Method for regeneration of polyester and recycling of polyester textile waste using a thermal treatment

Abstract

The invention relates generally to a recycling of polyesters such as polyethylene terephthalate (PET). The invention also relates to a process for producing a polyester the process comprising at least the following steps: a. providing a first polyester fragment; b. subjecting the first polyester fragment to a thermal treatment to obtain a second polyester fragment; c. contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; d. converting the further polyester fragment into a plurality of polyester solids. The first polyester fragment comprises a polyester polymer and a textile chemical. The second polyester fragment comprises less textile chemical than the first polyester fragment. The invention further relates to a polyester product obtainable by aforementioned process, a device for treating a polyester fragment and a use of polyester solids for a purpose such as de-esterification, an esterification, a fibre, a textile, a container, a film, or a combination of at least two thereof.

Description

[0001] METHOD FOR REGENERATION OF POLYESTER AND RECYCLING OF POLYESTER

[0002] TEXTILE WASTE USING A THERMAL TREATMENT

[0003] FIELD OF THE INVENTION

[0004] The invention relates generally to a recycling of polyesters such as polyethylene terephthalate (PET). The invention also relates to a process for producing a polyester the process comprising at least the following steps: a. providing a first polyester fragment; b. subjecting the first polyester fragment to a thermal treatment to obtain a second polyester fragment; c. contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; converting the further polyester fragment into a plurality of polyester solids. The first polyester fragment comprises a polyester polymer and a textile chemical. The further polyester fragment comprises less textile chemical than the second polyester fragment. The invention further relates to a polyester product obtainable by aforementioned process, a device for treating a polyester fragment and a use of polyester solids for a purpose such as a de-esterification, an esterification, a fibre, a textile, a container, a film, or a combination of at least two thereof.

[0005] BACKGROUND

[0006] Polyethylene terephthalate (PET) is one of the most widely used and economically important thermoplastic polymers. PET is used for, e.g., fibres for clothing, containers for food and beverages, such as bottles, and for films. As a result of the wide usage of PET and its nonbiodegradability, PET-containing products have created serious ecological concerns. Methods for recycling PET are thus very important in order to reduce the amount of PET waste. One method of recycling is the reduction of PET into the chemical components that are used to produce PET, followed by the polymerisation of the chemical components to obtain recycled PET. This is known as chemical recycling. Disadvantages of the chemical recycling process include the following: the recycling process is generally very energy inefficient, is ecologically unfriendly, and has a low through-put. In particular, if the PET is depolymerised to monomers, this requires long depolymerisation times, and leads to the production of large amounts of degradation products that can’t be removed from the recycled PET. Very often it is also required to mix the PET that is chemically recycled with virgin PET in order to obtain a recycled PET product of sufficiently high quality.

[0007] The chemical recycling of polyethylene terephthalate is described by, e.g., Bartolome et al. (2012), Recent Developments in the Chemical Recycling of PET, Material Recycling - Trends and Perspectives. EP3778744 Al discloses a method for recycling PET that includes mixing virgin PET liquid starting material with the recycled PET (virgin PET liquid starting material is defined as the chemical components required to produce virgin PET, i.e., PET that is not obtained using a recycling method). CN109134244 A discloses a method for recycling PET that uses both glycol and methanol to depolymerise PET. CN108395373 A discloses a method for recycling PET that uses ethylene glycol and propylene glycol.

[0008] In addition to selecting an appropriate method for recycling of polyesters and in particular PET, it is a further challenge to subject sufficiently pure and clean PET feed to the further steps of recycling. This holds in particular for polyester textiles such as PET fabrics which have been dyed and in particular those which have been treated with other textile chemicals. Attempts to provide a solution to this challenge are known for example from US 2022 / 0169786 Al and JP 7177449 B2. These two references focus on the use of a particular solvent.

[0009] OBJECTS

[0010] An object of the present invention is to at least partially overcome at least one of the disadvantages encountered in the state of the art.

[0011] It is a further object of the invention to provide a further intermediate product that has an improved colour quality.

[0012] It is a further object of the invention to provide a further intermediate product that has an improved purity.

[0013] It is a further object of the invention to provide an improved decolouration process for a textile having a coating. It is a further object of the invention to provide an improved decolouration process for a textile having a finisher.

[0014] It is a further object of the invention to provide an improved decolouration process for a high GSM textile.

[0015] It is a further object of the invention to provide a decolouration process having improved liquid penetration of a textile.

[0016] It is a further object of the invention to provide an improved recycling process for a textile having a coating.

[0017] It is a further object of the invention to provide an improved recycling process for a textile having a finisher.

[0018] It is a further object of the invention to provide an improved recycling process for a high GSM textile.

[0019] It is a further object of the invention to provide a recycling process having improved liquid penetration of a textile.

[0020] SUMMARY OF THE INVENTION

[0021] The invention provides a process in which a first polyester fragment is subjected to a thermal treatment to obtain a second polyester fragment, which is then contacted with an organic liquid to obtain a further polyester fragment, which in turn is converted into a plurality of polyester solids. One or more textile chemicals present in the first polyester fragment are at least partially removed by these steps, so that the further polyester fragment comprises less textile chemicals than the first polyester fragment. The invention further includes a polyester product obtainable by this process, a device for treating a polyester fragment with the process and a use of polyester solids or products obtained by this process for a variety of purposes.

[0022] BRIEF DESCRIPTION A contribution to the at least partial achievement of at least one of the aforementioned objectives is provided by the subject-matter of the independent claims. The features disclosed in the claims, the specification, and the drawings may be essential for different embodiments of the claimed invention, both separately and in any combination with each other.

[0023] A contribution to the at least partial achievement of at least one of the aforementioned objectives is provided by the subject-matter of the following embodiments labelled |1| etc..

[0024] |1| A process for producing a polyester product, the process comprising at least the following process steps: a. Providing a first polyester fragment; b. Subjecting the first polyester fragment to a thermal treatment to obtain a second polyester fragment; c. Contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; d. Converting the further polyester fragment into a plurality of polyester solids;

[0025] Wherein the first polyester fragment comprises at least 50 wt.-%, preferably at least 80 wt. %, more preferably at least 90 wt. %, of a polyester polymer;

[0026] Wherein the first polyester fragment comprises a textile chemical different from the polyester polymer; wherein the further polyester fragment comprises less of the textile chemical than the first polyester fragment.

[0027] |2| The process according to embodiment 111, wherein the first polyester fragment comprises the textile chemical in an amount in the range of 0.01 to 20 wt.-%, based on the total weight of the first polyester fragment, preferably in the range from 0.5 to 10 wt. %, more preferably in the range from 1 to 8 wt. %.

[0028] |3| The process according to embodiment |1| or |2|, wherein the first polyester fragment meets one or more of the following criteria: a. A dso maximum length in the range of 300 to 600 mm, preferably in the range from 325 to 575 mm, more preferably in the range from 350 to 550 mm; b. A GSM in the range of 30 to 400 g / m2, more preferably in the range of 50 to 350 g / m2, and even more preferably in the range of 100 to 250 g / m2; c. Comprises two or more fibres; d. An intrinsic viscosity (IV) in the range of 0.4 to 1.4, more preferably in the range of 0.5 to 1.2, and even more preferably in the range of 0.6 to 1.1; e. Bulk density in the range of 0.01 to 0.75 g / cm3, preferably in the range from 0.15 to 0.7 g / cm3, more preferably in the range from 0.2 to 0.6 g / cm3.

[0029] These criteria may be satisfied in various combinations, preferably selected from the group consisting of: a., b., a.+b., c., a.+c., b.+c., a.+b.+c., d., a.+d., b.+d., a.+b.+d., c.+d., a.+c.+d., b.+c.+d., a.+b.+c.+d., e., a.+e., b.+e., a.+b.+e., c.+e., a.+c.+e., b.+c.+e., a.+b.+c.+e., d.+e., a.+d.+e., b.+d.+e., a.+b.+d.+e., c.+d.+e., a.+c.+d.+e., b.+c.+d.+e. and a.+b.+c.+d.+e.

[0030] |4| The process according to any of the preceding embodiments, wherein the textile chemical is selected from the group consisting of a dye, a finisher, a softener, or a combination of at least two thereof.

[0031] |5| The process according to any of the preceding embodiments, wherein the polyester polymer comprises an amorphous domain; wherein the polyester polymer attains a temperature as high as or exceeding its glass transition temperature Tg.

[0032] |6| The process according to embodiment |5|, wherein the polyester polymer attains a temperature exceeding its glass transition temperature Tgby not more than 90 K, preferably not more than 85 K, more preferably not more than 80 K.

[0033] |7| The process according to any of the preceding embodiments, wherein the polyester polymer comprises a crystalline domain; wherein the polyester polymer attains a temperature not as high as its crystallization temperature Tc.

[0034] |8| The process according to any of the preceding embodiments, wherein the polyester polymer has not exceeded its melting temperature Tm.

[0035] |9| The process according to any of the preceding embodiments, wherein the heat treatment is performed in a heat treatment zone, and wherein the Contacting with the organic liquid is performed in a contacting zone downstream to the heating zone.

[0036] 110| The process according to embodiment |9|, wherein the contacting zone has an at least 2 times higher concentration of the organic liquid than the heating zone.

