JP2026519829A - Process for depolymerizing polyamides by hydrolysis - Google Patents

Abstract

A process for depolymerizing polyamide 6 contained in a solid material M by hydrolysis, the process comprising: supplying the solid material M; melting the solid material M in a melting unit U _M to obtain a liquid stream S _M having a pressure p _SM and a temperature T _SM ; supplying a liquid aqueous stream SW having a pressure p _SW and a temperature T _SW ; mixing stream S _M with stream _SW in a pre-reaction unit U _PR to obtain a liquid reaction supply stream S _F having _a pressure p _SF and a temperature T _SF ; supplying stream S _F to a chemical reaction unit U _R ; subjecting stream S _F in the reaction unit U _R to polyamide 6 depolymerization conditions including a depolymerization pressure p _D for polyamide 6 and a depolymerization temperature T _D for polyamide 6 to obtain an aqueous depolymerization mixture containing ε-caprolactam dissolved in water in U _R ; and removing the aqueous liquid reactor outlet stream S _R from U _R , wherein stream S A process comprising the steps of _R comprising ε-caprolactam dissolved in water, wherein 0.8 ≤ T _SF / T _D ≤ 1.05 and 0.9 ≤ p _SF / p _D ≤ 1.05.

Description

The present invention relates to a process for hydrolytically (i.e., by hydrolysis) depolymerizing a polyamide prepared from ε-caprolactam, and to an apparatus for carrying out the process for hydrolytically depolymerizing a polyamide prepared from ε-caprolactam, preferably an apparatus for carrying out the aforementioned process.

Polyamide, specifically polyamide 6 characterized by the formula (-NH-( _CH₂ ) _₅ -CO-) _n , can be found in many materials, such as packaging, automotive engineering plastics, and fiber filaments. The latter accounts for approximately 40% of the global market for polyamide 6. Currently, only a small portion of fiber filaments is recycled, yet it accounts for a significant portion of global _CO₂ emissions. Therefore, it is necessary to recycle polyamide 6 from such materials.

Processes exist for the alkali depolymerization of polyamides. Therefore, it is necessary to improve these processes to resolve the problems associated with them.

According to the present invention, it has been found that an efficient depolymerization reaction for hydrolyzing polyamide 6 can be achieved by realizing a specific arrangement of melting units and pre-reaction (preliminary reaction) units upstream of the chemical reaction unit where the depolymerization reaction actually occurs. Furthermore, it has been found that the process can be made even more efficient once a specific design of the chemical reaction unit is realized. Based on this, the present invention can provide a favorable overall process for recycling polyamide 6-containing materials, combined with the sequence of specific steps upstream and particularly downstream of the aforementioned chemical reaction unit, which enables water reuse (recycling) and highly effective use of heat within the process.

Therefore, the present invention is a process for depolymerizing polyamide 6 contained in a solid material M by hydrolysis,
(i) A step of supplying a solid material M,
(ii) The steps of melting the solid material M supplied according to (i) in a melting unit U _M to obtain a liquid stream S _M having a temperature T _SM at a pressure p _SM ,
(iii) A step of supplying a liquid aqueous stream _SW having a temperature T _SW at a pressure p _SW ,
The steps include: mixing the stream S _M obtained according to (iv)(ii) with the stream _SW supplied according to (iii) in a preliminary reaction unit U _PR to obtain a liquid reaction feed stream S _F having a temperature T _SF at a pressure p _SF ;
(v) The step of supplying the stream S _F obtained according to (iv) into the chemical reaction unit U _R ,
(vi) The step of subjecting the stream S _F in the chemical reaction unit U _R to polyamide 6 depolymerization conditions including a depolymerization pressure p _D for polyamide 6 and a depolymerization temperature T _D for polyamide 6 to obtain an aqueous depolymerization mixture containing ε-caprolactam dissolved in water in U _R ,
(vii) A process comprising the step of taking an aqueous liquid reactor outlet stream S _R from U _R , wherein the stream S _R comprises ε-caprolactam dissolved in water, where 0.8 ≤ T _SF / T _D ≤ 1.05 and 0.9 ≤ p _SF / p _D ≤ 1.05.

Preferably, according to the present invention, no depolymerization catalyst for polyamide 6, such as one or more mineral acids, such as hydrochloric acid, nitric acid, sulfuric acid, and phosphoric acid, and/or zinc salts, such as zinc chloride, zinc acetate, or zinc triflate, are added to prepare a stream S _F subjected to depolymerization conditions for hydrolyzed polyamide 6 according to (vi).

Preferably, 0.6 ≤ T _SM / T _SF ≤ 1.05 and 0.9 ≤ p _SM / p _SF ≤ 1.05. According to the present invention, one or more of the following ranges may be preferred: 0.6 ≤ T _SM / T _SF ≤ 0.7; 0.7 ≤ T _SM / T _SF ≤ 0.8; 0.8 ≤ T _SM / T _SF ≤ 0.9; 0.9 ≤ T _SM / T _SF ≤ 1.0; 1.0 ≤ T _SM / T _SF ≤ 1.05.

More preferably, 0.8 ≤ T _SW / T _SF ≤ 1.3 and 0.9 ≤ p _SW / p _SF ≤ 1.05. Furthermore, according to the present invention, one or more of the following ranges may be preferred: 0.8 ≤ T _SW / T _SF ≤ 0.9; 0.9 ≤ T _SW / T _SF ≤ 1.0; 1.0 ≤ T _SW / T _SF ≤ 1.1; 1.1 ≤ T _SW / T _SF ≤ 1.2; 1.2 ≤ T _SW / T _SF ≤ 1.3.

With respect to the pre-reaction unit _UPR according to (iv), there are no particular limitations as long as a liquid reaction feed stream _SF having a temperature _TSF at a pressure _pSF can be obtained. Preferably, the pre-reaction unit _UPR according to (iv) comprises a mixing unit, more preferably consisting of only such a unit, and more preferably the mixing unit is a static mixing unit. As used herein, the term “static mixing unit” refers to an arrangement of mixing elements installed in a pipe or duct and operating essentially without moving parts, preferably entirely without moving parts. According to the present invention, it may be preferable to configure it as a suitable pipe joint between a pipe for stream _SM and a pipe for stream _SW , and no specific mixing element exists.

According to the present invention, _SW and _SM are preferably mixed in UPR in a mixing ratio (mW/kg)/( _mP /kg) in the range of 1:1 to 20:1, more preferably in the range of 2:1 to 15:1, and more preferably in the range of 5:1 to ₁₀ :1, where _mW is the amount of water contained in _SW and _mP is the amount of polyamide 6 contained in _SM . Preferred ranges are, for example, 5:1 to 6:1, or 6:1 to 7:1, or 7:1 to 8:1, ₈ :1 to 9:1, or 9:1 to 10:1.

With respect to the melting unit _UM according to (ii), there are no particular limitations as long as a liquid stream _SM having a temperature T _SM at a pressure p _SM can be obtained. Preferably, the melting unit _UM according to (ii) comprises a kneader or an extruder, more preferably an extruder, more preferably the melting unit _UM according to (ii) consists only of an extruder, more preferably the extruder is a single-screw extruder or a twin-screw extruder, more preferably a twin-screw extruder. More preferably, the solid material M supplied according to (i) and having a temperature lower than T _SM is supplied into the extruder and melted therein as it is conveyed through the extruder. Preferably, the temperature of the solid material supplied into the extruder is in the range of 10 to 50°C, more preferably 15 to 40°C, more preferably 20 to 30°C. Even more preferably, the solid material is supplied into the extruder at a pressure in the range of 0.75 to 5 bar, more preferably 0.85 to 3 bar, more preferably 0.95 to 1.5 bar. To melt the material M, the extruder is preferably equipped with appropriate heating means for heating each portion of the material M, and when exiting the extruder, the liquid stream S _M has a temperature T _{S M.} The appropriate heating means can be arranged such that the extruder has one heating zone or two or more heating zones. To supply the solid material M, the extruder may have two or more feeding zones. Furthermore, according to the present invention, the extruder can operate with either a starved feed or a flood feed.

Preferably, the melting unit _UM , preferably the extruder, is equipped with a degassing system that helps remove one or more gases during the melting process in the extruder. The extruder may generally have two or more degassing zones, but it is preferable to have one degassing zone. Preferably, the degassing zone is located immediately before the pressure rise in the extruder discharge zone. If the melting unit _UM , preferably the extruder, is equipped with a degassing system, the process preferably includes a step of removing a gas stream _SGM from _UM during melting according to (ii). Preferably, the gas stream _SGM has a temperature _TGM at a pressure _pGM , with 0.95 ≤ _TGM / _TSM ≤ 1.05, preferably 0.95 ≤ _TGM / _TSM ≤ 1.0. Preferably, according to the present invention, the stream _SGM obtained from the melting unit _UM is subjected to one or more scrubbing processes, preferably wet scrubbing and dry scrubbing, more preferably wet scrubbing, in a scrubbing unit _US , the wet scrubbing preferably includes the step of passing the gas stream _SGM through a scrubbing column, preferably a packed scrubbing column. Before being subjected to scrubbing, the stream _SGM obtained from the melting unit _UM is preferably subjected to cooling, preferably in a vacuum system from which the stream _SGM is preferably removed from the melting unit _UM .

According to the present invention, the stream _SM has a pressure _pSM , where the pressure _pSM is preferably in the range of 0.9 ≤ _pSM / _pSF ≤ 1.05, and _pSF is in the range of 0.9 ≤ _pSF / _pD ≤ 1.05. As will be described later, the depolymerization pressure _pD of the polyamide 6 is preferably in the range of 40 to 140 bar. Therefore, according to the present invention, it is preferable that the pressure _pSM is higher, more preferably significantly higher, than the pressure at which the solid material M is supplied to the melting unit _UM , preferably the pressure at which it is supplied to the extruder. According to the present invention, it is conceivable that this pressure increase is achieved by the extruder itself. However, it is particularly preferable that the pressure increase is achieved by a suitable compression device included in the melting unit _UM , for example, a compression device located downstream of the extruder. In this preferred configuration, the liquid stream exiting the extruder is at essentially the same pressure as the solid material supplied to the extruder, and the liquid stream is then preferably appropriately compressed within the compressor to produce a stream S _M having a pressure p _SM and a temperature T _SM . Preferably, according to the present invention, the compressor comprises at least one suitable gear pump, more preferably consisting of only such pumps, and preferably two or more gear pumps are installed, with at least two gear pumps arranged in series.

Furthermore, according to the present invention, it may be preferable to pass the liquid stream _SM coming out of the melting unit _UM through the filter unit _UF before it is mixed with the liquid aqueous stream _SW according to (iv). Preferably, a filter unit _UF is located downstream of the melting unit _UM and upstream of the reaction unit _UR to separate particles having a particle size in the range of 100 to 500 micrometers, preferably in the range of 200 to 400 micrometers, from the liquid stream _SM , and the process includes passing the liquid stream _SM through _UF before mixing according to (iv). More further, if the melting _{unit UM} is equipped with a compression device as described above, it may be preferable that the liquid stream, preferably a liquid stream obtained from an extruder, passes through the filter device _UF before the stream passes through the compression device.

Furthermore, according to the present invention, the melting unit _UM can be equipped with two or more melting devices, preferably two or more extruders, for example, two or more extruders can be arranged in parallel.

Regarding the depolymerization conditions for polyamide 6 according to (vi), it is preferable that _TD is in the range of 230 to 330°C and _pD is in the range of 40 to 140 bar, more preferably _TD is in the range of 250 to 320°C and _pD is in the range of 40 to 125 bar, and more preferably _TD is in the range of 270 to 310°C and _pD is in the range of 40 to 110 bar.

Therefore, preferred ranges for _TD are, for example, 270 to 280°C, or 280 to 290°C, or 290 to 300°C, or 300 to 310°C, and preferred ranges for _pD are, for example, 40 to 55 bar, or 55 to 70 bar, or 70 to 85 bar, or 85 to 100 bar, or 100 to 110 bar.

According to the present invention, a reaction unit U _R according to (v) comprises at least one reactor in which a liquid stream S _F is subjected to depolymerization conditions according to (vi). Preferably, a reaction unit U _R according to (v) comprises z chemical reactors R _i , where i = 1...z, where z is in the range of 1 to 10, preferably in the range of 1 to 8, more preferably in the range of 1 to 6, more preferably in the range of 1 to 5, more preferably in the range of 1 to 4, and more preferably in the range of 1 to 3. More preferably, a reaction unit U _R according to (v) comprises three reactors _R1 , _R2 , and _R3 .

