Abstract: A method of recovering fluoropolymer from a three-dimensional printed object can include dissolving a fluoropolymer of a three-dimensional printed object in a fluoropolymer-dissolving solvent to generate dissolved fluoropolymer from the three-dimensional object, wherein the three-dimensional printed object includes from about 0.1 wt % to about 10 wt % particulate fusing compound and from about 90 wt % to about 99.9 wt % fluoropolymer. The method can further include separating the particulate fusing compound from the fluoropolymer-dissolving solvent and the dissolved fluoropolymer, and evaporating the fluoropolymer-dissolving solvent from the dissolved fluoropolymer.

Abstract: An example of a kit for three-dimensional (3D) printing includes an ultraviolet (UV) light fusing agent and a detailing agent. The UV light fusing agent including an aqueous vehicle and a plasmonic metal nanoparticle that i) provides absorption enhancement at radiation wavelengths ranging from about 340 nm to about 450 nm, and ii) is present in an amount up to 2 wt% based on a total weight of the UV light fusing agent. The detailing agent includes a surfactant, a co-solvent, and water.

Abstract: A three-dimensional printing kit can include a build material and a fusing agent. The build material can include from about 80 wt % to 100 wt % polymeric particles having a D50 particle size from about 10 ?m to about 150 ?m. The fusing agent can include an aqueous liquid vehicle and natural food-derived fusing compound dissolved or dispersed therein. The natural food-derived fusing compound can have an absorption peak from about 340 nm to about 780 nm.

Abstract: A method of recovering polyolefin polymer from a three-dimensional printed object can include dissolving a polyolefin polymer of a three-dimensional printed object in a polyolefin-dissolving solvent to generate dissolved polyolefin polymer from the three-dimensional object, wherein the three-dimensional printed object includes from about 0.1 wt % to about 10 wt% particulate fusing compound and from about 90 wt% to about 99.9 wt% polyolefin polymer. The method can further include separating the particulate fusing compound from the polyolefin-dissolving solvent and the dissolved polyolefin polymer, and evaporating the polyolefin-dissolving solvent from the dissolved polyolefin polymer.

Abstract: An example of an ultraviolet (UV) light fusing agent for three-dimensional (3D) printing includes a UV light absorber and a liquid vehicle. The UV light absorber consists of a fluorescent yellow dye. The liquid vehicle includes a surfactant, a co-solvent, and a balance of water. The UV light fusing agent is devoid of a saccharide.

Abstract: A three-dimensional printing kit can include a polymeric build material and a fusing agent. The polymeric build material can include polymer particles having a D50 particle size from about 2 ?m to about 150 ?m. The fusing agent can include an aqueous liquid vehicle including water and an organic co-solvent, a radiation absorber to generate heat from absorbed electromagnetic radiation, and from about 2 wt % to about 15 wt % of a carbamide-containing compound.

Abstract: In one example in accordance with the present disclosure, an additive manufacturing system is described. The additive manufacturing system includes a build material distributor to deposit powder build material on a surface and an agent distribution system to selectively deposit various colored fusing agents and an ultraviolet absorbing agent on the powder build material in a pattern of a layer of a three-dimensional (3D) object to be printed. An irradiation source selectively fuses powder build material with colored fusing agent disposed thereon. The additive manufacturing system also includes a controller. The controller, per location of the layer of the 3D object to be printed 1) determines an energy absorption at the location based on an absorptivity of colored fusing agents deposited at that location and 2) determines an additive manufacturing adjustment to be made at the location to bring the energy absorption at the location to a target level.

Abstract: This disclosure describes three-dimensional printing kits, methods, and systems for three-dimensional printing with phosphorescent pigments. In one example, a three-dimensional printing kit can include a powder bed material and a low-tint fusing agent. The powder bed material can include polymer particles and phosphorescent pigment particles mixed with the polymer particles. The low-tint fusing agent can include water and an electromagnetic radiation absorber. The electromagnetic radiation absorber can absorb radiation energy and convert the absorbed radiation energy to heat.

Abstract: An example of a three-dimensional (3D) build material composition includes from about 70 wt % to about 95 wt % of polyamide particles, based upon a total weight of the build material composition; and from about 5 wt % to about 30 wt % of biodegradable polyester filler particles, based upon the total weight of the build material composition. The biodegradable polyester filler particles are present in the build material composition without any additional filler particles.

Abstract: The present disclosure is drawn to food contact compliant three-dimensional printing kits, materials, compositions, systems, and methods. In one example, a multi-fluid kit of food contact compliant agents for three-dimensional printing can include a food contact compliant fusing agent and a food contact compliant detailing agent. The food contact compliant fusing agent can include from about 70 wt% to about 96 wt% water, from about 3 wt% to about 10 wt% by solids weight of a food contact compliant carbon black dispersion, and from about 1 wt% to about 25 wt% of a food contact compliant water-soluble first co-solvent. The food contact compliant detailing agent can include from about 75 wt % to about 99 wt% water and from about 0.01 wt% to about 1 wt% of a food contact compliant chelating compound.

