In a 3D printing method, a coalescent dispersion for forming a 3D object is selected. The dispersion includes an aqueous vehicle and an infrared or near-infrared binding agent dissolved or dispersed therein. The binding agent is a phthalocyanine having a polar group attached to each side chain or a naphthalocyanine having a polar group attached to each side chain. A sinterable material is deposited and heated to a temperature ranging from about 50 C to about 350 C. The dispersion is selectively applied on at least a portion of the sinterable material. The sinterable material and the dispersion applied thereon are exposed to infrared or near-infrared radiation. The binding agent absorbs the radiation and converts it to thermal energy. At least the portion of the sinterable material in contact with the binding agent is at least cured to form a first layer of the 3D object.

A method of forming a porous three-dimensional (3D) is disclosed. The method comprises (I) printing a first composition on a substrate (16) with the nozzle (12) of the apparatus (10) to form at least one first filament (14) comprising the first composition, (II) selectively controlling the distance and/or the speed such that the at least one first filament coils on the substrate to give a first layer on the substrate, the first layer comprising a coiled filament, optionally repeating steps I) and II) with independently selected composition(s) for any additional layer(s), and (III) exposing the layer(s) to a solidification condition. A porous three-dimensional (3D) article formed in accordance with the method is also disclosed.

A process for manufacturing a three-dimensional object from a powder by selective sintering the powder using electromagnetic radiation. The powder includes recycled PAEK. In one embodiment, the powder includes recycled PEKK. In one embodiment, the powder includes first recycle PEKK and second recycle PEKK. In one embodiment, the powder consists essentially of recycled PEKK. The process may include the step of maintaining a bed of a selective laser sintering machine at approximately 300 degrees Celsius and applying a layer of the powder to the bed. The average in-plane tensile strength of the three-dimensional object is greater than that of a three-dimension object manufactured by selective sintering using a powder including an unused PEKK powder.

A process for manufacturing a three-dimensional object from a powder by selective sintering the powder using electromagnetic radiation. The powder includes recycled PAEK. In one embodiment, the powder includes recycled PEKK. In one embodiment, the powder includes first recycle PEKK and second recycle PEKK. In one embodiment, the powder consists essentially of recycled PEKK. The process may include the step of maintaining a bed of a selective laser sintering machine at approximately 300 degrees Celsius and applying a layer of the powder to the bed. The average in-plane tensile strength of the three-dimensional object is greater than that of a three-dimension object manufactured by selective sintering using a powder including an unused PEKK powder.

A method for providing control data for a generative layer construction device has a first step of accessing a data record which, at least for a partial region of an object cross section, specifies in which temporal sequence an energy beam bundle is to be moved in scanning lines over the places of this partial region to scan the buildup material. In a second step, the data record is changed such that in at least one of the layers for the respective partial region of an object cross-section, a check is carried out to determine whether the scan time required to scan the buildup material along a scanning line falls below a predefined minimum duration tmin and either a lower energy density of the energy beam bundle during scanning of the buildup material along this scanning line is specified and/or a wait time is specified before the energy beam bundle is moved along a further scanning line.

A method for preparing an unsintered PTFE film capable of being continuously formed and with uniform density distribution and high density. The method for preparing the unsintered PTFE film includes filling a mixture obtained by adding a forming aid to PTFE fine powder in an extrusion forming die, extruding the filled mixture from the extrusion forming die to produce an extrusion forming body, rolling the extrusion forming body with a roll to produce a forming aid-removed film without the forming aid, and pinching the forming aid-removed film into a pinch roll made of a rubber roll formed by coating rubber on a metal shaft core at room temperature and compressing the forming aid-removed film so that thickness of the forming aid-removed film is reduced and density thereof is above 2.0 g/cm.sup.3.

The present invention relates to a method for producing a polyimide powder, particularly to a method for producing a polyimide powder, which includes a) preparing a dispersion by dispersing a dianhydride and a diamine in distilled water; and b) introducing the dispersion of step a) into a reactor and conducting the reaction at a stirring speed of 300 rpm or more under temperature and pressure conditions. In the present invention, it is possible to improve physical properties and control the particle size and dispersibility without additional processes by using water-based polymerization and controlling the stirring speed in the production process.

Composite particles comprising core particles completely or partially coated with a precipitated polymer, where the d.sub.50 median diameter of the core particles is 1 m or greater and the ratio of the d.sub.50 median diameter of the composite particles to the d.sub.50 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.

Composite particles comprising core particles completely or partially coated with a precipitated polymer, where the d.sub.50 median diameter of the core particles is 1 m or greater and the ratio of the d.sub.50 median diameter of the composite particles to the d.sub.50 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.

A method of additive manufacturing of a component includes cutting a plurality of sheets, each sheet corresponding to a respective cross-section of the component, tack welding the sheets to one another to form a stack, arranging the stack in a mold, and spark plasma sintering the tack-welded stack of sheets to reduce vacancies and dislocations between adjacent sheets of the stack.