When the reaction unit U _R according to (v) comprises two or more reactors _Ri , i.e., when z > 1, it is preferable that at least two reactors _Ri , preferably all z reactors _Ri are connected in series, where,
- According to (v), stream S _F is supplied to _Ri , where i = 1,
- An aqueous liquid stream S _i containing ε-caprolactam dissolved in water is taken out of reactor R _i and supplied to reactor R _i+1 , where i < z,
- According to (vii), the aqueous liquid stream S _z containing ε-caprolactam dissolved in water is taken out of reactor R _z as stream S _R ,
Here, in all reactors R _i , the depolymerization temperature T _Di is maintained at a depolymerization pressure p _Di , and independently of each other, T _Di is in the range of 230 to 330°C and p _Di is in the range of 40 to 140 bar, preferably T _Di is in the range of 250 to 320°C and p _Di is in the range of 40 to 125 bar, more preferably T _Di is in the range of 270 to 310°C and p _Di is in the range of 40 to 110 bar. Regarding the preferred arrangement of the three reactors R ₁ , R ₂ , and R ₃ , these three reactors are preferably connected in series, where,
- According to (v), stream S _F is supplied to R ₁ ,
- The aqueous liquid stream _S1 containing ε-caprolactam dissolved in water is removed from reactor _R1 and supplied to reactor _R2 .
- The aqueous liquid stream _S2 containing ε-caprolactam dissolved in water is removed from reactor _R2 and supplied to reactor _R3 .
- According to (vii), the aqueous liquid stream _S3 containing ε-caprolactam dissolved in water is removed from reactor _R3 as stream _SR ,
Here, in reactor _R1 , the depolymerization temperature _TD1 is maintained at a depolymerization pressure _pD1 , where _TD1 is in the range of 230 to 330°C and _pD1 is in the range of 40 to 140 bar, preferably TD1 is in the range of 250 to 320°C and _pD1 is in the range of 40 to 125 bar, more preferably _TD1 is in the range of 270 to _{310°C and pD1 is in the range of 40 to 110 bar, preferred ranges of TD1 are ,} for example, 270 to 280°C, or 280 to 290°C, or 290 to 300°C, or 300 to 310°C, and preferred ranges of _pD1 are, for example, 40 to 55 bar, or 55 to 70 bar, or 70 to 85 bar, or 85 to 100 bar, or 100 to 110 bar.
In reactor _R2 , the depolymerization temperature _TD2 is maintained at a depolymerization pressure _pD2 , where _TD2 is in the range of 230 to 330°C and _pD2 is in the range of 40 to 140 bar, preferably _TD2 is in the range of 250 to 320°C and _pD2 is in the range of 40 to 125 bar, more preferably TD2 is in the range of 270 to 310°C and _pD2 is in the range of 40 to 110 bar, preferred ranges of _{TD2 are} , for example, 270 to 280°C, or 280 to 290°C, or 290 to 300°C, or 300 to 310°C, and preferred ranges of _pD2 are, for example, 40 to 55 bar, or 55 to 70 bar, or 70 to 85 bar, or 85 to 100 bar, or 100 to 110 bar.
In reactor _R3 , the depolymerization temperature T _D3 is maintained at a depolymerization pressure p _D3 , where T _D3 is in the range of 230 to 330°C and p _D3 is in the range of 40 to 140 bar, preferably T _D3 is in the range of 250 to 320°C and p _D3 is in the range of 40 to 125 bar, more preferably T _D3 is in the range of 270 to 310°C and p _D3 is in the range of 40 to 110 bar, preferred ranges of T _D3 are, for example, 270 to 280°C, or 280 to 290°C, or 290 to 300°C, or 300 to 310°C, and preferred ranges of p _D3 are, for example, 40 to 55 bar, or 55 to 70 bar, or 70 to 85 bar, or 85 to 100 bar, or 100 to 110 bar.

In accordance with the present invention, when z > 1, z reactors R _i are arranged vertically, with R ₁ being the uppermost reactor and R _z being the lowermost reactor, and it is preferable that _Si obtained from R _i moves to R _{i + 1} by gravity, preferably by gravity alone. Regarding the preferred arrangement of three reactors R ₁ , R ₂ , and R ₃ , it is preferable that reactors R ₁ , R ₂ , and R ₃ are arranged vertically, with R ₁ being the uppermost reactor and R ₃ being the lowermost reactor, and it is preferable that S ₁ obtained from R ₁ moves to R ₂ by gravity, preferably by gravity alone, and S ₂ obtained from R ₂ moves to R ₃ by gravity, preferably by gravity alone.

Regarding the specific design of one or more reactors R _i , it is preferable that at least one reactor R _i is a stirred tank reactor, and more preferably that all z reactors are stirred tank reactors. Regarding the preferred arrangement of the three reactors _R1 , _R2 , and _R3 , it is preferable that reactors _R1 , _R2 , and _R3 are stirred tank reactors.

While there are no general limitations on the specific design of the stirred tank reactor, according to the present invention, at least one stirred tank reactor _Ri , preferably all stirred tank reactors _Ri , have two to six compartments, more preferably two to five compartments, more preferably two to four compartments, which are independent of each other, preferably arranged in series, more preferably in series and vertically, and it is particularly preferable that two adjacent compartments are separated by a partition including at least one flow opening. Preferably, at least one compartment in reactor _Ri is equipped with at least one stirrer, more preferably all compartments in all reactors _Ri are equipped with at least one stirrer, and more preferably all compartments in all reactors _Ri are equipped with one stirrer, and the process includes the step of stirring the depolymerization mixture in a given compartment for at least a portion of the time while it is subjected to depolymerization conditions in the compartment. Regarding the preferred arrangement of the three reactors _R1 , _R2 , and _R3 , it is more preferable that the stirred tank reactor _R1 has three vertically and in series-arranged compartments, all of which are equipped with a stirrer; the stirred tank reactor _R2 has three vertically and in series-arranged compartments, all of which are equipped with a stirrer; and the stirred tank reactor _R3 has three vertically and in series-arranged compartments, all of which are equipped with a stirrer. Refer in particular to Figure 5 of the present invention and its respective descriptions.

Alternatively, with respect to the specific design of the stirred tank reactor, according to the present invention, at least one stirred tank reactor _Ri , preferably all stirred tank reactors _Ri , independently of each other, preferably has 2 to 6 compartments, more preferably 2 to 5 compartments, more preferably 2 to 4 compartments, the compartments preferably arranged in series, more preferably in series and vertically, the reactor _Ri comprises at least one stirrer, two adjacent compartments are formed and separated by one or more suitable components of the stirrer, for example, blades included in the stirrer, and the process particularly preferably includes the step of stirring a depolymerization mixture in a given compartment for at least a portion of the time it is subjected to depolymerization conditions in the reactor compartment. In this regard, it is more preferable that the three reactors _R1 , _R2 , and _R3 are arranged in a series and vertically separated manner, with the stirred tank reactor _R1 having two vertical and series-arranged compartments formed by and separated by the appropriate components of the stirrer contained in _{R1 ;} the stirred tank reactor _R2 having two vertical and series-arranged compartments formed by and separated by the appropriate components of the stirrer contained in R2; and the stirred tank reactor _R3 having two vertical and series-arranged compartments formed by and separated by the appropriate components of the stirrer contained in _R3 .

Preferably, according to the present invention, the depolymerization conditions for polyamide 6 according to (vi) further comprise a total residence time _tD of the aqueous depolymerization mixture in unit U _R , preferably z reactors _Ri , more preferably z stirred tank reactors, wherein at least 85% by weight, preferably at least 90% by weight, and more preferably at least 95% by weight of the aqueous depolymerization mixture has a _tD in the range of 30 to 90 minutes. The term “total residence time” as used in this context of the present invention refers to the sum of the residence times of all the above chemical reactors _Ri . In particular, when z > 1, the residence time of the aqueous depolymerization mixture in reactor _Ri is _tDi , and it is preferable that 0.90 ≤ ( _tDi / _{tDi + 1} ) ≤ 1.10, preferably 0.95 ≤ ( _tDi / _{tDi + 1} ) ≤ 1.05. Thus, according to the present invention, it is preferable that a narrow residence time distribution is achieved. With respect to a preferred arrangement of three reactors _R1 , _R2 , and _R3 , the residence time of the aqueous depolymerization mixture in reactor _R1 is _tD1 , the residence time of the aqueous depolymerization mixture in reactor _R2 is _tD2 , and the residence time of the aqueous depolymerization mixture in reactor _R3 is _tD3 , and it is more preferable that 0.90 ≤ ( _tD1 / _tD2 ) ≤ 1.10, preferably 0.95 ≤ ( _tD1 / _tD2 ) ≤ 1.05, and 0.90 ≤ ( _tD2 / _tD3 ) ≤ 1.10, preferably 0.95 ≤ ( _tD2 / _tD3 ) ≤ 1.05.

Preferably, according to the present invention, at least one, preferably all, reactors _Ri have one or more outlet means for withdrawing a gas stream from each reactor _Ri , _i.e. , outlet means for degassing each reactor _Ri . Thus, the process of the present invention preferably includes the step of withdrawing a given gas stream S _Gi , having a temperature T _{Gi at a pressure p Gi ,} from at least one, preferably all z reactors _{Ri ,} respectively, where 0.95 ≤ _{T Gi /} T _Di ≤ 1.05. With respect to a preferred arrangement of three reactors _R1 , _R2 , and _R3 , the process more preferably includes the steps of: taking gas stream S _G1 from _R1 , where S _G1 has a temperature T _G1 at a pressure p _G1 , where 0.95 ≤ T _G1 / T _D1 ≤ 1.05; taking gas stream S _G2 from _R2 , where S _G2 has a temperature T _G2 at a pressure p _G2 , where 0.95 ≤ T _G2 / T _D2 ≤ 1.05; and taking gas stream S _G3 from _R3 , where S _G3 has a temperature T _G3 at a pressure p _G3 , where 0.95 ≤ T _G3 / T _D3 ≤ 1.05. According to the present invention, the process may preferably further include the step of combining at least one, more preferably all, of the gas streams S _Gi , more preferably gas streams S _G1 , S _G2 , and S _G3 with the gas stream S _GM as described above _, before subjecting the gas stream S _GM to scrubbing as described above.

In general, there are no specific restrictions on how the solid material M is supplied according to (i). Preferably, the solid material M is supplied according to (i).
(i.1) A step of supplying a solid material M into a delivery unit U _MD , wherein the U _MD preferably comprises one or more of at least one big bag station and at least one bulk container station,
(i.2) A step of passing a solid material M supplied in accordance with (i.1) from unit U _MD to material collection unit U _MC , preferably to a collection drum, wherein the first connection line preferably comprises one or more of at least one material receiving/discharging unit U _MRD , at least one first material supply unit U _FMF , and at least one first particle separation unit U _FMPS ,
(i.3) A step of passing a solid material M from unit U _MC through a second connection line to unit U _M , wherein the second connection line preferably comprises one or more of at least one second material supply unit U _SMF , at least one second particle separation unit U _SMPS , and at least one metal detector,
Includes.

Preferably, the first connection line according to (i.2) comprises at least one unit U _MRD , preferably at least one hopper, more preferably at least one one-zone hopper, further comprising at least one unit U _FMF , preferably at least one rotary feeder, and preferably at least one particle separation unit U _FMPS , more preferably at least one filter, more preferably at least one mesh filter.

More preferably, in order to pass the solid material M from unit U _MD to unit U _MC via a first connection line, at least one gas stream S _G passes through the first connection line, and the at least one gas stream preferably contains, and more preferably contains only, air or dilute air, where, prior to passing through the first connection line, the at least one gas stream is pretreated preferably by at least one of filtration, compression, and cooling, more preferably by filtration, compression, and cooling.

More preferably, the second connection line according to (i.3) preferably comprises a rotary feeder and a weight loss feeder, more preferably the rotary feeder comprises at least two units U _SMF located upstream of the weight loss feeder, and further comprises a unit U _SMPS , preferably a vibrating screen.

Preferably, according to (i), the solid material M is supplied in the form of particles, preferably supplied to U _M , where the particle size distribution of the particles is preferably characterized by one or more pairs of the following values, preferably two or more pairs of the following values, more preferably three pairs of the following values:
- D10 values for particle widths in the range of 0.3 to 15 mm, and D10 values for particle lengths in the range of 0.3 to 15 mm.
- D50 values for particle widths in the range of 0.5 to 20 mm, and D50 values for particle lengths in the range of 0.5 to 20 mm.
- D90 values for particle widths ranging from 0.8 to 30 mm and D90 values for particle lengths ranging from 0.8 to 30 mm.

A more preferable pair of values would be, for example,
- D10 values for particle widths in the range of 2 to 4 mm, and D10 values for particle lengths in the range of 3.5 to 5.5 mm.
- D50 values for particle widths in the range of 2.5 to 4.5 mm and D50 values for particle lengths in the range of 4 to 7 mm.
- D90 values for particle widths in the range of 3 to 5 mm, and D90 values for particle lengths in the range of 4.5 to 8.5 mm.