[0037] 1111 The process according to any of the preceding embodiments, wherein the heat treatment meets at least one or all of the following criteria:

[0038] (A) Involves a gas flow;

[0039] (B) Involves relative moving the first polyester fragments to each other, preferably by tumbling, mixing or turning;

[0040] (C) Requires a residence time of the first polyester fragment in the range of 1 to 6000 s, preferably in the range from 10 to 5000 s, more preferably in the range from 50 to 3000 s;

[0041] (D) Requires a temperature in the range of 80 to 260 °C, preferably in the range from 100 to 200 °C, more preferably in the range from 110 to 155 °C.

[0042] In one aspect of this embodiment, the above criteria are satisfied in one of the following combinations: (A), (B), (A)+(B), (C), (A)+(C), (B)+(C), (A)+(B)+(C), (D), (A)+(D), (B)+(D), (A)+(B)+(D), (C)+(D), (A)+(C)+(D), (B)+(C)+(D) and (A)+(B)+(C)+(D).

[0043] 112| The process according to any of the preceding embodiments, wherein the organic liquid has a boiling point at least 1 K above Tgof the polyester polymer, preferably at least 5 K, more preferably at least 10 K;

[0044] 1131 The process according to any of the preceding embodiments, wherein at least a part of the organic liquid is recovered after the contacting and returned into the contacting, preferably following purification, such as absorption, distillation or a combination of both. A preferred distillation is performed at atmospheric pressure (0.101325 MPa) or at a reduced pressure. 114| The process according to any of the preceding embodiments, wherein the organic liquid is a mixture of two or more different organic solvents.

[0045] |15| The process according to any of the preceding embodiments, wherein the organic liquid comprises at least 30 vol.-%, based on the total volume of the organic liquid, an aromatic molecule, preferably a halogenated aromatic molecule, preferably at least 50 vol.-%, more preferably at least 80 vol-%.

[0046] 116| The process according to any of the preceding embodiments, wherein the concentration of the textile chemical is increased in the organic liquid by the contacting.

[0047] 117| The process according to any of the preceding embodiments, wherein the concentration of the textile chemical in the organic liquid is decreased.

[0048] 118| The process according to the preceding embodiment, wherein the decrease is obtained by an absorption means.

[0049] |19| The process according to the preceding embodiment, wherein the absorption means is selected from the group consisting of a carbon particle, a silicon oxide particle, an ion exchange resin or at least two thereof.

[0050] |20| The process according to any of the preceding embodiments, wherein the organic liquid is at least partly removed prior to the conversion.

[0051] |211 The process according to any of the preceding embodiments, wherein shear or heat or both is applied in the conversion.

[0052] |22| The process according to any of the preceding embodiments, wherein the plurality of polyester solids is selected from the group consisting of chips, beads, flakes, pellets, fibres or a combination of at least two thereof. |231 The process according to any of the preceding embodiments, wherein the process comprises as additional process steps: e. Subjecting the polyester solids to a de-esterification reaction to obtain a de- esterification product (more contaminated); f. Optionally, subjecting the de-esterification product to a purification to obtain a purified de-esterification product; g. Subjecting the de-esterification product, or the purified de-esterification product, to an esterification reaction or other chemical modification or keeping the de- esterification product.

[0053] |24| The process according to the preceding embodiment, wherein the de-esterification product has an IV in the range of 1.3 to 0.005, preferably in the range from 1.2 to 0.01, more preferably in the range from 1.1 to 0.03.

[0054] |251 The process according to any of the preceding embodiments, wherein the polyester product has an IV in the range of more than 0.6 to 1.4, preferably in the range from 0.65 to 1.35, more preferably in the range from 0.7 to 1.3.

[0055] |26| The process according to any of the preceding embodiments, wherein the polyester product is a homo polymer, a co-polymer or both.

[0056] |27| The process according to any of the preceding embodiments, wherein the polyester product is selected from the group consisting of a flake, a pellet, a chip, a container, a yam, a fibre, a textile, a film or at least two thereof.

[0057] |28| The process according to any of the preceding embodiments, wherein at least 20 wt.-% of the textile chemical is a dye, preferably at least 25 wt.-%, more preferably at least 30 wt.- %.

[0058] |29| The process according to the preceding embodiment, wherein the dye is selected from the group consisting of an azo dye, an anthraquinone dye, a phthalocyanine dye, a reactive dye, a disperse dye, a direct dye, a vat dye, a sulphur dye, a cationic / basic dye, an acid dye, a solvent dye and a mordant dye, preferably a disperse dye.

[0059] |30| The process according to any of the preceding embodiments, wherein at least 50 wt.-% of the textile chemical is a finisher, preferably at least 60 wt.-%, more preferably at least 70 wt.-%, wherein the finisher is a polymer comprising at least one repeating unit which has no ester group.

[0060] |311 The process according to the preceding embodiment, wherein the finisher is one or more selected from the group consisting of: a silicone, a polyacrylate, a polyurethane, a fluorochemical, a spin finish oil, a coning oil and a surfactant. Preferred fluorochemicals are fluorosurfactants, fluoropolymers, or both

[0061] 1321 A device for treating a polyester fragment, comprising a moving means adapted and arranged i. to move two or more limp textile fragments, ii. to pass a gas and a liquid through the two or more limp textile fragments; wherein the moving means connects at least the following zones: iii. A feeder zone, adapted and arranged to receive the two or more polyester fragments, iv. A heat treatment zone, adapted and arranged to heat the two or more limp textile fragments, v. A contacting zone, adapted and arranged to contact the two or more limp textile fragments with an organic liquid, vi. Optionally a drying zone, adapted and arranged to remove at least a part of the organic liquid from the two or more polyester fragments, and vii. A converting zone, adapted and arranged to shear the two or more limp textile fragments.

[0062] |33| The device according to embodiment |162|, wherein a de-esterification zone is arranged downstream to the converting zone, which is adapted and arranged to reduce the molecular weight of a polyester. |34| The device according to the embodiment |32| or |33|, wherein an esterification zone is arranged downstream to the de-esterification zone, which is adapted and arranged to increase the molecular weight of a polyester.

[0063] |35| The device according to any of the embodiments |32| to |Error! Reference source not found.4|, wherein the process is performed in a device according to any of the embodiments 1 to Error! Reference source not found..

[0064] |36| A polyester product, obtainable by a process according to any of the embodiments |1| to |Error! Reference source not found.1| or embodiment |Error! Reference source not found.2| to |35|.

[0065] |37| Use of a plurality of polyester solids obtainable by a process comprising the following process steps: a. Providing a first polyester fragment; b. Subjecting the first polyester fragment to a heat treatment to obtain a second polyester fragment; c. Contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; d. Converting the further polyester fragment into the plurality of polyester solids; for a purpose selected from the group consisting of a chemical modification or a forming or both. Preferred chemical modifications are one or more selected from the group consisting of a functionalization, a de-esterification, an esterification. Preferred formed bodies are one or more selected from the group consisting of a fibre, a textile, a container and a film.

[0066] DETAILED DESCRIPTION

[0067] A first embodiment of the invention is a process for producing a polyester product, the process comprising at least the following process steps: a. Providing a first polyester fragment; b. Subjecting the first polyester fragment to a thermal treatment to obtain a second polyester fragment; c. Contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; and d. Converting the further polyester fragment into a plurality of polyester solids; wherein the first polyester fragment comprises at least 50 wt.-% of a polyester polymer; wherein the first polyester fragment comprises a textile chemical different from the polyester polymer; wherein the further polyester fragment comprises less of the textile chemical than the first or the second polyester fragment.

[0068] A preferred organic liquid comprises one or more organic compounds, preferably a total of at least 50 wt. % of organic compounds, more preferably at least 80 wt. %, more preferably still at least 90 wt. %, more preferably still at least 99 wt. %. One embodiment of an organic liquid is a single organic compound, preferably present in an amount of at least 50 wt. %, more preferably at least 80 wt. %, more preferably still at least 90 wt. %, more preferably still at least 99 wt. %. One embodiment of an organic liquid comprises 2 organic compounds, preferably present in an total amount of at least 50 wt. %, more preferably at least 80 wt. %, more preferably still at least 90 wt. %, more preferably still at least 99 wt. %. A preferred organic liquid may comprise non-organic compounds, preferably in an amount less than 50 wt. %, more preferably less than 20 wt. %, more preferably still less than 10 wt. %, more preferably still less than 1 wt. %.

[0069] In the present context, the term “fragments” refers to pieces which are obtained by fragmenting an item. The item can be any item known to and considered useful for the present invention by a skilled person. The item can be any material, such as textiles, fabrics, fleeces, sheets, films, flakes and yams, preferably textiles, fabrics, fleeces, sheets, films, and yams. In another aspect flakes are preferred. Preferably, the item is a limp material. A limp item in the present context is an item which is dimensionally unstable when low forces are applied, which has a low stiffness and thus, large deformations result from low forces or loads. Often, limp is associated as a property of an item having an overall bending rigidity of less than or equal to 0.2 gf- cm2 / cm (less than or equal to 3.5 • 10'5J). Bending rigidity is preferably determined according to the heart loop method laid out in Kara, S. Tekstil ve Konfeksiyon, 31(2), Year 2021, 82-90. A preferred item has a bulk density below 200 kg / m3. Bulk density is preferably determined according to DIN EN ISO 60 (1999). A preferred item is shape conformable, preferably conforming to the shape of a supporting solid under its own weight.

