CN110734578B - Method for separating and obtaining regenerated polyester from waste polyester raw material - Google Patents
Method for separating and obtaining regenerated polyester from waste polyester raw material Download PDFInfo
- Publication number
- CN110734578B CN110734578B CN201911107860.4A CN201911107860A CN110734578B CN 110734578 B CN110734578 B CN 110734578B CN 201911107860 A CN201911107860 A CN 201911107860A CN 110734578 B CN110734578 B CN 110734578B
- Authority
- CN
- China
- Prior art keywords
- polyester
- waste
- depolymerization
- polycondensation
- waste polyester
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J11/00—Recovery or working-up of waste materials
- C08J11/04—Recovery or working-up of waste materials of polymers
- C08J11/10—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation
- C08J11/18—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material
- C08J11/22—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds
- C08J11/24—Recovery or working-up of waste materials of polymers by chemically breaking down the molecular chains of polymers or breaking of crosslinks, e.g. devulcanisation by treatment with organic material by treatment with organic oxygen-containing compounds containing hydroxyl groups
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
- B29B9/00—Making granules
- B29B9/02—Making granules by dividing preformed material
- B29B9/06—Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
- B29C48/25—Component parts, details or accessories; Auxiliary operations
- B29C48/92—Measuring, controlling or regulating
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
- C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
- C08G63/16—Dicarboxylic acids and dihydroxy compounds
- C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
- C08G63/181—Acids containing aromatic rings
- C08G63/183—Terephthalic acids
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92504—Controlled parameter
- B29C2948/92514—Pressure
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92504—Controlled parameter
- B29C2948/9258—Velocity
- B29C2948/9259—Angular velocity
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92504—Controlled parameter
- B29C2948/92704—Temperature
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92819—Location or phase of control
- B29C2948/92857—Extrusion unit
- B29C2948/92876—Feeding, melting, plasticising or pumping zones, e.g. the melt itself
- B29C2948/92885—Screw or gear
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C2948/00—Indexing scheme relating to extrusion moulding
- B29C2948/92—Measuring, controlling or regulating
- B29C2948/92819—Location or phase of control
- B29C2948/92971—Fluids, e.g. for temperature control or of environment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
- C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/62—Plastics recycling; Rubber recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Sustainable Development (AREA)
- Separation, Recovery Or Treatment Of Waste Materials Containing Plastics (AREA)
Abstract
The application belongs to the field of waste polyester recycling, and particularly relates to a method for separating and obtaining regenerated polyester from waste polyester raw materials. A method for separating and obtaining recycled polyester from waste polyester raw materials comprises the following steps: 1) recycling the sorted polyester to prepare foam; 2) then carrying out melt granulation in a double-screw extruder, introducing a physical or chemical foaming agent in the granulation process, and forming micro holes on the surface and inside of the waste polyester granules after passing through a cooling water tank to obtain waste polyester granules containing micropores; 3) firstly, utilizing a dissolving agent to separate spandex and chinlon soluble impurities from the waste polyester granules containing micropores; 4) then depolymerizing the mixture and glycol in proportion under the action of a catalyst, and filtering to obtain high-purity waste polyester depolymerization liquid; 5) and finally, sending the prepared depolymerization product to a polycondensation kettle for pre-polycondensation, and performing final polycondensation to form a finished product. The method utilizes the foaming technology to prepare the waste polyester containing micropores, can carry out high-efficiency depolymerization, then prepares high-quality regenerated polyester, and realizes high-valued recycling of the waste polyester.
Description
Technical Field
The application belongs to the field of waste polyester recycling, and particularly relates to a method for separating and obtaining regenerated polyester from waste polyester raw materials.
Background
Polyethylene terephthalate (PET) is a polymer of terephthalic acid or dimethyl terephthalate and ethylene glycol. Due to good physical and chemical stability, processability and the like, the composite material is widely applied to the fields of textile clothing, decoration, food packaging and the like. However, because PET has very strong chemical inertness under natural conditions and is difficult to biodegrade, and a large amount of waste polyester exerts a great pressure on the environment, recycling waste polyester products, realizing effective recycling of resources, and reducing environmental pollution become important subjects of the polyester industry.
At present, the recycling of polyester waste materials mainly comprises a physical method and a chemical method. The physical method is mainly to make the waste polyester and the products thereof into regenerated chips through the processes of cutting, crushing, mixing, granulating and the like, and then reuse the regenerated chips, but the quality fluctuation of the regenerated chips is large, so that the preparation and the quality of the fibers are greatly influenced. The chemical method is mainly to depolymerize the waste polyester into raw materials or intermediates for producing the polyester by a chemical treatment method, such as a hydrolysis method, a methanol alcoholysis method, an ethylene glycol alcoholysis method and the like, and obtain high-quality raw material monomers by the procedures of purification, impurity removal and the like. At present, the pretreatment of materials before depolymerization mainly comprises the following steps: the waste silk and waste textile are cut or sheared and put into a depolymerization kettle, for example, the method of the 'pretreatment system of waste fiber and products' disclosed in the publication No. CN 105690600A. However, the bulk density of the waste is low, so that the waste is not easy to be soaked by a solvent, the liquid-solid ratio is increased, and the energy consumption and the material consumption are increased. In addition, waste silk and waste textile are made into foam materials by a friction granulation method, and then are put into a depolymerization kettle for depolymerization, for example, the method of 'recycling process of waste textile containing polyester' disclosed in the publication No. CN 105803585A. However, the rate of depolymerization is significantly reduced due to the larger size of the foam particles.
In addition, Chinese invention patents (such as publication numbers CN106283227A, CN106283226A, CN106279757A and the like) applied by Ningbo Dafa chemical fiber Limited company disclose a method for preparing high-quality melt by taking waste polyester textiles as raw materials, the method comprises the steps of adding alcohol with the mass of 1-8% of the raw materials into the raw materials, feeding the mixture into a screw extruder for blending, melting and extruding, wherein the melt viscosity of the melt discharged from the screw extruder is 0.40-0.50 dl/g, feeding the material into a thermal refining and viscosity adjusting device, and the melt viscosity of the melt discharged from the thermal refining and viscosity adjusting device is 0.620 dl/g-0.685 dl/g. In the applications, the problems of short filter period and large maintenance amount of a vacuum system are effectively solved while the melt viscosity is improved by adding a proper amount of glycol, and the additional value of the product can be improved while the production cost is reduced. However, these patents still do not solve the technical problem of significant reduction in depolymerization rate due to the large size of the foam particles.