As used in this context of the present invention, the term "particle" may optionally include pre-formed granules and also include fine fragments.

Preferably 10 to 100% by weight, more preferably 30 to 100% by weight, more preferably 50 to 100% by weight, more preferably 60 to 100% by weight, more preferably 70 to 100% by weight, and more preferably 80 to 100% by weight of the solid material M supplied according to (i) consists solely of polyamide 6. If the polyamide 6 content of the solid material M is less than 100% by weight, the solid material M may preferably further contain one or more elastanes. Generally, the solid material M may contain, in addition to the polyamide 6, at least one further polymer compound, which preferably includes at least one polyamide 6.6; at least one semi-aromatic polyamide containing one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer from two or more of the polymer compounds, including statistical copolymers, gradient copolymers, alternating copolymers, block copolymers, and graft copolymers; and at least one rubber material containing one or more of the at least one natural rubber material and at least one synthetic rubber material. Furthermore, in addition to the polyamide 6, the solid material M may further contain at least one pigment material and at least one glass fiber material.

Preferably, the solid material M supplied according to (i) comprises one or more of waste, more preferably textile waste and engineering plastic waste, more preferably textile waste, and more preferably only textile waste. Generally, the solid material M supplied according to (i) may consist of a single material or several different materials, i.e., w chemical materials _Mj , where j = 1, w and w ≥ 1. Furthermore, according to the present invention, preferably at least one, more preferably all, chemical materials _Mj comprise waste, preferably only textile waste, and the waste comprises preferably at least one textile waste, and more preferably only _textile waste. If w > 1, each of the two or more materials may have different chemical compositions, provided that the solid material M has the above-described composition, without any particular limitations.

According to the present invention, it is preferable _that 90 to 100% by weight, more preferably 91 to 100% by weight, more preferably 92 to 100% by weight, more preferably 93 to 100% by weight, more preferably 94 to 100% by weight, and more preferably 95 to 100% by weight of the liquid aqueous stream SW supplied according to (iii) consists solely of water. A more preferred range may be 96 to 100% by weight, or 97 to 100% by weight, or 99 to 100% by weight, or 99 to 100% by weight.

Preferably, according to the present invention, supplying a liquid aqueous stream _SW in accordance with (iii) includes the steps of generating an aqueous stream containing at least a portion of the water contained in stream S _R , and supplying back at least a portion of the generated aqueous stream to a chemical reaction unit U _R as or as part thereof the aqueous stream _SW .

With regard to the reuse of the water mentioned above, for example, the process includes the steps of: taking the stream S _R obtained from the chemical reaction unit U _R , optionally subjecting S _R to filtration, and then subjecting it to hot water separation to obtain an aqueous stream _SX ; and supplying at least a portion of the aqueous stream _SX back to the chemical reaction unit U _R as part of the aqueous stream _SW , wherein the hot water separation may preferably include one or more of distillation and drip membrane evaporation. Preferably, generating the aqueous stream _SX may include the step of taking the stream S _R obtained from the reaction unit U _R , optionally subjecting S _R to filtration, and then distilling it to obtain stream _SX . The distillation may preferably be carried out in a distillation column at a bottom temperature preferably in the range of 70 to 140°C, more preferably in the range of 80 to 120°C, more preferably in the range of 90 to 110°C, and a top pressure preferably in the range of 0.5 to 1.5 bar, more preferably in the range of 0.7 to 1.2 bar, more preferably in the range of 0.8 to 1.1 bar, and the stream _SX is obtained at the top of the distillation column. Furthermore, the distillation may preferably include a step of subjecting the vapor top stream to condensation to obtain a liquid stream _SX , at least a portion of which is supplied back to the chemical reaction unit _UR as part of _an aqueous stream _SW . The liquid stream _SX obtained by condensation may preferably be divided into two streams, the first stream obtained from the division being supplied back to the chemical reaction unit _UR as part of the aqueous stream _SW , and the second stream being supplied back to the top of the distillation column, the volume ratio of the first stream to the second stream being preferably in the range of 10:1 to 0.5:1, more preferably in the range of 7:1 to 1:1, and more preferably in the range of 5:1 to 2:1.

With regard to the reuse of the aforementioned water, according to the process of the present invention, in accordance with (vii), stream S _SR contains ε-caprolactam dissolved in water at concentration c _SR , stream S _SR further contains one or more impurities, and the process is as follows:
(viiii) The steps of passing a liquid aqueous stream S _R through an evaporation unit U _E to obtain a liquid aqueous stream S _L containing ε-caprolactam dissolved in water at a concentration c SL _L such that c _{SL L >} c _SR from S R, and further obtaining one or more aqueous vapor streams S _V from S _R ,
(ix) A step of passing an aqueous stream _SL through a heat-consuming purification unit _UP to obtain a stream _SCPL containing ε-caprolactam at a concentration _cSCPL such that _cSCPL >> _cSL from _SL , and further obtaining one or more aqueous streams _SRW from _SL , wherein at least a portion of the heat consumed in _UP is supplied by at least one of the one or more streams _SV , thereby obtaining at least one at least partially condensed aqueous stream _SVW from at least one stream _SV ,
(x) A step of recycling at least partially at least one stream S _VW to the reaction unit U _R , and recycling at least partially at least one stream S _RW to the reaction unit U _R ,
It is preferable to further include the following.

Recycling by (x) is preferably,
(x.1) The steps of supplying at least one stream S _VW and at least one stream S _RW to a water treatment unit U _W and obtaining at least one aqueous recycling stream S _W from U _W ,
(x.2) The step of recycling at least one aqueous stream _SW to a reaction unit _UR at least partially.

The water treatment unit _UW preferably comprises a water recovery unit _UWR and a wastewater unit _UWW , and (x.1) preferably consists of the following steps:
(x.1.1) The steps of supplying at least one stream S _VW and at least one stream S _RW to a water recovery unit U _WR and obtaining at least one aqueous recycling stream _SW and at least one aqueous stream S _SW from U _WR ,
(x.1.2) The further step includes supplying at least one stream S _SW to a wastewater unit U _WW and obtaining at least one wastewater stream S _WW from U _WW .

The purification unit _UP preferably comprises one or more of the heat-consuming water separation unit _UWS , the heat-consuming distillation unit _UD , and the heat-consuming crystallization unit _UC , more preferably two or more of the heat-consuming water separation unit _UWS , _{the heat-consuming distillation unit UD, and the heat-consuming crystallization unit UC, and at least a portion of the heat consumed by one or more of UWS, UD , and UC is provided by at} least one of one or more streams _SV .

For such a purification unit _UP , the process preferably includes one or more of (a-1), (a-2), and (a-3), more preferably at least two or more of (a-1), (a-2), and (a-3), more preferably (a-1), (a-2), and (a-3):
(a-1) A step of obtaining at least one at least partially condensed aqueous stream S _VW1 from U _WS ,
(a-2) A step of obtaining at least one at least partially condensed aqueous stream S _VW2 from _UD ,
(a-3) A step of obtaining at least one at least partially condensed aqueous stream S _VW3 from U _C.
Here, the process further includes the step of supplying one or more _SVW1 , _SVW2 , and _SVW3 , preferably two or more _SVW1 , _SVW2 , and _SVW3 , more preferably _SVW1 , _SVW2 , and _SVW3 , to a water treatment unit _UW , as defined in Embodiment 29.

Preferably, at least one of the stream S _RW is obtained from the U _WS .

Preferably, the purification unit _UP comprises a heat-consuming water separation (heat-consuming water separation) unit _UWS , a heat-consuming distillation (heat-consuming distillation) unit _UD , and a heat-consuming crystallization (heat-consuming crystallization) unit _UC , and the process includes the steps of supplying a stream _SL containing ε-caprolactam at a concentration of _cSL to _UWS , obtaining a stream _UWS containing ε-caprolactam at a concentration of _cUWS from _UWS , supplying stream _SUWS to the distillation _{unit UD} , obtaining a stream _SUD containing ε-caprolactam at a concentration of _cUD from UD, supplying stream _SUD to the crystallization unit _UC , and obtaining a stream _SCPL containing ε-caprolactam at a concentration of _cSCPL from _UC , where _cSL < _cUWS < _cUD < _cSCPL .

Preferably, the water separation unit _UWS comprises at least two heat-consuming water separation subunits _UWS1 and _UWS2 , more preferably two heat-consuming water separation subunits _UWS1 and _UWS2 coupled in series, where stream _SL is preferably supplied to _UWS1 , and at least a portion of the heat consumed in one or more of _UWS1 and _UWS2 is preferably supplied by at least one of one or more streams _SV .

In the case of such a water separation unit U _WS , the process preferably includes one of (b-1) and (b-2), preferably (b-1) and (b-2):
(b-1) A step of obtaining at least one at least partially condensed aqueous stream S _VW11 from U _WS1 ,
(b-2) A step of obtaining at least one partially condensed aqueous stream S _VW12 from U _WS2 .

Furthermore, in the case of such a water separation unit U _WS , it is preferable that at least one aqueous stream S _RW1 is obtained from U _WS1 , and at least one aqueous stream S _RW2 is obtained from U _WS2 , and at least one of S _RW1 and S _RW2 , preferably S _RW1 and S _RW2 , is supplied to U _W.

Furthermore, for such a water separation unit _UWS , it is preferable that a separation unit _UI is located downstream of _UWS1 and upstream of _UWS2 , and the process preferably includes the steps of obtaining an aqueous stream S _UWS1 from _UWS1 , supplying the stream S _UWS1 to the separation unit _UI , obtaining an aqueous stream S _UI from _UI , and supplying the stream S _UI to unit _UWS2 , wherein in _UI , one or more of the impurities are separated from S _UWS1 , thereby obtaining an impurity stream S _I from _UI , and the impurities preferably include at least one impurity contained in S _R according to (vii).

Preferably, the evaporation unit _UE comprises two or more evaporation subunits, and the process preferably includes the steps of obtaining at least two steam streams _SV1 and _SV2 , passing steam stream _SV1 through at least one heat consumption unit, and passing steam stream _SV2 through at least one heat consumption unit, wherein steam streams _SV1 and _SV2 differ from each other in either pressure and/or temperature.

Preferably, at least one solid-liquid separation unit is located downstream of the _UR , and at least one of the streams _SL and _SR passes through at least one solid-liquid separation unit before being passed to the next downstream unit.

According to the present invention, the solid material M supplied according to (i) preferably comprises one or more waste materials, preferably textile waste and engineering plastic waste, more preferably textile waste, and preferably consisting solely of such materials.

With respect to the stream S _CPL , i.e., the purified ε-caprolactam stream, it is preferable that the stream S _CPL be passed through the polyamide 6 production unit U _PP , where it is used as a starting material. If necessary, one or more further streams S _NCPL can be passed through the U _PP , the streams containing non-recycled ε-caprolactam, i.e., ε-caprolactam from a conventional source. The prepared polyamide 6 materials may then preferably be passed through the unit U _TP , where they are used as starting materials for preparing polyamide 6 materials, preferably polyamide 6 fibrous materials. If necessary, one or more further streams S _NPA6 can be passed through the U _TP , the streams containing non-recycled polyamide 6, i.e., polyamide 6 from a conventional source. Depending on the type of material to be prepared in the U _TP , further streams containing one or more starting materials other than polyamide 6 can also be passed through the U _TP . Next, the fibrous material _MT obtained from the material, preferably _UTP , is preferably brought to market and remains there for a given service life _TMT . Thereafter, the material that has reached the end of its service life is appropriately collected in a collection unit _UTC , preferably a fibrous material collection unit, and thereafter, as a solid material M or as part of a solid material M, it is optionally sorted as described herein and then appropriately passed through the process described above.

Therefore, according to the present invention, the process may preferably further include the step of supplying stream S _CPL to a polyamide 6 manufacturing unit U _PP , the polyamide 6 manufactured in U _PP is preferably supplied as a raw material to a fiber material manufacturing unit U _TP , and from unit U _TP ,
(A) A textile material _MT is brought into the market, and after the service life _TMT of the said textile material _MT is collected at least partially as textile waste in the textile material collection unit _UTC .
(B) The remaining material _MR is obtained as textile waste.
At least a portion of the textile waste from (A), or at least a portion of the textile waste from (B), or at least a portion of the textile waste from (A) and at least a portion of the textile waste from (B) shall be appropriately provided to _UR via _UM .

Accordingly, the present invention also relates to the use of S _CPL that can be obtained or obtained by the above process for preparing polyamide 6, wherein the use preferably further includes the step of using the polyamide 6 as a feedstock for preparing a fibrous material.

Furthermore, the present invention also relates to a method for preparing polyamide 6, the method comprising the step of using S _CPL which can be obtained or obtained by the method described above as a starting material, and the method preferably further comprising the step of using the polyamide 6 as a feed material for preparing a fibrous material.

