Abstract: The invention relates to a method for the treatment of waste containing polyamide comprising a) depolymerisation of the waste containing polyamide, whereby a caprolactam raw material (6) and a flow (3), comprising the secondary constituents and additives from the depolymerisation, are obtained, and b) leaching of the flow (3) at least once using an extracting agent.

Abstract: This invention relates to a continuous and efficient method for the manufacture of highly pure caprolactam suitable for the polycondensation of Polyamide 6 (polycaprolactam) from polyamide waste. In particular the invention relates to a method for the manufacture of caprolactam from waste containing polyamides, including the steps a) depolymerisation of the waste containing polyamides, whereby a caprolactam raw material and a flow containing secondary constituents or additives is obtained, b) at least one distillation of the caprolactam raw material, and c) at least one crystallisation of the caprolactam material obtained in step b), by which means caprolactam is obtained, whereby at least part of the caprolactam obtained in step c) with a permanganate number of<10000 sec. and a UV transmission of<85% is added to the waste containing polyamides before and/or during the depolymerisation.

Abstract: The invention relates to a method for the continuous production of caprolactam from waste containing polyamide, comprising a) depolymerisation of the waste containing polyamide, whereby a caprolactam raw material and, where applicable, a flow containing secondary constituents or additives is obtained, and b) irradiation of the caprolactam raw material with UV radiation.

Abstract: The invention relates to a method for the continuous production of caprolactam from waste containing polyamide, comprising a) depolymerisation of the waste containing polyamide, whereby a caprolactam raw material and, where applicable, a flow containing secondary constituents or additives is obtained, and b) irradiation of the caprolactam raw material with UV radiation.

Abstract: The invention relates to a method for the treatment of waste containing polyamide comprising a) depolymerisation of the waste containing polyamide, whereby a caprolactam raw material (6) and a flow (3), comprising the secondary constituents and additives from the depolymerisation, are obtained, and b) leaching of the flow (3) at least once using an extracting agent.

Abstract: This invention relates to a continuous and efficient method for the manufacture of highly pure caprolactam suitable for the polycondensation of Polyamide 6 (polycaprolactam) from polyamide waste. In particular the invention relates to a method for the manufacture of caprolactam from waste containing polyamides, including the steps a) depolymerisation of the waste containing polyamides, whereby a caprolactam raw material and a flow containing secondary constituents or additives is obtained, b) at least one distillation of the caprolactam raw material, and c) at least one crystallisation of the caprolactam material obtained in step b), by which means caprolactam is obtained, whereby at least part of the caprolactam obtained in step c) with a permanganate number of <10000 sec. and a UV transmission of <85% is added to the waste containing polyamides before and/or during the depolymerisation.

Abstract: The invention comprises a method for synthesizing polyethylene terephthalate from waste polyethylene terephthalate by cleavage with ethylene glycol and separation of bis(hydroxyethylene) terephthalate from the cleavage mixture with a specific temperature program, recrystallization from water, and esterification and polycondensation with the addition of terephthalic acid.The invention further comprises a method for synthesis of polyethylene naphthalate from waste polyethylene naphthalate in a similar manner.

Abstract: Process for separating preshredded carpet materials into as many as three main components of different densities which comprises finely comminuting the carpet materials in the liquid phase. The density of the liquid phase is adjusted to a level between two adjacent densities of the components. Separation of one component from the other components and from the liquid phase in the suspension is effected in a double-cone full-jacketed screw centrifuge. The process is repeated if there are two materials of different densities in the other components fraction. The process is useful for recovering nylon, polyester, or polypropylene from carpet scraps which nylon or polyester can be depolymerized to reusable monomers and which polypropylene can be reprocessed into pellets, non-wovens or fibers.