Therefore, how to overcome the above-mentioned problem that exists in the waste polyester depolymerization edulcoration process, realize effectively not only can effectively to waste polyester depolymerization product edulcoration purification, can ensure filter equipment can last stable operation again, and it is the key of this application to prepare high-quality regeneration polyester.
Disclosure of Invention
In order to solve the technical problems, the present application aims to provide a method for separating and obtaining recycled polyester from waste polyester raw materials, wherein the method utilizes a foaming technology to prepare waste polyester containing micropores, can perform efficient depolymerization, then prepares high-quality recycled polyester, and realizes high-valued recycling of waste polyester.
In order to achieve the above object, the present application adopts the following technical solutions:
a method for separating and obtaining recycled polyester from waste polyester raw materials comprises the following steps:
1) sorting the recycled sorted polyester;
2) then carrying out melt granulation in a double-screw extruder, introducing a physical or chemical foaming agent in the granulation process, and forming micro holes on the surface and inside of the waste polyester granules after passing through a cooling water tank to obtain waste polyester granules containing micropores;
3) firstly, utilizing a dissolving agent to separate spandex and chinlon soluble impurities from the waste polyester granules containing micropores;
4) then depolymerizing the mixture and glycol in proportion under the action of a catalyst, and filtering to obtain high-purity waste polyester depolymerization liquid;
5) and finally, sending the prepared depolymerization product to a polycondensation kettle for pre-polycondensation, and performing final polycondensation to form a finished product.
Preferably, the recycled classified polyester includes one or more of recycled polyester bottle chips, polyester pulp, polyester fiber products and polyester waste filaments; wherein: firstly, densifying a polyester film or a polyester fiber product by a hot friction forming process to prepare a foam material, wherein the temperature of the preferred hot friction forming process is 150-260 ℃, the pressure is 0.1-10 MPa, and the time is 5-15 min; and cleaning and drying the polyester bottle chips or the polyester pulp blocks.
Preferably, the average cell diameter of the waste polyester pellets of step 2) is 30 to 200 μm, and the relative density is 0.3 to 0.7.
Preferably, the physical foaming agent in the step 2) is one or more of nitrogen, carbon dioxide, inert gas and the like; the chemical foaming agent is one or more of foaming agent AC (azodicarbonamide), foaming agent DPT (N, N-dinitrosopentamethylenetetramine), foaming agent ABIN (azodiisobutyronitrile), foaming agent OBSH (4, 4-disulfonylhydrazinodiphenyl ether) and foaming agent NTA (N, N-dimethyl-N, N-diterephthalamide), and is preferably foaming agent DPT.
Preferably, the temperature of the double-screw granulator is 220-320 ℃, the feeding percentage is 5-15%, the rotating speed of the screw is 40-80rpm, and the pressure is 70-100 Mpa; the gas introduction amount is 0.05-0.3L/min, and the ratio of the foaming agent to the waste polyester material is 1: 100-500.
Preferably, the double-screw granulator is added with a filtering device before the die head, and the filtering device is regulated to be 100-200 meshes.
Preferably, the dissolving agent in step 3) is one or a combination of several components selected from dimethylacetamide, N-dimethylformamide, dimethyl sulfoxide, diethyl ether, xylene, N-butanol, formic acid, m-cresol, triethylene glycol, tetrahydrofuran, 1-ethyl-3-methylimidazole bromide salt, trifluoroethanol, benzenediol, o-dichlorobenzene, cyclohexanone, cyclopentanone, acetone and N-methylpyrrolidone, and preferably N-dimethylformamide, dimethyl sulfoxide and formic acid; the dissolving temperature is 20-180 deg.C, and the dissolving time is 10-40 min.
Preferably, zinc acetate is preferably used as the depolymerization catalyst in the step 4).
Preferably, the depolymerization reaction in step 4) is carried out according to the ratio of the waste polyester repeating unit: putting the ethylene glycol into a depolymerization kettle according to the molar percentage of 1: 1-6, wherein the depolymerization kettle contains ethylene terephthalate and oligomers which account for 10-30% by mass of the total amount of the waste polyester, and a depolymerization catalyst is added; controlling the depolymerization reaction temperature to be 190-210 ℃, the reaction time to be 30 minutes-5 hours and the pressure to be 0.1-0.3 Mpa; multistage filtration is arranged between the polycondensation kettles of the depolymerization kettles, and the filtration precision is sequentially improved; obtain the depolymerization product containing the glycol terephthalate and the oligomer.
Preferably, the pre-polycondensation in the step 5) is performed by two steps, namely, a first polycondensation and a second polycondensation, wherein the reaction temperature of the first polycondensation is 230-250 ℃, the vacuum degree is 5-30 KPa, and the residence time is 1-3 hours, the reaction temperature of the second polycondensation is 250-280 ℃, the vacuum degree is 1-5 KPa, and the residence time is 1-3 hours; the final polycondensation reaction temperature is 275-290 ℃, the vacuum degree is 0.05-1 KPa, and the reaction time is 1-5 hours.
Preferably, the filtration is set to two stages, the first filtration is carried out after the depolymerization is finished, the second filtration is finished after the pre-polycondensation, the filtration precision is all 100-200 meshes, and the two precisions are sequentially improved.
Preferably, the polycondensation reaction needs to add a stabilizer in a pre-polycondensation stage, the stabilizer is triphenyl phosphate, triphenyl phosphite, trimethyl phosphate and the like, and triphenyl phosphate is preferred.
