Abstract: A PET recycling (the reprocessing of polyethylene terephthalate wastes) has already been practised for many decades in a variety of different ways, since PET is available in large quantities. Environmental protection and sustainability in resource utilization, however, call for ever higher recycling rates in the decades to come. If the concept of a circular economy is to be achieved, this rate must ultimately amount, sooner or later, to 100%.

Abstract: A method for training a machine-learning module of a computer-implemented prediction model for predicting product quality parameter values for one or more quality parameters of a chemical product produced by a chemical production plant. The production plant includes a plurality of sensors, each of which is configured to acquire process parameter values for one or more process parameters of a chemical process carried out by the production plant for producing the chemical product during operation of the production plant. A priori information about the production plant and the process carried out by the production plant is used, including chronological sequence information about a chronological sequence of the process carried out within the production plant, for which sensors sensor-specific time shifts between an acquisition time of training process parameter values and a production time of a product unit, during the production of which the corresponding training process parameter value was acquired.

Abstract: Apparatuses and processes may be utilized for mixing used polyester into a polyester melt. In some processes an intermediate product stream is branched off from an intermediate stage in a virgin polyester production process. The intermediate product stream is then mixed with recycled polyester flakes in a dynamic mixer, where not more than 60% of a melting energy required to melt all the recycled polyester flakes is generated and/or supplied in the dynamic mixer. The mixture produced in this way is fed into a subsequent stage downstream of the intermediate stage and converted up to the desired degree of polycondensation. In this way, it is possible to physically reutilize used polyester or polyester waste.

Abstract: A method for removing compounds in the gaseous aggregate state from PLA-containing products in the viscous aggregate state by means of a thin-film evaporator. The compounds may be present in the liquid or solid aggregate state in the products under standard conditions. The invention further relates to a polylactide resin prepared in accordance with the method of the invention.

Abstract: Apparatuses and processes may be utilized for mixing used polyester into a polyester melt. In some processes an intermediate product stream is branched off from an intermediate stage in a virgin polyester production process. The intermediate product stream is then mixed with recycled polyester flakes in a dynamic mixer, where not more than 60% of a melting energy required to melt all the recycled polyester flakes is generated and/or supplied in the dynamic mixer. The mixture produced in this way is fed into a subsequent stage downstream of the intermediate stage and converted up to the desired degree of polycondensation. In this way, it is possible to physically reutilize used polyester or polyester waste.

Abstract: A method for removing compounds in the gaseous aggregate state from PLA-containing products in the viscous aggregate state by means of a thin-film evaporator. The compounds may be present in the liquid or solid aggregate state in the products under standard conditions. The invention further relates to a polylactide resin prepared in accordance with the method of the invention.

Abstract: Disclosed is a method for producing a titanium containing catalyst, wherein the catalyst includes one or more titanium alpha-hydroxy carboxylate species, e.g., titanium citrate, and one or more titanium oxide species, e.g., TiOx, wherein x is greater than 0 and less than or equal to 2, wherein the sum of all of the above titanium oxide species relative to the sum of all titanium alpha-hydroxy carboxylate species in the titanium containing catalyst is greater than 0 but less than 1.00 mol.-%. The method of production involves, for example, reacting tetraisopropyl orthotitanate with an aqueous solution of citric acid, and removing the byproduct of 2-propanol by distillation. Also disclosed is a method for the production of polyesters by the use of the catalyst.

Abstract: In a practicable continuous or batchwise process for the preparation of a crystallizable polylactic acid mixture, lactic acid may be polycondensed to yield an oligomer, which may then be depolymerized to yield a crude lactide. The crude lactide may be purified to yield a pure lactide, wherein fractionation may be carried out in the purification into an L- or D-lactide-rich fraction and also a meso-lactide-rich fraction. Subsequently a separate ring-opening polymerization of the resulting lactide fractions can be carried out. The individual polylactic acid batches or streams generated by the ring-opening polymerization may then be mixed. The present disclosure further relates to apparatuses for carrying out such processes and polylactic acid mixtures.

Abstract: The present invention relates to a device and also to a method for separating and recovering a cyclic diester, in particular dilactide or glycolide from polymer melts which include the cyclic diester as impurity. The device and also the method according to the invention allow recovery of the cyclic diester with a high yield and at the same time high purity.

Abstract: A method may facilitate the crystallization of granules of a crystallizable thermoplastic material in conjunction with removal of low molecular mass components contained in the thermoplastic material. The crystallizable thermoplastic material may have a crystalline melting temperature of at least 130° C. According to the method, a crystallization stage and a removal stage may be performed at different temperatures of the granules. Often the crystallization may occur at a lower temperature than the removal of the low molecular mass components. In the crystallization and removal stages, a flow of gas may pass countercurrent to a direction along which the granules are conveyed. Further, example devices disclosed herein may be utilized to perform the exemplary methods disclosed herein.

