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.

In some examples, an additive manufacturing process may be operated by a method that includes depositing a plurality of preliminary layers of build material over a build surface and applying thermal energy governed by closed-loop control to heat the preliminary layers. The method includes analyzing a temperature distribution across a layer of the preliminary layers to map the locations of any hot spots relative to the build surface. The method includes selecting a spray pattern to apply a cooling agent to the mapped locations.

In some examples, an additive manufacturing process may be operated by a method that includes depositing a plurality of preliminary layers of build material over a build surface and applying thermal energy governed by closed-loop control to heat the preliminary layers. The method includes analyzing a temperature distribution across a layer of the preliminary layers to map the locations of any hot spots relative to the build surface. The method includes selecting a spray pattern to apply a cooling agent to the mapped locations.

In an example implementation, a method of printing a multi-structured three-dimensional (3D) object includes forming a layer of sinterable material. The method includes processing a first portion of the sinterable material using first set of processing parameters and processing a second portion of the sinterable material using a second set of processing parameters. The processed first and second portions form, respectively, parts of a first and second structure of a multi-structured 3D object.

A method of layerwise fabrication of a three-dimensional object is disclosed. The method comprises, for each of at least a few of the layers: dispensing at least a first modeling formulation and a second modeling formulation to form a core region using both the first and the second modeling formulations, and at least one envelope region at least partially surrounding the core region using one of the first and the second modeling formulations but not the other one of the first and the second modeling formulations. The method can also comprise exposing the layer to curing energy. The first modeling formulation is characterized, when hardened, by heat deflection temperature (HDT) of at least 90° C., and the second modeling formulation is characterized, when hardened, by Izod impact resistance (IR) value of at least 45 J/m.

A method of layerwise fabrication of a three-dimensional object is disclosed. The method comprises, for each of at least a few of the layers: dispensing at least a first modeling formulation and a second modeling formulation to form a core region using both the first and the second modeling formulations, and at least one envelope region at least partially surrounding the core region using one of the first and the second modeling formulations but not the other one of the first and the second modeling formulations. The method can also comprise exposing the layer to curing energy. The first modeling formulation is characterized, when hardened, by heat deflection temperature (HDT) of at least 90° C., and the second modeling formulation is characterized, when hardened, by Izod impact resistance (IR) value of at least 45 J/m.

In example implementations, a method for extracting layers of build material into a carrier. The method includes providing a layer of build material onto a bed. Portions of the layer of build material on the bed are digitally printed with a liquid functional material (LFM). The method repeats providing the layer of build material and digitally printing without applying energy to the LFM to define a structure in layers of build material on the bed. The layers of build material are extracted into a carrier and the carrier is removed.

Methods and apparatus for the fabrication of solid three-dimensional objects from liquid polymerizable materials at high resolution. A material is coated on a film non-digitally, excess material is removed digitally, by laser, leaving an image of a layer to be printed, and the image is then engaged with existing portions of an object being fabricated and exposed to a non-digital UV curing light source. Since the only part of the process that is digital is the material removal, and this part is done by laser, the speed of printing and the robustness of the manufacturing process is improved significantly over conventional additive or 3D fabrication techniques.

The present disclosure provides a light curing non-transparent material for 3D printing and a preparation method thereof, a 3D printed product and a 3D printer. The light curing non-transparent material for 3D printing provided by the present disclosure can be used to print non-transparent 3D printed products without adding white pigments such as white pigments powder, and therefore has the characteristic of high stability, and also ensures fluency of the 3D printing process, good quality of the 3D printed products, as well as good performances of the 3D printer that containing light curing non-transparent material for 3D printing.