a patent document or other matter which is given as prior art is not to be taken as an admission that the document or matter was known or that the information it contains was part of the common general knowledge as at the priority date of any of the claims.

[004] Textile wastes present a challenge to the recycling industry because many fabrics and garments contain a mixture of materials, either in the form of blended fabrics and/or as different components of the same garment. In general, recycling streams require pure material inputs, and only very limited options are available to recycle mixed materials. Mixed materials, such as blended or mixed fabrics, thus pose an issue for recycling facilities since they cannot be recycled through conventional recycling streams that rely on mechanical processing. As long as the material is not contaminated, waste fabrics such as cotton can be processed into regenerated cellulose, and materials such as polyester can also be recycled into new products. As recycling often requires significantly less energy and water resources than would be required to create virgin materials, it is highly desirable to be able to separate mixed wastes into their individual components, which can then be conventionally recycled.

[005] Currently, existing technologies for recycling blend fabrics have focused on chemical separation through hydrothermal or similar solvent-based processes, in which one component is solubilised or destroyed. Prior art in this area includes WO 2019/047174 A1 , CN 106674588 B, WO 2019/140245 A1 , US 2020/0262108, Negrier et a., RSC Sustainability, 2023, 1 :335, Rossen & Byrne, Cellulose, 2022, 29:4255, Rossen et al., J. Text. Inst. 2024, 115:656, Sun et al., Adv. Mater. 2021 , 33:2105174, Resources, Environment and Sustainability, 2023, 13:100118, and Kahoush & Kadi, Sustainable Materials and Technologies 2022, 34:e00513. These processes focus on hydrothermal or similar processes in which one material is dissolved, whilst the other(s) remain solid, thus requiring specific solvents, heat, and pressure, existing separately from current textile value chain. This makes these separation techniques limited in deployability, as extensive new infrastructure is required. These methods also change the nature of the morphology of the components, resulting in the loss of morphological features which may be of interest to retain (such as for fibres being reused as fillers, e.g., in concrete, composite panels, and the like). Thus, an alternative separation method that avoids these disadvantages would be beneficial.

[006] Oil-water extraction is a method used commonly to extract organic compounds such as some plant extracts for use in food and pharmaceuticals (vitamin B molecules, for instance). These techniques can also be considered solvent-based, as they are used primarily to extract soluble compounds by dissolving them in oil, which remains immiscible with water. In this regard, the oil acts as a solvent, and the target of these processes remains the dissolution of a compound of interest. Accordingly, these processes comprise a precipitation or evaporation step to recover the product as a solid. Conversely, the separation of solids dispersed in a liquid phase is often achieved via froth flotation, where air bubbles attach to hydrophobic solids, and the use of surfactants and foaming agents trap the solids in a froth layer on the surface. In this case, the water and other additives acts only as a medium, as the solid particles retain their morphology and thus can be physically separated by filtration. This approach, however, is restricted to very small particle sizes and also requires very fine air bubbles and very specific surfactant and chemical combinations. WO 2013/182801 A1 describes a textile separation approach that relies purely on flotation, in that very fine air bubbles adhere to the surface of the more hydrophobic material, causing them to float despite their similar density. However, this approach is limited to small particles and settling is required after flotation, rendering the method suitable for batch processing only.

[007] Improved methods of separating mixed wastes, such as of separating mixed textile and fabric waste, that address one or more of the above problems or at least provide a useful alternative, are therefore desirable.

[008] In one aspect, the invention described herein provides a combined oil-water separation approach with an oil-water flotation system that can separate mixed solids with much greater flexibility in design, and that has simpler requirements in terms of chemical choices than existing methods known in the art.

Summary of the Invention

[009] The present invention is directed to a method and/or a system in which blended fabrics and other entangled solid material can be separated into its constituent components. The invention is also directed to a product or a combination of products obtained through the described method and/or system.

[010] In some embodiments, this method and/or system comprises a process of deconstruction, dispersion, separation, and filtration:

• Deconstruction: comprises cutting material into short snippets in order to deconstruct the material into non-entangled particles/short fibres of the individual components; • Dispersion: comprises dispersing the particles/short fibres in a non-oil miscible medium in order to maximise the difference in hydrophilicity of the different components and wet one of the components;

• Separation: comprises separating the particles/short fibres using a combination of oil-water separation and flotation, where the particles/short fibres of the individual components are separated and accumulated in the oil or water phase;

• Filtration: comprises filtering the oil and/or water phase to recover now separated components of the original material.

[011 ] According to a first aspect of the present invention, there is provided a method of separating a mixture of non-entangled particles/short fibres of two or more individual components, the method comprising: dispersing the non-entangled particles/short fibres in a non-oil miscible medium, wherein the nonoil miscible medium is mixed with an oil to form an oil-water phase medium; separating the non-entangled particles/short fibres using a combination of oil-water separation and flotation, wherein individual components of the non-entangled particles/short fibres are separated and accumulated in an oil phase and/or a water phase; and filtering the oil and/or water phase to recover the separated and accumulated non-entangled particles/short fibres individual components therein.

[012] According to a second aspect of the present invention, there is provided a method of separating a blended fabric or entangled mixture of solid material comprising two or more individual components, the method comprising: cutting the blended fabric or entangled mixture of solid material into deconstructed nonentangled particles/short fibres; dispersing the non-entangled particles/short fibres in a non-oil miscible medium, wherein the non-oil miscible medium is mixed with an oil to form an oil-water phase medium; separating the non-entangled particles/short fibres using a combination of oil-water separation and flotation, wherein individual components of the non-entangled particles/short fibres are separated and accumulated in an oil phase and/or a water phase; and filtering the oil and/or water phase to recover the separated and accumulated individual components therein.

[013] In one embodiment of the second aspect, the blended fabric is a polyester-cotton blend. In one embodiment of the second aspect, the cutting is performed using a cutting mill.

[014] In the first and second aspects, the non-oil miscible medium may comprise at least one additive to maximise a difference in hydrophilicity of the individual components and fully wet one of the individual components. The additive may be selected from an alkaline salt, a neutral salt, an acid, a surfactant, and any combination thereof. In one embodiment, the at least one additive is an alkaline salt. The alkaline salt may comprise sodium carbonate or sodium bicarbonate, or may be a mixture of the two of these. The alkaline salt may be present in the non-oil miscible medium in an amount of from 0.1 to 5 wt%. The non-oil miscible medium may be water. The oil may be a non-emulsifiable oil. In one embodiment, the oil comprises a silicone oil, a mineral oil, a castor oil, or a paraffin oil, or a mixture thereof.

[015] Separating the non-entangled particles/short fibres may comprise using an oil-water system comprising water as the non-oil miscible medium, wherein the oil is a non-emulsifiable oil. In such embodiments, the non-emulsifiable oil may be selected from silicone oil, mineral oil, castor oil, paraffin oil, and a mixture thereof. The oil-water system may comprise a ratio by volume of oil to water of from 1 :2 to 1 :100. In one embodiment, oil-water system may comprise a ratio by volume of oil to water of from 1 :2 to 1 :50. In another embodiment, oil-water system may comprise a ratio by volume of oil to water of from 1 :5 to 1 :30. The combination of oil-water separation and flotation may comprise using air bubbles to facilitate movement of individual components having hydrophobic character from the water phase into the oil phase. Separating the non-entangled particles/short fibres may further comprise an agitation step, wherein agitation mixes the oil-water system thereby facilitating separation and accumulation of individual components in the oil phase and/or the water phase. The agitation step may produce and/or use air bubbles. In preferred embodiments, the individual components separate and accumulate into either the oil phase or the water phase. In one embodiment, the non-entangled particles/short fibres may comprise a mixture of polyester and cotton, wherein the polyester nonentangled particles/short fibres accumulate in the oil phase and the cotton non-entangled particles/short fibres accumulate in the water phase. Filtering of the oil phase and the water phase may be performed separately. In one embodiment, the oil and water phases are separately filtered and recycled into the method after filtration.