Furthermore, according to the present invention, the process further comprises the step of supplying stream S _CPL to a polyamide 6 manufacturing unit U _PP , the polyamide 6 manufactured in U _PP is preferably supplied as a raw material to an engineering plastics material manufacturing unit U _EP , and from that unit U _EP ,
(A) Engineering plastic material _ME is brought into the market, and after the service life T _ME of the engineering plastic material _ME is collected at least partially as engineering plastic waste in the engineering plastic collection unit U _EC .
(B) The remaining material M _R is obtained as engineering plastic waste.
At least a portion of the engineering plastic waste from (A), or at least a portion of the engineering plastic waste from (B), or at least a portion of the engineering plastic waste from (A) and at least a portion of the engineering plastic waste from (B) are preferably appropriately provided to _UR as _SM via _UM .

Accordingly, the present invention also relates to the use of S _CPL that can be obtained or obtained by the above process for preparing polyamide 6, wherein the use preferably further includes the step of using the polyamide 6 as a feedstock for preparing engineering plastic material.

Furthermore, the present invention also relates to a method for preparing polyamide 6, the method comprising using S _CPL which can be obtained or obtained by the above process as a starting material, and the method further preferably comprises the step of using the polyamide 6 as a feedstock for preparing engineering plastic material.

In a further embodiment, the present invention relates to an integrated process for preparing polyamide 6,
(α) A step of preparing a stream S _CPL according to the process described herein, wherein the stream S _CPL comprises purified ε-caprolactam,
(β) The step of passing the stream S _CPL through the polyamide 6 manufacturing unit U _PA ,
(γ) The step of subjecting the stream S _CPL in U _PA to ε-caprolactam polymerization conditions to obtain a stream from U _PA containing polyamide 6 material M _P , water and one or more ε-caprolactam oligomers,
(δ) optionally, a stream containing water and one or more ε-caprolactam oligomers is subjected to concentration with respect to one or more ε-caprolactam oligomers in at least one concentration step to obtain a concentrated stream containing water and one or more ε-caprolactam oligomers,
(ε) A step of passing a concentrated stream containing water and one or more ε-caprolactam oligomers through at least one of the melting unit U _M and water separation subunit U _WS2 described herein,
This includes information about the integration process.

Preferably, the stream, which may be concentrated by an optional means, contains water and one or more ε-caprolactam oligomers according to (ε), further comprising ε-caprolactam, i.e., monomer ε-caprolactam. More preferably, the integration process is
(γ) The step of subjecting the stream S _CPL in U _PA to ε-caprolactam polymerization conditions to obtain a stream S _EW from U _PA containing polyamide 6 material M _P , water at concentration c _EW (W), ε-caprolactam at concentration c _EW (C), and one or more ε-caprolactam oligomers at total concentration c _EW (O),
(δ) A step of enriching stream S _EW ,
(δ.1) The stream S _EW is subjected to concentration in a first concentration unit U _C1 to obtain a concentrated stream S C1 from U _C1 containing water at concentration c _C1 (W), ε-caprolactam at concentration c _C1 (C), and one or more ε-caprolactam oligomers at total concentration c _C1 (O), where c _C1 (W) < c _EW (W), c _C1 (C) > c _EW (C), and c _C1 (O) > c _EW (O), and further obtain an aqueous stream S _W1 from U _C1 containing water at concentration _{c W1} (W) > c _EW (W),
(δ.2) The step of subjecting stream S _C1 to concentration in a second concentration unit U _C2 , thereby obtaining a concentrated stream S C2 from U _C2 containing one or more ε-caprolactam oligomers with a total concentration c _C2 (O) and c _C2 (O) > c _C1 (O), and further obtaining an aqueous stream S _W2 from U _C2 containing water with a concentration _{c W2 (} W) and ε-caprolactam with a concentration c _W2 (C), where c _W2 (W) > c _W1 (W) and c _W2 (C) > c _W1 (C),
(ε) The step of passing stream S _C2 to subunit U _M and stream _SW2 to subunit U _WS2 .

As described above, the stream _SEW obtained from the polyamide 6 polymerization unit U _PA contains water, ε-caprolactam monomer, and one or more ε-caprolactam oligomers. Typically, this aqueous stream _SEW further contains one or more additional organic compounds other than ε-caprolactam monomer and one or more ε-caprolactam oligomers. Therefore, it is preferable that the stream _SEW , at a total concentration _cEW (X), further contains one or more organic compounds X other than ε-caprolactam and its oligomers, and the process by (δ) includes the following steps:
(δ.1) The stream S _EW is subjected to concentration in the first concentration unit U _C1 to obtain a concentrated stream S C1 from U _C1 containing water at a concentration _{c C1 (} W), ε-caprolactam at a concentration c _C1 (C), one or more ε-caprolactam oligomers at a total concentration c _C1 (O), and one or more organic compounds X at a total concentration c _C1 (X), wherein c _C1 (W) < c _EW (W), c _C1 (C) > c _EW (C), c _C1 (O) > c _EW (O), and c _C1 (X) > c EW (X), and further, an aqueous stream S _W1 containing water at a concentration c _W1 (W) > c _EW ( _W ) is obtained from U _C1 ,
(δ.2) The process includes the step of subjecting stream S _C1 to concentration in a second concentration unit U _C2 , thereby obtaining a concentrated stream S _C2 from U _C2 containing one or more ε-caprolactam oligomers with a total concentration c _C2 (O) and one or more organic compounds X with a total concentration c _C2 (X), wherein c _C2 (O) > c _C1 (O) and c _C2 (X) > c C1 (X), and further obtaining an aqueous stream S _W2 from U _C2 containing water with a concentration c _W2 ( _W ) and ε-caprolactam with a concentration c _W2 (C), wherein c _W2 (W) > c _W1 (W) and c _W2 (C) > c _W1 (C).

More preferably, according to the present invention, (γ) is the following step:
(γ.1) The step of passing stream S _CPL and preferably aqueous stream S _AQ0 through polymerization step ST ₀ to obtain the crude polyamide 6 product stream S _PA1 and aqueous stream S _WA1 from ST ₀ ,
(γ.2) The step of passing stream S _PA1 and preferably aqueous stream S _AQ1 through granulation step ST ₁ to obtain coarse-grained polyamide 6 material M _PA2 and aqueous stream S _WA2 from ST ₁ ,
(γ.3) The step of passing material M _PA2 and preferably aqueous stream S _AQ2 through extraction step ST ₂ to obtain purified granular polyamide 6 material M _PA3 and aqueous stream S _WA3 from ST ₂ ,
(γ.4) The process includes passing material M _PA3 through a drying step ST ₃ to obtain polyamide 6 material M _P and aqueous stream S _WA4 from ST ₃ .

Assuming that some of the polyamide 6 material obtained from manufacturing unit U _PA does not meet the specifications, the process may preferably further include passing at least some of the material M _PR through unit U _M.

The process of the present invention described above may preferably be a continuous process. However, one or more process steps may be performed in batch mode, and one or more steps may be performed in semi-continuous mode.

The present invention is further described by the following set of embodiments and combinations of embodiments arising from the dependencies and backreferences shown. In particular, it should be noted that in each example where the scope of an embodiment is referred to, for example, in the context of the term, e.g., “any one process of Embodiments 1 to 4,” all embodiments within this scope are expressly disclosed to those skilled in the art; that is, the wording of this term should be understood by those skilled in the art as synonymous with “any one process of Embodiments 1, 2, 3, and 4.” Furthermore, it should be explicitly noted that the following set of embodiments represents a well-structured portion of a general description directed toward preferred aspects of the present invention and therefore appropriately supports, but does not represent, the claims of the present invention.

1. A process for depolymerizing polyamide 6 contained in solid material M by hydrolysis, wherein the process is:
(i) A step of supplying a solid material M,
(ii) The steps of melting the solid material M supplied according to (i) in a melting unit U _M to obtain a liquid stream S _M having a temperature T _SM at a pressure p _SM ,
(iii) A step of supplying a liquid aqueous stream _SW having a temperature T _SW at a pressure p _SW ,
The steps include: mixing the stream S _M obtained according to (iv)(ii) with the stream _SW supplied according to (iii) in a preliminary reaction unit U _PR to obtain a liquid reaction feed stream S _F having a temperature T _SF at a pressure p _SF ;
(v) The step of supplying the stream S _F obtained according to (iv) into the chemical reaction unit U _R ,
(vi) The step of subjecting the stream S _F in the chemical reaction unit U _R to polyamide 6 depolymerization conditions including a depolymerization pressure p _D for polyamide 6 and a depolymerization temperature T _D for polyamide 6 to obtain an aqueous depolymerization mixture containing ε-caprolactam dissolved in water in U _R ,
(vii) A process comprising the step of taking an aqueous liquid reactor outlet stream S _R from U _R , wherein the stream S _R comprises ε-caprolactam dissolved in water, where 0.8 ≤ T _SF / T _D ≤ 1.05 and 0.9 ≤ p _SF / p _D ≤ 1.05.

2. The process of Embodiment 1, wherein 0.6 ≤ T _SM / T _SF ≤ 1.05 and 0.9 ≤ p _SM / p _SF ≤ 1.05.

3. The process of Embodiment 1, wherein 0.8 ≤ T _SW / T _SF ≤ 1.3 and 0.9 ≤ p _SW / p _SF ≤ 1.05.

4. Any one of the processes of Embodiments 1 to 3, wherein the preliminary reaction unit U _PR according to (iv) includes, preferably only, a mixing unit, preferably a static mixing unit.

5. A process according to (iv), wherein _SW and _SM are mixed in UPR in a mixing ratio ( _mW /kg)/( _mP /kg) in the range of 1:1 to 20:1, preferably in the range of 2:1 to 15:1, more preferably in the range of ₅ :1 to 10:1, where _mW is the amount of water contained in _SW and _mpP is the amount of polyamide 6 contained in _SM , any one of Embodiments 1 to 4.

6. Any one of the processes from Embodiments 1 to 5, wherein the melting unit _UM comprises, preferably a single-screw extruder or a twin-screw extruder, preferably consisting solely of the extruder.

7. The process of any one of Embodiments 1 to 6, preferably Embodiment 6, wherein the melting unit _UM is equipped with a degassing system, and the process includes the step of removing a gas stream _SGM from _UM during melting according to (ii), wherein the gas stream _SGM has a temperature _TGM at a pressure _pGM , where 0.95 ≤ _TGM / _TSM ≤ 1.05.

8. The process of Embodiment 7, wherein the gas stream _SGM extracted from _UM is subjected to one or more scrubbing processes, preferably wet scrubbing and dry scrubbing, in a scrubbing unit _US , and the wet scrubbing process preferably includes the step of passing the gas stream _SGM through a scrubbing column, preferably a packed scrubbing column.

9. A filtration unit _UF is positioned downstream of the melting unit _UM and upstream of the reaction unit _UR , for separating particles having a particle size in the range of 100 to 500 micrometers, preferably in the range of 200 to 400 micrometers, from the liquid stream _SM , and the process includes the step of passing the stream liquid stream _SM through _UF before mixing by (iv ₎ , any one of the processes of Embodiments 1 to 8.

10. According to (vi), any one of the processes of Embodiments 1 to 9, wherein _TD is in the range of 230 to 330°C and _pD is in the range of 40 to 140 bar, preferably _TD is in the range of 250 to 320°C and _pD is in the range of 40 to 125 bar, more preferably _TD is in the range of 270 to 310°C and _pD is in the range of 40 to 110 bar.

11. Any one of the processes of Embodiments 1 to 10, wherein the reaction unit U _R according to (v) comprises z chemical reactors R _i , i = 1...z, and z is in the range of 1 to 10, preferably in the range of 1 to 8, more preferably in the range of 1 to 6, more preferably in the range of 1 to 5, more preferably in the range of 1 to 4, and more preferably in the range of 1 to 3.

12. If z > 1, at least two reactors _Ri , preferably z reactors Ri _, are connected in series.
- According to (v), the stream S _F is supplied to _Ri , where i = 1,
- An aqueous liquid stream S _i containing ε-caprolactam dissolved in water is taken from reactor R _i and supplied to reactor R _i+1 , where i < z,
- According to (vii), an aqueous liquid stream S _z containing ε-caprolactam dissolved in water is taken out of reactor R _z as stream S _R ,
Here, in all reactors _Ri , the depolymerization temperature T _Di is maintained at the depolymerization pressure p _Di , and independently of each other, T _Di is in the range of 230 to 330°C and p _Di is in the range of 40 to 140 bar, preferably T _Di is in the range of 250 to 320°C and p _Di is in the range of 40 to 125 bar, more preferably T _Di is in the range of 270 to 310°C and p _Di is in the range of 40 to 110 bar.
The process of Embodiment 11.