Further, the application also discloses that the waste polyester depolymerization liquid obtained in the step 4) is subjected to precipitation adsorption treatment and magnetic fluid sedimentation treatment to obtain the high-purity waste polyester depolymerization liquid, and the application introduces the whole contents of Chinese patent application numbers 2019110064695, 2019110065132 and 2019110065113.
[ l1] preferably, the precipitating agent for precipitation removal comprises the following components:
4-12 parts of nano calcium oxide
2-10 parts of diatomite
5-15 parts of nano aluminum oxide
1-6 parts of potassium hydroxide
2-10 parts of calcium carbonate
1-5 parts of hydroxyethyl cellulose sodium
2-10 parts of polyacrylamide.
As a further preference, the precipitant consists of:
6-8 parts of nano calcium oxide
3-5 parts of diatomite
8-10 parts of nano aluminum oxide
2-4 parts of potassium hydroxide
4-6 parts of calcium carbonate
2-3 parts of hydroxyethyl cellulose sodium
3-4 parts of polyacrylamide.
The application also discloses a preparation method of the precipitator, which comprises the steps of adding nano calcium oxide, diatomite, nano aluminum oxide, calcium carbonate, hydroxyethyl cellulose sodium and polyacrylamide into a grinder for grinding, sieving by a 100-mesh sieve, adding potassium hydroxide, mixing, adding into a stirring kettle for fully stirring at a stirring speed of 600 revolutions per minute for 50 minutes, and thus obtaining the precipitator.
As a further improvement, the impurity removal method also comprises the steps of removing impurities by magnetic fluid adsorption, continuously putting the filtrate into a magnetic fluid impurity remover after precipitation and impurity removal, rotationally mixing FeO magnetic fluid and the filtrate in the impurity remover, then disconnecting a magnetic base of the impurity remover to change the magnetic base into a permanent magnetic field, and after 10-20 minutes, downwards precipitating and layering magnetic particles to filter and remove nylon, spandex, a delustering agent, titanium dioxide and the like; preferably, the FeO magnetofluid is prepared by adopting an alcohol-water co-heating method according to Fe3+And Fe2+Fe in a molar ratio of 1-3:12(SO4)3Solution and FeSO4Mixing the solutions, heating to 60-70 deg.C, maintaining constant temperature, adding NaOH solution dropwise, stirring thoroughly to adjust pH to 10-12, stirring and adding anhydrous ethanol, standing for 20-30 min, adjusting pH, increasing temperature, stirring rapidly and adding 0.4-0.8 times of Fe2+The coating was carried out with the amount of sodium oleate surfactant, and then the formation of black magnetic particles was observed.
The beneficial effect of this application does: 1) the contact surface of the waste polyester granules containing micropores and the glycol is increased, so that the depolymerization reaction rate is accelerated, the yield of depolymerization products is improved, and the energy consumption and the production cost are reduced; 2) a certain amount of mother liquor is remained in the alcoholysis kettle, which can improve the depolymerization efficiency and stabilize the quality of depolymerization products; 3) The waste polyester granules containing micropores have high specific surface area, and are beneficial to dissolving out residual foaming agent and contained spandex, chinlon and the like; 4) the production of depolymerizable high polymers can be effectively reduced by adopting a lower reaction temperature and adding a stabilizer from depolymerization to esterification to polycondensation; 5) the final product formed by polycondensation has the intrinsic viscosity value of 0.60-0.70 dl/g, the melting point of 210-230 ℃, the ash content of less than or equal to 0.06% and the number of agglomerated particles of less than or equal to 1/mg.
Drawings
FIG. 1 is a graph showing the effects of the waste polyester granules containing fine pores prepared in example 1.
Detailed Description
Example 1
And cleaning and drying the recycled and classified Polyester (PET) bottle chips and Polyester (PET) pulp blocks, and then carrying out melt granulation in a double-screw extruder. Heating temperatures of all zones of the double-screw extruder are respectively 250 ℃, 260 ℃, 270 ℃, 280 ℃, 275 ℃, 270 ℃, feeding percentage of the screw is 15%, rotating speed is 50rpm, pressure is 3Mpa, foaming agent AC is selectively added to a micropore forming substance, the mass ratio of the foaming agent to the waste polyester is 1:200, the foaming agent is introduced into a fourth heating zone of the screw, and micropores are stably formed after granulation passes through a cooling water tank.
The waste polyester granules containing micropores prepared by the above-mentioned granulating step of microporous waste polyester have an average cell diameter of 85 μm and a relative density of 0.35. Average cell diameter test, the average of 100 average cell diameters was continuously measured as the diameter of the cells using an optical microscope. The method for testing the relative density of the microporous waste polyester refers to the GB1033-86 plastic density and relative density test method.
Putting the waste Polyester (PET) granules containing micropores into a dissolving agent containing N-N dimethylformamide and formic acid in a ratio of 1:1, heating to 120 ℃, fully soaking for 20min, performing solid-liquid separation, rinsing the waste Polyester (PET) granules containing micropores in a purified water cleaning pool, and finally drying at 150 ℃ to prepare the waste polyester granules containing micropores to be subjected to alcoholysis.
The prepared waste polyester (repeating unit) granules containing micropores and ethylene glycol are put into a depolymerization reaction kettle according to the proportion of 1:3 in mole percent, and depolymerization reaction is carried out for 1.5 hours at 196 ℃ under the catalysis of 0.2 MPa and 0.2% w of zinc acetate, thus preparing the depolymerization product containing the ethylene glycol terephthalate. The prepared depolymerized liquid passes through a 100-mesh filtering device, and impurities and insoluble substances in the depolymerized liquid are filtered out primarily. Obtaining high-purity depolymerization liquid.
In the depolymerization solution after the depolymerization impurity removal step, the content of chinlon is less than 0.03 percent, the content of spandex is less than 0.05 percent, and the alcoholysis rate of PET is 99.2 percent.