[0070] When referring to a “fragment”, not necessarily a one and only fragment is meant. Moreover, this term may include pluralities of fragments. Fragment refers to a piece and implies that this piece is result of an action which makes many pieces out of a single one. Some examples of such actions are shredding, chopping, slicing, cutting, milling and breaking.

[0071] A first polyester fragment is provided as a feed material. The feed may include material from any source known by a skilled person and considered suited to be used in the present invention. For example, the polyester fragment can be a polyester used before by a consumer or commercial, so- called waste. It can also be composed of a share of used polyester fragments and another share of virgin polyester fragments. “Virgin” in the present context refers to material which has been manufactured but not yet used. E.g., such a product has been manufactured from starting materials which do not commence from recycling, and converted into a fabric, which again has been converted into a cloth. The cloth, however, has not been worn or used otherwise by a consumer.

[0072] A “fragment” of a first polyester preferably has physical dimensions (e.g., length, width, thickness) that are all below an upper value. It is preferred that this upper value is less than 50 cm, more preferably less than 30 cm, and further preferably less than 20 cm. An example of a plurality of “fragments” are PET textile fragments of PET flakes, which are well-known to the skilled person employed in the technical field of recycling, preferably textile fragments.

[0073] A “first dimension” of a fragment should preferably be understood to mean either the width, the length, or both, of the fragment. A “length” of a fragment should preferably be understood as referring to the largest dimension of the fragment. A “width” of a fragment should preferably be understood as referring to the second largest dimension of the fragment. A “thickness” of a fragment should preferably be understood as referring to the smallest dimension of a fragment.

[0074] In a preferred aspect of the invention, the geometric shape of the fragments is not limited. A preferred shape is a lamella shape. A preferred lamella shape has a length, width and thickness, the length and width each being at least 2 times the thickness, preferably at least 5 times, more preferably at least 10 times. A preferred lamella can be based on a polygonal 2-dimensional shape or a non-polygonal 2-dimensional shape. The preferred polygonal 2-dimensional shape is foursided.

[0075] In an embodiment, the first polyester fragment may comprise at most 90 wt.-% of waste polyester and at least 10 wt.-% of virgin polyester, for example from 40 to 90 wt.-%, or from 50 to 90 wt.- %, or from 50 to 80 wt.-%, or from 40 to 85 wt.-% of waste polyester, while the remainder to 100% is virgin polyester, the wt.-% always based on the total amount of first polyester fragment provided. Further, the composition of first polyester fragment provided in step a. may vary over time, in particular when referring to a continuous process, or from batch to batch for discontinuous processing.

[0076] The polyester be any polyester known to and considered useful for the present invention by a skilled person. Examples of suited polyester are aliphatic, cycloaliphatic, and aromatic polyesters, as well as co-poly esters, polyester-co-polymers and any other kind of feed comprising polyester.

[0077] Examples of aliphatic polyesters are polylactide or polyglycolic acid, or both. Examples of cycloaliphatic polyesters are based on cyclohexanedimethanol.

[0078] Examples of aromatic polyester are polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate; polyethylene naphthalate; polycarbonate; polyester carbonate; polyester resin.

[0079] Examples of aromatic co-polyesters are polyesters containing co-monomers selected from the group consisting of cyclohexanedimethanol (CHDM), diethylene glycol (DEG), oligo ethylene glycol (OEG), isophthalic acid (IP A), or a combination of at least two thereof.

[0080] Examples of aromatic polyester-copolymers are poly(ester-amide), poly(ester-ether), or both.

[0081] In a preferred embodiment of the process, the first polyester has a density in the range of 1.25 g / cm3to 1.55 g / cm3, more preferably in the range of 1.28 g / cm3to 1.50 g / cm3, and further preferably in the range of 1.31 g / cm3to 1.47 g / cm3. Densities of the first polyester are well-known in the art, and can be found, e.g., C. A. Harper, Modern Plastics Handbook: Handbook, McGraw- Hill Professional, New York, 2000, and at https: / / en.wikipedia.org / wiki / Polyethylene_terephthalate. In an aspect of this embodiment, examples of the first polyester are amorphous PET with a density in the range of 1.33 g / cm3to of 1.39 g / cm3, and single crystal PET with a density of 1.455 g / cm3.

[0082] In a preferred embodiment of the process, the first polyester, in particular in form of a plurality of fragments, has a bulk density in the range of 0.01 g / cm3to 0.75 g / cm3, more preferably in the range of 0.15 g / cm3to 0.65 g / cm3, even more preferably in the range of 0.18 g / cm3to 0.50 g / cm3, further preferably in the range of 0.20 g / cm3to 0.40 g / cm3and even further preferably in the range of 0.22 g / cm3to 0.37 g / cm3.

[0083] Further, the first polyester fragment may comprise two or more different polyester, as well as up to 20 wt.-%, for example 15 wt.-% or less, for example 10 wt.-% or less, for example 5 wt.-% or less, or 2 wt.-% or less of plastics different from the polyester.

[0084] In any way, the first polyester fragment comprises at least 50 wt.-%, for example 55, 60, 65, 70, 75, 80, 85, 90 or at least 95 wt.-% of polyester polymer, the wt.-% based on the total amount of first polyester fragment. Often, the first polyester fragment comprises less than 5, for example 3 or 1 wt.-% of non-polyester, the wt.-% based on the total amount of first polyester fragment. Nonpolyester can be any material which is not a polyester.

[0085] In an embodiment of the process, the first polyester fragment may meet at least one, preferably two or more, or even all of the following criteria:

[0086] (a) A dso maximum length in the range of 300 to 600 mm;

[0087] (b) A GSM in the range of 30 to 400 g / m2, more preferably in the range of 50 to 350 g / m2, and even more preferably in the range of 100 to 250 g / m2;

[0088] (c) Comprises two or more fibres;

[0089] (d) An intrinsic viscosity (IV) in the range of 0.4 to 1.4, more preferably in the range of 0.5 to 1.2, and even more preferably in the range of 0.6 to 1.1;

[0090] (e) Bulk density in the range of 0.01 to 0.75 g / cm3.

[0091] The d50maximum length is the d50value for the largest extension of the fragment.

[0092] From the above list, the first polymer fragment may be characterized by a combination of any one of these list elements: (a), (b), (a)+(b), (c), (a)+(c), (b)+(c), (a)+(b)+(c), (d), (a)+(d), (b)+(d), (a)+(b)+(d), (c)+(d), (a)+(c)+(d), (b)+(c)+(d), (a)+(b)+(c)+(d), (e), (a)+(e), (b)+(e), (a)+(b)+(e), (c)+(e), (a)+(c)+(e), (b)+(c)+(e), (a)+(b)+(c)+(e), (d)+(e), (a)+(d)+(e), (b)+(d)+(e),

[0093] (a)+(b)+(d)+(e), (c)+(d)+(e), (a)+(c)+(d)+(e), (b)+(c)+(d)+(e) or (a)+(b)+(c)+(d)+(e).

[0094] The first polyester fragment can be of any physical constitution, for example at least one selected from the group consisting of films, fibers, yarns, fabric, textiles, sheet, or a combination of two or more thereof.

[0095] The polyester constituting the first, second and further polyester fragment is a semicrystalline polymer. Semicrystalline means that a fragment of the polyester has crystalline regions and other which are not crystalline, i.e. amorphous. Crystalline regions are characterized in that the polymer is arranged in a parallel, structured packing. Amorphous regions are those in which no structural organization is observed. This is schematically shown in Fig. 2. It can be determined by DSC analysis, as detailed in the test method herein. The extent of crystallinity and / or amorphousness of a sample of polyester can be determined by various analytical methods.

[0096] DSC analysis is preferably performed according to the test method described herein. When using a DSC, the so-called thermogram of a sample delivers useful information. To record a thermogram, a sample is put in a special crucible and heated at a given heating rate from a low temperature to above its melting temperature, while difference in temperature measured for this sample is compared against an empty crucible. The DSC produces an Enthalpy in J / g vs. Temperature plot. An exemplary plot for polyethylene terephthalate is shown in Fig. 3. Typically, a glass transition temperature Tsis found in a range of 70 to 90 °C, a crystallization temperature Tcin the range of 120 to 200 °C, and a melting temperature Tmin the range of 240 to 260 °C. AHmois the standard heat of melting of 100% crystalline PET and is typically in the range from about 120 to about 140 J / g, as is known from the literature (see Panowicz, R.; Konarzewski, M.; Durejko, T.; Szala, M.; Lazinska, M.; Czerwinska, M.; Prasula, P. Materials, 2021, 14, 3833-3848). The melting enthalpy AHmis obtained by calculating the area under the melt signal and a baseline fit from onset to onset. Similarly, the heat of crystallization AHCis calculated. The degree of crystallinity, expressed as % crystallinity can be calculated this way: * , * 100 The glass transition temperature Tgis the temperature at which a softening of a solid semicrystalline or an amorphous polymer occurs. By definition, a Tgis by a step in the baseline of the measurement curve (Fig.3b). It is characterized by its onset, peak, inflection and end temperature. Tgis defined at the intersection between the curve and half height of the step. The evaluation procedure is described in e.g., ISO 11357.

[0097] The crystallization temperature Tcis the temperature at which some polymers re-crystallize. With PET, this is where amorphous regions organize to crystals. The temperature is defined as the maximum of an exothermic peak.

[0098] The melt temperature Tmin the context of the present invention is the temperature at the maximum of an endothermic peak. This is, where the whole sample is in melt form and no crystalline or other solids remain.

