METHOD FOR IMPROVING RECOVERY RATE OF RECYCLED BIS(2-HYDROXYETHYL) TEREPHTHALATE

    公开(公告)号:US20230081251A1

    公开(公告)日:2023-03-16

    申请号:US17872287

    申请日:2022-07-25

    Abstract: A method for improving a recovery rate of recycled bis(2-hydroxyethyl) terephthalate (BHET) is provided, which includes: providing a recycled polyester fabric; using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing BHET; dissolving the BHET in water to form a aqueous phase liquid; cooling the aqueous phase liquid from a dissolution temperature to a first crystallization temperature, so as to crystallize at least a part of the BHET; and cooling the aqueous phase liquid from the first crystallization temperature to a second crystallization temperature, so as to crystallize at least another part of the BHET.

    METHOD FOR PRODUCING RECYCLED POLYESTER CHIPS FROM RECYCLED POLYESTER FABRIC

    公开(公告)号:US20230080748A1

    公开(公告)日:2023-03-16

    申请号:US17862730

    申请日:2022-07-12

    Abstract: A method for producing recycled polyester chips from a recycled polyester fabric is provided. The method includes: providing the recycled polyester fabric attached with dyes and/or coating glue; performing a color removal process to at least partially remove the dyes and/or the coating glue attached to the polyester fabric; performing a de-polymerization process which includes: using a chemical de-polymerization liquid to chemically depolymerize the recycled polyester fabric, so as to form a de-polymerization product containing bis(2-hydroxyethyl) terephthalate (BHET) and oligomers; performing a purification process, so as to enhance a purity of the BHET in the de-polymerization product; and performing a granulation process, so as to re-polymerize the purified BHET and form the recycled polyester chips (r-PET).

    METHOD FOR RECYCLING POLYESTER FABRIC

    公开(公告)号:US20230093536A1

    公开(公告)日:2023-03-23

    申请号:US17862369

    申请日:2022-07-11

    Abstract: A method for recycling a polyester fabric is provided. The method includes providing a polyester fabric that is dyed and has dye and water repellent attached thereon, providing a composite solvent containing water and acetic acid mixed with each other, performing an extraction operation including infiltrating the polyester fabric with the composite solvent and extracting the dye and the water repellent, and carrying out a liquid state polycondensation reaction on the polyester fabric so that an intrinsic viscosity of the polyester fabric is increased and residual impurities of the polyester fabric are further removed.

    METHOD FOR DECOLORIZING POLYESTER FABRIC

    公开(公告)号:US20230090987A1

    公开(公告)日:2023-03-23

    申请号:US17865356

    申请日:2022-07-14

    Abstract: A method for decolorizing a polyester fabric is provided, which includes: providing a dyed polyester fabric, in which a material of the dyed polyester fabric contains a dye and a water repellent; providing a composite solvent, in which the composite solvent includes propylene glycol methyl ether (PM) and acetic acid that are mixed together; and performing an extraction process, which includes using the composite solvent to wet the dyed polyester fabric and remove the dye and the water repellent from the material of the polyester fabric by extraction, so as to obtain a reduced polyester fabric.

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