And (3) adding the depolymerization liquid after impurity removal and a stabilizer into a pre-polycondensation kettle together, and starting low-vacuum pre-polycondensation reaction twice under the negative pressure condition. The first pre-polycondensation is stably pumped from normal pressure to about 24Kpa absolute pressure, the temperature is controlled at 270 ℃, and the reaction time is 30 min; filtering by using a filter screen with the specification of 150 meshes after the first pre-polycondensation is finished; carrying out second pre-polycondensation reaction on the filtrate, reducing the reaction pressure to 4Kpa absolute, controlling the reaction temperature at 275 ℃ and the reaction time to be 30 min; then, the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is reduced to 0.2Kpa absolute pressure, the reaction temperature is controlled at 285 ℃, the reaction time is 3 hours, and the high-quality regenerated polyester is prepared.
The prepared regenerated polyester has the intrinsic viscosity value of 0.61dl/g, the melting point of 244 ℃, the ash content of less than or equal to 0.05 percent and the number of agglomerated particles of less than or equal to 1/mg.
Example 2
The recycled and classified Polyester (PET) film and Polyester (PET) fiber products (curtains, carpets, clothes and the like) are densified by a hot friction forming process under the conditions of 220 ℃ of temperature, 3MPa of pressure and 10min of time to prepare the foam material. And then melting and granulating the foam material in a double-screw extruder. Heating temperatures of all zones of the double-screw extruder are 265 ℃, 270 ℃, 275 ℃, 280 ℃, 275 ℃, 270 ℃ and 270 ℃, feeding percentage of the screw is 30%, rotating speed of the screw is 65rpm, pressure is 6Mpa, foaming agent ABIN is selected as a micropore forming substance, the mass ratio of the foaming agent to the waste polyester is 1:250, the foaming agent is mixed in a fourth heating zone of the screw, and micropores are stably formed after the granulation is finished and pass through a cooling water tank.
The waste polyester pellets containing fine pores prepared by the above-mentioned fine pore waste polyester pelletizing step had an average cell diameter of 82 μm and a relative density of 0.55.
Putting the waste Polyester (PET) granules containing micropores into a dissolving agent containing N-N dimethylformamide and formic acid in a ratio of 1:1, heating to 120 ℃, fully soaking for 20min, performing solid-liquid separation, rinsing the waste Polyester (PET) granules containing micropores in a purified water cleaning pool, and finally drying at 150 ℃ to prepare the waste polyester granules containing micropores to be subjected to alcoholysis.
The prepared waste polyester (repeating unit) granules containing micropores and ethylene glycol are put into a depolymerization reaction kettle according to the proportion of 1:3 in mole percent, and depolymerization reaction is carried out for 1.5 hours at 196 ℃ under the catalysis of 0.2 MPa and 0.2% w of zinc acetate, thus preparing the depolymerization product containing the ethylene glycol terephthalate. The prepared depolymerized liquid passes through a 100-mesh filtering device, and impurities and infusible matters in the depolymerized liquid are filtered out primarily. Obtaining high-purity depolymerization liquid.
In the depolymerization solution after the depolymerization impurity removal step, the content of the chinlon is less than 0.04 percent, the content of the spandex is less than 0.05 percent, and the alcoholysis rate of the PET is 99.2 percent.
And (3) adding the depolymerization liquid after impurity removal and a stabilizer into a pre-polycondensation kettle together, and starting low-vacuum pre-polycondensation reaction twice under the negative pressure condition. The first pre-polycondensation is stably pumped from normal pressure to about 24Kpa absolute pressure, the temperature is controlled at 270 ℃, and the reaction time is 30 min; filtering by using a filter screen with the specification of 150 meshes after the first pre-polycondensation is finished; carrying out second pre-polycondensation reaction on the filtrate, reducing the reaction pressure to 4Kpa absolute, controlling the reaction temperature at 275 ℃ and the reaction time to be 30 min; then, the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is reduced to 0.2Kpa absolute pressure, the reaction temperature is controlled at 285 ℃, the reaction time is 3 hours, and the high-quality regenerated polyester is prepared.
The prepared regenerated polyester has the intrinsic viscosity value of 0.60dl/g, the melting point of 248 ℃, the ash content of less than or equal to 0.05 percent and the number of agglomerated particles of less than or equal to 1/mg.
Example 3
And cleaning and drying the recycled and classified Polyester (PET) bottle chips and Polyester (PET) pulp blocks, and then carrying out melt granulation in a double-screw extruder. Heating temperatures of all zones of the double-screw extruder are respectively 260 ℃, 270 ℃, 280 ℃, 285 ℃, 275 ℃, 270 ℃ and 270 ℃, screw feeding percentage is 45%, rotation speed is 45rpm, pressure is 75Mpa, screw feeding percentage is 45%, screw rotation speed is 65rpm, pressure is 8.5Mpa, foaming agent DPT and foaming agent ADC are selected as micropore forming substances, the ratio is 1:1, the mass ratio of the foaming agent to the waste polyester is 1:500, the foaming agent is mixed in a fourth heating zone of the screw in a feeding mode, and after granulation is finished, micropores are stably formed after passing through a cooling water tank.
The waste polyester pellets containing fine pores prepared by the above-mentioned fine pore waste polyester pelletizing step had an average cell diameter of 75 μm and a relative density of 0.68.
Putting the waste Polyester (PET) granules containing micropores into a dissolving agent containing N-N dimethylformamide and formic acid in a ratio of 1:1, heating to 120 ℃, fully soaking for 20min, performing solid-liquid separation, rinsing the waste Polyester (PET) granules containing micropores in a purified water cleaning pool, and finally drying at 150 ℃ to prepare the waste polyester granules containing micropores to be subjected to alcoholysis.
The prepared waste polyester (repeating unit) granules containing micropores and ethylene glycol are put into a depolymerization reaction kettle according to the proportion of 1:3 in mole percent, and depolymerization reaction is carried out for 1.5 hours at 196 ℃ under the catalysis of 0.2 MPa and 0.2% w of zinc acetate, thus preparing the depolymerization product containing the ethylene glycol terephthalate. The prepared depolymerized liquid passes through a 100-mesh filtering device, and impurities and infusible matters in the depolymerized liquid are filtered out primarily. Obtaining high-purity depolymerization liquid.