[016] The non-entangled particles/short fibres may have maximum lengths of less than 2 mm. In one embodiment, the non-entangled particles/short fibres have maximum lengths of from 0.2 mm to 0.5 mm.

[017] According to a third aspect of the present invention, there is provided a system for separating a blended fabric or entangled mixture of solid material, the system comprising: a separation tank configured to accommodate an oil-water phase medium, wherein the oil-water phase medium comprises a non-oil miscible medium and an oil phase medium; an agitator configured to be immersed in the oil-water phase medium to agitate the oil-water phase medium; a non-oil phase outlet located at a lower end of the separation tank to extract the non-oil miscible medium and components therein, optionally into a first settling tank; and, an oil-phase outlet located at an upper end of the separation tank to extract the oil-phase medium and components therein, optionally to the first settling tank or a second settling tank.

[018] In one embodiment of the third aspect, the agitator is an aerator, an impeller, a magnetic or mechanic stirrer, a rotating drum mixer or a water pump mixer. In one embodiment, the system further comprises a first settling tank for receiving the non-oil miscible medium and components therein. In one embodiment, the non-oil phase outlet located at a lower end of the separation tank extracts the non-oil miscible medium and components therein into the first settling tank. In one embodiment, the oil-phase outlet located at an upper end of the separation tank extracts the oil-phase medium and components therein to the first settling tank. In one embodiment, the system further comprises a second settling tank for receiving the oil-phase medium and components therein. In one embodiment, the oil-phase outlet located at an upper end of the separation tank extracts the oil-phase medium and components therein to the second settling tank. In one embodiment, the system further comprises a filtration unit for filtering the oil-phase medium and components therein and/or the non-oil miscible medium and components therein.

[019] According to a fourth aspect of the present invention, there is provided a system according to the third aspect when used to implement the method of the first or second aspect. In other words, there is provided use of a system according to the third aspect to implement the method of the first or second aspect.

[020] According to a fifth aspect of the present invention, there is provided separated individual components obtained by the method of the first or second aspect or when obtained using the system of the third aspect. In one embodiment, the separated individual components of the fifth aspect are from a deconstructed blended fabric or entangled mixture of solid material.

[021 ] Unless the context indicates otherwise, where the terms “comprise”, “comprises” and “comprising” are used in the specification (including the claims) they are to be interpreted as specifying the stated features, integers, steps or components, but not precluding the presence of one or more other features, integers, steps or components, or group thereof.

[022] It should be understood that any numerical range recited herein is intended to include all subranges subsumed therein. For example, a range of "from x to y" or “between x and y” is intended to include all sub-ranges between x and y and also range end points x and y.

[023] As used herein, the singular forms “a,” “an,” and “the” may refer to plural articles unless specifically stated otherwise.

Brief Description of Drawings

[024] Embodiments of the invention will herein be illustrated by way of example only with reference to the accompanying drawings in which:

[025] Figure 1 shows the concept of deconstruction of a blend fabric;

[026] Figure 2 shows a schematic of a separation tank used in a batch separation process according to an embodiment of the invention described herein;

[027] Figure 3 shows a schematic of a separation tank used in a continuous separation process according to an embodiment of the invention described herein;

[028] Figure 4 shows a schematic of a separation tank used in a continuous process according to an embodiment of the invention described herein with an additional settling step to improve purity of the separated material;

[029] Figure 5 shows a Fourier Transform Infrared Spectroscopy (FTIR) analysis of polyester and cotton separated from a blend fabric according to an embodiment of the invention described herein compared to the original blend fabric; [030] Figure 6 shows a Thermogravimetric Analysis (TGA) of polyester and cotton separated from a blend fabric according to an embodiment of the invention described herein compared to the original blend fabric;

[031 ] Figure 7 shows a Fourier Transform Infrared Spectroscopy (FTIR) analysis of polyester and cotton separated from a 50:50 mixture of polyester and cotton fabrics according to an embodiment of the invention described herein compared to the original mixture;

[032] Figure 8 shows a Thermogravimetric Analysis (TGA) of polyester and cotton separated from a 50:50 mixture of polyester and cotton fabrics according to an embodiment of the invention described herein; and

[033] Figure 9 shows a Thermogravimetric Analysis (TGA) of polyester separated from a blend fabric according to an embodiment of the invention described herein and how an additional settling step improves the purity of the recovered polyester.

Detailed Description

[034] Described herein in one embodiment is a method of separating a mixture of non-entangled particles/short fibres of two or more individual components. The method comprises a step of dispersing the non-entangled particles/short fibres in a non-oil miscible medium, wherein the non-oil miscible medium is mixed with an oil to form an oil-water phase medium. This embodiment is particularly suitable where the waste material is provided as non-entangled particles or short fibres and exists as non-entangled mixture, such as factory spinning floor waste, where the material is already a mixture of individual short fibres rather than a blend fabric or yarn. However, in other embodiments, the method herein may be used to separate a blended fabric or entangled mixture of solid material comprising two or more individual components. In such cases, the blended fabric or entangled mixture may be prepared for separation prior to the dispersing step. In such embodiments, the method may comprise a step prior to dispersing that comprises cutting the blended fabric or entangled mixture of solid material into deconstructed non-entangled particles/short fibres. Once dispersed, separating the non-entangled particles/short fibres is performed in the method herein using a combination of oil-water separation and flotation, wherein individual components of the nonentangled particles/short fibres are separated and accumulated in an oil phase and/or a water phase. The method then further comprises filtering the oil and/or water phase(s) to recover the separated and accumulated non-entangled particles/short fibre individual components therein.

[035] Certain embodiments of the presently described methods offer a number of advantages over the methods known in the art, including but not limited to any one or more of the following:

• The method can be more closely integrated with existing supply chains;

• The method is a simpler, more cost-effective, and/or more energy efficient way of achieving recycling at scale; and,

• The method utilises froth flotation, which is a continuous process that allows input to be fed into the flotation tank and allows continual recovery of separate output streams. [036] The present inventors have discovered that combining an oil-water separation approach with an oil-water flotation system can surprisingly separate solids, including traditionally difficult to separate entangled solids and blended fabrics, with much greater flexibility in design and simple requirements in terms of chemicals. Using an oil layer as a collector layer allows solids to be separated without the need to add surfactants, and also allows larger and heavier particles to be collected than conventional flotation would allow, since ordinarily particles would need to be sufficiently small and light in order to successfully float to form a surface layer. This combination also simplifies the design of the system, as mixing of the two phases can be enhanced by agitation, and separation of material on the surface no longer depends on the attachment of air bubbles to a hydrophobic surface but rather depends on the affinity of a material with the oil phase. However, unlike oil-water extraction - where the material of interest is dissolved in the oil phase - the flotation approach merely suspends solid particles in the oil phase, allowing for recovery by filtration as well as potential reuse of both the water medium and the oil medium.

[037] In one embodiment, agitation by aeration is an efficient way to introduce mixing of the oil and water phases. The oil (collector) layer, being less dense than the non-oil miscible/water phase, sits on top of the non-oil miscible or water medium, and air is hydrophobic. Unlike in conventional flotation, air bubbles in the methods and systems herein are not required to provide buoyancy to the particles, so the formation of very large, coarse bubbles is sufficient to separate particles, whereas very fine bubbles are needed in conventional flotation. Due to the hydrophobic nature of the air bubbles and their density, they are well suited to draw hydrophobic components to the top of the mixture, where they are trapped and held by the oil phase, while leaving the hydrophilic components in the non-oil miscible/water phase. This approach thus incorporates the beneficial properties of air as a method of agitation that also enhances separation, but without the complexity of conventional flotation where high pressure is often required.

Mixture comprising individual components

[038] The method and system herein may be used to separate two or more individual components of a mixture, such as a mixture of waste material. Although the waste material is not particularly limited, in certain embodiments, the waste material is or comprises fabric, such as cloth formed by knitting or weaving fibres. In other embodiments, the waste material is or comprises fibres used to make fabric.

