In one example, a non-transitory processor readable medium with instructions thereon that when executed cause an additive manufacturing machine to inhibit build material in an overlying layer of build material from fusing with a first slice formed in an underlying layer of build material.

Certain examples described herein relate to adjusting an energy source of a 3D printing system. In certain cases, a build bed of a 3D printing system is arranged to receive a layer of build material and the energy source of the 3D printing system is controllable to provide energy to a zone of the build bed. The energy provided by the energy source associated with the zone is adjusted based on a difference between a predetermined heat loss of the build bed and a determined heat loss for the zone, where individual adjustments of energy provided to at least some zones of the build bed collectively provide a uniform heat loss across the build bed.

Certain examples described herein relate to adjusting an energy source of a 3D printing system. In certain cases, a build bed of a 3D printing system is arranged to receive a layer of build material and the energy source of the 3D printing system is controllable to provide energy to a zone of the build bed. The energy provided by the energy source associated with the zone is adjusted based on a difference between a predetermined heat loss of the build bed and a determined heat loss for the zone, where individual adjustments of energy provided to at least some zones of the build bed collectively provide a uniform heat loss across the build bed.

The disclosure relates to a light-curing 3D printer. The light-curing 3D printer includes a plurality of light-emitting sources which are uniformly arranged and simultaneously emit scattered lights; a grid plate which is located above the light-emitting sources, and has a vertical optical channel corresponding to a position right above one of the light-emitting sources which are located in the center of the optical channel which is surrounded by vertical and opaque side walls limiting the reflection of light; a lens which is located above a light-guiding member, and has a condensing lens unit formed corresponding to a position right above one of the optical channels; a liquid crystal display (LCD) transmitting screen which is located above the lens and has pixel lattices.

The disclosure relates to a light-curing 3D printer. The light-curing 3D printer includes a plurality of light-emitting sources which are uniformly arranged and simultaneously emit scattered lights; a grid plate which is located above the light-emitting sources, and has a vertical optical channel corresponding to a position right above one of the light-emitting sources which are located in the center of the optical channel which is surrounded by vertical and opaque side walls limiting the reflection of light; a lens which is located above a light-guiding member, and has a condensing lens unit formed corresponding to a position right above one of the optical channels; a liquid crystal display (LCD) transmitting screen which is located above the lens and has pixel lattices.

This disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and systems for three-dimensional printing. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and a detailing agent. The fusing agent can include water and metal oxide nanoparticles dispersed therein. The metal oxide nanoparticles can be selected from titanium dioxide, zinc oxide, cerium oxide, indium tin oxide, or a combination thereof. The metal oxide nanoparticles can have an average particle size from about 2 nm to about 500 nm. The detailing agent can include a detailing compound.

This disclosure describes multi-fluid kits for three-dimensional printing, three-dimensional printing kits, and systems for three-dimensional printing. In one example, a multi-fluid kit for three-dimensional printing can include a fusing agent and a detailing agent. The fusing agent can include water and metal oxide nanoparticles dispersed therein. The metal oxide nanoparticles can be selected from titanium dioxide, zinc oxide, cerium oxide, indium tin oxide, or a combination thereof. The metal oxide nanoparticles can have an average particle size from about 2 nm to about 500 nm. The detailing agent can include a detailing compound.

Systems and methods for three-dimensional printing using microwave assisted deposition are disclosed herein. An example device includes a reservoir of carbonaceous nanocomposite thermoset, a microwave resonance cavity that cures the carbonaceous nanocomposite thermoset, and a sensor to measure the extrusion temperature of the resin when curing the carbonaceous nanocomposite thermoset at the point of deposition during extrusion-based 3D printing.

Systems and methods for three-dimensional printing using microwave assisted deposition are disclosed herein. An example device includes a reservoir of carbonaceous nanocomposite thermoset, a microwave resonance cavity that cures the carbonaceous nanocomposite thermoset, and a sensor to measure the extrusion temperature of the resin when curing the carbonaceous nanocomposite thermoset at the point of deposition during extrusion-based 3D printing.

Examples of a 3D printing apparatus arranged to perform a print operation using build material, and methods of operating such a 3D printing apparatus, are described. In one case, a 3D printer is arranged to perform a print operation using build material whilst a build material temperature sensed by the printer is below a threshold temperature of the build material. The printer is arranged to obtain a threshold temperature indicator in advance of a respective print operation.