In the depolymerization solution after the depolymerization impurity removal step, the content of chinlon is less than 0.03 percent, the content of spandex is less than 0.05 percent, and the alcoholysis rate of PET is 99.5 percent.
And (3) adding the depolymerization liquid after impurity removal and a stabilizer into a pre-polycondensation kettle together, and starting low-vacuum pre-polycondensation reaction twice under the negative pressure condition. The first pre-polycondensation is stably pumped from normal pressure to about 24Kpa absolute pressure, the temperature is controlled at 270 ℃, and the reaction time is 30 min; filtering by using a filter screen with the specification of 150 meshes after the first pre-polycondensation is finished; carrying out second pre-polycondensation reaction on the filtrate, reducing the reaction pressure to 4Kpa absolute, controlling the reaction temperature at 275 ℃ and the reaction time to be 30 min; then, the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is reduced to 0.2Kpa absolute pressure, the reaction temperature is controlled at 285 ℃, the reaction time is 3 hours, and the high-quality regenerated polyester is prepared.
The prepared regenerated polyester has the intrinsic viscosity value of 0.62dl/g, the melting point of 249 ℃, the ash content of less than or equal to 0.05 percent and the number of agglomerated particles of less than or equal to 1/mg.
Example 4
Adding the recycled Polyester (PET) bottle flakes, Polyester (PET) slurry blocks and the like into a screw granulator, and introducing nitrogen gas to perform melt granulation together. The heating temperature of each zone of the screw granulator is 250 ℃, 260 ℃, 270 ℃, 280 ℃, 275 ℃, 270 ℃, the screw feeding percentage is 15 percent, the rotating speed is 45rpm, the pressure is 75Mpa, the gas inlet amount is 0.1L/min, and the filtration specification is 100 meshes. And introducing nitrogen gas at the gas introduction amount of 0.1L/min at the fourth heating zone of the screw for forming the micropores, stably forming the micropores after the extruded material belt passes through a cooling water tank, and finally cutting into granules.
The waste polyester pellets containing fine pores prepared by the above waste polyester granulation step had an average cell diameter of 115 μm and a relative density of 0.70.
Putting the waste Polyester (PET) granules containing micropores into a dissolving agent containing N-N dimethylformamide and formic acid in a ratio of 1:1, heating to 120 ℃, fully soaking for 20min, performing solid-liquid separation, rinsing the waste Polyester (PET) granules containing micropores in a purified water cleaning pool, and finally drying at 150 ℃ to prepare the waste polyester granules containing micropores to be subjected to alcoholysis.
The prepared waste polyester (repeating unit) granules containing micropores and ethylene glycol are put into a depolymerization reaction kettle according to the proportion of 1:3 in mole percent, and depolymerization reaction is carried out for 1.5 hours at 196 ℃ under the catalysis of 0.2 MPa and 0.2% w of zinc acetate, thus preparing the depolymerization product containing the ethylene glycol terephthalate. The prepared depolymerized liquid passes through a 100-mesh filtering device, and impurities and infusible matters in the depolymerized liquid are filtered out primarily. Obtaining high-purity depolymerization liquid.
In the depolymerization solution after the depolymerization impurity removal step, the content of chinlon is less than 0.03 percent, the content of spandex is less than 0.05 percent, and the alcoholysis rate of PET is 99.4 percent.
And (3) adding the depolymerization liquid after impurity removal and a stabilizer into a pre-polycondensation kettle together, and starting low-vacuum pre-polycondensation reaction twice under the negative pressure condition. The first pre-polycondensation is stably pumped from normal pressure to about 24Kpa absolute pressure, the temperature is controlled at 270 ℃, and the reaction time is 30 min; filtering by using a filter screen with the specification of 150 meshes after the first pre-polycondensation is finished; carrying out second pre-polycondensation reaction on the filtrate, reducing the reaction pressure to 4Kpa absolute, controlling the reaction temperature at 275 ℃ and the reaction time to be 30 min; then, the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is reduced to 0.2Kpa absolute pressure, the reaction temperature is controlled at 285 ℃, the reaction time is 3 hours, and the high-quality regenerated polyester is prepared.
The prepared regenerated polyester has the intrinsic viscosity value of 0.62dl/g, the melting point of 253 ℃, the ash content of less than or equal to 0.04 percent and the number of agglomerated particles of less than or equal to 1/mg.
Example 5
The recycled and classified Polyester (PET) film and Polyester (PET) fiber products (curtains, carpets, clothes and the like) are densified by a hot friction forming process under the conditions of 220 ℃ of temperature, 3MPa of pressure and 10min of time to prepare foam materials, and then the foam materials are melted and granulated in a double-screw extruder. The heating temperature of each zone of the double-screw extruder is 265 ℃, 270 ℃, 275 ℃, 280 ℃, 275 ℃, 270 ℃ and 270 ℃, the screw feeding percentage is 30 percent, the screw rotating speed is 60rpm, the pressure is 4.5Mpa, and the specification of the filtering device is 200 meshes. Selective introduction of CO for micropore formation2The gas introduction amount is 0.3L/min, the introduction position is a fourth heating area of the screw, and the micropore forming is stable after the granulation is finished and passes through the cooling water tank.
The waste polyester granules containing micropores prepared by the above-mentioned granulating step of microporous waste polyester have cells of 110 μm and a relative density of 0.68.
Putting the waste Polyester (PET) granules containing micropores into a dissolving agent containing N-N dimethylformamide and formic acid in a ratio of 1:1, heating to 120 ℃, fully soaking for 20min, performing solid-liquid separation, rinsing the waste Polyester (PET) granules containing micropores in a purified water cleaning pool, and finally drying at 150 ℃ to prepare the waste polyester granules containing micropores to be subjected to alcoholysis.
The prepared waste polyester (repeating unit) granules containing micropores and ethylene glycol are put into a depolymerization reaction kettle according to the proportion of 1:3 in mole percent, and depolymerization reaction is carried out for 1.5 hours at 196 ℃ under the catalysis of 0.2 MPa and 0.2% w of zinc acetate, thus preparing the depolymerization product containing the ethylene glycol terephthalate. The prepared depolymerized liquid passes through a 100-mesh filtering device, and impurities and infusible matters in the depolymerized liquid are filtered out primarily. Obtaining high-purity depolymerization liquid.