[039] Accordingly, the mixture to be separated herein may be a mixture of non-entangled particles/short fibres of two or more individual components, or it may be a blended fabric or entangled mixture of solid material comprising two or more individual components.

[040] In one embodiment, the mixture of non-entangled particles/short fibres comprises two or more individual components, where the individual components are fibres. In one embodiment, the fibres may be natural fibres, synthetic fibres, or a mixture thereof. In one embodiment, the fibres may be a mixture of natural fibres, such as cotton, wool, linen, hemp, jute, silk, bamboo, flax, or the like. In one embodiment, the fibres may be a mixture of synthetic fibres, such as polyester, nylon, acrylic, polyurethane, rayon (viscose), or the like. In one embodiment, the fibres may be a mixture of natural and synthetic fibres, such as a mixture of cotton, wool, linen, hemp, jute, silk, bamboo, flax, or the like, and polyester, nylon, acrylic, polyurethane, rayon (viscose), or the like. In another embodiment, the mixture of non-entangled particles/short fibres comprises two or more individual components, where the individual components are particles. Such mixtures may include mixed plastic recycling streams. In some embodiments, the mixture of non-entangled particles/short fibres comprises two or more individual components having different hydrophilicity or hydrophobicity.

[041 ] In another embodiment, the mixture to be separated is a blended fabric or entangled mixture of solid material comprising two or more individual components. In such embodiments, the individual components may be fibres, or may be other entangled solid particles. In one embodiment, the blended fabric may comprise natural fibres, synthetic fibres, or a mixture thereof. In one embodiment, the blended fabric may comprise a mixture of natural fibres, such as cotton, wool, linen, hemp, jute, silk, bamboo, flax, or the like. In one embodiment, the blended fabric may comprise a mixture of synthetic fibres, such as polyester, nylon, acrylic, polyurethane, rayon (viscose), or the like. In one embodiment, the blended fabric may comprise a mixture of natural and synthetic fibres, such as a mixture of cotton, wool, linen, hemp, jute, silk, bamboo, flax, or the like and polyester, nylon, acrylic, polyurethane, rayon (viscose), or the like. Such mixtures in fabric form may also be referred to herein as a “blend” or “fabric blend”. In one embodiment, the method and system described herein is for separation of individual components of a blended fabric. In a preferred embodiment, the blended fabric is a polyester-cotton blend. In some embodiments, the blended fabric or entangled mixture of solid material comprises two or more individual components having different hydrophilicity or hydrophobicity.

[042] In one embodiment, the entangled mixture of solid material may comprise mixed plastic recycling streams or composite materials. Composite materials may comprise natural fibres or wood- or cellulose-based materials mixed with plastics, or textiles comprising plastic-based adhesives. In one embodiment, the entangled mixture of solid material may comprise plastic-lined paper packaging, an adhesive-contaminated textile such as carpet backing, or a plastic-laminated wood composite, such as melamine board.

[043] In one embodiment, the mixture to be separated comprises two individual components, such as is a binary mixture or blend. In another embodiment, the mixture comprises three individual components, such as is a ternary mixture or blend. In other embodiments, mixtures comprising four or more individual components may be separated. In instances where more than two individual components are present in the mixture, the method or certain steps thereof may be performed more than once to separate the mixture into all of its separate constituent individual components, such as in sequential steps.

[044] In one embodiment, the material comprises a mixture of two or more individual components having different physical properties. In one embodiment, the physical property is hydrophobicity or hydrophilicity.

[045] As noted above, in one embodiment, the mixture is of non-entangled particles/short fibres of two or more individual components, such as could be found in factory spinning floor waste. Here, the material may already be a mixture of individual short fibres suitable for further processing without a deconstruction or cutting step. By way of example only, suitable maximum dimensions of short fibres that may be suitable for dispersion without further processing are of less than 2 mm, or in certain embodiments, of from 0.2 mm to 0.5 mm. In such cases, the mixture may be used in the method, such as added to the separation/dispersion step, without further mechanical processing.

[046] However, in other embodiments, the method herein may be used to separate a blended fabric or entangled mixture of solid material comprising two or more individual components prior to separation/dispersion. In such cases, the blended fabric or entangled mixture may be prepared for separation prior to the dispersing step through a process of deconstruction or cutting as described further below. The product of the deconstruction or cutting step for blended fabrics or entangled mixtures of solid material is non-entangled particles/short fibres.

[047] In one embodiment, the non-entangled particles/short fibres (including after deconstruction/cutting, if such a step is required) have maximum lengths of less than 2 mm, or of from 0.1 -1.8 mm, 0.1 -1.6 mm, 0.1 -1.4 mm, 0.1 -1.2 mm, 0.1 -1.2 mm, 0.1 -1.0 mm, 0.1 -0.8 mm, 0.1 -0.6 mm, 0.1 -0.4 mm, 0.2-0.5 mm, 0.2-2 mm, 0.2-1 .8 mm, 0.2-1 .6 mm, 0.2-1.4 mm, 0.2-1.2 mm, 0.2-1.2 mm,

0.2-1.0 mm, 0.2-0.8 mm, 0.2-0.6 mm, 0.4-2 mm, 0.4-1 .8 mm, 0.4-1.6 mm, 0.4-1.4 mm, 0.4-1.2 mm,

0.4-1.2 mm, 0.4-1.0 mm, 0.4-0.8 mm, 0.4-0.6 mm, 0.6-2 mm, 0.6-1.8 mm, 0.6-1.6 mm, 0.6-1.4 mm,

0.6-1.2 mm, 0.6-1.2 mm, 0.6-1.0 mm, 0.6-0.8 mm, 0.8-2 mm, 0.8-1.8 mm, 08-1.6 mm, 0.8-1.4 mm,

0.8-1 .2 mm, 0.8-1 .2 mm, 0.8-1 .0 mm, 1 -2 mm, 1 -1 .8 mm, 1 -1 .6 mm, 1 -1 .4 mm, 1 -1 .2 mm, 1 .2-1 .4 mm, 1 .2-1 .6 mm, 1 .4-1 .6 mm, 1 .6-1 .8 mm, 1 .6-2 mm, or 1 .8-2 mm. In one embodiment, the non-entangled particles/short fibres have maximum lengths of from 0.2 mm to 0.5 mm.

Deconstruction/Cutting

[048] As described above, the method and system herein optionally comprise a step of deconstruction or cutting. In some embodiments, the deconstruction step is optional if the waste material is already of the required length and exists as non-entangled mixture, such as factory spinning floor waste, where the material is already a mixture of individual short fibres rather than a blend fabric or yarn.