Abstract: The invention relates to a reactor in the form of a VK tube (VK: simplified continuous), for the polymerisation of polyamides, the reactor being subdivided into an upper and lower reactor region, which are controllable independently of each other. Likewise, the invention relates to a method for the production of polyamides in which such a reactor is used.

Abstract: The invention relates to an additive having at least two functionalities being able to undergo a condensation reaction in combination with a tetraalkylpiperidinyl radical and also a tertiary amine functionality. By the combination of these functionalities, a universal additive can be provided, which, on the one hand, makes possible a narrower molar mass distribution and, at the same time, improves the performance for spun polymers. According to the invention, likewise corresponding additivated polyamide molding compounds and also an additive solution are provided. The additives according to the invention are used in particular in the production of polyamide for textile applications.

Abstract: A process for producing polyamides makes flow guidance within the process more efficient. In some respects, the process is based on the polymerization of lactam to a polyamide-containing polymer melt, the subsequent granulation of the polymer melt to polyamide granules using granulation liquid, and the subsequent extraction of monomeric and oligomeric constituents from the PA granules in an extraction column. In some examples, a temperature of the granulation liquid before being fed into an extraction liquid stream is lower than a temperature of the extraction liquid stream before the granulation liquid is fed into the extraction liquid stream. The invention relates also to a device for carrying out processes such as this one.

Abstract: A process for preparing a high molecular weight heteraromatic polyester or copolyester is disclosed. A process for preparing a high molecular weight heteroaromatic polyester or copolyester includes the steps of: (a) processing comonomers by mixing together to form a homogeneous solution (1) at least one heteroaromatic dicarboxylic acid having 2-12 carbon atoms or a diester or an acid anhydride derived therefrom, or a mixture thereof; (2) at least one alcohol having 2 to 12 carbon atoms and at least two hydroxyl functionalities; and (3) optionally aromatic or aliphatic dicarboxylic acids or diesters or acid anhydrides derived therefrom; (b) converting the paste/solution obtained in step a) into an esterification product containing at least one diester or at least one oligoester formed from the at least one heteroaromatic dicarboxylic acid and the at least one alcohol; and (c) polycondensing/copolycondensing the reaction product obtained from step b) under reduced pressure.

Abstract: The present application relates to an extraction reactor with which granular material, in particular granular polyamide, can undergo extraction, soluble components being dissolved out of the granular material with an extraction liquid during the extraction. In the case of polyamide materials, these are for example oligomeric or monomeric components which have remained in the granular material during the polycondensation reaction for the production of the polyamide materials.

Abstract: The present invention relates to a drying-/degassing device (7) for drying or degassing a polyester granulate, which has a temperature-control zone, a cooling zone, an inlet (6) and an outlet (6) for polyester granulate and also in addition a separate removal possibility (14) for removing hot polyester granulate. In addition, the present invention relates to a device for the direct production of molded articles from polyester melts which comprises the drying-/degassing device according to the invention. In addition, the present invention describes a method for the production of molded articles from polyesters.

Abstract: The invention relates to a conveying device for conveying granular material that is stored in a source (10), for example polyamide 6 (PA6) granules, to multiple receiving points (11, 12, 13, . . . ), the conveying device having a number of injectors (11, 12, 13, . . . ) corresponding to the number of receiving points. Also disclosed is a method for conveying granular material, for example PA6 granules, from a source (10) to multiple receiving points.

Abstract: The invention relates to a method for the continuous production of a solution of salts, in particular for the production of hexamethylenediamine adipate and a device for implementing such a method. According to the invention, it is proposed to convert, in a first step, a substoichiometric quantity of alkane diamine in a ratio to the alkane dicarboxylic acid in water and, in a subsequent second step, to implement making-up with alkane diamine, adjustment of the stoichiometric ratios being effected via a pH value measurement at a constant temperature.

Abstract: In a practicable continuous or batchwise process for the preparation of a crystallizable polylactic acid mixture, lactic acid may be polycondensed to yield an oligomer, which may then be depolymerized to yield a crude lactide. The crude lactide may be purified to yield a pure lactide, wherein fractionation may be carried out in the purification into an L- or D-lactide-rich fraction and also a meso-lactide-rich fraction. Subsequently a separate ring-opening polymerization of the resulting lactide fractions can be carried out. The individual polylactic acid batches or streams generated by the ring-opening polymerization may then be mixed. The present disclosure further relates to apparatuses for carrying out such processes and polylactic acid mixtures.

Abstract: The present invention relates to a method for the production of cyclic carboxylic acid esters, in particular intramolecular lactones, such as e.g. dilactide, the production of these cyclic esters from oligomeric carboxylic acids being effected by cyclizing depolymerization. During this reaction, a condensation product of these oligomeric carboxylic acids is produced as by-product, i.e. a mixture of higher-molecular oligomeric carboxylic acids which are hydrolyzed in a further step and hence recovered. This hydrolysate can be added again to the cyclizing depolymerization which is implemented in the first step.