Abstract: A process for continuous or discontinuous synthesis of elastomeric copolyesters from polybutylene terephthalate (PBT) and polyoxytetramethylene glycol is described in which the tetrahydrofuran (THF) obtained as a byproduct in synthesis of polybutylene terephthalate from 1,4-butanediol is rectified and then reacted by ring-opening polymerization to form polyoxytetramethylene glycol which condenses with the free or esterified carboxyl groups of PBT to form the copolyester, whereby chain termination and catalyst deactivation are accomplished by adding 1,4-butanediol without separating the catalyst.

Abstract: The invention relates to a method for generating a vacuum and for separating volatile compounds during esterification, transesterification and/or polycondensation reactions. One or several jets of steam comprising a spray condenser, which is arranged up or downstream, are connected to the suction side of a reactor which is to be evacuated and phenol or steam containing phenol is used as propellant steam at a pressure of 0.5 hPa to approximately 1.5 MPa and liquid phenol or a liquid containing phenol is used as a spraying agent.

Abstract: A safety cabinet has a plurality of walls defining a front open side and a pair of doors pivotal about respective horizontally spaced axes on the walls between a closed and an open position. Guides in the cabinet are each associated with a respective one of the doors, and respective links each have a front end connected to a respective one of the doors and a rear end shiftable front-to-back in a respective one of the guides. A connector extends between the rear ends of the links and shifts front-to-back with them. A closer is operatively engageable with the connector, and a spring applies bears on the closer to urge it against the connector for pushing same into the rear end position and closing the doors. An actuator normally holds the closer out of engagement with the connector during movement of same between the front and rear end positions.

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: The invention relates to a method for treating vapours and condensates which arise during the production of polycondensates from bisphenols or high-value phenols by esterification and/or transesterification with alkyl or aryl esters of at least bivalent organic or inorganic acids. According to the invention, the treatment is carried out in a plurality of condensates and/or distillation columns which are connected in a step-by-step manner behind each other, each distillation column comprising a connected condensate. The dew point and the pressure in each condensate are adjusted such that in each step, monomers, oligomers or decomposition and transformation products are removed.

Abstract: The invention relates to a method for the analysis of refuse objects (2) containing polymers, in particular of carpets, in a recycling plant (1) and an automatic analytical device (7). In order to determine the polymer constituents of the refuse object (2), according to the invention, part of the refuse object (2) is vaporised and examined by a mass spectrometer (18). Using the method according to the invention and the automatic analytical device according to the invention, the refuse objects (2) can be classified for further processing (9, 10, 11) more accurately and more reliably during transport on a conveyor device (6).

Abstract: The invention relates to a method, which is used to monitor the composition of a polymer blend, melt and/or solution used to produce a polymer and to an automatic analysis device (27). To produce the polymer, the polymer blend, melt and/or solution is guided through an installation volume and a sample gas that is formed from said polymer blend, melt and/or solution is withdrawn, preferably at several sampling sites (30 to 36). The sample gas is fed to a mass spectrometer (28), which automatically emits an analysis signal representing the composition of the sample gas. The sampling site is connected to the mass spectrometer in a switchable manner via an automatically switchable shut-off device (47, 48), in such a way that several sampling sites can be sampled in succession by the mass spectrometer (28).

Abstract: A process for continuous or discontinuous synthesis of elastomeric copolyesters from polybutylene terephthalate (PBT) and polyoxytetramethylene glycol is described in which the tetrahydrofuran (THF) obtained as a byproduct in synthesis of polybutylene terephthalate from 1,4-butanediol is rectified and then reacted by ring-opening polymerization to form polyoxytetramethylene glycol which condenses with the free or esterified carboxyl groups of PBT to form the copolyester, whereby chain termination and catalyst deactivation are accomplished by adding 1,4-butanediol without separating the catalyst.

Abstract: Disclosed are a method and a device for batchwise production of high-molecular polyphosphonates, polysulfones, polyarylates, polyamides, polyarylene ethers, or polyether ketones by melt-condensing a monomer compound carrying hydroxyl groups, carboxyl groups, anhydride groups, phosphoric acid groups, phosphono groups, phosphonate groups, phosphino groups, phosphinate groups, carbonyl groups, sulfonyl groups, sulfonate groups, siloxane groups or amino groups on its own or along with at least one diphenol, dialcohol, diamine, or a dicarbonate component.

Abstract: A method is disclosed for producing a vacuum and for separating condensable components present in vapor which accumulates during the production of a polymer by melt-phase polycondensation under vacuum. Vapor produced during the production of polymers by melt-phase polycondensation in at least one reaction step under vacuum is drawn of by at least one steam jet vacuum pump with a down stream injection condenser. The steam jet vacuum pump is driven with alkylene carbonate in vapor form and liquid alkylene carbonate is then supplied to the injection condenser as coolant.

Abstract: In a method for the continuous manufacture of polymers by means of melt condensation of a monomer in each case with itself or with at least one other monomer the molten monomers are esterified or transesterified in the presence of a catalyst, subsequently the esterification/transesterification product is fed for the precondensation to a disc ring reactor, then the precondensation product is fed to an LVS disc ring reactor for the polycondensation and finally the polycondensation product is fed to the end polycondensation.

Abstract: Comminuted carpet pieces are fed to a first stirred tank together with an aqueous solution containing separating salt, to form a first suspension, which is fed to a first mechanical separating stage. A first high-solids phase, a second high-solids phase containing polymer fiber material, and a liquid phase are obtained therefrom. The second high-solids phase is mixed with a water-containing separation solution in a stirred tank, to give a second suspension, which is fed to a second mechanical separating stage. A third high-solids phase, a polymer fiber material-rich phase and a liquid phase are withdrawn therefrom. An acid which is stronger than H2CO3 is introduced into the stirred tank together with the water-containing separation solution, and the pH of the liquid in the stirred tank is adjusted to 2–6.

Abstract: The invention relates to a method for the production of polymers by means of melt-phase polycondensation in at least one reaction step under vacuum. The vapor produced is drawn off by at least one steam jet vacuum pump with a downstream injection condenser from the reaction step. In order to improve the method, the steam jet vacuum pump is driven with alkylene carbonate in vapor form and liquid alkylene carbonate is supplied to the injection condenser as coolant.

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 analysis of refuse objects (2) containing polymers, in particular of carpets, in a recycling plant (1) and an automatic analytical device (7). In order to determine the polymer constituents of the refuse object (2), according to the invention, part of the refuse object (2) is vaporised and examined by a mass spectrometer (18). Using the method according to the invention and the automatic analytical device according to the invention, the refuse objects (2) can be classified for further processing (9, 10, 11) more accurately and more reliably during transport on a conveyor device (6).

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: Comminuted carpet pieces are fed to a first stirred tank together with an aqueous solution containing separating salt, to form a first suspension, which is fed to a first mechanical separating stage. A first high-solids phase, a second high-solids phase containing polymer fiber material, and a liquid phase are obtained therefrom. The second high-solids phase is mixed with a water-containing separation solution in a stirred tank, to give a second suspension, which is fed to a second mechanical separating stage. A third high-solids phase, a polymer fiber material-rich phase and a liquid phase are withdrawn therefrom. An acid which is stronger than H2CO3 is introduced into the stirred tank together with the water-containing separation solution, and the pH of the liquid in the stirred tank is adjusted to 2-6.

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.