[049] The deconstruction/cutting step, when used, involves cutting the blended fabric or entangled mixture of solid material into deconstructed non-entangled particles/short fibres. In the deconstruction process, the entangled components in the yarns and fabrics are separated, resulting in a mixture of particles/short fibres of the individual components. Accordingly, the purpose of the deconstruction step is to untangle the different components of the material, such that the result is a mixture of particles/short fibres that are able to move in a liquid medium without being entangled to another particle/short fibre. The deconstruction is done by cutting the material, preferably with a cutter mill, to any suitable length. In one embodiment, the cutting deconstructs the blended fabric or entangled solid material into non-entangled particle/short fibres with a length of less than 2 mm, preferably of from 0.2-0.5 mm. Preferably, the deconstruction results in a mixture of non-entangled particle/short fibres with a length below 2 mm, preferably of from 0.1 -2 mm, 0.1 -1 .8 mm, 0.1 -1 .6 mm, 0.1 -1 .4 mm, 0.1 -1 .2 mm, 0.1 -1 .2 mm, 0.1 -1 .0 mm, 0.1 -0.8 mm, 0.1 -0.6 mm, 0.1 -0.4 mm, 0.2-0.5 mm, 0.2-2 mm, 0.2-1 .8 mm, 0.2-1 .6 mm, 0.2-1 .4 mm, 0.2-1 .2 mm, 0.2-1 .2 mm, 0.2-1 .0 mm, 0.2-0.8 mm, 0.2-0.6 mm, 0.4-2 mm, 0.4-1 .8 mm, 0.4-1 .6 mm, 0.4-1 .4 mm, 0.4-1 .2 mm, 0.4-1 .2 mm, 0.4-1 .0 mm, 0.4-0.8 mm, 0.4-0.6 mm, 0.6-2 mm, 0.6-1.8 mm, 0.6-1.6 mm, 0.6-1.4 mm, 0.6-1.2 mm, 0.6-1 .2 mm, 0.6-1 .0 mm, 0.6-0.8 mm, 0.8-2 mm, 0.8-1 .8 mm, 08-1 .6 mm, 0.8-1 .4 mm, 0.8-1 .2 mm, 0.8-1 .2 mm, 0.8-1 .0 mm, 1 -2 mm, 1 -1.8 mm, 1 -1.6 mm, 1 -1.4 mm, 1 -1.2 mm, 1.2-1 .4 mm, 1.2-1 .6 mm, 1.4-1 .6 mm, 1.6-1.8 mm, 1.6-2 mm, or 1 .8-2 mm, etc. The particle/short fibre size/length selected for any particular blended fabric or entangled solid material may be determined by the level of entanglement in the original material and/or its dispersibility in a liquid medium. It will be appreciated that in some embodiments, smaller particles/shorter fibres than those described in this paragraph may also be used, depending on the method used for deconstruction and the nature of the original material and its individual components. [050] In one embodiment, the cutting is performed using a cutting mill. However, in other embodiments, other apparatus such as a granulator may be used, and such apparatus will be known to those of skill in the art. In some embodiments, the deconstruction process/cutting can be done manually, but in other embodiments, may utilise a machine capable of cutting the material into particles/short fibres of suitable length. Suitable apparatus may include a Waste Initiatives PC3260 granulator, a Netzsch CS-Z Fine Cutting Mill, or the like.

Dispersion

[051 ] The method herein comprises dispersing the non-entangled particles/short fibres in a non-oil miscible medium. The non-oil miscible medium is mixed with an oil to form an oil-water phase medium or system. Accordingly, the oil-water medium comprises an oil phase and a non-oil miscible or water phase. The method herein utilises this oil-water medium or system to disperse and separate the nonentangled particles/short fibres.

[052] The non-oil miscible medium may be any suitable medium. In one embodiment, the non-oil miscible medium comprises water, an alcohol, a glycol, or a mixture of two or more of these. In one embodiment, the non-oil miscible medium comprises water, optionally in combination with an alcohol and/or a glycol. In one embodiment, the non-oil miscible medium is water, an alcohol, a glycol, or a mixture of two or more of these. In one embodiment, the alcohol is selected from a C1-C4 alcohol, such as is selected from methanol, ethanol, iso-propanol, and butanol. In one embodiment, the glycol is selected from ethylene glycol, propylene glycol, butylene glycol, and polyethylene glycol, preferably having a molecular weight of 500 g/mol or less. If a mixture of water and an alcohol and/or glycol is used, the water may be present in any suitable proportion by volume, such as in some embodiments being present at up to 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 40% 30%, 20% or 10% by volume, or at from 50 to 99.9%, or from 75 to 99%, or from 50 to 80%, or from 70 to 90%, or from 60 to 95%, or from 10 to 99%, or from 10 to 50% by volume. If a mixture of water and an alcohol and/or glycol is used, the alcohol may be present in any suitable proportion by volume, such as in some embodiments being present at less than 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 40% 30%, 20% or 10% by volume, or in an amount of from 50 to 99.9%, or from 75 to 99%, or from 50 to 80%, or from 70 to 90%, or from 60 to 95%, or from 10 to 99%, or from 10 to 50% by volume. If a mixture of water and an alcohol and/or glycol is used, the glycol may be present in any suitable proportion by volume, such as in some embodiments being present at less than 99%, 95%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 40% 30%, 20% or 10% by volume, or in an amount of from 50 to 99.9%, or from 75 to 99%, or from 50 to 80%, or from 70 to 90%, or from 60 to 95%, or from 10 to 99%, or from 10 to 50% by volume.

[053] In one embodiment, the non-oil miscible medium is water. The term “non-oil miscible medium” may be used interchangeably with the term “water phase”, where the term ‘water phase’ as used herein may refer to water or any other non-oil miscible liquid used as a medium in the process. The non-entangled particles/short fibres or deconstructed material from the deconstruction/cutting step is dispersed in the non-oil miscible medium, in one embodiment through shear mixing, until a mixed dispersion with a suitable flow characteristic is obtained. The term “mixed dispersion” refers to a dispersion containing non-entangled particles/short fibres of two or more individual components of a material in a non-oil miscible or water liquid medium. The dispersion of non-entangled particles/short fibres is advantageously performed in the non-oil miscible medium to fully wet the more hydrophilic components in the mixture, and/or to prevent them from being adsorbed into the oil phase of the oilwater system during the dispersion and separation process. In one embodiment, shear mixing is used to disperse the non-entangled particles/short fibres in the water/non-oil miscible medium, but other dispersing apparatus may be suitable, including but not limited to a static mixer, ribbon blender, rum mixer, paddle mixer, stirred tank mixer, or the like.

[054] In one embodiment, the non-oil miscible medium comprises one or more additives. The additives may assist in separating the individual components of the non-entangled particles/short fibres on the basis of their hydrophilicity and/or may assist by fully wetting one of the individual components. Accordingly, in one embodiment, the non-oil miscible medium comprises at least one additive to maximise a difference in hydrophilicity of the individual components and fully wet one of the individual components. In one embodiment, the additive comprises an alkaline salt, a neutral salt, an acid, or a surfactant, or any combination thereof. In one embodiment, the additive is selected from an alkaline salt, a neutral salt, an acid, a surfactant, and any combination thereof. In one embodiment, the at least one additive is an alkaline salt. In one embodiment, the alkaline salt comprises sodium carbonate or sodium bicarbonate, or a mixture thereof. In a preferred embodiment, the non-oil miscible medium contains an alkaline salt dissolved in water, most preferably where the alkaline salt is sodium carbonate or sodium bicarbonate. The non-oil miscible medium may comprise sodium carbonate in a concentration range of 0.1 -5 wt%, or in one embodiment of from 0.5-1 wt%. The alkaline salt may be present in any suitable amount, or in one embodiment in an amount of from 0.1 to 5 wt%. Preferably, the ratio of alkaline salt, such as sodium carbonate or sodium bicarbonate or mixture of thereof, is present in the range of from 0.1 -5%, and preferably 0.1 -1 %, 0.2-1%, 0.3-1 %, 0.4-1 %, 0.5-1%, 0.6-1 %, 0.7-1%, 0.8-1%, 0.9-1%, 0.5-1 .5%, 0.5-2%, 0.5-2.5%, 0.5-3.5%, 0.5-4.5%, wherein the percentage refers to the weight percent of the salt in the non-oil miscible medium, such as the weight percent of the salt in water. If a combination of different alkaline salts is used, such as a mixture of sodium carbonate and sodium bicarbonate, the salts may be present in any suitable ratio by weight. In one embodiment, where two different alkaline salts are used, such as a mixture of sodium carbonate and sodium bicarbonate, the salts may be present at a ratio by weight of sodium carbonate:sodium bicarbonate of 1 :1 , 1 :1 :5, 1 :2, 1 :2.5, 1 :3, 1 :3.5, 1 :4, 1 :4.5, 1 :5, etc., or of from 1 :1 to 1 :5, or of from 1 :1 to 1 :2.5, or of 1 :2.5 to 1 :5. In a preferred embodiment, the non-oil miscible medium is water, and the additive is an alkaline salt such as sodium carbonate or sodium bicarbonate or a mixture thereof. Accordingly, the non-entangled particles/short fibres may be dispersed in a medium of non-oil miscible liquid, preferably water, containing one or more additives. In one embodiment, the one or more additives are selected from an alkaline salt, a neutral salt, an acid, a surfactant, and any combination thereof. Alkaline salts, neutral salts, acids, and surfactants suitable as additives are known in the art and available commercially, such as from commercial chemical suppliers or the like. In one embodiment, a suitable neutral salt may be a Group I or Group II metal chloride or sulfate, such as may be sodium chloride, sodium sulfate, or calcium chloride. In one embodiment, a suitable acid may be an organic acid or may be a mineral acid, such as may be acetic acid or hydrochloric acid. In one embodiment, a suitable surfactant may be a non-ionic surfactant, such as may be a polyethelyne glycol, a TWEEN® (polysorbate), or a SPAN® (sorbitan fatty acid ester) surfactant.

