The present invention relates to a process for recycling glass fiber-reinforced plastics, in particular plastics based on polyamide, polybutylene terephthalate or polyethylene terephthalate, to recover both the monomers of the polymer and the glass used for the glass fibers.

The present invention relates to an enzymatic process for depolymerization of post-consumer poly(ethylene terephthalate) by a glycolysis reaction. This invention also relates to a process for recycling post-consumer poly(ethylene terephthalate) and to the recycled poly(ethylene terephthalate) obtained by said process.

The present invention relates to an enzymatic process for depolymerization of post-consumer poly(ethylene terephthalate) by a glycolysis reaction. This invention also relates to a process for recycling post-consumer poly(ethylene terephthalate) and to the recycled poly(ethylene terephthalate) obtained by said process.

A method for producing a decolorized polyester according to the present invention includes: a step of preparing a polyester colored with a colorant, and a decolorizing agent containing a glycol ether-type compound having a boiling point at atmospheric pressure of 160° C. or higher; and a step of removing the colorant, by bringing the decolorizing agent into contact at least once with the colored polyester while heating the decolorizing agent to a temperature equal to or lower than a melting point of the polyester, to thereby obtain the decolorized polyester.

A depolymerization reaction of a polyester input with an organocatalyst and an alcohol solvent produces (i) a recycled monomeric or oligomeric diester from the polyester, (ii) the organocatalyst for reuse, and (iii) the alcohol solvent, which may also be reused. The presence of volatile impurities, such as water, acetyl aldehyde, and organic solvents can interfere with the success of the depolymerization reaction. A pre-reaction distillation step removes volatile impurities from the polyester input resulting in an efficient depolymerization reaction with consistency among batches. The polyester input may be further treated with a water azeotrope to remove water from the polyester input prior to the pre-reaction distillation.

A waste polyester material is prepared for recycling by dissolving the material in a solution comprising hexafluoroisopropyl (HFIPA) and a chlorinated hydrocarbon, such as dichloromethane (DCM) and/or an aromatic hydrocarbon, such as toluene or xylene, to form a dissolved polyester sample. The dissolved polyester may be prepared for recycling by evaporation, spray drying, and/or precipitation, which produces a purified solid polyester product. The dissolution solution, which is separated from the purified solid polyester product, is also recycled through distillation with purification.

Polyester-free cotton is obtained from a fabric and/or fibers containing polyester and cotton by reacting the fabric and/or fibers with an amine organocatalyst and/or carboxylic acid salt of same and an alcohol solvent. The reaction, which may be run in batches or as a continuous flow process, recovers (i) polyester-free cotton as a solid inert by-product of the reaction, (ii) the amine organocatalyst and/or carboxylic acid salt of same for reuse, (iii) a polyester monomer product, and (iv) unreacted alcohol. The reaction works on any polyester-cotton fabric and/or fibers, including those that have at least one additional material, such as polyethers polyolefins, polyurethanes, nylon, rayon, acetate, viscose, modal, acrylic, wool, and combinations thereof.

Polyester-free magnetic and/or metallic components are obtained from a multicomponent polyester device by reacting the multicomponent polyester device with an amine organocatalyst and/or carboxylic acid salt of same and an alcohol solvent. The reaction recovers (i) the polyester-free magnetic and/or metallic components as solid inert by-products of the reaction, (ii) the amine organocatalyst and/or carboxylic acid salt of same for reuse, (iii) unreacted alcohol for reuse, and (iv) a polyester monomer product. Where the multicomponent device includes a non-polyester material, such as polystyrene, the polystyrene is fully recovered from the reaction. Where the multicomponent polyester device includes recording media, the reaction process sanitizes the inert byproducts of the recording media, thus scrubbing any personal data from the reacted recording media.

A method for recovering natural fibers from a textile comprising polyester and natural fibers. The method comprises the steps of: providing said textile soaked in a mixture comprising a solvent and a catalyst, providing and maintaining a temperature of said mixture comprising said textile within a range of 80-240° C. during depolymerization of polyester in said textile; and recovering natural fibers after said depolymerization, wherein, in said step of providing said textile soaked in said mixture, said catalyst of said mixture comprises calcium oxide.

A method for recovering natural fibers from a textile comprising polyester and natural fibers. The method comprises the steps of: providing said textile soaked in a mixture comprising a solvent and a catalyst, providing and maintaining a temperature of said mixture comprising said textile within a range of 80-240° C. during depolymerization of polyester in said textile; and recovering natural fibers after said depolymerization, wherein, in said step of providing said textile soaked in said mixture, said catalyst of said mixture comprises calcium oxide.