[0099] In an embodiment of the process, the first polyester fragment comprises at least one textile chemical in an amount in the range of 0.01 to 20 wt.-%, based on the total weight of the first polyester fragment. For example, the amount of textile chemical can be from 0.5 to 15, or 2 to 14, or 2.5 to 9 wt.-%.

[0100] In an embodiment of the process, the textile chemical may be at least one element selected from the group consisting of a dye, a finishing, such as a softener, a coating, a print, a pigment, adhesives, or a combination of at least two thereof. Preferably the textile chemical may be a dye, or a finisher or both, more preferably a dye. This includes two or more elements of the same group, but may as well refer to elements from different groups. Often, the textile chemical is a package comprising several elements from different groups, for example three dyes, a finisher and two softeners.

[0101] Each of these group of the above elements may include a variety of different kinds of chemical compounds. It is understood by a skilled person that the above indications are for exemplary purposes, since the number of possible variations is unlimited. However, a skilled person knows when evaluating a polyester waste as a feed material, whether this waste and its components are suited to be processed. In an embodiment of the process, at least 50 wt.-%, for example 55, 60, 65, 70, 75, 80 or at least 85 wt.-% of the textile chemical is one or more finishers, wherein the one or more finishers are polymers, each comprising at least one repeating unit which has no ester group. The wt.-% are based with regard to the total amount of the textile chemical. Typically, finishers are applied or are present on the fibre used in or to prepare a fabric. Accordingly, it is preferred that the concentration of the finisher is higher on the fibre than on the fabric made out or using a plurality of the fibres comprising the finisher. Also, typically, coatings are applied or are present on the fabric or textile but not in or on the fibre used in or to prepare a fabric. Thus, it is preferred that the concentration of the coating is higher on the fabric than on or in the fibre used to make the fabric.

[0102] Usually, prints are understood to comprise a colorant, like a dye or a pigment or both, and a matrix, preferably an organic matrix, more preferably a resin. It is preferred that the matrix contains the dye or the pigment or both. Prints are present in the first polyester fragment, wherein the concentration of the print on polyester fragment and thus preferably on the fabric or textile, is higher than in the polyester fragment and preferably higher than in the fibres of the polyester fragment and in particular the fabric or textile. It is quite often observed that the print is present as a colorant coating on the surface of the polyester fragment and preferably on the fabric or textile. In many cases, prints are applied on a polyester fragment, preferably a fabric or a textile, in form of a liquid or paste and then cured, by heat treatment, IR treatment, UV treatment, or the like, in order to harden the precursor of the matrix to form the matrix.

[0103] Often, a pigment is present on the polyester fragment in form of particles. A typical d50particle size of these pigment particles is in the range of 0.01 to 15 pm. Usually, pigments are applied on a textile fragment, in particular on a fabric or textile, in a dispersion. In this context it is preferred that the pigments are dispersed in a matrix, preferably the above-mentioned matrix.

[0104] The finisher can be any which is known by and considered suited as a finisher for a polyester polymer by skilled person. Examples of finishers are molecules comprising at least one repeating unit which has no ester group. Typically, a finisher is selected from the group consisting of silicones, polyacrylates, polyurethanes (each of these polymers independently of each other, with or without any pendant groups such as amino, amido or epoxy, or at least two thereof), fluorochemicals (preferably fluorosurfactants, fluoropolymers, or both), spin finish oil, coning oil, surfactants, or a combination of at least two thereof. The previously mentioned polymer classes could be also on out of more sections or branches of a copolymer. The finish typically imparts certain functionality or added property to or onto the polyester fragment, such as the fibre or fabric. Preferably, such functionality or property is selected from the group consisting of water repellency, moisture management, flame retardancy, anti-slip, anti-static, wrinkle-free, softening, moth protection, or a combination of a least two thereof.

[0105] In the context of this invention, adhesives are organic compounds capable of connecting parts, such as fibres, present in the polyester fragments or on the polyester fragment. In the latter case, the adhesive may serve to connect two or more polyester fragments to a polyester fragment agglomerate. Examples of adhesives are selected from the group of hot melts, preferably based on polyolefins, polyurethanes, polyacrylates, polyesters or a combination of at least two thereof, glues, limes, or a combination of at least two thereof. Typically, the Tmof an adhesive is at least 20 °C, more preferably at least 40 °C, and most preferably at least 60 °C, less than the Tmof the polyester fragment.

[0106] In an embodiment of the process, at least 10 wt.-%, for example 20, 30, 40, 50, 60, 70, 80 or at least 85 wt.-% of the textile chemical is one or more dyes, the wt.-% based with regard to the total amount of the textile chemical.

[0107] The dyes can be any which are known by and considered suited as dyes for a polyester polymer by a skilled person. Examples of suited dyes include, without being limited, azo dyes, anthraquinone dyes, phthalocyanine dyes, reactive dyes, disperse dyes, direct dyes, vat dyes, sulphur dyes, cationic / basic dyes, acid dyes, solvent dyes, mordant dyes, etc; preferably disperse dyes. In general dyes, in particular disperse dyes, are typically identified by their colour index (C.I.) nomenclature and include C.I. Compounds classified according to the colour they impart such as C.I. Disperse Black, C.I. Disperse Red, C.I. Disperse Blue, C.I. Disperse Orange, C.I. Disperse Yellow, C.I. Disperse Green, C.I. Disperse Violet, C.I. Disperse Brown, or a combination of two or more thereof. A textile may contain either one or more than one of the above mentioned disperse dyes. Similarly, the pigments which may act as colorants include compounds identified by C.I. nomenclature and include compounds classified according to the colour they impart, such as C.I. Pigment Black, C.I. Pigment Red, C.I. Pigment Blue, C.I. Pigment Orange, C.I. Pigment Yellow, C.I. Pigment Violet, C.I. Pigment Green, C.I. Pigment Brown, or a combination of two or more thereof. A textile may contain either one or more than one of the above-mentioned pigments. Further details regarding dyes can be obtained from the text book of Klaus Hunger, Industrial Dyes - Chemistry, Properties and Applications, 2003, Wiley VCH.

[0108] It can be often found in polyester fragments that either dye(s) or pigments(s) as such or a mixture of at least one dye and at least one pigment are employed in an amount in the range of 0.05 to 8 wt.-%, preferably in the range of 1.5 to 6 wt.-% and more preferably in a range of 2 to 5.5 wt.-%, each based on the total weight of the polyester fragment. It is also quite often observed in polyester fragments that either finisher(s) or coating(s) as such or a mixture of at least one finisher and at least one coating are employed in an amount in the range of 0.1 to 18 wt.-%, preferably in the range of 1.5 to 16 wt.-% and more preferably in a range of 6 to 14 wt.-%, each based on the total weight of the polyester fragment.

[0109] In an embodiment of the process, at least 20 wt.-%, for example 30, 40, 50, 60, 70, 80 or at least 85 wt.-% of the textile chemical is one or more softeners, the wt.-% based with regard to the total amount of the textile chemical.

[0110] The softener can be any which is known by and considered suited as softener for a polyester material by skilled person. With regard to typical examples of suited softeners reference is made to the materials and chemicals as well as formulation used as finishers, as disclosed herein above.

[0111] In an embodiment of the process, the polyester polymer comprises at least one, preferably two or more amorphous domains.

[0112] In an embodiment of the process, the polyester polymer comprises at least one, preferably two or more amorphous domains, and the polyester polymer has a glass transition temperature Tgat a temperature in the range from 60 to 90 °C, for example from 65 to 85 °C, or from 70 to 80 °C.

[0113] In an embodiment of the process, the polyester polymer comprises at least one, preferably two or more crystalline domains, and the polyester polymer has a crystallization temperature Tcat a temperature in the range from 100 to 150 °C, for example from 110 to 140 °C, or from 125 to 135 In an embodiment of the process, the polyester polymer comprises at least one, preferably two or more amorphous domains and at least one, preferably two or more crystalline domains. The polyester polymer may have both,

[0114] {a} a glass transition temperature Tgat a temperature in the range from 65 to 95 °C, for example from 67 to 93 °C, or from 70 to 90 °C; and

[0115] {b}a crystallization temperature Tcat a temperature in the range from 110 to 150 °C, for example from 115 to 145. °C, or from 120 to 140 °C.

[0116] Further preferred, the polyester polymer has a glass transition temperature Tgof about 80 °C and a crystallization temperature Tcof about 130 °C. About in the present context may be understood by a skilled person as ± 20°C.

[0117] In an embodiment of the process, the polyester polymer a melting temperature Tmin the range from 230 to 270 °C, or from 240 to 260 °C.

[0118] The providing in step a. may be accomplished by any means known to and considered suited by a skilled person for the process of the invention. Usually, the providing is a disposing of a first polymer fragment into a device, in which at least a part of the process is performed.

[0119] In step b., the first polyester fragment is subjected to a thermal treatment to obtain a second polyester fragment. The thermal treatment transfers heat to the first polyester fragment. This can be achieved by virtually any means of heat and transfer of heat known to a skilled person and considered suited, which does not cause any one or more of destruction, decomposition, degradation, side reactions, or depolymerization to the polyester fragment.

[0120] In an embodiment of the process the first polyester fragment is heated to obtain the second polyester fragment, wherein the polyester fragment attains a temperature as high as or exceeding the glass transition temperature of the polyester polymer in the polyester fragment.