13. The process of Embodiment 12, in the case z > 1, where z reactors _Ri are arranged vertically, _R1 is the uppermost reactor, _Rz is the lowermost reactor, and _Si obtained from Ri moves to Ri _{+1 by} gravity, preferably by gravity alone.

14. Any one of the processes in embodiments 11 to 13, wherein at least one, preferably z, reactors _Ri are stirred tank reactors.

15. The process of Embodiment 14, wherein all stirred tank reactors _Ri have 2 to 6 compartments, preferably 2 to 5 compartments, more preferably 2 to 4 compartments, independently of each other, and the compartments are preferably arranged in series, more preferably in series and vertically, and two adjacent compartments are separated by a partition including at least one flow opening.

16. The process of Embodiment 15, wherein at least one compartment in reactor _Ri is equipped with at least one stirrer, preferably all compartments in all reactors _Ri are equipped with at least one stirrer, and more preferably all compartments in all reactors _Ri are equipped with one stirrer, and the process includes the step of stirring the depolymerization mixture in a given compartment for at least a portion of the time while the compartment is subjected to depolymerization conditions.

17. The process of any one of Embodiments 1 to ₁₆ , preferably any one of Embodiments 11 to 16, more preferably Embodiment 15 or 16, wherein the depolymerization conditions of polyamide 6 according to (vi) further comprise a total residence time tD of the aqueous depolymerization mixture in unit U _R , preferably z reactors R _i , more preferably z stirred tank reactors, and at least 85% by weight, preferably at least 90% by weight, more preferably at least 95% by weight of the aqueous depolymerization mixture has a _tD in the range of 30 to 90 minutes.

18. The process of Embodiment 17, as far as Embodiment 17 is concerned, depends on any one of Embodiments 11 to 16, preferably Embodiment 15 or 16, of z > 1, wherein the residence time of the aqueous depolymerization mixture in reactor _Ri is t _Di , and 0.90 ≤ (t _Di / t _{Di + 1} ) ≤ 1.10, preferably 0.95 ≤ (t _Di / t _{Di + 1} ) ≤ 1.05.

19. Any one of the processes from Embodiments 11 to 18, wherein a gas stream S _Gi is taken from at least one reactor _Ri , preferably from all z reactors _Ri , and the gas stream S _Gi has a temperature T _Gi at a pressure p _Gi , where 0.95 ≤ T _Gi / T _Di ≤ 1.05.

20. The process of Embodiment 19, further comprising the step of combining at least one, preferably all _{, of the gas streams S Gi with} the gas stream S _GM as defined in Embodiment 7 before subjecting the gas stream S _GM to scrubbing as defined in Embodiment 8.

21. Supplying the solid material M in accordance with (i)
(i.1) A step of supplying a solid material M into a delivery unit U _MD , wherein the U _MD preferably comprises one or more of at least one big bag station and at least one bulk container station.
(i.2) A step of passing the solid material M supplied in accordance with (i.1) from unit U _MD to material collection unit U _MC , preferably collection drum, via a first connection line, wherein the first connection line preferably comprises one or more of at least one material receiving and discharging unit U _MRD , at least one first material supply unit U _FMF , and at least one first particle separation unit U _FMPS ,
(i.3) A step of passing a solid material M from unit U _MC to unit U _M via a second connection line, wherein the second connection line preferably comprises one or more of at least one second material supply unit U _SMF , at least one second particle separation unit U _SMPS , and at least one metal detector.
The process according to any one of embodiments 1 to 20, including the process described in any one of embodiments 1 to 20.

22. The process of Embodiment 21, wherein the first connection line according to (i.2) comprises at least one unit U _MRD , preferably at least one hopper, more preferably at least one one-zone hopper, and further comprises at least one unit U _FMF , preferably at least one rotary feeder, and further preferably at least one particle separation unit U _FMPS , more preferably at least one filter, more preferably at least one mesh filter.

23. The process of Embodiment 21 or 22, wherein, in order to pass a solid material M from unit U _MD to unit U _MC via a first connection line, at least one gas stream S _G passes through the first connection line, the at least one gas stream preferably contains air or dilute air, more preferably consists only of the above, and before passing through the first connection line, at least one gas stream is pretreated preferably by at least one of filtration, compression, and cooling, more preferably by filtration, compression, and cooling.

24. Any one of the processes of embodiments 21 to _{23, wherein the second connection line according to (i.3) comprises at least two Unit U SMFs ,} preferably a rotary feeder and a weight loss feeder, wherein the rotary feeder is located upstream of the weight loss feeder and further comprises a Unit U _SMPS , preferably a vibrating screen.

25. In accordance with (i), a solid material M is supplied in the form of granules, preferably supplied to U _M , and the particle size distribution of the granules is preferably characterized by one or more pairs of the following values, preferably two or more pairs of the following values, more preferably three pairs of the following values, in any one of the processes of Embodiments 1 to 24:
- D10 values for particle widths in the range of 0.3 to 15 mm, and D10 values for particle lengths in the range of 0.3 to 15 mm.
- D50 values for particle widths in the range of 0.5 to 20 mm, and D50 values for particle lengths in the range of 0.5 to 20 mm.
- D90 values for particle widths ranging from 0.8 to 30 mm and D90 values for particle lengths ranging from 0.8 to 30 mm.

26. Any one of Embodiments 1 to 25, wherein 10 to 100% by weight, more preferably 30 to 100% by weight, more preferably 50 to 100% by weight, more preferably 60 to 100% by weight, more preferably 70 to 100% by weight, and more preferably 80 to 100% by weight of the solid material M consists solely of polyamide 6.

27. A process any one of Embodiments 1 to 26, comprising the steps of supplying a liquid aqueous stream _SW in accordance with (iii) to generate an aqueous stream containing at least a portion of the water contained in the stream _SW , and supplying back at least a portion of the generated aqueous stream to a chemical reaction unit _UR as or as part thereof the aqueous stream _SW .

28. According to (vii), Stream S _SR contains ε-caprolactam dissolved in water at concentration c _SR , and Stream S _SR further contains one or more impurities, and the process is as follows:
(viiii) The step of passing a liquid aqueous stream S _R through an evaporation unit U _E to obtain a liquid aqueous stream S _L containing ε-caprolactam dissolved in water at a concentration c _SL > _{c SR} from S _R , and further obtaining one or more aqueous vapor streams S _V from S _R ,
(ix) A step of passing an aqueous stream S _L through a heat-consuming purification unit _UP to obtain a stream S _CPL containing ε-caprolactam at a concentration c _SCPL such that c _SCPL >> c _SL from S _L , and further obtaining one or more aqueous streams S _RW from S _L , wherein at least a portion of the heat consumed in _UP is supplied by at least one of the one or more streams S _V , thereby obtaining at least one at least partially condensed aqueous stream S _VW from at least one stream S _V ,
(x) any one of embodiments 1 to 27 further comprising the step of recycling at least one stream S _VW to a reaction unit U _R and recycling at least one stream S _RW to a reaction unit U _R.

29. Recycling according to (x)
(x.1) The steps of supplying at least one stream S _VW and at least one stream S _RW to a water treatment unit U _W and obtaining at least one aqueous recycling stream S _W from U _W ,
(x.2) The process of Embodiment 28, comprising the step of recycling at least one aqueous stream _SW into a reaction unit _UR at least partially.

30. The water treatment unit U _W comprises a water recovery unit U _WR and a wastewater unit U _WW , and (x.1) is
(x.1.1) The steps of supplying at least one stream S _VW and at least one stream S _RW to a water recovery unit U _WR and obtaining at least one aqueous recycling stream _SW and at least one aqueous stream S _SW from U _WR ,
(x.1.2) The process of Embodiment 29, further comprising the step of supplying at least one stream S _SW to a wastewater unit U _WW and obtaining at least one wastewater stream S _WW from U _WW .

31. Any one of the processes of Embodiments 28 to 30, wherein the purification unit _UP comprises one or more of the heat-consuming water separation unit _UWS , the heat-consuming distillation unit _UD , and the heat-consuming crystallization unit _UC , preferably two or more of _the heat-consuming water separation unit _UWS , the _heat -consuming distillation unit _UD , and the heat-consuming crystallization unit _UC , and at least _a portion of the heat consumed by one or more of _UWS , _UD , and _UC is supplied by at least one of one or more streams _SV .

32. The process of Embodiment 31, comprising one or more of (i-1), (i-2), and (i-3) below, preferably at least two or more of (i-1), (i-2), and (i-3), more preferably (i-1), (i-2), and (i-3):
(i-1) A step of obtaining at least one at least partially condensed aqueous stream S _VW1 from U _WS ,
(i-2) A step of obtaining at least one at least partially condensed aqueous stream S _VW2 from _UD ,
(i-3) A step of obtaining at least one at least partially condensed aqueous stream S _VW3 from U _C ,
Here, the process further includes the step of supplying one or more _SVW1 , _SVW2 , and _SVW3 , preferably two or more _SVW1 , _SVW2 , and _SVW3 , more preferably _SVW1 , _SVW2 , and _SVW3 , to a water treatment unit _UW, as in Embodiment 29.

33. A process of embodiment 31 or 32, wherein at least one of the streams S _RW is obtained from U _WS .

34. The purification unit _UP comprises a heat-consuming water separation unit _UWS , a heat-consuming distillation unit _UD , and a heat-consuming crystallization unit _UC , and the process includes the steps of: supplying a stream _SL containing ε-caprolactam at a concentration of _cSL to _UWS ; obtaining a stream _UWS containing ε-caprolactam at a concentration of _cUWS from _UWS ; supplying the stream _SUWS to the distillation unit _UD ; obtaining a stream _SUD containing ε-caprolactam at a concentration _{of cUD} from UD; supplying the stream _SUD to the crystallization unit _UC ; and obtaining a stream _SCPL containing ε-caprolactam at a concentration of _cSCPL from _UC ,
Any one of the processes from embodiment 28 to 33, wherein c _SL < c _UWS < c _UD < c _SCPL .

35. Any one of embodiments 28 to 34, wherein the water separation unit _UWS comprises at least two heat-consuming water separation subunits _UWS1 and _UWS2 , preferably two heat-consuming water separation subunits _UWS1 and _UWS2 coupled in series, and a stream _SL is supplied to _UWS1 , and at least a portion of the heat consumed in one or more of _{UWS1 and UWS2} is provided by at least one of one or more streams _SV .

36. Process of Embodiment 35, comprising one or more of (ii-1) and (ii-2), preferably (ii-1) and (ii-2):
(iii-1) A step of obtaining at least one at least partially condensed aqueous stream S _VW11 from U _WS1 ,
(ii-2) A step of obtaining at least one at least partially condensed aqueous stream S _VW12 from U _WS2 .

37. The process of Embodiment 36, wherein at least one aqueous stream _SRW1 is obtained from _UWS1 , at least one aqueous stream _SRW2 is obtained from _UWS2 , and at least one of _SRW1 and _SRW2 , preferably _SRW1 and _SRW2 , is supplied to _UW .

38. A separation unit _UI is located downstream of _UWS1 and upstream of _UWS2 , and the process comprises the steps of obtaining an aqueous stream S _UWS1 from _UWS1 , supplying the stream S _UWS1 to the separation unit _UI , obtaining an aqueous stream S _UI from _UI , and supplying the stream S _UI to unit _UWS2 , wherein in _UI , one or more impurities are separated from S _UWS1 , thereby obtaining an impurity stream S _I from _UI , the impurities preferably containing at least one impurity included in S _R according to (vii), any one of the processes of embodiments 35 to 37.

39. Any one of the processes of Embodiments 28 to 38, wherein the evaporation unit _UE comprises two or more evaporation subunits, and the process includes the steps of obtaining at least two steam streams _SV1 and _SV2 , passing steam stream _SV1 through at least one heat consumption unit, and passing steam stream _SV2 through at least one heat consumption unit, wherein steam streams _SV1 and _SV2 differ from each other in either pressure and/or temperature.

40. Any one of the processes from Embodiments 28 to 39, wherein at least one solid-liquid separation unit is located downstream of the _{U UR} , and preferably at least one of the streams _SL and _SR passes through at least one solid-liquid separation unit before being passed to the next downstream unit.

41. The process further includes supplying stream S _CPL to a polyamide 6 manufacturing unit U _PP , wherein the polyamide 6 manufactured in U _PP is preferably supplied as a feed material to a fiber material manufacturing unit U _TP , and from unit U _TP ,
(A) A textile material _MT is brought into the market, and after the service life _TMT of the said textile material _MT is collected at least partially as textile waste in the textile material collection unit _UTC .
(B) The remaining material M _R is obtained as fiber waste.
Any one of the processes of Embodiments 28 to ₄₀ , wherein at least a portion of the textile waste from (A), or at least a portion of the textile waste from (B), or at least a portion of the textile waste from (A) and at least a portion of the textile waste from (B) is appropriately supplied to _UR via UM.

