Abstract: A process can be used for the surface treatment of three-dimensional objects which have been produced in additive manufacturing processes from at least one polymer. The process involves a) immersing the three-dimensional object in a substance mixture A, b) leaving the three-dimensional object in the substance mixture A for a time, and c) removing the three-dimensional object from the substance mixture A. The process then involves d) immersing the three-dimensional object in a substance mixture B, e) leaving the three-dimensional object in the substance mixture B for a time, and f) removing the three-dimensional object from the substance mixture B. The substance mixture A has a temperature (process temperature A) which is above the melting point of the polymer, and the substance mixture B has a temperature (process temperature B) which is below the melting point of the polymer.

Abstract: A polyamide powder for powder bed fusion methods is described. The polymer exhibits a solution viscosity to ISO 307 of 1.55 to 1.75 and an increase in solution viscosity of 10% to 40%, preferably 20% to 30%, when under a nitrogen atmosphere it is subjected to a temperature 10° C. below its melting temperature for 24 h.

Abstract: A powder can be used for additive manufacturing processes. The powder contains composite particles containing an NIR-absorbing component as core particles. This allows uniform melting of the powder. A process for manufacturing the powder includes bringing a polymer into contact with a medium having a solvent capable of dissolving the first polymer in the presence of core particles under elevated pressure and/or temperature, and subsequently precipitating the polymer out of the solution.

Abstract: A polyamide powder for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polyamide powder has a solution viscosity to ISO 307 of 1.8 to 2 and a rise in the solution viscosity of 0% to 25% when it is subjected to a temperature 20° C. below its melting temperature under air for 20 hours.

Abstract: A polymer composition can be used for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polymer has open mesopores and the cumulative pore volume distribution of the mesopores, measured to DIN 66134, is at least 0.01 cm3/g.

Abstract: A device produces three-dimensional objects layer by layer in a powder bed fusion process. The device includes a building space, at least one energy source, a building area with a building space platform and a building space container laterally confining the building space platform. The building space platform has an upper side, facing a powder, and an underside, facing away from the powder. The upper side of the building space platform includes a material with a thermal conductivity of at least 20 W/(m·K) and the underside of the building space platform includes a material with a thermal conductivity of a maximum of 0.5 W/(m·K). The contact surface of the upper side of the building space platform with respect to the powder or with respect to the cooling medium is raised by at least 20% in comparison with the planar surface of a building space platform.

Abstract: A process can be used for the surface treatment of three-dimensional objects which have been produced in additive manufacturing processes from at least one polymer. The process involves a) immersing the three-dimensional object in a substance mixture A, b) leaving the three-dimensional object in the substance mixture A for a time, and c) removing the three-dimensional object from the substance mixture A. The process then involves d) immersing the three-dimensional object in a substance mixture B, e) leaving the three-dimensional object in the substance mixture B for a time, and f) removing the three-dimensional object from the substance mixture B. The substance mixture A has a temperature (process temperature A) which is above the melting point of the polymer, and the substance mixture B has a temperature (process temperature B) which is below the melting point of the polymer.

Abstract: A polymer composition can be used for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polymer has open mesopores and the cumulative pore volume distribution of the mesopores, measured to DIN 66134, is at least 0.01 cm3/g.

Abstract: A process for melting/sintering powder particles for layer-by-layer production of three-dimensional objects is performed by a) applying a layer of a powder material solidifiable under the action of electromagnetic radiation, b) heating the powder material to not more than 10 K below the melting point according to DIN 53765 by a radiation from a heat-radiating element whose maximum radiation intensity is at a wavelength of 5000 nm or at longer wavelengths, c) selective melting/sintering of at least a region of the powder material which corresponds to the cross section of the three-dimensional object, d) repeating steps a) to c) until the three-dimensional object is obtained.

Abstract: A polymer powder having a surface energy of less than 35 mN/m is suitable for melting/sintering powder particles for layer-by-layer production of three-dimensional objects.

Abstract: A polyamide powder for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polyamide powder has a solution viscosity to ISO 307 of 1.8 to 2 and a rise in the solution viscosity of 0% to 25% when it is subjected to a temperature 20° C. below its melting temperature under air for 20 hours.

Abstract: A polymer composition can be used in selective absorbing sintering, SAS, or selective inhibition sintering, SIS, methods. The polymer of the polymer composition has open mesopores, where a cumulative pore volume distribution of the mesopores, measured according to DIN 66134, is at least 0.01 cm3/g.

Abstract: A polyamide powder for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polyamide powder has a solution viscosity to ISO 307 of 1.8 to 2 and a rise in the solution viscosity of 0% to 25% when it is subjected to a temperature 20° C. below its melting temperature under air for 20 hours.

Abstract: A polymer powder which is suitable for a powder bed fusion method contains a polymeric material coated with a hydrophobic substance that is at least one selected from the group consisting of a saturated fatty alcohol, an unsaturated fatty alcohol, a saturated fat, an unsaturated fat, a wax, a lactam, an alkene, and an alkane.

Abstract: A device produces three-dimensional objects layer by layer in a powder bed fusion process. The device includes a building space, at least one energy source, a building area with a building space platform and a building space container laterally confining the building space platform. The building space platform has an upper side, facing a powder, and an underside, facing away from the powder. The upper side of the building space platform includes a material with a thermal conductivity of at least 20 W/(m.K) and the underside of the building space platform includes a material with a thermal conductivity of a maximum of 0.5 W/(m·K), The contact surface of the upper side of the building space platform with respect to the powder or with respect to the cooling medium is raised by at least 20% in comparison with the planar surface of a building space platform.

Abstract: A process for melting/sintering powder particles for layer-by-layer production of three-dimensional objects is performed by a) applying a layer of a powder material solidifiable under the action of electromagnetic radiation, b) heating the powder material to not more than 10 K below the melting point according to DIN 53765 by a radiation from a heat-radiating element whose maximum radiation intensity is at a wavelength of 5000 nm or at longer wavelengths, c) selective melting/sintering of at least a region of the powder material which corresponds to the cross section of the three-dimensional object, d) repeating steps a) to c) until the three-dimensional object is obtained.

Abstract: A polymer powder having a surface energy of less than 35 mN/m is suitable for melting/sintering powder particles for layer-by-layer production of three-dimensional objects.

Abstract: A process for melting/sintering powder particles for layer-by-layer production of three-dimensional objects is performed by a)applying a layer of a powder material solidifiable under the action of electromagnetic radiation, b) heating the powder material to not more than 10 K below the melting point according to DIN 53765 by a radiation from a heat-radiating element whose maximum radiation intensity is at a wavelength of 5000 nm or at longer wavelengths, c) selective melting/sintering of at least a region of the powder material which corresponds to the cross section of the three-dimensional object, d)repeating steps a) to c) until the three-dimensional object is obtained.

Abstract: A polymer powder having a surface energy of less than 35 mN/m is suitable for melting/sintering powder particles for layer-by-layer production of three-dimensional objects.

Abstract: Composite particles comprising core particles completely or partially coated with a precipitated polymer, where the d50 median diameter of the core particles is 1 ?m or greater and the ratio of the d50 median diameter of the composite particles to the d50 median diameter of the core particles is 1.15 or greater, are provided. A method to prepare the particles includes dissolution of a polymer in a solvent and reprecipitation of the polymer in the presence of a suspension of the core particles. Further provided is a layer by layer moulding process employing the composite particles and mouldings obtained therefrom.