[0121] In an embodiment of the process the first polyester fragment is heated to obtain the second polyester fragment wherein the polyester polymer attains a temperature exceeding its glass transition temperature Tgby not more than 90 K, for example not more than 60 or 50 K. According to one aspect, it is preferred that said temperature remains below the boiling temperature Tbof the organic liquid, preferably at least 5 K, or 10 K or 15 K below said boiling temperature. In an embodiment of the process the first polyester fragment is heated to obtain the second polyester fragment wherein the polyester polymer has not exceeded its melting temperature Tm.

[0122] In an embodiment of the process the heat treatment in step b. meets at least one, preferably two or more or even all of the following criteria:

[0123] (A) it involves a gas flow;

[0124] (B) it involves relative moving the first polyester fragments to each other;

[0125] (C) it requires a residence time of the first polyester fragments in the range of 1 to 6000 s, preferably 60 to 3000 s, and more preferably 300 to 900 s;

[0126] (D)it requires a temperature in the range of 80 to 260 °C.

[0127] The gas flow as in (A) may comprise one or more of the following gases: nitrogen, or ambient air. The gas flow may also employ compresseed gas such as nitrogen, or ambient air.

[0128] Relative moving of the first polyester fragments to each other can be realized by any means known to and considered suited by a skilled person, such as, e.g. by conducting step (B) in a tumbler, a rotary kiln, a screw, or a combination of two or more thereof. The first polyester fragments may be subjected to the heat treatment of step b. in the range from 1 to 6000 s, or from 60 to 3000 s, or from 300 to 900 s. The heat treatment in step b. may be conducted at a temperature in the range from 80 to 260 °C, or from 90 to 230 °C, or from 100 to 200 °C.

[0129] From the above list, heat treatment in step b. may be characterized by a combination of any one of these list elements: (A), (B), (C), (D); (A), (B), (C); (A), (B), (C); (A), (C), (D); (A), (B), (D); (A), (B); (C), (D); (A), (D); (B), (D); (A), (C).

[0130] According to the invention, the further polyester fragment comprises less of the textile chemical than the first polyester fragment. In other words, step c. aims to reduce the amount of textile chemical in the polyester fragment. Without being bound to a theory or mechanism, it is assumed that this occurs due to evaporation, degradation, chemical conversion, reaction, extraction, washing out or any other process known to and considered possible by a skilled person.

[0131] In an embodiment of the invention, the amount of textile chemical in the second polyester fragment, preferably before contact of organic liquid, is in the range from 1 to 99 %, or from 15 to 85 %, or from 30 to 60 %, with regard to the amount of textile chemical in the first polyester fragment. In step c., the second polyester fragment is contacted with an organic liquid. Thereby a further polyester fragment is obtained. In general, the contacting in step c. can be performed by any means and technique, known to a skilled person and considered suited in the present invention. In an embodiment of the process, the contacting in step c. may comprise one or more of the following techniques: spraying, soaking, flushing, immersing or a combination of two or more thereof.

[0132] Upon contact, the organic liquid dissolves at least a part of the textile chemical of the second polyester fragment thereby forming a further polyester fragment. It is preferred that, if any, only small amounts of the polyester are lost in step c.. The total weight of polyester in the further polyester fragment is preferably not reduced by more than 10 %, more preferably not more than 5 %, most preferably not more than 1.5 % below that of the first or second polyester fragment in the contacting step.

[0133] According to one aspect of the invention it is preferred that concentration of polyester dissolved in the organic liquid when the contacting in step c. is finished is less than 20 wt.-%, preferably less than 15 wt.-%, more preferably less than 10 wt.-%, further preferred less than 7 wt.-%, moreover preferred less than 4 wt.-% and in particular preferred less than 1 wt.-%, each based on the total weight of organic liquid. It is preferred that the beforementioned soluble content of the polyester in the organic liquid is determined at 20°C.

[0134] According to one aspect of the invention it is preferred that the amount of organic liquid in step b. is lower than in step c. In this context it is preferred that the amount of organic liquid present in step b. is at least 2 times, preferably at least 10 times and more preferably at least 20 times lower than the amount of organic liquid present in step c. It is preferred that step b. is substantially or totally free of the organic liquid.

[0135] The boiling point of the organic liquid is at least 1 K, for example 2, 3, 4, 5 or 6 K above the Tgof the polyester polymer. The boiling point of the organic liquid may be as high as perhaps 350 K, for example 10, 40, 80, 100 or 200 K above the Tgof the polyester polymer.

[0136] The maximal solubility of the polyester in the organic liquid may be less than 4 %, preferably 3 % and more preferably less than 2 %, and most preferably less than 1 %, or less than 0.5 %. In a further embodiment of the process, the contacting in step c. is performed at or below the boiling point of the organic liquid, for example at a temperature which is at least 1, 2, 3, 4, 5, 10 or 20 K below the boiling point of the organic liquid.

[0137] In an embodiment of the process at least a part of the organic liquid is recovered after the contacting and returned into the contacting, preferably following purification, such as absorption, distillation or a combination of both. A preferred distillation is performed at atmospheric pressure (0.101325 MPa) or at a reduced pressure. Preferably, the recovery can be achieved in subsequent step d., or independent from that.

[0138] In an embodiment of the process the organic liquid may be one or more, for example two, three or four of the organic solvents selected from the list consisting of: Hydrocarbons, in aromatic, aliphatic or cycloaliphatic form, each independently with or without any other functional group. Preferred are aromatic hydrocarbons with chemical groups directly attached to aromatic ring, preferably halogens-group(s), in particular fluoro-, chloro-, bromo-, iodo-group(s), more preferably chloro-group(s), or a combination of at least two thereof. Another preferred aspect of organic solvents are molecules containing at least an aromatic ring and one ester unit, molecules containing at least an aromatic ring and a phenolic or hydroxyl group, molecules containing halogen- and hydroxy- group(s), molecules containing an ether linkage, a hydroxy linkage or an ester linkage, or a combination of at least two thereof, molecules containing only hydrocarbons and halogens, or a combination of at least two thereof.

[0139] In one embodiment, a preferred organic liquid is one or more selected from the group consisting of: xylene, chlorobenzene, anisole and cyclohexanone. In one aspect of this embodiment, a preferred organic liquid is xylene. In another aspect of this embodiment, a preferred organic liquid is chlorobenzene. In another aspect of this embodiment, a preferred organic liquid is anisole. In another aspect of this embodiment, a preferred organic liquid is cyclohexanone.

[0140] In an embodiment of the process the organic liquid is a mixture of two or more, for example three, four or five different organic solvents, in particular selected from the above-mentioned organic solvents.

[0141] Preferably, the organic liquid comprises at least 10 wt.-%, preferably at least 40 wt.-%, more preferably at least 70 wt.-%, and even more preferred at least 87 wt.-%, for example 70 to 96 wt.-% of one of an organic solvent, preferably chlorobenzene, each wt.-% based on the total weight of the organic liquid. The organic liquid may further comprise an amount of a non-solvent with regard to the textile chemicals, for example water.

[0142] In an embodiment of the process the organic liquid comprises at least 30 vol.-%, for example at least 40, 50, 60 or at least 70 vol.%, based on the total volume of the organic liquid, an aromatic molecule, preferably a methyl substituted or halogenated aromatic molecule. A preferred halogenated aromatic molecule is chlorobenzene. Preferred methyl substituted aromatic molecules are mono-substituted or di -substituted. Preferred methyl substituted aromatic molecules are toluene and xylene.

[0143] In an embodiment of the process the concentration of the textile chemical is increased in the organic liquid by the contacting. For example, the concentration of the textile chemical in the organic liquid can be over 3000 grams of textile chemical / kg of organic liquid, for example more than 0.01 ppm (milligrams of textile chemical / kg of organic liquid) and up to 2000 grams of textile chemical / kg of organic liquid

[0144] In an embodiment of the process the concentration of the textile chemical in the further polyester fragment is less than in the second polyester fragment. For example, the concentration of textile chemical is 50 % or less, e.g. 40, 30, 20, 10, or 5 % or less in the further polyester fragment based on the amount of textile chemical in the second polyester fragment.

[0145] In a further embodiment of the process the decrease in the concentration of textile chemicals is obtained by a certain purification technique. This purification technique can be selected from the group consisting of adsorption, absorption, precipitation, gravimetric separation, centrifugation, etc. preferably, an adsorption means. In a further embodiment of the process the adsorption means is selected from the group consisting of a carbon particle, an activated carbon, a bentonite, a silicon oxide particle, an ion exchange resin, a polymeric adsorbent, or at least two thereof.

[0146] In an embodiment of the process the organic liquid is at least partly removed prior to the conversion, for example at least 10, 20, 30, 40 or 50 vol.% of the organic liquid are removed from the further polyester fragment prior to conversion of the further polyester fragment, the vol.% with reference to the amount of organic liquid in the moment of contacting.

[0147] In an embodiment of the process, the thermal treatment of step b. is performed in a thermal treatment zone and the contacting of step c. with the organic liquid is performed in a contacting zone downstream of the thermal treatment zone. Preferably, the contacting zone has an at least 2 times higher concentration of the organic liquid than the thermal treatment zone. In an embodiment of the process, converting the further polyester fragment into a plurality of polyester solids in step d. can be achieved by any means and techniques known to a skilled person and considered suited in the present invention. Converting may be performed by a technique selected from the group consisting of: solvent removal (evaporation), extrusion, dry blowing, granulation, flaking or any other technique involving melting of further polyester fragments, feeding of the melt to a die or a form of desired shape and size, quenching of an outlet coming after die or a form to below melting temperature to obtain solid polyester, or a combination of two or more thereof.