[055] In the methods and systems herein, the non-oil miscible medium, or water, or water phase, may preferentially suspend the more hydrophilic individual component of the mixture, blended fabric, or entangled mixture of solid material.

[056] The oil may be any suitable oil. In one embodiment, the oil is a non-emulsifiable oil. In one embodiment, the oil is a non-emulsified oil. In one embodiment, the oil comprises a silicone oil, a mineral oil, a castor oil, or a paraffin oil, or a mixture thereof. In one embodiment, the oil is a silicone oil, a mineral oil, a castor oil, or a paraffin oil, or a mixture thereof. In the methods and systems herein, the oil or oil phase may preferentially suspend the less hydrophilic, or more hydrophobic, individual component of the mixture, blended fabric, or entangled mixture of solid material. The term “oil phase” herein refers to any oil which is not miscible or emulsifiable with the water phase and has a lower density than the water phase. In some embodiments, the oil is paraffin oil.

[057] The oil-water phase medium or system may comprise any suitable ratio of oil to water. In one embodiment, the oil-water phase medium or system comprises a ratio by volume of oil to non-oil miscible medium or water, of from 1 :2 to 1 :100, or of from 1 :2 to 1 :50, or of from 1 :5 to 1 :30. In one embodiment, the oil dispersion :water dispersion ratio by volume is in the range of 1 :2 to 1 :100, preferably in the range of 1 :2 to 1 :50, and more preferably in the range of 1 :5 to 1 :30, for example, 1 :2, 1 :5, 1 :10, 1 :15, 1 :20, 1 :25, 1 :30, etc. In one embodiment, the proportion by volume of oil phase in the reactor is from 1 -30%, suitably from 5-25%, and most preferably from 10-15%, and the proportion by volume of water phase is 70-99%, suitably from 75-95%, and most preferably from 85- 90%. The ratio or proportion by volume can be selected according to the amount of blended fabric particles/short fibres to be separated. In one embodiment, the relative proportion of hydrophobic to hydrophilic individual components may guide the ratio of oil to non-oil miscible phase/water, with a higher ratio (i.e. , more oil) being used when relatively more individual components are hydrophobic, or a lower ratio (i.e., more non-oil miscible medium) being used when relatively more individual components are hydrophilic.

Separating and accumulating

[058] The method herein comprises a step of separating the non-entangled particles/short fibres, where, using a combination of oil-water separation and flotation, the individual components are separated and accumulated in the oil phase and/or the water phase. The separation and accumulation step uses a combination of oil-water separation and flotation. The oil-water separation utilises the oil layer as a collector layer for suspended hydrophobic particles (larger than those that might be conventionally separated during floatation), and the flotation aspect utilises hydrophobic air bubbles, optionally generated through mixing, to assist with migration of these hydrophobic particles through the oil-water phase medium/system into the oil collector layer. The hydrophilic components remain in the non-oil miscible/water phase.

[059] In the separation step, the mixed dispersion comprising individual components of the nonentangled particles/short fibres is mixed with the oil such that the individual components are separated and accumulate in the oil phase and/or the water phase. In one embodiment, the individual components of the non-entangled particles/short fibres are separated and accumulate separately in either the oil phase or the water phase. In one embodiment, the separation and accumulation of the individual components in the oil and/or water phase is assisted by the different hydrophobic/hydrophilic characteristics of the individual components of the non-entangled particles/short fibres. In the methods and systems herein, the non-oil miscible medium, or water, or water phase, may preferentially suspend the more hydrophilic individual component of the mixture, blended fabric, or entangled mixture of solid material, and the oil or oil phase may preferentially suspend the less hydrophilic, or more hydrophobic, individual component of the mixture, blended fabric, or entangled mixture of solid material.

[060] In one embodiment, the method herein comprises separating the non-entangled particles/short fibres comprises using an oil-water system comprising water as the non-oil miscible medium, and wherein the oil is a non-emulsifiable oil or a non-emulsified oil. In one embodiment, the non- emulsifiable oil or non-emulsified oil is selected from silicone oil, mineral oil, castor oil, paraffin oil, and mixtures thereof. In one embodiment, the separation is performed using an oil-water system comprising a non-oil miscible medium, preferably water, and a non-emulsifiable oil phase, suitably silicone oil, mineral oil, castor oil, or paraffin oil, or a mixture thereof.

[061 ] The separation may be done in any suitable apparatus. In one embodiment, the separation is done in a separation tank. The term “separation tank” herein refers to any device that contains the water phase/mixed dispersion and oil phase required for the process, and within which the separation process occurs. In a preferred embodiment, the separation tank comprises a tank, an inlet in which the mixed dispersion can be introduced, a water phase optionally containing one or more additives, an oil phase, and separate outlets through which the oil phase and water phase can be separately recovered. In one embodiment, the oil phase and water phase are contained within the tank, at a quantity commensurate with its overall volume so that the oil phase reaches the height of its outlet. In other embodiments, the outlet for the oil phase is set at the height of the oil phase within the separation tank. Depending on the system, the separation tank may be designed for a batch process, a continuous process, or a multistep process with an additional step, such as a settling step, to improve the purity of the recovered material. The system can also be set to have successive separation tanks to process the material to be separated to maximise yield. In one embodiment, the separation tank for the separating and accumulation step may be constructed as shown in Figure 2. Referring to Figure 2, there is depicted a side on cross-sectional view of a cylindrical vessel 10 defined by outer wall 11 with an aerator 15 mounted near the bottom for agitation and having air supply line 16. Although a cylindrical separation tank is shown, it will be appreciated that other shaped tanks may be suitable. Although an aerator is shown, it will be appreciated that other agitators may be used. An oil phase 13 is shown on top of a water phase 12. Fresh water phase comprising non-entangled particles/short fibres and optional additive(s) (“mixed dispersion”) may be injected below the oil layer through inlet 17. The separation tank may be churned by aeration (using the aerator, as shown, or any suitable alternative agitator) for several minutes, after which in the case of an aerator, the air supply may be turned off, or in the case of an alternative agitator, the agitator may be turned off, and the two layers allowed to separate for recovery and filtration.

[062] In one embodiment, the separation tank provides an environment in which the mixture of nonentangled particles/short fibres can be introduced into a water phase, the oil phase can be introduced, and the mixture mixed or agitated in such a way that the water phase mixture comes in contact with the oil phase, which allows the more hydrophobic material, such as polyester, to transfer from the water phase into the oil phase, to accumulate different solid components in the two different phases. Through this process, the hydrophobic individual component in the mixture of non-entangled particles/short fibres is allowed to come into contact and be trapped in the oil phase, while the hydrophilic individual component remains in the water/non-oil miscible/aqueous phase. This results in an oil dispersion containing one component, and a water dispersion containing another. The term “oil dispersion” herein refers to the oil phase recovered from the separation tank containing a component of the mixture of non-entangled particles/short fibres, and the term “water dispersion” herein refers to water (or other non-oil miscible medium) recovered from the separation tank containing another component of the mixture of non-entangled particles/short fibres. In a preferred embodiment, the mixture of non-entangled particles/short fibres comprises a mixture of polyester and cotton particles/short fibres, and during separation/after agitating/aerating, the polyester is accumulated in the oil phase to form the oil dispersion, while the cotton is accumulated in the water phase to form the water dispersion.