42. Any one of the processes of _Embodiments 1 to 41, wherein 90 to 100% by weight, preferably 91 to 100% by weight, more preferably 92 to 100% by weight, more preferably 93 to 100% by weight, more preferably 94 to 100% by weight, and more preferably 95 to 100% by weight of the liquid aqueous stream SW supplied according to (iii) consists solely of water.

43. A process from any one of Embodiments 1 to 42, which is a continuous process, a semi-continuous process, or a batch process.

44. Any one of the processes from Embodiments 1 to 43, wherein the solid material M supplied according to (i) comprises one or more waste materials, preferably textile waste and engineering plastic waste, more preferably textile waste, and preferably solely thereof.

45. Use of S _CPL that can be obtained or obtained by any one process of Embodiments 28 to 44 for preparing polyamide 6, wherein the use further comprises the step of using the polyamide 6 as a feedstock for preparing one or more of fibrous materials and engineering plastic materials, more preferably for preparing fibrous materials.

46. A method for preparing polyamide 6, wherein the method comprises the step of using S _CPL obtained by any one process of Embodiments 28 to 44 as a starting material, and the method further comprises the step of using the polyamide 6 as a feedstock for preparing one or more of fibrous materials and engineering plastic materials, more preferably for preparing fibrous materials.

47. Use of _SCPL obtainable or obtained by any one process of Embodiments 28 to 44 for preparing one or more polymers and polymer products, or a method for preparing one or more polymers and polymer products, the method comprising the step of using _SCPL obtainable or obtained by any one process of Embodiments 28 to 44 as a starting material.

48. Use or method of Embodiment 47, wherein the polymer, or polymer product, or polymer and polymer product is in the form of at least one of granules, strands, rods, plates, pipes, foils, layers, films, sheets, fibers, filaments, coatings, extruded articles, molded articles, flexible foams, semi-rigid foams, and rigid foams.

49. Use or method of Embodiment 47 or 48, wherein the polymer, or polymer product, or polymer and polymer product comprises polyamide 6 and, optionally, at least one further polymer compound, wherein the at least one further polymer compound preferably comprises at least one polyamide 6.6; at least one semi-aromatic polyamide comprising one or more of polyamide 6T and polyamide 6I; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer of two or more of the polymer compounds comprising statistical copolymers, gradient copolymers, alternating copolymers, block copolymers, and graft copolymers; and one or more of at least one rubber material comprising one or more of the at least one natural rubber material and at least one synthetic rubber material.

50. Use or method of any one of Embodiments 47 to 49, wherein the polymer, or polymer product, or polymer and polymer product is one of the following, or part of one of the following:
- Parts of an automobile, preferably cylinder head covers, engine covers, intake radiator housings, intake radiator flaps, intake pipes, intake manifolds, connectors, gear wheels, fan wheels, coolant boxes, heat exchanger housings or housing components, coolant coolers, intake radiators, thermostats, water pumps, radiators, fastening components or parts of battery systems for electric transport, dashboards, steering column switches, seats, headrests, center consoles, transmission components, door modules, automotive exteriors for A, B, C or D pillar covers, spoilers, door handles, exterior mirrors, windshield wipers, windshield wiper protective housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna panels, headlights, taillights, airbags, and/or cushions;
- Cloth, clothing, preferably shirts, trousers, pullovers, boots, shoes, soles, tights and/or jackets;
- Electrical components, preferably electrical components, passive electronic components, active electronic components, printed circuit boards, housing components, wheels, lines, switches, e.g., microswitches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, bobbins, lamps, diodes, e.g., LEDs, transistors, connectors, regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microbuttons, semiconductors, e.g., reflector housings for light-emitting diodes, fasteners, spacers, bolts, strips, slide-in guides, screws, nuts, film hinges, snap hooks (snap-ins), and/or spring tongues for electrical and/or electronic components;
- Consumer and/or pharmaceutical products, preferably tennis strings, climbing ropes, bristols, brushes, artificial grass, 3D printing filaments, lawnmowers, zippers, hook-and-loop fasteners, paper machine garments, extruded coatings, fishing lines, fishing nets, seabed lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, plain bearings, rollers, wheels, gears, rollers, ring gears, screws and spring dampers, hoses, pipelines, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes and/or bottles, mattresses, cushions, insulation materials;
- Packaging for the food industry, preferably single-layer and/or multi-layer inflated films, cast films (single-layer and/or multi-layer), biaxially oriented films, and laminate films.

51. Any one use or method of Embodiments 47 to 50, wherein the polymer, or polymer product, or polymer and polymer product contains polyamide 6 in an amount of 1% by weight or more, preferably 2% by weight or more, more preferably 5% by weight or more, more preferably 15% by weight or more, more preferably 30% by weight or more, more preferably 40% by weight or more, more preferably 60% by weight or more, more preferably 80% by weight or more, more preferably 90% by weight or more, more preferably 95% by weight or less, and/or 100% by weight or less, preferably 95% by weight or less, more preferably 90% by weight or less, more preferably 50% by weight or less, more preferably 25% by weight or less, and more preferably 10% by weight or less.

With respect to Embodiment 51, the respective amounts are preferably determined based on identity retention and/or separation and/or mass balance and/or book and claims management models, more preferably based on mass balance, and more preferably based on International Sustainability and Carbon Certification (ISCC) standards.

With regard to embodiments 47 to 51, the preparation of polymers, polymer products, or polymers and polymer products may include one or more synthesis steps and can be carried out by conventional synthesis and techniques well known to those skilled in the art. Examples of synthesis steps are found in "Industrial Organic Chemistry," Vol. 3, Wiley-VCH, 1997; ISBN: 978-3-527-28838-0; "Kunststoffhandbuch," Vol. 11 of 17 sub-volumes, Carl Hanser Verlag, especially Vol. 6, "Polyamides," 1st edition, 1966; "Injection Molding Reference Guide, ^4th edition, CreateSpace Independent Publishing""Platform," 2011, ISBN: 978-1466407824; described in International Publication No. 2008/155271 and International Publication No. 2013/139827, which are incorporated herein by reference, respectively.

As used herein, the term "bar" refers to "bar (abs)," that is, bar (absolute value), and is sometimes also referred to as "bara."

As used herein, the term “textile material” encompasses fibrous and non-textile raw materials processed into linear, planar, and spatial structures by various methods. This includes linear fibrous structures manufactured from fibrous materials, e.g., yarns, twisted yarns, and ropes; sheet-like fibrous structures, e.g., woven fabrics, knitted fabrics, braids, stitch-bonded fabrics, nonwoven fabrics, and felts; and three-dimensional fibrous structures, i.e., main structures, e.g., fibrous hoses, stockings, or fibrous semi-finished products; and further, finished products made ready for sale by configuration, opening up, and/or other actions for processing, trading, or end consumers. As used herein, the term “textile waste” encompasses the fibrous materials defined above, whose inherent value has been consumed from the perspective of the current owner, and thus the material is at the end of its lifespan for that owner.

As used herein, the term “engineering plastics” refers to high-performance plastic grades that possess physical properties enabling them to be used in structural applications, over a wide temperature range, under mechanical stress, and for extended periods in challenging chemical and physical environments, for example, to manufacture plastic components as an alternative to conventional engineering materials such as metals and ceramics. Engineering plastics are particularly applicable to the manufacture of mechanical components across several industries, such as automotive, medical, electrical and electronic, aerospace, construction, and consumer products. As used herein, the term “engineering plastic waste” encompasses the engineering plastic materials defined above, whose inherent value has been consumed from the perspective of the current owner, and thus constitutes a material at the end of its lifespan for that owner.

As used herein, the term "elastane" is also referred to as "spandex," and common trade names for spandex include Lycra, Elaspan, Acepora, Creora, Inviya, Roica, Dorlastan, Linel, or ESPA.

In the context of the present invention, the phrase "X is one or more of A, B, and C" should be understood as disclosing that X is either A, B, or C, or A and B, or A and C, or B and C, or A, B, and C. In this regard, those skilled in the art can translate the above abstract terms into concrete examples, for example, X is a chemical element and A, B, and C are specific elements, e.g., Li, Na, and K, or X is a temperature and A, B, and C are specific temperatures, e.g., 10°C, 20°C, and 30°C. In this regard, those skilled in the art should further note that it is possible to extend the above terminology to less specific realizations of the features, for example, by disclosing that "X is one or more of A and B" means that X is either A, B, or A and B, or a more specific realization of the features, or by disclosing that "X is one or more of A, B, C, and D" means that X is either A, B, C, or D, or A and B, or A and C, or A and D, or B and C, or B and D, or C and D, or A and B and C and D.

Preferred embodiments of the present invention are further shown in Figures 1 to 14, as described below.