[0148] In an embodiment of the process, shear or heat or both is applied in the conversion in step d.

[0149] For example, step d. may be performed at a temperature in the range of 80 to 400 °C, or of 130 to 300 °C, or of 200 to 280 °C. For the extrusion, a pressure across a filter or screen is preferably in the range from 30- 105to 35 - 105Pa. For the extrusion, a pressure across a die head is preferably not above 40- 105Pa.

[0150] An extruder is a device useful for realizing this embodiment. A skilled person is able to select a suited extruder from the variations of extruder commercially available. Here, the skilled person in particular considers to avoid damage to the material to be extruded.

[0151] In an embodiment of the process, the plurality of polyester solids formed in step d. is selected from the group consisting of chips, beads, flakes, pellets, granules, blocks, fibres, or a combination of at least two thereof.

[0152] Optionally, a step of drying the further polyester fragment may be included. This step may be performed after completion of step c. and prior to step d. Drying can be achieved by any means and techniques known to a skilled person and considered suited in the present invention. Drying may be performed by a technique selected from the group consisting of: applying heat, applying a reduced pressure, circulation of dry and hot gas, or a combination of at least two thereof.

[0153] In an embodiment of the process, the process comprises these additional process steps: e. Subjecting the plurality of polyester solids to a de-esterification reaction to obtain a deesterification product; f. Optionally, subjecting the de-esterification product to a purification to obtain a purified de-esterification product; g. Subjecting the de-esterification product, or the purified de-esterification product, to an esterification reaction or other chemical modification or keeping the de-desertification product, preferably by stopping the process after de-esterified product has been obtained.

[0154] In an embodiment of the process the de-esterification product has an intrinsic viscosity (IV) in the range of 1.3 to 0.005, for example of 0.6 to 0.05, or of 0.2 to 0.01.

[0155] In an embodiment of the process the polyester product after esterification has an intrinsic viscosity in the range of more than 0.6 to 1.4 mPa s, for example from 0.4 to 1.0 mPa s, or from 0.6. to 0.9. mPa s.

[0156] The de-esterification product is preferably subjected to a purification to obtain a purified de- esterification product. Any purification methods and aids can be applied. Amongst these, those are preferred which allow a depletion of colour, particles, or other impurities. In this context a filtration is preferred. Many suitable filtration aids may be employed. Amongst these, membranes, preferably based on polymers, such as ion exchange resins, and particulated filter aids, particularly preferred are inorganic filter aids, like bentonite, clay, activated carbon, silicate, or a combination of two or more thereof, are particular preferred.

[0157] In an embodiment of the process the polyester product is characterized by one or both of the following features:

[0158] [I] a melting temperature Tmin the range from 245 to 251 °C;

[0159] [II] a di ethylene glycol content of at least 1.5 wt. %, preferably at least 2 wt. %, more preferably at least 2.4 wt. %. The diethylene glycol content might be as high as 4 wt. %.

[0160] In an embodiment of the process the first polyester fragment, or the polyester product, or both is a homopolymer or a copolymer.

[0161] In an embodiment of the process the polyester product is selected from the group consisting of a flake, a pellet, a chip, a container, a yarn, a fiber, a textile, a film or at least two thereof. Another embodiment of the invention is a device for treating a polyester fragment, comprising a moving means, at least a feeder zone, a heat treatment zone, a contacting zone and a converting zone, and optionally a drying zone, wherein the moving means is adapted and arranged i. to move two or more polyester fragments; ii. to pass a gas and a liquid through the two or more polyester fragments; wherein the moving means connects at least the following zones: iii. A feeder zone, adapted and arranged to receive the two or more polyester fragments, iv. A heat treatment zone, adapted and arranged to heat the two or more polyester fragments, v. A contacting zone, adapted and arranged to contact the two or more polyester fragments with an organic liquid, vi. Optionally a drying zone, adapted and arranged to remove at least a part of the organic liquid from the two or more polyester fragments, and vii. A converting zone, adapted and arranged to shear the two or more fragments.

[0162] In an embodiment of the device, the device comprises these further zones: viii. A de-esterification zone, preferably downstream of the converting zone, adapted and arranged to obtain a de-esterification product from the two or more sheared fragments, ix. Optionally a filtration zone, adapted and arranged to remove at least some impurities from the two or more de-esterified fragments, and x. An esterification zone, adapted and arranged to obtain an esterification product from the de-esterified fragments.

[0163] The moving means can be of any kind or apparatus known to a skilled person and considered suited to host sections i. - v. and vii., and optionally section vi. of the above embodiment. The zones iii. to vii. are arranged in the above order, by preference.

[0164] In an embodiment of the device, the device is suited and configured to perform the process of the invention in the device, the process as defined in any of the above embodiments. For example, step a. of the 1stembodiment of the process of the invention can be performed in step iii. Of the device. For example, step b. of the 1stembodiment of the process of the invention can be performed in step iv. Of the device. For example, step c. of the 1stembodiment of the process of the invention can be performed in step v. of the device. For example, step d. of the 1stembodiment of the process of the invention can be performed in step vii. Of the device. For example, an optional further step of drying the polyester fragment as described with regard to the 1stembodiment of the process of the invention can be performed in optional step vi. of the device.

[0165] In an embodiment of the device, the feeder zone is adapted and arranged to receive two or more polyester fragments. Moreover, the feeder zone is adapted and arranged to provide the two or more polyester fragments to the moving means. The feeder zone may comprise a hopper, a flap, a dosing device capable of measuring volume or weight of feed, sensors and sorters capable of detecting and sorting feed materials outside of set specifications such as based on size, colour, chemical composition, or a combination of two or more thereof.

[0166] In an embodiment of the device, the device is adapted and arranged to move polyester fragments which are limp.

[0167] In an embodiment of the device, moving means may comprise one or more screws, belts, plurality of moving beakers, or a combination of two or more thereof.

[0168] The moving means may include a housing which is suited and configured to connect the zones forming the device.

[0169] In an embodiment of the device, the device is suited and configured to pass a gas through the moving means and at least one, preferably two or more, or even all zones forming the device.

[0170] In an embodiment of the device, the heating zone is at least one element selected from the list consisting of a rotary kiln, a pre-oven, a tumbler, a screw conveyor, or a combination of two or more thereof.

[0171] In an aspect of the device, the heating zone may comprise at least one element selected from the list consisting of a conveyor belt having a plurality of holes, a conveyor net, screw conveyor with holes or mesh, or a combination of two or more thereof.

[0172] In an embodiment of the device, the contacting zone is at least one element selected from the list consisting of a tank, a device capable of converting volume of liquid into plurality of drops, an adsorbent bed, temperature sensor, flame arrestors, or a combination of two or more thereof.

[0173] In an aspect of this embodiment of the device, the moving means is configured to pass through the contacting zone. Further, an insert may be positioned between the moving means and the bottom of the contacting zone, which contains at least one adsorbent, e.g. selected from charcoal, activated carbon, bentonite, ion exchange resins, polymeric absorbents or a combination of two or more thereof.

[0174] In an aspect of the above embodiment of the device, the contacting zone may comprise a providing means suited and configured to provide an organic liquid to polyester fragments being conveyed by and / or on the moving means. The providing means may be selected from the group consisting of a nozzle, a sprayer, a hose, a pipe, a faucet, or a combination of two or more thereof.

[0175] In a further aspect of the above embodiment of the device, the contacting zone may comprise collecting and circulation means suited and configured to collect organic liquid at the bottom of the contacting zone and to circulate it to the providing means of the contacting zone. For example, the organic liquid may be collected at the bottom of the providing means through an outlet and pumped to the providing means using a pump. In a further aspect, the circulation means useful for circulating the organic liquid may comprise further means for regeneration of the organic liquid prior to re-using it. For example, the organic liquid may be evaporated and condensed during regeneration to purify the liquid and to separate it from any impurities, for example from any textile chemicals, such as dyes, finishers and so on, coming from the polyester fragments. In an alternative or even additional configuration, the contacting zone is configured so that at least some of the organic liquid collected at the bottom of the contacting zone may, optionally regenerated, be provided to the feeding zone or the heating zone, or both, to contact with the polyester fragments.

[0176] In an embodiment of the device, the drying zone is at least one element selected from the list consisting of a mesh with a hot air supply, a rotary oven, a vessel with heating coils, a vessel with heating jackets, or a combination of at least two thereof.

[0177] In an embodiment of the device, the converting zone comprises at least one element selected from the list consisting of an extruder, a kneader vessel, a vessel with heating coils, a vessel with heating jackets, a die or form, both preferably to pass a melt under pressure, each followed by a quenching section, or a combination of at least two thereof.

[0178] In an embodiment of the device, a recipient is arranged downstream of the converting zone. This could be a vessel or tank, both of which could be heated. In another embodiment of the device, a de-esterification zone is arranged downstream to the converting zone, which is adapted and arranged to reduce the molecular weight of a polyester.