[063] The combination of oil-water separation and flotation may comprise using air bubbles to facilitate movement of individual components having hydrophobic character from the water phase into the oil phase. The air bubbles may be generated on agitation and/or may be provided in the form or aeration of the oil-water phase medium/system. Accordingly, in one embodiment, separating the nonentangled particles/short fibres comprises an agitation step. The agitation step advantageously enhances mixing of the oil-water phase medium/system thereby facilitating separation and accumulation of individual components in the oil phase and/or the water phase. The agitation step may comprise providing air bubbles to the oil-water phase medium/system and/or may comprise generating air bubbles through mechanical mixing processes. In one embodiment of the separation process, agitation is used to mix the water phase and the oil phase, which allows the accumulation of one component of the material to be separated to enter and accumulate in the oil phase. The oil phase and water phase are then recovered and filtered separately to recover the now-separated individual components. Preferably, agitation involves the use of mechanical force to agitate the mixture. Agitation may comprise, but is not limited to, use of an aerator, or use of a mechanical agitator such as an impeller, a magnetic or mechanic stirrer, a rotating drum mixer (e.g., a cement mixer), a water pump mixer (which is similar to an aerator but uses water pumped from the bottom of the tank to pour above the surface), or the like. In one embodiment, and aerator and a mechanical agitator are used together. In one embodiment, an aerator is used that simultaneously aerates and agitates the mixture. In another embodiment, a mechanical agitator is used that simultaneously mixes and incorporates air bubbles into the mixture. Apparatus suitable for agitating and/or introducing air bubbles will be known to those of skill in the art. In a preferred embodiment, agitation is provided by an aerator, where the airflow is set to break through the surface of the oil phase. The airflow is specific to the geometry of the tank, total quantity of liquids, and type of aerator used.

[064] It will be appreciated that any suitable volume of oil and non-oil miscible medium/water may be used, depending on the amount of non-entangled particles/short fibres to be separated and the size of the tank/system.

[065] In a preferred embodiment, the separation tank consists of a tank, an aerator whose length is kept shorter than the tank, an inlet in which the mixture of non-entangled particles/short fibres can be introduced, a water phase containing water with 1% w/w sodium carbonate, an oil phase containing paraffin oil, and separate outlets through which the oil and water phase can be separately recovered. In one embodiment, the non-entangled particles/short fibres comprise a mixture of polyester and cotton, wherein the polyester non-entangled particles/short fibres accumulate in the oil phase and the cotton non-entangled particles/short fibres accumulate in the water phase.

[066] For higher yields, the separation setup can be performed with the water phase being reused in successive steps. Similar to froth flotation, the yield in the oil dispersion is likely limited by the total solids, and as such several separation steps can be performed successively in some embodiments to increase the total material recovery.

Filtration

[067] After the separation and accumulation step, the method herein comprises filtering the oil and/or water phase to recover the separated and accumulated solid non-entangled particles/short fibres individual components therein. In one embodiment, the oil and/or water phase are both filtered to recover the separated and accumulated non-entangled particles/short fibres individual components therein. In one embodiment, filtering of the oil dispersion and the water dispersion is performed separately. This allows recovery of the separated individual components. In one embodiment, the oil phase is recycled into the method after filtration. In one embodiment, the water phase is recycled into the method after filtration. In one embodiment, the oil and water phases are both recycled into the method after filtration.

[068] Filtration can be completed using any available method suitable for the quantity of the material recovered. Suitably, filtration can include, but is not limited to, vacuum filtration, centrifuge filtration, or a combination thereof. Suitable filtration apparatus will be known to those of skill in the art.

[069] In some embodiments, the quantity of oil dispersion and water dispersion is 0.1 -1 .5 litres and 0.2-5 litres, respectively, and filtration is done by vacuum filtration, where the oil and water dispersions are filtered separately. In such embodiments, the oil and water phase after filtration may be recovered for reuse. However, in some embodiments, the quantity of oil and water dispersions are greater than 3 litres, and the filtration is done using centrifuge filtration. In such embodiments, again, the oil and water phase may be recovered for reuse. It will be appreciated that any suitable volume of oil dispersion and water dispersion may be filtered using a technique suitable for the given volume. In some embodiments, centrifuge filtration may be more suitable for larger volumes. In other embodiments, vacuum filtration may be preferable.

[070] The final product of the method may comprise separated individual components of the mixture of non-entangled particles/short fibres. The final product may comprise two separate individual components, which may be recovered from the filtration step. These products may be washed and dried or otherwise prepared for subsequent use/recycling. In one embodiment, where the mixture of non-entangled particles/short fibres comprises two individual components and the final product of the method is two separate individual components, each individual component may have any suitable purity. In one embodiment, each individual component may have a purity of up to 100% by weight, or up to 99%, or up to 98%, or up to 97%, or up to 96%, or up to 95%, or up to 90%, or of at least 85%, 90%, 95%, 96%, 97%, 98%, 99% or 99.9%, or of from 85-100%, 90-100%, 95-100%, 98-100%, or 99- 100%. In one embodiment, each individual component may be purified to these levels of purity by performing the method once. In other embodiments, each individual component may be purified to these levels of purity by performing the method more than once, such as twice, or three times, where the mixture of non-entangled particles/short fibres starts at a higher purity with each successive repeat of the method. The non-oil miscible/water phase and oil phases may be reused in one or more successive repeats of the method.

[071 ] In one embodiment, the starting material is polyester/cotton mixture, and the method results in an effective separation of the polyester and cotton particles/short fibres. As described in further detail in the following Examples, Fourier-Transform infrared spectroscopic (FT-IR) analysis of the separated material from blend fabrics is shown in Figure 5, while separated materials from a mixture of polyester and cotton fabrics is shown in Figure 7. The thermogravimetric characterisation (TGA) of polyester and cotton separated from a blend fabric is shown in Figure 6, while separated materials from a mixture of polyester and cotton fabrics is shown in Figure 8. As shown, the FTIR spectrum for the solids recovered from the oil dispersion shows an abundance of polyester and very little cellulose. This was further confirmed by TGA analysis, which shows that the oil phase contains almost exclusively polyester. The use of an additional settling tank to allow complete separation of the oil and water phase further improves the purity of the recovered polyester, as shown by TGA analysis in Figure 9.

System

[072] The present invention relates to a system for carrying out a separation method, such as the method of separating a mixture of non-entangled particles/short fibres or method of separating a blended fabric or entangled mixture of solid material comprising two or more individual components as also described herein.

[073] Described in one embodiment is a system for separating a blended fabric or entangled mixture of solid material, or non-entangled particles/short fibres of a solid material. The system comprises a separation tank configured to accommodate an oil-water phase medium. The separation tank may be as described above. The oil-water phase medium comprises a non-oil miscible medium and an oil phase medium as described elsewhere herein. The system may also comprise an agitator configured to be immersed in the oil-water phase medium. The agitator is configured to agitate the oil-water phase medium, such as in some embodiments generate and/or release bubbles. The agitator may be any suitable apparatus as described above, such as in certain embodiments is an aerator, an impeller, a magnetic or mechanic stirrer, a rotating drum mixer or a water pump mixer. Accordingly, in some embodiments, the agitator produces or releases bubbles that effect mixing of the oil phase and water phase. In other embodiments, the agitator has a mixing action that generates air bubbles. The system further comprises a non-oil phase outlet located at a lower end of the separation tank to extract the non-oil miscible medium and components therein. By “lower end”, it will be understood that the non- oil miscible medium will generally be denser than the oil, and by virtue of its immiscibility with the oil, will thus by gravity settle to the bottom or lower end of the separator tank. In one embodiment, the non-oil miscible medium (“water dispersion”) is extracted into a first settling tank. In some embodiments, the first settling tank is used for settling the water dispersion prior to filtration, such as to allow additional time for any oil dispersion in the water dispersion to separate from the water prior to filtration. The system also comprises an oil-phase outlet located at an upper end of the separation tank to extract the oil-phase medium and components therein. By “upper end”, it will be understood that the oil will generally be less dense than the non-oil miscible medium, and by virtue of its immiscibility, will tend to settle to the top or upper end of the separator tank. In one embodiment, the oil (“oil dispersion”) is extracted to the first settling tank, such as to allow additional time for the oil and water dispersions to separate from each other. In another embodiment, the oil (“oil dispersion”) is extracted to a second settling tank. The second settling tank is separate to the first settling tank. The second settling tank may allow additional time for any water dispersion in the oil dispersion to separate from the oil prior to filtration.