Figure 1 shows the process according to the present invention. A properly supplied solid material M containing polyamide 6 is fed into a melting unit U _M , from which a liquid stream S _M is obtained, which is then passed through a pre-reaction unit U _PR , where it is mixed with a liquid aqueous stream _SW . The liquid stream S _F obtained from unit U _PR is then passed through a reaction unit U _R , where it is subjected to depolymerization conditions for polyamide 6 to obtain an aqueous depolymerization mixture containing ε-caprolactam dissolved in water. The aqueous liquid reactor outlet stream S _R containing ε-caprolactam dissolved in water is removed from unit U _R. Figure 2 shows a process according to the present invention. In addition to the process design shown in Figure 1, the melting unit U _M according to Figure 2 is equipped with a degassing system. Through this degassing system, the gas stream S _GM obtained when the solid material M is melted in U _M is removed. The stream S _GM is then passed through the scrubbing unit U _S. Figure 3 shows the process according to the present invention. In addition to the process design shown in Figure 2, a filtration unit _UF is positioned downstream of the melting unit _UM and upstream of the reaction unit _UR . The stream _SM obtained from unit _UM passes through this filtration unit and, downstream of _UF , is passed to the pre-reaction unit _UPR as a properly filtered stream _SM . This figure shows the process according to the present invention. A preferred design of reaction unit U _R is shown in comparison to the process design shown in Figure 3. According to this preferred design, unit U _R consists of three reactors _R1 , _R2 , and _R3 arranged in series, preferably vertically. Stream S _SF obtained from the preliminary reaction unit U _PR is supplied to reactor _R1 , where it is subjected to depolymerization conditions for polyamide 6, from which a liquid aqueous stream _{S1 is} obtained, which contains ε-caprolactam dissolved in water and further contains undepolymerized polyamide 6. Stream _S1 is then preferably passed through reactor _R2 by gravity alone, where it is subjected to depolymerization conditions for polyamide 6, from which a liquid aqueous stream _S2 containing ε-caprolactam dissolved in water and further containing undepolymerized polyamide 6 is obtained. Next, stream _S2 is preferably passed through reactor _R3 by gravity alone, where it is subjected to depolymerization conditions for polyamide 6, from which a liquid aqueous stream _S3 containing ε-caprolactam dissolved in water is obtained. This stream _S3 is then removed from reaction unit _UR as stream _SR . Figure 5 shows a preferred design for reactor _Ri used according to the present invention. For example, as described above in relation to Figure 4, when two or more reactors _Ri are used, it is preferable that all reactors _Ri exhibit this preferred design. Figure 5 shows reactor _Ri which is a stirred tank reactor. In Figure 5, the following reference numbers are used: (1) Vertically arranged three-compartment reactor _Ri (2) Outlet means for degassing the reactor (3) Outlet means for removing the liquid reaction mixture from _Ri (4) Inlet means for supplying a liquid stream to _Ri , for example, stream S _F to _R1 (5) Heating jacket (6.1) Upper compartment (6.2) Middle compartment (6.3) Bottom compartment (7.1) Stirrer in the upper compartment (7.2) Stirrer in the middle compartment (7.3) Stirrer in the middle compartment (8) Drive unit for the stirrers described in (7.1) to (7.3) (9.1) Partition between the upper and middle compartments with a flow opening (9.2) Partition between the middle and bottom compartments with a flow opening (10.1) Inlet means for passing the heating medium through the heating jacket (5) (10.2) Outlet means for removing the heat medium from the heating jacket (5) Figure 6 shows a process according to the present invention. Compared to the process design shown in Figure 4, the preferred design shows how the solid material M is supplied. According to Figure 6, the solid material is supplied into a delivery unit M _MD , which may include, for example, one or more big bag stations and/or one or more bulk container stations. The material is then appropriately passed from unit U _MD to a material collection unit M _MC , which preferably includes, more preferably consists only of, a drum. The material is then appropriately passed from unit M _MC to a melting unit U _M. Figure 7 shows a process according to the present invention. Compared to the process design shown in Figure 6, the preferred process shows how the solid material is passed from the delivery unit U _MD to the collection unit U _MC via a first connection line. The unit U _MD according to Figure 7 comprises, for example, one bulk container station and two big bag stations through which the material M is passed to a particle separation unit U _FMPS (1). From the first big bag station, the material M is passed to the particle separation unit U _FMPS (2.1), and from the second big bag station, the material M is passed to the particle separation unit U _FMPS (2.2). Then, from U _FMPS (1), the material M passes through a supply unit U _FMF (1), for example, a rotary feeder, and through U _FMF (1), it is passed to receiving and discharging means U _MRD (3), preferably a hopper, and U _MRD (4), preferably a hopper, and may be distributed as optional. Furthermore, the material M may be optionally distributed from U _FMPS (2.1) to the receiving and discharging means U _MRD (2.1), preferably a hopper, through the supply unit U _FMF (2.1), for example, a rotary feeder, and through U _FMF (2.1) to _the receiving and discharging means U _MRD (3) and U _MRD (4). Similarly, the material M may be optionally distributed from U _FMPS (2.2) to the receiving and discharging means U _MRD (2.2), preferably a hopper, through the supply unit U _FMF (2.2), for example, a rotary feeder, and through U _FMF (2.2) to _the receiving and discharging means U _MRD (3) and U _MRD (4). Next, from either U _MRD (3) and/or U _MRD (4), the material M is passed through the collection unit UMC via either unit U _FMF (3), preferably a rotary feeder, and/or unit U _FMF (4), preferably a rotary feeder. Furthermore, Figure 7 shows gas streams _SG (1), _SG (2), and _SG (3), which are passed through each section of the first connection line to transport the material M (pneumatically) to their respective downstream units as shown. At least one, preferably all, of the gas streams are preferably subjected to gas filtration, followed by compression and subsequent cooling before being passed through each section of the first connection line (not shown). Figure 8 shows a process according to the present invention. Compared to the process design shown in Figure 6, the preferred process shows how the solid material is passed from a collection unit U _MC , which preferably has a collection drum, through a second connection line to a melting unit U _M. According to Figure 8, the solid material M is passed from unit U _MC through a first feed unit U _SMF (1), e.g., a rotary feeder, to a particle separation unit U _SMPS , e.g., a vibrating screen. Then, from U _SMPS , the material M is passed to a second feed unit U _SMF (2), preferably a weight loss feed means, e.g., a weight loss screw, from which the material M is appropriately passed to the melting unit U _M. Preferably, a preferred process upstream of unit U _M , as shown in Figure 8, should be seen in relation to a preferred process, as shown in Figure 6. Figure 9 shows a process according to the present invention. Compared to the process design shown in Figure 4, it is further shown that gas streams S _Gi are obtained in each reactor _Ri contained in unit _U and removed therefrom. These gas streams, specifically S _G1 , S _G2 , and S _G3 , are then appropriately combined and passed through scrubber unit U _S. Note that the streams S _Gi may be passed through unit U _S separately (alternative examples are not shown). It is further conceivable that one or more of the streams S _Gi may be combined with gas stream S _GM obtained from molten unit U _M before being supplied to U _S (alternative examples are not shown). Figure 10 shows a process according to the present invention. Figure 10 shows a preferred sequence of steps downstream of the reaction unit _UR and preferred recycling (reuse) of water via stream _SW . According to the process in Figure 10, a liquid aqueous stream _S3 is obtained from the final reactor _R3 of unit UR containing ε-caprolactam and one or more impurities, and is removed therefrom as stream _SR . This stream _SR is then passed through the evaporation unit _UE , from which a liquid aqueous stream _SL and one or more aqueous vapor streams _SV are obtained and removed, although only one vapor stream _SV is shown in Figure 10. Stream _SL has a higher ε-caprolactam concentration than stream _SR . Stream _SL is then passed through a heat-consuming purification unit _UP where further purification of the ε-caprolactam takes place. From the stream _SL supplied to _UP , a product stream _SCPL containing ε-caprolactam at a significantly higher concentration than that of stream _SL is finally obtained. According to the process of the present invention, at least a portion of the heat consumed in the purification unit _UP is at least partially supplied by at least one of one or more steam streams _SV , and based on _SV , one or more at least partially condensed aqueous streams _SVW are obtained and removed from _UP , although only one stream _SVW is shown in Figure 10. Furthermore, one or more aqueous streams _RW are obtained from _SL from the purification unit _UP . Then, at least one stream _SVW is at least partially recycled (reused) to the reaction unit _UR , and at least one stream _RW is at least partially recycled to the reaction unit _UR , and for the purpose of the aforementioned recycling, streams _SVW and _RW are passed through the water treatment unit _UW , from which a stream SW is obtained which is then (at least partially) recycled to the reaction unit _UR as an aqueous stream _SW (or a portion thereof _{). Furthermore, one or more wastewater streams WW are} obtained from _UW which are not recycled into the process. Preferably, the water treatment unit _UW may comprise a water recovery unit _UWR and optionally a wastewater unit _UWW . Preferably, streams _SVW and _SRW are passed through the water treatment unit _UW , where they are appropriately purified and/or collected to obtain one or more aqueous recycling streams. The streams obtained from such purification may then be passed through a wastewater treatment unit _UWW to obtain a wastewater stream _SWW . Figure 11 shows a process according to the present invention. The process according to Figure 11 shows further use of stream S _CPL , i.e., purified ε-caprolactam. According to the present invention, stream S _CPL is preferably passed through a polyamide 6 production unit U _PP , where it is used as a starting material. If necessary, one or more further streams S _NCPL can be passed further through the U _PP , the streams containing non-recycled ε-caprolactam, i.e., ε-caprolactam from a conventional source. The prepared polyamide 6 materials are then passed through a unit U _TP , where they are used as starting materials for preparing polyamide 6-containing materials, preferably polyamide 6-containing fiber materials. If necessary, one or more further streams S _NPA6 can be passed further through the U _TP , the streams containing non-recycled polyamide 6, i.e., polyamide 6 from a conventional source. Depending on the type of material being prepared in the _UTP , a further stream containing one or more starting materials other than polyamide 6 may also be passed through the _UTP . The material, preferably the fibrous material _MT obtained from the _UTP , is then put into the market and remains there for a given service life _TMT . Thereafter, each end-of-life material is appropriately collected in a collection unit _UTC , preferably a fibrous material collection unit, and from there is appropriately passed as a stream _SM , or as part of a stream _SM , preferably through a unit _UM for supplying the stream _SM to _the reaction unit _UR . Such a unit _UM usually comprises any apparatus capable of appropriately passing the solid material M into the reaction unit _UR . Preferably, the _UM comprises apparatus, for example, one or more silos, one or more hoppers, one or more truck unloading stations, one or more big bag unloading stations, etc. Furthermore, Figure 11 shows that in the manufacturing unit _UTP , the remaining material _MR is obtained from the manufacturing process, i.e., material not included in _MT . For example, _MR may be in the form of fiber cutting. This material can be supplied to _UR as stream _SM or as part of stream _SM either via _UTC and/or directly via _UM , preferably according to the process shown in Figures 6, 7, and 8 above. Figure 12 is a diagram illustrating the process according to the present invention. Compared with Figure 11, a preferred design of unit _UP is shown, i.e., the process shown in Figure 12 represents a preferred method for purifying stream _SL with respect to ε-caprolactam. According to this process, stream _SL is first passed through a water separation unit _UWS , from which one or more streams _SRW are obtained, preferably passed through a water treatment unit _UW , as already shown in Figure 11. Furthermore, at least one of the streams _SV is passed through _UWS to at least partially satisfy the heat demand of _UWS , and based on this at least one stream _SV passed through _UWS , one or more at least partially condensed streams _SVW1 are obtained, preferably further passed through a water treatment unit _UW , specifically _UWR . The streams _SUWS containing ε-caprolactam are then passed through a distillation unit _UD for further purification, preferably with respect to ε-caprolactam. Furthermore, at least one of the streams _{SV is} passed through UD to at least partially satisfy the heat requirements of _UD , and based on this at least one stream _SV passed through _UD , one or more at least partially condensed streams _SVW2 are obtained, which are preferably further passed through the water treatment unit _UW , specifically _UWR . The stream _SVUD containing ε-caprolactam is then preferably passed through the crystallization unit _UC for further purification of ε-caprolactam. Furthermore, at least one of the streams _SV is passed through _UC to at least partially satisfy the heat requirements of _UC , and based on this at least one stream _SV passed through _UC , one or more at least partially condensed streams _SVW3 are obtained, which are preferably further passed through the water treatment unit _UW , specifically _UWR . Figure 13 is a diagram illustrating the process according to the present invention. Compared to Figure 13, a preferred design of unit _UWS is shown, i.e., the process shown in Figure 13 illustrates a preferred method for separating water from stream _SL . According to this process, stream _SL is first passed through a first stage of water separation carried out in unit _UWS1 . From _UWS1 , stream S _UWS1 containing ε-caprolactam is then passed through an intermediate processing stage _UI , where impurities may be removed. The thus purified stream S _UI obtained from _UI is then further passed through a second stage of water separation carried out in unit _UWS2 . From unit _UWS2 , stream S _UWS2 containing ε-caprolactam is obtained, which corresponds to stream S _UWS shown in Figure 12, and is then preferably passed through distillation unit _UD . From the intermediate unit UI, streams _{S I containing} the separated impurities are removed and may be further utilized depending on the amount and/or chemical properties of the impurities. This process yields one or more aqueous streams S _RW1 , which are then preferably passed through a water treatment unit U _W , specifically U _WR . Furthermore, this process yields one or more aqueous streams S _RW2 , which are then preferably passed through a water treatment unit U _W , specifically U _WR . Preferably, at least one of the streams _SV is passed through U WS1 to at least partially satisfy the heat requirements of U _WS1 , and based on this at least one stream _SV passed through _{U WS1 ,} one or more at least partially condensed streams _SVW11 are obtained, which are preferably further passed through a water treatment unit U _W , specifically U _WR . Preferably, at least one of the streams _SV is passed through U _WS2 to at least partially satisfy the heat requirements of U _WS2 , and based on this at least one stream _SV passed through U _WS2 , one or more at least partially condensed streams _SVW12 are obtained, which are preferably further passed through a water treatment unit U _W , specifically U _WR . Figure 14 shows the process according to the present invention. Compared with Figure 13, it further shows a preferred recycling loop as already shown in Figure 11, as well as the processing of the gas stream S _Gi obtained in and removed from reactors _R1 , _R2 , and _R3 , as already shown in Figure 9.

Claims (15)