[0179] In an embodiment of the device, a filtration zone is arranged downstream to the de-esterification zone, which is adapted and arranged to remove at least some impurities from the de-esterification product. The filtration zone may comprise at least one or more elements selected from the list consisting of membranes, preferably based on polymers, such as ion exchange resins, and particulated filter aids, particulated inorganic filter aids, like bentonite, clay, activated carbon, silicate, such as celite, or a combination of two or more thereof, are particularly preferred.

[0180] In an embodiment of the device, an esterification zone is arranged downstream to the de- esterification zone, which is adapted and arranged to increase the molecular weight of a polyester. In an embodiment of the device, a chemical modification zone is arranged downstream to the de- esterification zone, which is adapted and arranged to perform any chemical reaction different to a polymerization reaction. Thus, it is preferred that this chemical modification zone differs from the esterification zone.

[0181] For example, step e. of the process of the invention can be performed in a zone viii., the de- esterification zone of the device. For example, optional step f. of the process of the invention can be performed in a zone ix., the filtration zone of the device. For example, step g. of the process of the invention can be performed in a zone x., the esterification or chemical reaction zone of the device.

[0182] In a further embodiment, the process of the invention described above is performed in a device according to any one of the above embodiments.

[0183] A further embodiment is a polyester product obtainable by a process according to any one of the above embodiments.

[0184] A further embodiment is a use of a plurality of polyester solids obtainable by a process comprising the following process steps: a. Providing a first polyester fragment; b. Subjecting the first polyester fragment to a thermal treatment to obtain a second polyester fragment; c. Contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; d. Converting the further polyester fragment into the plurality of polyester solids; for a purpose selected from the group consisting of a chemical modification, preferably, a functionalization, de-esterification, esterification, formation of a body, preferably a fibre, a textile, a container, a film, or a combination of at two or more thereof.

[0185] BRIEF DESCRIPTION OF THE DRAWINGS

[0186] The following schematic drawings show aspects of the invention for improving the understanding of the invention in connection with some exemplary illustrations. The drawings are solely for the purpose of illustration. Accordingly, it is not intended to limit the invention to the extent shown in the drawings, nor are the drawings meant to be on scale if not explicitly stated.

[0187] Figure 1 shows a schematic presentation of the process according to claim 1.

[0188] Figure 2 shows a schematic view on a polyester fragment having crystalline and amorphous regions.

[0189] Figures 3a and 3b show characteristic DSC graphs for a polymer material.

[0190] Figure 4 shows a schematic presentation of optional further steps.

[0191] Figure 5 shows a schematic design of a device as claimed.

[0192] DETAILED DESCRIPTION OF THE DRAWINGS

[0193] Figure 1 shows a flow diagram of the process according to this disclosure. A first step, labelled a. is the provision of a first polyester fragment. A first polyester fragment has a polyester polymer as its major constituent and is preferably a textile. The first polyester fragment is contaminated with textile chemical, which can be a single chemical or a combination of more than one chemicals. The textile chemical typically comprises dye, finisher and ink as major constituents. A second step, labelled b. is a thermal treatment. The thermal treatment converts the first polyester fragment into a second polyester fragment. A third step, labelled c., is the contacting step, which is performed on a second polyester fragment. In step c., the second polyester fragment is contacted with an organic liquid. At least some of the textile chemical is dissolved in the organic liquid, thus reducing the content of textile chemical in the polyester fragment and increasing the content in the organic liquid. Step c. thus results in a further polyester fragment. In a further step d., the further polyester fragment is converted into a plurality of polyester solids. Step d. may include for example an extrusion step to produce pellets as feed-stock for further de-esterification processes.

[0194] Figure 2 shows a sketch of a partially crystallised polymer material. Regions of ordered crystalline polymer can be observed amongst regions of disordered amorphous polymer. Figures 3a and 3b show graphs for a thermal heating profile for a PET textile. Two melting temperatures are seen at 245.6 °C and 256.4 °C. A crystallisation temperature at 184 °C is observed in the first cooling cycle. In the second heating cycle, a glass transition temperature is observed at around 80 °C and a melting temperature is observed at 253.8 °C.

[0195] Figure 4 shows further downstream processes which could follow the process of the invention. A de-esterification step e., an optional purification step f. of the de-esterified product and an esterification step g. can be performed on the plurality of polyester solids produced by the process of this invention.

[0196] Figure 5 shows a schematic for a device according to the invention. Part i. is a moving means for moving textile fragments. The moving means connects at least the zones i. to v.. i. is a feeder zone, adapted and arranged to receive the two or more polyester fragments, ii. is a heat treatment zone, adapted and arranged to heat the two or more limp textile fragments, iii. is a contacting zone, adapted and arranged to contact the two or more limp textile fragments with one or more organic liquids, each comprising an organic compound having a ring with at least one C atom. iv. is an optional drying zone, adapted and arranged to remove at least a part of the organic liquid from the two or more polyester fragments, vi. is a converting zone, adapted and arranged to shear the two or more limp textile fragments.

[0197] Test methods

[0198] A. Bending Rigidity Testing

[0199] Bending rigidity was determined according to the heart loop method laid out in Kara, S. Tekstil ve Konfeksiyon, 31(2), Year 2021, 82-90 that uses ASTM D1388-18 for sample preparation, testing methodology and mathematical equations to calculate bending rigidity. The testing was performed on a Fabric Stiffness Tester (commercially available from Hefei Fanyuan Instrument Co. Ltd., Hefei, China; model number: FY207B).

[0200] B. Bulk density

[0201] When a feedstock comprises a plurality of fragments, the bulk density of the feedstock is calculated according to the standard ASTM DI 895- 17 B (Method C). The method is performed using a feedstock of PET textile fabrics in the form of 2 cm x 2 cm squares as the sample. In the event that 60 g of material used for the test does not fit into a 1000 cm3container without compression, a larger container is used. The bulk density of the feedstock, e.g. polyester fragments, is measured prior to contacting the feedstock with the first amount of the first organic compound.

[0202] C. Intrinsic viscosity

[0203] The intrinsic viscosity IV of a polymer, e.g. the first polyester, is measured according to the standard ASTM D4603:2018, with the following change: the flow time of the solution in a capillary viscometer is determined at 25 °C, instead of 30 °C (as given in the standard).

[0204] D. Residence time

[0205] The residence time TRESis determined by the following equation:

[0206] ?RES=^REACTOR / -^PRODUCT VOLUME RATE, where P REACTOR is the volume of a volume space, e.g., a reactor volume, and FPRODUCT VOLUME RATE is the volume rate of a mixture exiting (e.g., the first intermediate mixture, the further intermediate mixture) the volume section.

[0207] E. GSM

[0208] The test method provided below applies to all the fabrics (griege, dyed and coated) which were used in this study. Mass per unit area of PET textile fabric (Gram per Square Meter) was measured as per ASTM D-3776 (Option C). PET textile fabric samples were hand-cut using a scissor (commercially available from Fiskars®, Finland; Grade: Fiskars 8-inch Original Orange Handled- Scissor) in 10 cm * 10 cm (total area = 100 cm2) area (measured using a scale with a precision of 0.1 mm) and conditioned at 30 °C and 50 % Relative Humidity for 1 hour. Mass of conditioned samples of PET textile fabrics were weighed on an analytical balance (commercially available from Citizen Scale Incorporated, USA; Model: CX 220). Following equation was used for calculating GSM as reported in ASTM D-3776. g / m2= 106G / Lw

[0209] Where, G = mass of specimen, g

[0210] L = length of specimen, mm

[0211] W = width of specimen, mm

[0212] This test method is also applicable for determining the GSM of polyester fabrics other than PET.

[0213] F. DSC analysis

[0214] The polymer material is analysed using a differential scanning calorimeter (DSC) instrument (Perkin Elmer DSC-8000). The sample is first held at 40 °C for 1 minute, then heated from 40 °C to 300 °C (1stHeating), then cooled from 300 °C to 40 °C (1stCooling), then held at 40 °C for 1 minute, then heated from 40 °C to 300 °C (2ndHeating) under nitrogen stream, at a standard heating / cooling rate of 30 °C / min. The crystallization temperature (Tc) is determined from DSC curve of the first cooling run. The glass transition temperature Tgis determined from the second heating run, as the midpoint temperature and the melting temperature (Tm) was calculated as the peak of the melting endotherm.

[0215] Examples

[0216] Some examples are described in this section to demonstrate the invention. The examples are merely illustrative, and not intended to limit the scope of the invention.

[0217] 1) Effect of thermal pre-treatment step on wetting and absorption of organic liquid on fabric surface

[0218] Procedure: In a glass petri-dish (commercially available from BOROSIL®’ India; diameter = 9.0 cm; height = 1.5 cm) PET fibre woven fabric piece of 2 cm * 2 cm was kept. 4 drops of organic liquid were added at different locations across the fabric using a 10 ml glass pipette (commercially available from BOROSIL®, India). The drops were placed relative to each other in such a way that no two drops merge with each other forming a drop of larger volume and size. Wetting or spreading and absorption behaviour of drop within first 15 seconds of contact with fabric was observed. Real-time visual observations are noted as per below. Two organic liquids were evaluated separately: chlorobenzene (CB; CAS No.: 108-90-7) and tetra ethylene glycol dimethyl ether (TEGDME; CAS No.: 143-24-8). Fabrics were heated using an oven (commercially available from EIE Instruments Pvt. Ltd., India; Model No. EIE-101) and temperature of fabrics measured using a portable, hand-held infrared laser thermometer (in-direct contact) (commercially available from Fluke Technologies Pvt. Ltd., India; Model No.: Fluke 62 Max). Organic liquid was heated using heating mantle and glassware.