[074] In one embodiment, the system has a construction as depicted in Figure 3. Referring to Figure 3, there is shown a system 20 comprising a separation tank 11 having a water phase 12 and an oil phase 13 therein (an oil-water phase medium/system) and comprising an inlet 17 for a mixture of non- entangled particles/short fibres of two or more individual components in water phase. The separation tank 11 in Figure 3 is shown as a rectangular vessel with a long aerator 15 at the bottom fed by an air inlet 16, a spillover trough 22 for the oil phase at the top, and a release channel 21 for the water phase at the bottom. Alternative configurations where the separation tank has a different shape may be envisaged. Alternative configurations where the aerator is replaced by an alternative agitator, such as stirrer, may be envisaged. In the embodiment depicted in Figure 3, there is a spillover for recovery of the oil phase (oil dispersion). In some embodiments, the spillover may be controlled by a valve or the like to retain the oil phase in the separator vessel under the completion of the separation and accumulation step. The release channel 21 may similarly be controlled by a valve or the like to retain the water phase in the separator vessel. The embodiment of Figure 3 shows an aeration unit 15 that may be turned on so that the bubbles continually break the surface. In other embodiments, an alternative agitator may be used. In other embodiments, alternative positioning of the aerator/agitator within the separation tank may be used. An inlet 17 for the “mixed dispersion” or mixture of nonentangled particles/short fibres in non-oil miscible/water medium (optionally containing one or more additives) is shown injecting below the oil layer via a tube. Insertion of the mixed dispersion under the oil layer advantageously allows the hydrophilic individual components to remain dispersed in the water and avoids adsorption of the particles/short fibres onto the oil before agitation. In some embodiments, the water phase/water dispersion may be collected at a rate that maintains the height of the oil phase to be just above the spillover point, noting that fresh mixed dispersion may be fed continuously or on a batch -by-batch basis in through the inlet. Oil may be added to the separation tank to replace oil that has been collected. The oil phase/dispersion and the water phase/dispersion, once separated, may then be filtered separately to recover the separated individual components particles. The oil phase may be recovered after filtration for reuse. The water phase may be recovered after filtration for reuse. [075] Referring to Figure 4, there is depicted another embodiment of a system 30 as described herein. Unless otherwise stated, all reference numerals are as per those described above for Figure 3. In Figure 4, the system 30 may be as per Figure 3 described above, but the oil phase 13 in this embodiment is not sent immediately for filtration. Instead, the oil phase/oil dispersion 13 is fed into a settling tank 32 to separate any water that may have spilled over with the oil phase. There may be a water phase outlet 21a at the lower end of the settling tank to facilitate collection of the water phase. There may be an oil phase outlet 31 at the upper end of the settling tank to facilitate collection of the oil phase/oil dispersion for filtration. The water dispersion 12 collected through outlet 21 from the separation tank 11 may also be sent to a settling tank (not shown), which may also contain an outlet at its lower end for recovery of the water phase/water dispersion, and an outlet at its upper end for recovery of the oil phase/oil dispersion. The system of Figure 3 and/or Figure 4 may additionally comprise a filtration unit (not shown) for receiving and filtering the oil dispersion and/or water dispersion.

[076] Described herein is a system as described above when used to implement the method as described herein. Also described herein is use of a system as described above in the method as described herein. [077] Also described herein is separated individual components, optionally deconstructed from a blended fabric or entangled mixture of solid material, obtained by the method as described herein. Also described herein is separated individual components, optionally deconstructed from a blended fabric or entangled mixture of solid material, obtained by the method as described herein using the system as described herein.

Embodiments

Embodiment 1. A method of separating blended fabrics and other entangled solid material comprising steps of:

Cutting the material into short snippets to deconstruct the material into non-entangled particle/short fibres;

Dispersing the particles/short fibres in a non-oil miscible medium, wherein the non-oil miscible medium is mixed with an oil to form an oil-water phase medium;

Separating the particles/short fibres using a combination of oil-water separation and flotation, wherein the particles/short fibres of the individual components are separated and accumulated in an oil and/or a water phase;

Filtering the oil or water phase to recover the separated and accumulated components from either oil phase or water phase.

Embodiment 2. A method according to Embodiment 1 , wherein the non-oil miscible medium is mixed with at least one additive to maximise the differences in hydrophilicity of the different components and fully wet one of the components.

Embodiment 3. A method according to Embodiment 1 , wherein the blend fabric is a polyester-cotton blend.

Embodiment 4. A method according to Embodiment 1 , wherein the non-oil miscible medium is water, and the at least one additive is an alkaline salt, preferably the alkaline salt includes sodium carbonate or sodium bicarbonate or the mixture thereof.

Embodiment 5. A method according to Embodiment 1 , wherein the separating of particles/short fibres is performed using an oil-water system comprising of a non-oil miscible medium, preferably water, and a non-emulsifiable oil phase, preferably silicone oil, mineral oil, castor oil, or paraffin oil, or the mixture thereof.

Embodiment 6. A method according to Embodiment 1 and 6, wherein the separating of particles/short fibres further comprising an agitation step wherein the agitation is used to mix the water phase and the oil phase, and allows the accumulation of one component of the material to be separated to enter and accumulate in either the oil phase and/or water phase.

Embodiment 7. A system for of separating blended fabrics and other entangled solid material comprising: a separation tank is configured to accommodate an oil-water phase medium, wherein the oilwater phase medium includes a non-oil miscible medium and an oil phase medium; wherein, an aerator is configured to immerse into the oil-water phase medium to agitate the oil-water phase medium; a non-oil phase outlet is located at a lower end of the separation tank to extract the non-oil miscible medium and the separated contents within the non-oil medium into a settling tank; an oil-phase outlet is located at an upper end of the separation tank to extract the oil-phase medium and the separated contents within the oil-phase medium to the same or second settling tank. Embodiment 8. A product or a combination of products obtained through the method of Embodiment 1.

Embodiment 9. A product or a combination of products obtained through the system of Embodiment 7.

Embodiment 10. A product comprises separated and accumulated components recovered from blended fabrics and other entangled solid material as obtained through the method of Embodiment 1 and/or the system of Embodiment 7.

Examples

Example 1

[078] In Example 1 , separation was done by a batch process. A 65/35 polyester cotton blend fabric was cut in a cutting mill with a 1 mm sieve to deconstruct the fabric into non-entangled short fibres and particles. These were then dispersed in 1% sodium carbonate in water to create a mixed dispersion in water. The separation tank used is depicted in Figure 2, and comprised a cylindrical vessel with an aerator at the bottom, containing 1 % sodium carbonate in water as the water phase and paraffin oil as the oil phase, with an 85:15 by volume water:oil ratio. The mixed dispersion was then injected below the oil layer and the separation tank was continually churned by aeration for several minutes, after which the air supply was turned off and the two layers were separately recovered and filtered. The filtered materials were then washed and analysed to confirm the separation by FTIR (Figure 5) and TGA (Figure 6) analysis.