In the depolymerization solution after the depolymerization impurity removal step, the content of the chinlon is less than 0.04 percent, the content of the spandex is less than 0.05 percent, and the alcoholysis rate of the PET is 99.3 percent.
And (3) adding the depolymerization liquid after impurity removal and a stabilizer into a pre-polycondensation kettle together, and starting low-vacuum pre-polycondensation reaction twice under the negative pressure condition. The first pre-polycondensation is stably pumped from normal pressure to about 24Kpa absolute pressure, the temperature is controlled at 270 ℃, and the reaction time is 30 min; filtering by using a filter screen with the specification of 150 meshes after the first pre-polycondensation is finished; carrying out second pre-polycondensation reaction on the filtrate, reducing the reaction pressure to 4Kpa absolute, controlling the reaction temperature at 275 ℃ and the reaction time to be 30 min; then, the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is reduced to 0.2Kpa absolute pressure, the reaction temperature is controlled at 285 ℃, the reaction time is 3 hours, and the high-quality regenerated polyester is prepared.
The prepared regenerated polyester has the intrinsic viscosity value of 0.62dl/g, the melting point of 255 ℃, the ash content of less than or equal to 0.03 percent and the number of agglomerated particles of less than or equal to 1/mg.
Example 6
And cleaning and drying the recycled and classified Polyester (PET) bottle chips and Polyester (PET) pulp blocks, and then carrying out melt granulation in a double-screw extruder. The heating temperature of each zone of the double-screw extruder is 260 ℃, 270 ℃, 280 ℃, 285 ℃, 275 ℃, 270 ℃ and 270 ℃, the screw feeding percentage is 45 percent, the rotating speed is 80rpm, the pressure is 75Mpa, the screw feeding percentage is 12 percent, the rotating speed is 65rpm, and the pressure is 7.5Mpa, selecting the specification of the filtering device to be 100 meshes. Selective introduction of N into the pore former2：CO2The mixed gas is 1:1, the gas is introduced into the fourth heating zone of the screw in a way of introducing the mixed gas with the gas at the introduction amount of 0.5L/min, and the mixed gas passes through a cooling water tank after granulation is finished and then is stably formed by micropores.
The waste polyester pellets containing fine pores prepared by the above-mentioned fine pore waste polyester pelletizing step had an average cell diameter of 113 μm and a relative density of 0.60. Average cell diameter test, the average of 100 average cell diameters was continuously measured as the diameter of the cells using an optical microscope. The method for testing the relative density of the microporous waste polyester refers to the GB1033-86 plastic density and relative density test method.
Putting the waste Polyester (PET) granules containing micropores into a dissolving agent containing N-N dimethylformamide and formic acid in a ratio of 1:1, heating to 120 ℃, fully soaking for 20min, performing solid-liquid separation, rinsing the waste Polyester (PET) granules containing micropores in a purified water cleaning pool, and finally drying at 150 ℃ to prepare the waste polyester granules containing micropores to be subjected to alcoholysis.
The prepared waste polyester (repeating unit) granules containing micropores and ethylene glycol are put into a depolymerization reaction kettle according to the proportion of 1:3 in mole percent, and depolymerization reaction is carried out for 1.5 hours at 196 ℃ under the catalysis of 0.2 MPa and 0.2% w of zinc acetate, thus preparing the depolymerization product containing the ethylene glycol terephthalate. The prepared depolymerized liquid passes through a 100-mesh filtering device, and impurities and infusible matters in the depolymerized liquid are filtered out primarily. Obtaining high-purity depolymerization liquid.
In the depolymerization solution after the depolymerization impurity removal step, the content of chinlon is less than 0.03 percent, the content of spandex is less than 0.05 percent, and the alcoholysis rate of PET is 99.5 percent.
And (3) adding the depolymerization liquid after impurity removal and a stabilizer into a pre-polycondensation kettle together, and starting low-vacuum pre-polycondensation reaction twice under the negative pressure condition. The first pre-polycondensation is stably pumped from normal pressure to about 24Kpa absolute pressure, the temperature is controlled at 270 ℃, and the reaction time is 30 min; filtering by using a filter screen with the specification of 150 meshes after the first pre-polycondensation is finished; carrying out second pre-polycondensation reaction on the filtrate, reducing the reaction pressure to 4Kpa absolute, controlling the reaction temperature at 275 ℃ and the reaction time to be 30 min; then, the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is reduced to 0.2Kpa absolute pressure, the reaction temperature is controlled at 285 ℃, the reaction time is 3 hours, and the high-quality regenerated polyester is prepared.
The prepared regenerated polyester has the intrinsic viscosity value of 0.63dl/g, the melting point of 246 ℃, the ash content of less than or equal to 0.03 percent and the number of agglomerated particles of less than or equal to 1/mg.
Comparative example 1
The recycled and classified Polyester (PET) bottle chips and Polyester (PET) pulp blocks are washed and dried, and then are subjected to melt granulation in a screw extruder. The heating temperature of each zone of the double-screw extruder is respectively 250 ℃, 260 ℃, 270 ℃, 280 ℃, 275 ℃, 270 ℃, the screw feeding percentage is 20 percent, the rotating speed is 50rpm, the pressure is 5.5Mpa, and the specification of the filtering device is 200 meshes. The extruded material belt passes through a cooling water tank and is cut into granules.
The relative density of the waste polyester pellets prepared through the above waste polyester granulation step was 1.27.
The dissolving agent is selected from N-N dimethylformamide and formic acid according to the ratio of 1:1, the dipping time is controlled to be 30min, the dipping temperature is 110 ℃, the waste polyester (repeating unit) and ethylene glycol are in a molar percentage of 1:3, the depolymerization reaction temperature is 200 ℃, the pressure is 0.2 MPa, and the depolymerization time is 2.5 hours, so that the final depolymerized liquid contains 0.10% of chinlon, 0.08% of spandex and 98.2% of PET alcoholysis rate.