[0219] Table 1 : Wetting and absorption with chlorobenzene

[0220] +++: drop is wetting the fabric, being absorbed by the fabric very rapidly (< 5 seconds), ++: drop is wetting the fabric, being absorbed by the fabric rather slowly (> 5 seconds) +: drop is not wetting the surface of fabric and is maintaining its shape for longer period. Table 1 shows that the thermal pre-treatment significantly improves penetration of the organic liquid into the fabric for decolouration, even in presence of finishers or coatings. This penetration is of particular importance for de-dyeing.

[0221] Table 2: Wetting and absorption with TEGDME

[0222] Table 2 shows that dyed and coated fabrics subjected to thermal pre-treatment show an improved wetting and absorption of organic liquid. This holds in particular in case of higher GSM. a. Dyes: Black (commercially available from Colourtex Industries Pvt. Ltd., India; Grade: Coralene Black 2RC) and Orange (commercially available from Colourtex Industries Pvt. Ltd., India; Grade: Coralene Yellow Brown 2RFL) b. Commercially available from Nicca Chemical Company Limited, Japan; Grade: Neoseed

[0223] NR-8800 c. Commercially available from Colourtex Industries Pvt. Ltd., India; Grade: CBENE Navy

[0224] Blue 2GLS d. Commercially available from Colourtex Industries Pvt. Ltd., India; Grade: Coralene Black

[0225] 2RC e. Commercially available from Schill+Seilacher GmbH, Germany; Grade: Silastol AE 101 f. Commercially available from Dongsung Chemical Company Limited, Korea; Grade: D-

[0226] ACE 1340TF g. Commercially available from Croda India Company Pvt Ltd., India; Grade: Permalose®

[0227] Aqua h. Commercially available from Jintex Corporation Limited, Taiwan; Grade: JinsofECO

[0228] TWM-2

[0229] 2) Effect of thermal pre-treatment step on speed and extent of decolouration

[0230] Procedure: Green-dyed (dye commercially available from Colourtex Industries Pvt. Ltd., India; Grade: Coralene Green XF) and silicone coated PET fibre woven fabric pieces (2 cm * 2 cm) and organic liquid of chlorobenzene were brought in contact with each other (organic liquid was taken in a round bottom flask and fabric was immersed in the organic liquid and mixed gently for 2 minutes). After 2 minutes, the fabric was removed. The results are shown in Table 3, below. Fabrics were heated using an oven (commercially available from EIE Instruments Pvt. Ltd., India; Model No. EIE- 101) and temperature of fabrics measured using a portable, hand-held Infrared thermometer (in-direct contact) (commercially available from Fluke Technologies Pvt. Ltd., India; Model No.: Fluke 62 Max). Organic liquid was heated using heating mantle and glassware. The assessment was performed by employing 10 test persons for visual inspection. An average was built for each assessment. Table 3: Speed and extent of decolouration with chlorobenzene

[0231] +: slow speed; ++: moderate speed; +++: fast speed

[0232] Table 3 shows that dyed and silicone coated fabrics subjected to thermal pre-treatment show an improved de-dyeing by an organic liquid. This holds in particular if the fabric has been heated above Tg of PET in the thermal pre-treatment and contacted with chlorobenzene also above Tg of PET, like in No. 5 and No. 6 of Table 3. 3) Effect of thermal pre-treatment step on speed and extent of decolouration

[0233] Procedure: Green-dyed (dye commercially available from Colourtex Industries Pvt. Ltd., India; Grade: Coral ene Green XF) and silicone coated PET fibre woven fabric pieces (2 cm * 2 cm) and organic liquid of TEGDME were brought in contact with each other (organic liquid was taken in a round bottom flask and fabric was immersed in the organic liquid and mixed gently for 2 minutes). After 2 minutes, the fabric was removed. The results are shown in Table 4, below.

[0234] Fabrics were heated using an oven (commercially available from EIE Instruments Pvt. Ltd., India; Model No. EIE- 101) and temperature of fabrics measured using a portable, hand-held Infrared thermometer (in-direct contact) (commercially available from Fluke Technologies Pvt. Ltd., India; Model No.: Fluke 62 Max). Organic liquid was heated using heating mantle and glassware. The assessment was performed by employing 10 test persons for visual inspection. An average was built for each assessment.

[0235] Table 4: Speed and extent of decolouration with TEGDME

[0236] +: slow speed; ++: moderate speed; +++: fast speed

[0237] Table 4 shows that dyed and silicone coated fabrics subjected to thermal pre-treatment show an improved de-dyeing by an organic liquid.

Claims

CLAIMS1. A process for producing a polyester product, the process comprising at least the following process steps: a. Providing a first polyester fragment; b. Subjecting the first polyester fragment to a thermal treatment to obtain a second polyester fragment; c. Contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; d. Converting the further polyester fragment into a plurality of polyester solids; wherein the first polyester fragment comprises at least 50 wt.-% of a polyester polymer; wherein the first polyester fragment comprises a textile chemical different from the polyester polymer; wherein the further polyester fragment comprises less of the textile chemical than the first polyester fragment.

2. The process according to claim 1, wherein the first polyester fragment comprises the textile chemical in an amount in the range of 0.01 to 20 wt.-%, based on the total weight of the first polyester fragment.

3. The process according to claim 1 or 2, wherein the first polyester fragment meets at least one or all of the following criteria: a. An d50maximum length in the range of 300 to 600 mm; b. A GSM in the range of 30 to 400 g / m2; c. Comprises two or more fibres; d. An intrinsic viscosity (IV) in the range of 0.4 to 1.4; e. Bulk density in the range of 0.01 to 0.75 g / cm3.

4. The process according to any of the preceding claims, wherein the textile chemical is selected from the group consisting of a dye, a finisher, a softener, or a combination of at least two thereof.

5. The process according to any of the preceding claims, wherein the polyester polymer comprises an amorphous domain; wherein the polyester polymer attains a temperature as high as or exceeding its glass transition temperature Tg.

6. The process according to claim 5, wherein the polyester polymer attains a temperature exceeding its glass transition temperature Zgby not more than 90 K.

7. The process according to any of the preceding claims, wherein the polyester polymer comprises a crystalline domain; wherein the polyester polymer attains a temperature not as high as its crystallization temperature Tc.

8. The process according to any of the preceding claims, wherein the polyester polymer has not exceeded its melting temperature Tm.

9. The process according to any of the preceding claims, wherein the heat treatment is performed in a heat treatment zone, and wherein the Contacting with the organic liquid is performed in a contacting zone downstream to the heating zone.

10. The process according to any of the preceding claims, wherein the heat treatment meets at least one or all of the following criteria:(A) Involves a gas flow;(B) Involves relative moving the first polyester fragments to each other;(C) Requires a residence time of the first polyester fragment in the range of 1 to 6000 s;(D)Requires a temperature in the range of 80 to 260 °C.

11. The process according to any of the preceding claims, wherein the concentration of the textile chemical is increased in the organic liquid by the contacting.

12. The process according to any of the preceding claims, wherein the plurality of polyester solids is selected from the group consisting of chips, beads, flakes, pellets, fibres or a combination of at least two thereof.

13. The process according to any of the preceding claims, wherein the process comprises as additional process steps: e. Subjecting the polyester solids to a de-esterification reaction to obtain a deesterification product; f. Optionally, subjecting the de-esterification product to a purification to obtain a purified de-esterification product; g. Subjecting the de-esterification product, or the purified de-esterification product, to an esterification reaction or other chemical modification or keeping the de- esterification product.

14. The process according to any of the preceding claims, wherein the polyester product is selected from the group consisting of a flake, a pellet, a chip, a container, a yam, a fibre, a textile, a film or at least two thereof.

15. The process according to the preceding claim, wherein the dye is selected from the group consisting of an azo dye, an anthraquinone dye, a phthalocyanine dye, a reactive dye, a disperse dye, a direct dye, a vat dye, a sulphur dye, a cationic / basic dye, an acid dye, a solvent dye and a mordant dye.

16. A device for treating a polyester fragment, comprising a moving means adapted and arranged i. to move two or more limp textile fragments, ii. to pass a gas and a liquid through the two or more limp textile fragments; wherein the moving means connects at least the following zones: iii. A feeder zone, adapted and arranged to receive the two or more polyester fragments,iv. A heat treatment zone, adapted and arranged to heat the two or more limp textile fragments, v. A contacting zone, adapted and arranged to contact the two or more limp textile fragments with an organic liquid, vi. Optionally a drying zone, adapted and arranged to remove at least a part of the organic liquid from the two or more polyester fragments, and vii. A converting zone, adapted and arranged to shear the two or more limp textile fragments.

17. A polyester product, obtainable by a process according to any of the claims 1 to 16.

18. A use of a plurality of polyester solids obtainable by a process comprising the following process steps: a. Providing a first polyester fragment; b. Subjecting the first polyester fragment to a heat treatment to obtain a second polyester fragment; c. Contacting the second polyester fragment with an organic liquid to obtain a further polyester fragment; d. Converting the further polyester fragment into the plurality of polyester solids; for a purpose selected from the group consisting of a chemical modification, preferably, a functionalization, de-esterification, an esterification, formed body, preferably a fibre, a textile, a container, a film, or a combination of at two or more thereof.

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