Example 2

[079] In Example 2, equal amounts of 100% cotton fabric and 100% polyester fabric were mixed and then cut in a cutting mill with 0.5 mm sieve to deconstruct both fabrics into a mixture of nonentangled cotton and polyester short fibres and particles. These were then dispersed in 1% sodium carbonate in water to create a mixed dispersion in water. The separation tank used is depicted in Figure 3, and comprised a rectangular vessel with a long aerator at the bottom, a spillover through for the oil phase at the top and a release channel for the water phase at the bottom. The separation tank was filled with 1 % sodium carbonate in water as the water phase and paraffin oil as the oil phase, with a 90:10 by volume water:oil ratio. The aeration was turned on so that the bubbles continually broke the surface, and the mixed dispersion containing both the polyester and the cotton was injected below the oil layer via a tube onto the aerator. During the run, as more mixed dispersion was injected, the oil phase spilled over into a trough and was collected. The water phase was collected separately through a tap in proportion to the mixed dispersion injected in order to maintain the height of the oil phase to be just above the spillover point. More oil was added to the separation tank in proportion to the oil collected. The oil phase and the water phase were then filtered separately to recover the cotton and polyester particles. The separation was confirmed by FTIR (Figure 7) and TGA (Figure 8) analysis.

Example 3

[080] In Example 3, 65/35 polyester-cotton blend fabric was cut in a cutting mill with an 0.5 mm sieve to deconstruct both fabrics into a mixture of non-entangled cotton and polyester short fibres and particles. These were then dispersed in 1% sodium carbonate in water solution to create a mixed dispersion in water. The separation tank used is depicted in Figure 4, and comprised a rectangular vessel with a long aerator at the bottom, a spillover trough for the oil phase at the top going to a settling tank and a release channel for the water phase at the bottom. The separation tank was filled with 1% sodium carbonate in water as the water phase and paraffin oil as the oil phase, with a 90:10 by volume water:oil ratio. The aeration was turned on so that the bubbles continually broke the surface, and the mixed dispersion containing both the polyester and the cotton was injected below the oil layer via a tube onto the aerator. During the run, as more mixed dispersion was injected, the oil phase spilled over into a trough and was collected. The oil phase was kept in a settling tank to separate any water that accidentally spilled over with the oil phase. The water phase was collected from the separation tank separately through a tap in proportion to the mixed dispersion injected in order to maintain the height of the oil phase to be just above the spillover point. More oil was added to the separation tank in proportion to the oil collected. The oil phase and the water phase were then filtered separately to recover the cotton and polyester particles. The addition of the settling tank improved the purity of the polyester content in the oil phase, as confirmed by TGA analysis (Figure 9).

[081 ] The present invention is described with reference to the above examples. It is to be understood that the examples are illustrative of and not limiting to the invention described herein.

[082] It will be apparent to the person skilled in the art that while the invention has been described in some detail for the purposes of clarity and understanding, various modifications and alterations to the embodiments and methods described herein may be made without departing from the scope of the inventive concept disclosed in this specification.

Claims

Claims

1 . A method of separating a mixture of non-entangled particles/short fibres of two or more individual components, the method comprising: dispersing the non-entangled particles/short fibres in a non-oil miscible medium, wherein the non-oil miscible medium is mixed with an oil to form an oil-water phase medium; separating the non-entangled particles/short fibres using a combination of oil-water separation and flotation, wherein individual components of the non-entangled particles/short fibres are separated and accumulated in an oil phase and/or a water phase; and filtering the oil and/or water phase to recover the separated and accumulated nonentangled particles/short fibres individual components therein.

2. A method of separating a blended fabric or entangled mixture of solid material comprising two or more individual components, the method comprising: cutting the blended fabric or entangled mixture of solid material into deconstructed non-entangled particles/short fibres; dispersing the non-entangled particles/short fibres in a non-oil miscible medium, wherein the non-oil miscible medium is mixed with an oil to form an oil-water phase medium; separating the non-entangled particles/short fibres using a combination of oil-water separation and flotation, wherein individual components of the non-entangled particles/short fibres are separated and accumulated in an oil phase and/or a water phase; and filtering the oil and/or water phase to recover the separated and accumulated individual components therein.

3. The method according to claim 2, wherein the blended fabric is a polyester-cotton blend.

4. The method according to claim 2 or claim 3, wherein the cutting is performed using a cutting mill.

5. The method according to any one of claims 1 to 4, wherein the non-oil miscible medium comprises at least one additive to maximise a difference in hydrophilicity of the individual components and fully wet one of the individual components.

6. The method according to claim 5, wherein the additive is selected from an alkaline salt, a neutral salt, an acid, a surfactant, and any combination thereof.

7. The method according to claim 5 or claim 6, wherein the at least one additive is an alkaline salt, preferably wherein the alkaline salt comprises sodium carbonate or sodium bicarbonate or a mixture thereof.

8. The method according to claim 7, wherein the alkaline salt is present in the non-oil miscible medium in an amount of from 0.1 to 5% by weight.

9. The method according to any one of claims 1 to 8, wherein the non-oil miscible medium is water.

10. The method according to any one of claims 1 to 9, wherein the oil is a non-emulsifiable oil, preferably wherein the oil comprises a silicone oil, a mineral oil, a castor oil, or a paraffin oil, or a mixture thereof.

11 . The method according to any one of claims 1 to 10, wherein separating the non-entangled particles/short fibres comprises using an oil-water system comprising water as the non-oil miscible medium, and wherein the oil is a non-emulsifiable oil, preferably selected from silicone oil, mineral oil, castor oil, paraffin oil, and a mixture thereof.

12. The method according to any one of claims 1 to 11 , wherein the oil-water phase medium comprises a ratio by volume of oil to water of from 1 :2 to 1 :100, from 1 :2 to 1 :50, more preferably from 1 :5 to 1 :30.

13. The method according to any one of claims 1 to 12, wherein the combination of oil-water separation and flotation comprises using air bubbles to facilitate movement of individual components having hydrophobic character from the water phase into the oil phase.

14. The method according to any one of claims 1 to 13, wherein separating the non-entangled particles/short fibres further comprises an agitation step, wherein agitation is used to mix the oil-water phase medium thereby facilitating separation and accumulation of individual components in the oil phase and/or the water phase.

15. The method according to any one of claims 1 to 14, wherein the non-entangled particles/short fibres comprise a mixture of polyester and cotton, wherein the polyester non-entangled particles/short fibres accumulate in the oil phase and the cotton non-entangled particles/short fibres accumulate in the water phase.

16. The method according to any one of claims 1 to 15, wherein the non-entangled particles/short fibres have maximum lengths of less than 2 mm, preferably wherein the nonentangled particles/short fibres have maximum lengths of from 0.2 mm to 0.5 mm.

17. The method according to any one of claims 1 to 16, wherein filtering of the oil phase and the water phase is performed separately, preferably wherein the oil and/or water phases are recycled into the method after filtration.

18. A system for separating a blended fabric or entangled mixture of solid material, the system comprising: a separation tank configured to accommodate an oil-water phase medium, wherein the oil-water phase medium comprises a non-oil miscible medium and an oil phase medium; an agitator configured to be immersed in the oil-water phase medium to agitate the oil-water phase medium; a non-oil phase outlet located at a lower end of the separation tank to extract the non-oil miscible medium and components therein, optionally into a first settling tank; and, an oil-phase outlet located at an upper end of the separation tank to extract the oilphase medium and components therein, optionally to the first settling tank or a second settling tank.

19. The system of claim 18, wherein the agitator is an aerator, an impeller, a magnetic or mechanic stirrer, a rotating drum mixer or a water pump mixer.

20. The system of claim 18 or claim 19, when used to implement the method of any one of claims 1 to 17.

21 . Separated individual components, optionally deconstructed from a blended fabric or entangled mixture of solid material, obtained by the method of any one of claims 1 to 17 or when obtained using the system of any one of claims 18 to 20.