Abstract: An example of a jettable antioxidant formulation is for three-dimensional (3D) printing. The jettable antioxidant formulation includes an antioxidant blend; a surfactant, a dispersant, or a combination thereof; a water soluble or water miscible organic co-solvent; and water. The antioxidant blend consists of a primary antioxidant and a secondary antioxidant.

Abstract: An example of a multi-fluid kit for three-dimensional (3D) printing kit includes a fusing agent and a build material reactive functional agent. The fusing agent includes water and an electromagnetic radiation absorber. The build material reactive functional agent includes a vehicle and trifluoroacetic anhydride. The multi-fluid kit may also be part of a 3D printing kit.

Abstract: Hydrogel three-dimensional printing kits, methods of three-dimensional printing and three-dimensional printed hydro-gels are described. In one example, a three-dimensional printing kit can comprise a particulate build material, a crosslinking agent and a structural modifier. The particulate build material may comprise a polyhydroxylated polymer having hydroxyl groups. The crosslinking gent is for crosslinking the polyhydroxylated polymer by a reaction with the hydroxyl groups. The structural modifier can have a plurality of functional groups for forming a network within the hydrogel, and where the structural modifier may have a reactivity that is chemically orthogonal to the reaction with the hydroxyl groups for crosslinking the polyhydroxylated polymer.

Abstract: A three-dimensional printing kit can include a polymeric build material including from about (80) wt% to (100) wt% polymer particles having an average particle size from about (10) µm to about (150) µm, and can also include a fusing agent including an aqueous liquid vehicle and from about (2) wt% to about (20) wt% of a mixture of organic dye radiation absorbers. The mixture of organic dye radiation absorbers can include a charged yellow water-soluble organic dye and a cyan water-soluble organic dye. The mixture of the organic dye radiation absorbers can be from about (1) wt% to about (40) wt% soluble in water.

Abstract: The present disclosure is drawn to food contact compliant three-dimensional printing kits and systems. In one example, a multi-fluid kit of food contact compliant agents for three-dimensional printing can include a food contact compliant fusing agent and a food contact compliant detailing agent. The fusing agent can include from about 70 wt % to about 96 wt % water, a food contact compliant carbon black dispersion in an amount of from about 3 wt % to about 10 wt % by solids weight of the carbon black dispersion, and food grade propylene glycol in an amount from about 1 wt % to about 15 wt %. The detailing agent can include from about 70 wt % to about 90 wt % water, food grade propylene glycol in an amount from about 10 wt % to about 25 wt %, and a food contact compliant chelating compound in an amount of from about 0.01 wt % to about 1 wt %.

Abstract: A method of recovering polymer from a three-dimensional printed object can include dissolving a polyamide polymer of a three-dimensional printed object in a polyamide-dissolving solvent to generate dissolved polyamide polymer from the three-dimensional object, where the three-dimensional printed object can include a particulate fusing compound and from about 90 wt % to about 99.9 wt % of the polyamide polymer; separating the particulate fusing compound from the polyamide-dissolving solvent and the dissolved polyamide polymer; and evaporating the polyamide-dissolving solvent from the dissolved polyamide polymer.

Abstract: The present disclosure is drawn to food contact compliant three-dimensional printing kits, materials, compositions, systems, and methods, in some examples, described herein is a food contact compliant fusing agent comprising: at least about 75 wt % water based on the total weight of the food contact compliant fusing agent, food contact compliant carbon black dispersion in an amount of from about 3 wt % to about 10 wt % based on the total weight of the food contact compliant fusing agent, at least one food contact compliant water soluble first co-solvent present in the food contact compliant fusing agent in an amount of from about 1 wt % to about 25 wt % based on the total weight of the food contact compliant fusing agent, and at least one food contact compliant pH adjuster or at least one food contact compliant liquid additive.

Abstract: 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 that absorbs radiation energy and converts the radiation energy to heat. The antioxidant agent can include a liquid vehicle with water and from about 0.5 wt % to about 15 wt % hindered phenolic antioxidant dispersed in the liquid vehicle.

Abstract: A three-dimensional printing kit can include a polymeric build material including thermoplastic elastomeric particles having a D50 particle size from about 2 ?m to about 150 ?m, and a fusing agent. The fusing agent can include water, from about 5 wt % to about 40 wt % lower alkyldiol organic co-solvent, and a radiation absorber to generate heat from absorbed electromagnetic radiation.

Abstract: This disclosure describes hydrogel three-dimensional printing kits, methods of three-dimensional printing hydrogels, and hydrogel three-dimensional printing systems. In one example, a hydrogel three-dimensional printing kit can include a particulate build material and an aqueous agent. The particulate build material can include from about 90 wt % to 100 wt % of a mixture of a powdered polyhydroxylated swellable polymer dry blended with powdered water-soluble crosslinker that is reactive with hydroxyl groups of the polyhydroxylated swellable polymer to crosslink the polyhydroxylated swellable polymer. The aqueous agent can include water and an organic co-solvent, and the aqueous agent may not include the crosslinker.