A process for depolymerizing polyamide 6 contained in solid material M by hydrolysis, wherein this process is
(i) A step of supplying a solid material M,
(ii) The steps of melting the solid material M supplied according to (i) in a melting unit U _M to obtain a liquid stream S _M having a temperature T _SM at a pressure p _SM ,
(iii) A step of supplying a liquid aqueous stream _SW having a temperature T _SW at a pressure p _SW ,
The steps include: mixing the stream S _M obtained according to (iv)(ii) with the stream _SW supplied according to (iii) in a preliminary reaction unit _UPR to obtain a liquid reaction feed stream S _F having a temperature T _SF at a pressure p _SF ;
(v) The step of supplying the stream S _F obtained according to (iv) into the chemical reaction unit U _R ,
(vi) The step of subjecting the stream S _F in the chemical reaction unit U _R to polyamide 6 depolymerization conditions including a polyamide depolymerization pressure p _D and a polyamide 6 depolymerization temperature T _D , to obtain an aqueous depolymerization mixture containing ε-caprolactam dissolved in water in U _R ,
(vii) A step of taking the aqueous liquid reactor outlet stream S _R from U _R , wherein the stream S _R contains ε-caprolactam dissolved in water,
A process including, where 0.8 ≤ T _SF / T _D ≤ 1.05 and 0.9 ≤ p _SF / p _D ≤ 1.05. The process according to claim 1, wherein 0.6 ≤ T _SM / T _SF ≤ 1.05 and 0.9 ≤ p _SM / p _SF ≤ 1.05, and 0.8 ≤ T _SW / T _SF ≤ 1.3 and 0.9 ≤ p _SW / p _SF ≤ 1.05. The preliminary reaction unit _UPR according to (iv) includes, preferably only, a mixing unit, preferably a static mixing unit, and according to (iv), _SW and _SM are mixed in UPR at a specific mixing ratio ( _mW /kg)/( _mP /kg), preferably in the range of 1:1 to 20:1, more preferably in the range of 2: ₁ to 15:1, and more preferably in the range of ₅ : ₁ to 10:1, where _mW is the amount of water contained in _SW and _mP is the amount of polyamide 6 contained in _SM .
The process according to claim 1 or 2, wherein the melting unit U _M includes an extruder, preferably a single-screw extruder or a twin-screw extruder, preferably consisting only of an extruder, wherein the melting unit U _M is preferably equipped with a degassing system, and the process includes a step of removing a gas stream S _GM from U _M during melting, preferably according to (ii), wherein the gas stream S _GM has a temperature T _GM at a pressure p _GM , where preferably 0.95 ≤ T _GM / T _SM ≤ 1.05, and the gas stream S _GM removed from U _M is preferably subjected to scrubbing in a scrubbing unit U _S. The process according to any one of claims 1 to 3, wherein a filtration unit _UF is located downstream of the melting unit _UM and upstream of the reaction unit _UR , for separating particles having a particle size in the range of 100 to 500 micrometers, preferably in the range of 200 to 400 micrometers, from the liquid _{stream SM} , wherein the process includes passing the stream liquid stream _SM through _UF before mixing according to (iv). The process according to any one of _claims 1 to 4, wherein, in accordance with (vi), _TD is in the range of 230 to 330°C and _pD is in the range of 40 to 140 bar, preferably _TD is in the range of 250 to 320°C and pD is in the range of 40 to 125 bar, more preferably _TD is in the range of 270 to 310°C and _pD is in the range of 40 to 110 bar. If the reaction unit U _R according to (v) comprises z chemical reactors _Ri , i = 1...z, where z is in the range of 1 to 10, preferably 1 to 8, more preferably 1 to 6, more preferably 1 to 5, more preferably 1 to 4, more preferably 1 to 3, and z > 1, then at least two reactors _Ri , preferably z reactors _Ri are connected in series,
- According to (v), the stream S _SF is supplied into _Ri , i = 1,
- An aqueous liquid stream S _i containing ε-caprolactam dissolved in water is taken from reactor R _i and supplied to reactor R _i+1 , where i < z,
- According to (vii), an aqueous liquid stream S _z containing ε-caprolactam dissolved in water is taken out of the reactor R _z as stream S _R ,
Herein, in all reactors _Ri , the depolymerization temperature T _Di is maintained at a depolymerization pressure p _Di , independently of each other, with T _Di in the range of 230 to 330°C and p _Di in the range of 40 to 140 bar, preferably T _Di in the range of 250 to 320°C and p _Di in the range of 40 to 125 bar, more preferably T _Di in the range of 270 to 310°C and p _Di in the range of 40 to 110 bar, and when z > 1, the z reactors _Ri are preferably arranged vertically, with R ₁ being the uppermost reactor and R _z being the lowermost reactor, and _Si obtained from _Ri moves to Ri _{+ 1} preferably by gravity, more preferably by gravity alone, according to any one of claims 1 to 5. At least one, preferably z, reactors _Ri are stirred tank reactors, preferably all stirred tank reactors _Ri have two to six compartments, more preferably two to five, more preferably two to four, independently of each other, the compartments are preferably arranged in series, more preferably in series and vertically, two adjacent compartments are separated by a partition including at least one flow opening, preferably at least one compartment in reactor _Ri has at least one stirrer, more preferably each compartment of all reactors _Ri has at least one stirrer, more preferably each compartment of all reactors _Ri has one stirrer, and the process includes the step of stirring the depolymerization mixture in a given compartment for at least a portion of the time while it is subjected to depolymerization conditions in the compartment.
Here, the depolymerization conditions for the polyamide 6 according to (vi) further comprise a total residence time tD of the aqueous depolymerization mixture in preferably unit U _R , more preferably z reactors _Ri , and more preferably z stirred tank reactors, wherein at least 85% by weight, preferably at least 90% by weight, and more preferably at least 95% by weight of the aqueous depolymerization mixture has _{a tD in} the range of 30 to 90 minutes.
The process according to claim 6, wherein, when z > 1, the residence time of the aqueous depolymerization mixture in reactor _Ri is t _Di , and preferably 0.90 ≤ (t _Di / t _{Di + 1} ) ≤ 1.10, more preferably 0.95 ≤ (t _Di / t _{Di + 1} ) ≤ 1.05. The process according to claim 6 or 7 _, comprising the step of taking a given gas stream S _Gi having a pressure p _Gi and a temperature T _Gi from at least one reactor _Ri , preferably all z reactors _Ri , such that 0.95 ≤ T _Gi / T _Di ≤ 1.05, wherein the process further comprises the step of combining at least one of the gas streams S _Gi , preferably all of the streams S _Gi , with the gas stream S _GM as defined in claim 3, before subjecting the gas stream S _GM to scrubbing, preferably as defined in claim 3. (i) The supply of the solid material M in accordance with (i)
(i.1) A step of supplying the solid material M into a delivery unit U _MD , wherein the U _MD preferably comprises one or more of at least one big bag station and at least one bulk container station.
(i.2) A step of passing the solid material M supplied in accordance with (i.1) from the unit U _MD to the material collection unit U _MC , preferably a collection drum, via a first connection line, wherein the first connection line preferably comprises one or more of at least one material receiving and discharging unit U _MRD , at least one first material supply unit U _FMF , and at least one first particle separation unit U _FMPS ,
(i.3) A step of passing the solid material M from the unit U _MC to the unit U _M via a second connection line, wherein the second connection line preferably comprises one or more of at least one second material supply unit U _SMF , at least one second particle separation unit U _SMPS , and at least one metal detector,
Here, the first connection line according to (i.2) preferably comprises at least one unit U _MRD , preferably at least one hopper, more preferably at least one one-zone hopper, and preferably further comprises at least one unit U _FMF , preferably at least one rotary feeder, and preferably further comprises at least one particle separation unit U _FMPS , more preferably at least one filter, more preferably at least one mesh filter,
To pass the solid material M from unit U _MD to unit U _MC via a first connection line, at least one gas stream S _G is preferably passed through the first connection line, and the at least one gas stream preferably contains, and more preferably contains, air or dilute air, and is present thereafter, before passing through the first connection line, the at least one gas stream is preferably pretreated by at least one of filtration, compression, and cooling, more preferably by filtration, compression, and cooling.
The process according to any one of claims 1 to 8, wherein the second connection line according to (i.3) preferably comprises at least two Unit U _SMFs , preferably at least two Unit U _SMFs comprising a rotary feeder and a weight loss feeder, wherein more preferably the rotary feeder is located upstream of the weight loss feeder and further comprises a Unit U _SMPS , preferably a vibrating screen. In accordance with (i), the solid material M is supplied in the form of granules, preferably supplied to U _M , where the particle size distribution of the granules is preferably characterized by one or more pairs of the following values, preferably two or more pairs of the following values, more preferably three pairs of the following values,
- D10 values for particle widths in the range of 0.3 to 15 mm, and D10 values for particle lengths in the range of 0.3 to 15 mm.
- D50 values for particle widths in the range of 0.5 to 20 mm, and D50 values for particle lengths in the range of 0.5 to 20 mm.
- D90 values for particle widths in the range of 0.8 to 30 mm, and D90 values for particle lengths in the range of 0.8 to 30 mm.
The process according to any one of claims 1 to 9, wherein preferably 10 to 100% by weight, more preferably 30 to 100% by weight, more preferably 50 to 100% by weight, more preferably 60 to 100% by weight, more preferably 70 to 100% by weight, and more preferably 80 to 100% by weight of the solid material M consists solely of polyamide 6. The process according to any one of _claims 1 to 10, wherein 90 to 100% by weight, preferably 91 to 100% by weight, more preferably 92 to 100% by weight, more preferably 93 to 100% by weight, more preferably 94 to 100% by weight, and more preferably 95 to 100% by weight of the liquid aqueous stream SW supplied in accordance with (iii) consists solely of water. The process according to any one of claims 1 to 11, wherein the solid material M supplied in accordance with (i) comprises, preferably, one or more of waste materials, preferably textile waste and engineering plastic waste, more preferably, textile waste, and preferably, solely thereof. According to (vii), the stream S _r comprises ε-caprolactam dissolved in water at concentration c _r , the stream S _r further comprises one or more impurities, and the process is as follows:
(viiii) The step of passing the liquid aqueous stream S _R through the evaporation unit U _E to obtain a liquid aqueous stream S _L containing ε-caprolactam dissolved in water at a concentration c SL _L such that c _{SL L >} c _SR from S R, and further obtaining one or more aqueous vapor streams S _V from S _R ,
(ix) A step of passing the aqueous stream _SL through a heat-consuming purification unit _UP to obtain a _{stream SCPL containing} ε-caprolactam from SL at a concentration _{cSCPL such that cSCPL >> cSL} , and further obtaining one or more aqueous streams _SRW from _SL , wherein at least a portion of the heat consumed in _UP is supplied by at least one of the one or more streams _SV , thereby obtaining at least one at least partially condensed aqueous stream _SVW from the at least one stream _SV ,
(x) The process according to any one of claims 1 to 12, further comprising the step of recycling at least one stream S _VW to the reaction unit U _R , and recycling at least one stream S _RW to the reaction unit U _R. The process further includes the step of supplying the stream S _CPL obtained according to (ix) to a polyamide 6 manufacturing unit U _PP , wherein the polyamide 6 produced in U _PP is preferably supplied as a raw material to a fiber material manufacturing unit U _TP , and from unit U _TP ,
(A) A textile material _MT is brought into the market, and after the service life _TMT of the textile material _MT , it is collected at least partially as textile waste in the textile material collection unit _UTC .
(B) The remaining material M _R is obtained as fiber waste.
The process according to claim 13, wherein at least a portion of the textile waste from (A), or at least a portion of the textile waste from (B), or at least a portion of the textile waste from (A) and at least a portion of the textile waste from (B) are appropriately supplied to _UR via _UM . Use of _SCPL that can be obtained or obtained by the process described in claim 16 for producing one or more polymers and polymer products, wherein the polymer, or the polymer product, or the polymer and the polymer product is in the form of at least one of granules, strands, rods, plates, pipes, foils, layers, films, sheets, fibers, filaments, coatings, extruded articles, molded articles, flexible foams, semi-rigid foams, and rigid foams; and the polymer, or the polymer product, or the polymer and the polymer product comprises polyamide 6 and optionally, optionally, at least one further polymer compound, wherein the at least one further polymer compound preferably comprises at least one polyamide 6.6; polyamide 6T and polyamide 6I A semi-aromatic polyamide; at least one polyethylene terephthalate; at least one polyurethane; at least one polyester; at least one polyether; at least one polyvinyl chloride; at least one natural fiber material, e.g., wool and cotton; at least one cellulose material; at least one natural elastomer; at least one synthetic elastomer; at least one copolymer of two or more of the aforementioned polymer compounds, including statistical copolymers, gradient copolymers, alternating copolymers, block copolymers and graft copolymers; and at least one rubber material comprising at least one natural rubber material and at least one synthetic rubber material,
The polymer, or the polymer product, or the polymer and the polymer product are preferably one or part of one of the following:
- Parts of an automobile, preferably cylinder head covers, engine covers, intake radiator housings, intake radiator flaps, intake pipes, intake manifolds, connectors, gear wheels, fan wheels, coolant boxes, heat exchanger housings or housing components, coolant coolers, intake radiators, thermostats, water pumps, radiators, fastening components or parts of battery systems for electric transport, dashboards, steering column switches, seats, headrests, center consoles, transmission components, door modules, automotive exteriors for A, B, C or D pillar covers, spoilers, door handles, exterior mirrors, windshield wipers, windshield wiper protective housings, decorative grilles, cover strips, roof rails, window frames, sunroof frames, antenna panels, headlights, taillights, airbags, and/or cushions;
- Cloth, clothing, preferably shirts, trousers, pullovers, boots, shoes, soles, tights and/or jackets;
- Electrical components, preferably electrical components, passive electronic components, active electronic components, printed circuit boards, housing components, wheels, lines, switches, e.g., microswitches, plugs, sockets, distributors, relays, resistors, capacitors, inductors, bobbins, lamps, diodes, e.g., LEDs, transistors, connectors, regulators, integrated circuits (ICs), processors, controllers, memory, sensors, microbuttons, semiconductors, e.g., reflector housings for light-emitting diodes, fasteners, spacers, bolts, strips, slide-in guides, screws, nuts, film hinges, snap hooks (snap-ins), and/or spring tongues for electrical and/or electronic components;
- Consumer and/or pharmaceutical products, preferably tennis strings, climbing ropes, bristols, brushes, artificial grass, 3D printing filaments, lawnmowers, zippers, hook-and-loop fasteners, paper machine garments, extruded coatings, fishing lines, fishing nets, seabed lines and ropes, vials, syringes, ampoules, bottles, sliding elements, spindle nuts, chain conveyors, plain bearings, rollers, wheels, gears, rollers, ring gears, screws and spring dampers, hoses, pipelines, cable sheaths, sockets, switches, cable ties, fan wheels, carpets, cosmetic boxes and/or bottles, mattresses, cushions, insulation materials;
- Packaging for the food industry, preferably single-layer and/or multi-layer inflated films, cast films (single-layer and/or multi-layer), biaxially oriented films, and laminate films.