Abstract: A process for reducing the amount of hydroxyl-end-groups of a polyester, wherein the polyester is prepared from at least one dicarboxylic acid and at least one dihydroxy alcohol, and at least one additive selected from the group consisting of carboxylic acid anhydride and mono-isocyanate, and wherein the additive is added during a step of prepolycondensation and/or during a step of polycondensation and/or after a step of polycondensation.

Abstract: The application relates to a process for reducing the amount of hydroxyl-end-groups of polyesters, wherein the polyester is prepared from at least one dicarboxylic acid and at least one dihydroxy alcohol, and at least one additive selected from the group consisting of dicarboxylic acid anhydride and/or monoisocyanate is added during and/or after the process of preparing the polyester.

Abstract: The invention relates to a continuous or discontinuous method for the production of highly condensed polyesters in the solid state, comprising a crystallization of a polyester material, wherein the crystallization is carried out in the presence of a gas with a dew point of (less than or equal to) ?approximately ?10° C. The invention also relates to a method for the production of polyester formed bodies using the polyester material obtained for the production of bottles, films and high strength threads.

Abstract: A method of making shaped articles from highly condensed polyester melt and especially preforms for the blow molding of food and especially beverage containers. A melt is continuously withdrawn from the polycondensation reactor and is fed to the shape-imparting units, especially a multiplicity of injection-molding machines without solidification between the final reactor and the injection molders and without degassing between the final reactor and the injection molding machines.

Abstract: The invention relates to a method for producing a granulate with a low acetaldehyde content and improved processing properties from a high-viscosity polyester melt, wherein the polyester melt strand is fragmented under water at the highest possible temperature, the accompanying water is separated from the granulate with the least possible cooling of the granulate, the low-water granulate obtained in this way is passed after removal of the water directly into a dealdehydisation container and the granulate in the dealdehydisation container is treated with a flow of rinsing air, plus a device for carrying out this method.

Abstract: The invention relates to a continuous or discontinuous method for the production of highly condensed polyesters in the solid state, comprising a crystallisation of a polyester material, wherein the crystallisation is carried out in the presence of a gas with a dew point of (less than or equal to) ?approximately ?10° C. The invention also relates to a method for the production of polyester formed bodies using the polyester material obtained for the production of bottles, films and high strength threads.

Abstract: The invention relates to a method for producing a granulate with a low acetaldehyde content and improved processing properties from a high-viscosity polyester melt, wherein the polyester melt strand is fragmented under water at the highest possible temperature, the accompanying water is separated from the granulate with the least possible cooling of the granulate, the low-water granulate obtained in this way is passed after removal of the water directly into a dealdehydisation container and the granulate in the dealdehydisation container is treated with a flow of rinsing air, plus a device for carrying out this method.

Abstract: Latent heat crystallized polyesters and copolyesters of a degree of crystallization greater than 38% and made by a process in which, without prior additive admixtures and without further cooling, the granulate is fed directly from the latent heat crystallization into a solid phase polycondensation reactor and condensed to a higher viscosity and subjected to acetaldehyde reduction. Alternatively without additive admixtures the granulate is subjected to dealdehydization and then worked up into bottles.

Abstract: The present invention provides a process of reducing acrolein byproduct from polytrimethylene terephthalate using selected phosphorous compounds to contact the polytrimethylene terephthalate or reactants in the process of producing polytrimethylene terephthalate. The selected phosphorous compounds are retained in the polytrimethylene terephthalate. The present invention also provides polytrimethylene terephthalate compositions containing amounts of phosphorous compounds.

Abstract: Latent heat crystallized polyesters and copolyesters of a degree of crystallization greater than 38% and made by a process in which, without prior additive admixtures and without further cooling, the granulate is fed directly from the latent heat crystallization into a solid phase polycondensation reactor and condensed to a higher viscosity and subjected to acetaldehyde reduction. Alternatively without additive admixtures the granulate is subjected to dealdehydization and then worked up into bottles.

Abstract: A method of making shaped articles from highly condensed polyester melt and especially preforms for the blow molding of food and especially beverage containers. A melt is continuously withdrawn from the polycondensation reactor and is fed to the shape-imparting units, especially a multiplicity of injection-molding machines without solidification between the final reactor and the injection molders and without degassing between the final reactor and the injection molding machines.