And (3) adding the depolymerization liquid after impurity removal and a stabilizer into a pre-polycondensation kettle together, and starting low-vacuum pre-polycondensation reaction twice under the negative pressure condition. The first pre-polycondensation is stably pumped from normal pressure to about 24Kpa absolute pressure, the temperature is controlled at 270 ℃, and the reaction time is 30 min; filtering by using a filter screen with the specification of 150 meshes after the first pre-polycondensation is finished; carrying out second pre-polycondensation reaction on the filtrate, reducing the reaction pressure to 4Kpa absolute, controlling the reaction temperature at 275 ℃ and the reaction time to be 30 min; then, the vacuum pumping is continued, the polycondensation reaction in the high vacuum stage is carried out, the reaction pressure is reduced to 0.2Kpa absolute pressure, the reaction temperature is controlled at 285 ℃, the reaction time is 3 hours, and the high-quality regenerated polyester is prepared.
The prepared regenerated polyester has the intrinsic viscosity value of 0.60dl/g, the melting point of 248 ℃, the ash content of less than or equal to 0.15 percent and the number of agglomerated particles of less than or equal to 5/mg.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present disclosure, including any person skilled in the art, having the benefit of the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (13)
1. A method for separating and obtaining recycled polyester from waste polyester raw materials is characterized by comprising the following steps:
1) sorting the recycled sorted polyester;
2) then carrying out melt granulation in a double-screw extruder, introducing a physical or chemical foaming agent in the granulation process, and forming micro holes on the surface and inside of the waste polyester granules after passing through a cooling water tank to obtain waste polyester granules containing micropores; the average cell diameter of the waste polyester granules is 30-200 mu m, and the relative density is 0.3-0.7;
3) firstly, utilizing a dissolving agent to separate spandex and chinlon soluble impurities from the waste polyester granules containing micropores; the dissolving agent is one or a combination of more of dimethylacetamide, N-N dimethylformamide, dimethyl sulfoxide, diethyl ether, xylene, N-butanol, formic acid, m-cresol, triethylene glycol, tetrahydrofuran, 1-ethyl-3-methylimidazole bromine salt, trifluoroethanol, benzenediol, o-dichlorobenzene, cyclohexanone, cyclopentanone, acetone and N-methylpyrrolidone; the dissolving temperature is 20-180 deg.C, and the dissolving time is 10-40 min;
4) then depolymerizing the mixture and glycol in proportion under the action of a catalyst, and filtering to obtain high-purity waste polyester depolymerization liquid;
the depolymerization reaction is carried out according to the repeated unit of the waste polyester: putting the ethylene glycol into a depolymerization kettle according to the molar percentage of 1: 1-6, wherein the depolymerization kettle contains ethylene terephthalate and oligomers which account for 10-30% by mass of the total amount of the waste polyester, and a depolymerization catalyst is added; controlling the depolymerization reaction temperature to be 190-210 ℃, the reaction time to be 30 minutes-5 hours and the pressure to be 0.1-0.3 Mpa; multistage filtration is arranged between the depolymerization kettle and the polycondensation kettle, and the filtration precision is sequentially improved; obtaining a depolymerization product containing the glycol terephthalate and the oligomer;
5) and finally, sending the prepared depolymerization product to a polycondensation kettle for pre-polycondensation, and performing final polycondensation to form a finished product.
2. The method for separating and obtaining recycled polyester from waste polyester raw material according to claim 1, wherein the recycled classified polyester comprises one or more of recycled polyester bottle chips, polyester pulp, polyester fiber products and polyester waste silk; wherein: firstly, densifying the polyester fiber product by a hot friction forming process to prepare a foam material; and cleaning and drying the polyester bottle chips or the polyester pulp blocks.
3. The method for separating and obtaining the recycled polyester from the waste polyester raw material according to claim 2, wherein the temperature of the hot friction forming process is 150-260 ℃, the pressure is 0.1-10 MPa, and the time is 5-15 min.
4. The method for separating and obtaining recycled polyester from waste polyester raw material according to claim 1, wherein the physical foaming agent in step 2) is one or more of nitrogen, carbon dioxide and inert gas; the chemical foaming agent is one or a combination of more of foaming agent AC, foaming agent DPT, foaming agent ABIN, foaming agent OBSH and foaming agent NTA.
5. The method for separating recycled polyester from waste polyester as claimed in claim 4, wherein the twin-screw extruder temperature is 220 ℃ and 320 ℃, the feeding percentage is 5% -15%, the screw rotation speed is 40-80rpm, and the pressure is 70-100 MPa.
6. The method for separating and obtaining recycled polyester from waste polyester raw material as claimed in claim 4, wherein the gas is introduced in an amount of 0.05-0.3L/min when the physical foaming agent is introduced; when the chemical foaming agent is adopted, the ratio of the chemical foaming agent to the waste polyester material is 1: 100-500.
7. The method for separating and obtaining recycled polyester from waste polyester raw material as claimed in claim 1, wherein the twin-screw granulator is added with a filtering device before the die head, and the filtering device is regulated to be 100-200 mesh.
8. The method for separating and obtaining recycled polyester from waste polyester raw material according to claim 1, wherein the depolymerization catalyst of step 4) is preferably zinc acetate.
9. The method for separating and obtaining the recycled polyester from the waste polyester raw material according to claim 1, wherein the pre-polycondensation in the step 5) is performed twice, namely, a first polycondensation and a second polycondensation, wherein the reaction temperature of the first polycondensation is 230-250 ℃, the vacuum degree is 5-30 kPa, the residence time is 1-3 hours, the reaction temperature of the second polycondensation is 250-280 ℃, the vacuum degree is 1-5 kPa, and the residence time is 1-3 hours; the final polycondensation reaction temperature is 275-290 ℃, the vacuum degree is 0.05-1 kPa, and the reaction time is 1-5 hours.
