A process of producing a surface-modified 3-dimensional article, the process comprising the steps of providing a radiation-curable composition, building-up a 3-dimensional article by radiation-curing the radiation-curable composition layer by layer, preferably by using a stereolithography or digital light processing unit, partially removing radiation-curable composition which sticks to the surface of the 3- dimensional article, treating only a portion of the surface of the 3- dimensional article to which the radiation-curable composition is stuck with particles, applying an additional curing step to the 3-dimensional article, preferably by applying heat and/or radiation. A 3-dimensional article which can be obtained by such a process and a kit of parts comprising such a 3-dimensional article.

A process of producing a surface-modified 3-dimensional article, the process comprising the steps of providing a radiation-curable composition, building-up a 3-dimensional article by radiation-curing the radiation-curable composition layer by layer, preferably by using a stereolithography or digital light processing unit, partially removing radiation-curable composition which sticks to the surface of the 3- dimensional article, treating only a portion of the surface of the 3- dimensional article to which the radiation-curable composition is stuck with particles, applying an additional curing step to the 3-dimensional article, preferably by applying heat and/or radiation. A 3-dimensional article which can be obtained by such a process and a kit of parts comprising such a 3-dimensional article.

The present disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed objects. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and an antioxidant agent. The fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation energy and convert the radiation energy to heat. The antioxidant agent can include water and a dispersion of a secondary antioxidant.

The present disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and methods of making three-dimensional printed objects. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and an antioxidant agent. The fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation energy and convert the radiation energy to heat. The antioxidant agent can include water and a dispersion of a secondary antioxidant.

A 3D printing apparatus is disclosed herein. The apparatus comprises a container, a build material extraction module, an energy source and a controller. The container is to receive a build volume comprising portions in which an un-cured thermally curable binder has been applied to define a 3D object to be generated and portions on which no binder has been applied. The build material extraction module is to remove part of the build material on which no binder has been applied. The energy source to heat the contents of the container. And the controller is to control the build material extraction module to remove part of the build material on which no binder has been applied; and control the energy source to heat the build material to thermally cure any binder in the container.

A 3D printing apparatus is disclosed herein. The apparatus comprises a container, a build material extraction module, an energy source and a controller. The container is to receive a build volume comprising portions in which an un-cured thermally curable binder has been applied to define a 3D object to be generated and portions on which no binder has been applied. The build material extraction module is to remove part of the build material on which no binder has been applied. The energy source to heat the contents of the container. And the controller is to control the build material extraction module to remove part of the build material on which no binder has been applied; and control the energy source to heat the build material to thermally cure any binder in the container.

Aspects of this disclosure include a method for repairing a component having narrow passage, a three-dimensional printer, and composition for three-dimensional printing. One embodiment of the method may comprise mixing a filler material for three-dimensional printing with a carrier fluid, and applying a controlled electromagnetic field to bias the filler material towards a repair location in a narrow passage of a component. The method may further comprise coating a ferromagnetic material with the filler material to form a microcapsule, wherein the ferromagnetic material is adapted to interact with the controlled electromagnetic field to attract the microcapsule to the repair location. 3D printing techniques may be used to coat the ferromagnetic core with the filler material.

Aspects of this disclosure include a method for repairing a component having narrow passage, a three-dimensional printer, and composition for three-dimensional printing. One embodiment of the method may comprise mixing a filler material for three-dimensional printing with a carrier fluid, and applying a controlled electromagnetic field to bias the filler material towards a repair location in a narrow passage of a component. The method may further comprise coating a ferromagnetic material with the filler material to form a microcapsule, wherein the ferromagnetic material is adapted to interact with the controlled electromagnetic field to attract the microcapsule to the repair location. 3D printing techniques may be used to coat the ferromagnetic core with the filler material.

A three-dimensional printing system can include polymeric build material and jettable fluid(s). The polymeric build material can have an average particle size from 20 μm to 150 μm, a first melt viscosity, and a melting temperature from 75° C. to 350° C. In one example, the jettable fluid can include water, from 0.1 wt % to 10 wt % of electromagnetic radiation absorber, and from 10 wt % to 35 wt % of an organic solvent plasticizer. Contacting a first portion of a layer of the polymeric build material with the jettable fluid can provide an organic solvent plasticizer loading from 2 wt % to 10 wt % based on the polymeric build material content. The first melt viscosity of the polymeric build material at the first portion can be reduced and the melting temperature of the polymeric build material at the first portion can be decreased by 3° C. to 15° C.

A three-dimensional printing system can include polymeric build material and jettable fluid(s). The polymeric build material can have an average particle size from 20 μm to 150 μm, a first melt viscosity, and a melting temperature from 75° C. to 350° C. In one example, the jettable fluid can include water, from 0.1 wt % to 10 wt % of electromagnetic radiation absorber, and from 10 wt % to 35 wt % of an organic solvent plasticizer. Contacting a first portion of a layer of the polymeric build material with the jettable fluid can provide an organic solvent plasticizer loading from 2 wt % to 10 wt % based on the polymeric build material content. The first melt viscosity of the polymeric build material at the first portion can be reduced and the melting temperature of the polymeric build material at the first portion can be decreased by 3° C. to 15° C.