10. The method of claim 9, wherein the polycondensation reaction requires the addition of a stabilizer, which is triphenyl phosphate, triphenyl phosphite or trimethyl phosphate, during the pre-polycondensation stage.
11. The method for separating and obtaining recycled polyester from waste polyester raw material as claimed in claim 10, wherein the stabilizer is triphenyl phosphate.
12. The method as claimed in claim 1, wherein the filtration is performed in two stages, the first filtration is performed after the depolymerization is completed, the second filtration is performed after the pre-polycondensation, the filtration precision is all within 200 meshes, and the two filtration precisions are sequentially improved.
13. The method for separating and obtaining recycled polyester from waste polyester raw material according to claim 1, wherein the dissolving agent is N-N dimethylformamide, dimethyl sulfoxide or formic acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911107860.4A CN110734578B (en) | 2019-11-13 | 2019-11-13 | Method for separating and obtaining regenerated polyester from waste polyester raw material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911107860.4A CN110734578B (en) | 2019-11-13 | 2019-11-13 | Method for separating and obtaining regenerated polyester from waste polyester raw material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110734578A CN110734578A (en) | 2020-01-31 |
| CN110734578B true CN110734578B (en) | 2022-03-11 |
Family
ID=69272829
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911107860.4A Active CN110734578B (en) | 2019-11-13 | 2019-11-13 | Method for separating and obtaining regenerated polyester from waste polyester raw material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110734578B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114350017B (en) * | 2022-01-26 | 2024-04-16 | 余姚大发化纤有限公司 | Production system for efficiently removing spandex in waste polyester textiles |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102352091A (en) * | 2010-04-29 | 2012-02-15 | 阿玛赛尔企业有限公司 | Cellular polyester made of post-consumer flakes and the use of products made thereof |
| CN110273197A (en) * | 2019-05-20 | 2019-09-24 | 福建师范大学福清分校 | A kind of regeneration coloured silk yarn and preparation method thereof of discarded terylene textile fabric production |
| CN110382604A (en) * | 2017-03-10 | 2019-10-25 | 阿尔温莱纳股份有限两合公司阿尔普拉工厂 | Prepare the method for foaming granule material and the purposes of the foaming granule material |
-
2019
- 2019-11-13 CN CN201911107860.4A patent/CN110734578B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102352091A (en) * | 2010-04-29 | 2012-02-15 | 阿玛赛尔企业有限公司 | Cellular polyester made of post-consumer flakes and the use of products made thereof |
| CN110382604A (en) * | 2017-03-10 | 2019-10-25 | 阿尔温莱纳股份有限两合公司阿尔普拉工厂 | Prepare the method for foaming granule material and the purposes of the foaming granule material |
| CN110273197A (en) * | 2019-05-20 | 2019-09-24 | 福建师范大学福清分校 | A kind of regeneration coloured silk yarn and preparation method thereof of discarded terylene textile fabric production |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110734578A (en) | 2020-01-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN111138641B (en) | Method for preparing bottle-grade slices by recycling waste polyester bottles | |
| CN110845723B (en) | Method for preparing copolyester amide by online adding polyamide to depolymerized waste polyester | |
| CN111088545B (en) | Preparation method of cationic dye dyeable regenerated cotton-like polyester fiber | |
| WO2012027935A1 (en) | Method for producing terylene fiber using polyester waste | |
| CN1418184A (en) | Method of chemical recycling of polyethylene terephthalate waste | |
| JP2012041463A (en) | Method for regenerating recovered polyester resin and molded article using recycled polyester resin | |
| CN110616474B (en) | Method for preparing skin-core composite low-melting-point regenerated polyester fiber from waste polyester textile | |
| CN110698658B (en) | Method for preparing colored polyester by chain decomposition of waste polyester | |
| CN110862535B (en) | Method for preparing copolyester amide by depolymerizing waste polyester containing chinlon | |
| CN108486683B (en) | PET/PVA sea-island fiber with water-soluble sea phase and production process thereof | |
| CN110734578B (en) | Method for separating and obtaining regenerated polyester from waste polyester raw material | |
| CN112680829A (en) | Preparation method of recycled polyester and polypropylene sheath-core composite fiber | |
| CN112725932A (en) | Preparation method of antimony-free polyester POY (polyester pre-oriented yarn) filament with high moisture absorption and sweat releasing performance | |
| CN110818943B (en) | Method for preparing waste polyester particles containing micropores by gas foaming | |
| CN110791063B (en) | Waste polyester particles containing micropores and preparation method and application thereof | |
| CN110760097A (en) | Method for separating polyester and polyamide depolymerization from polyamide-containing waste polyester material | |
| CN114015112A (en) | PET waste recycling and regenerating method and polyester material prepared by same | |
| CN112608514A (en) | Method for preparing antibacterial regenerated polyester by using waste polyester alcoholysis method | |
| CN114921868B (en) | Preparation method of nano biochar modified melt direct-spun superfine denier polyester fiber | |
| CN115896976A (en) | Regenerated low-melting-point polyester composite fiber with flame retardant function and preparation method thereof | |
| CN115726057A (en) | Regenerated low-melting-point polyester composite fiber with ultraviolet shielding function and preparation method thereof | |
| CN113699606A (en) | Production method of waste polyester regenerated melt direct-spinning high-strength polyester industrial yarn | |
| CN113087885B (en) | Production method of recycled polyester chips | |
| CN110835420B (en) | Waste polyester blending particle containing chinlon, and preparation method and application thereof | |
| CN116695284A (en) | Method for producing regenerated fibers by taking waste terylene/chinlon hybrid fabrics as raw materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20220810 Address after: No.266 Binhai 2nd Road, Hangzhou Bay New District, Ningbo City, Zhejiang Province Patentee after: Ningbo Dafa New Material Co.,Ltd. Address before: 315300 Binhai 2nd Road, Hangzhou Bay New Area, Cixi Economic Development Zone, Ningbo City, Zhejiang Province Patentee before: NINGBO DAFA CHEMICAL FIBER Co.,Ltd. |
|
| TR01 | Transfer of patent right |