Abstract: A metered volume microfluidic device can include fluid flow microfluidics. The fluid flow microfluidics can include an inflow channel, a metered volume chamber positioned to receive working fluid from the inflow channel, a metered volume outflow channel positioned to receive and direct a metered volume of the working fluid when discharged from the metered volume chamber, and a capillary check valve. The capillary check valve can allow excess working fluid to exit the metered volume chamber when filling the metered volume chamber via the inflow channel. The capillary check valve can also prevent excess working fluid that has passed there through from being reintroduced into the metered volume chamber when the working fluid is discharged into the metered volume outflow channel.

Abstract: A build material recovery system for a three-dimensional (3D) printer can include a selective solidification device to create a 3D object using build material, a build processing device to separate the 3D object from unfused build material, a material separating and conditioning device to condition the unfused build material, and a material storage device to store the conditioned build material.

Abstract: A metered volume microfluidic device can include fluid flow microfluidics. The fluid flow microfluidics can include an inflow channel, a metered volume chamber positioned to receive working fluid from the inflow channel, a metered volume outflow channel positioned to receive and direct a metered volume of the working fluid when discharged from the metered volume chamber, and a capillary check valve. The capillary check valve can allow excess working fluid to exit the metered volume chamber when filling the metered volume chamber via the inflow channel. The capillary check valve can also prevent excess working fluid that has passed there through from being reintroduced into the metered volume chamber when the working fluid is discharged into the metered volume outflow channel.

Abstract: In one example, a build material recovery system for additive manufacturing includes: a receiving station to receive a portable container containing a build material; a separator to remove build material from a stream of air; a first conduit to carry build material in the stream of air from the receiving station to the separator; a source of negative air pressure to pull the stream of air with the build material through the first conduit from the receiving station to the separator; a humidifier to add moisture to the stream of air; and a second conduit to carry build material from the separator to the receiving station.

Abstract: A three-dimensional (3D) printer includes a selective solidification module to selectively solidify portions of successive layers of a build material on a build platform. The 3D printer also includes a cartridge receiver to hold a removable material cartridge that accepts material from the 3D printer and makes material available to the 3D printer for printing of the 3D object.

Abstract: A three-dimensional (3D) printer and method of additive manufacture are disclosed. The method includes building a three-dimensional (3D) object via a 3D printing process. After the 3D printing process, the 3D object is contained within a cake comprising the 3D object and partially fused excess build material. The method further includes vibrating the cake to loosen the excess build material. The frequency of the vibration is swept across a predetermined range of frequencies over a predetermined sweep interval.

Abstract: Techniques for controlling moisture content of build material in a three dimensional printer are provided. An example system includes a build material vessel to contain the build material and receive a flow of air, and a humidifier to adjust the humidity of the air flowing into the build material vessel. The system also includes one or more sensors to determine a dew point of the air flowing into the build material vessel. The humidity level of the air flowing into the hopper is controlled by the humidifier to maintain the dew point at a level that will prevent condensation of water inside the build material vessel.

Abstract: In one example in accordance with the present disclosure, an additive manufacturing platform is described. The additive manufacturing platform includes a vibrating bed on which a volume of build material is to be disposed. The bed is to vibrate to remove excess build material and operates in at least two extraction modes during a build material extraction period. The additive manufacturing platform also includes a non-vibrating frame to support the vibrating bed.

Abstract: An example method to remove build material from a container is described. In that example a pulsed gas flow may be induced in a conduit to aspirate build material in pulses from the container.

Abstract: A three-dimensional (3D) printer and method including a material cartridge receiver to hold a removable material cartridge to accept build material from the 3D printer and to make build material available from the material cartridge to the 3D printer for printing of the 3D object. A liquid cartridge receiver holds a removable liquid cartridge to make available print liquid from the liquid cartridge for a print assembly.

Abstract: A build material management system for a 3D printing system is described in which one or more input ports of a housing of the build material management system is to connect to one or more respective transportable containers. The transportable containers contain a volume of build material comprising 3D printed parts and a portion of non-fused build material. A pump also comprised within the housing is operable to provide a pressure differential across a conduit network of the build material management system. The pump is connected to the input port(s) by the conduit network. An air-flow caused through at least one of the one or more input ports is controlled by processing circuitry also comprised within the housing. The air-flow causes cooling within the respective transportable container. In one alternative, the housing comprises at least two input ports.

Abstract: Example implementations relate to different mixtures of build materials deliverable during a three dimensional (3D) print operation. In some examples, a 3D print apparatus may include a delivery hopper to deliver build material to a print zone of the 3D print apparatus and a plurality of build material hoppers to which the delivery hopper is connected for receipt of at least one of a corresponding plurality of build materials. A controller of the 3D print apparatus may direct that variable proportions of a first build material relative to a second build material are receivable by the delivery hopper from the plurality of build material hoppers during the 3D print operation, where different mixtures of the variable proportions of the first build material and the second build material are deliverable to the delivery hopper during the 3D print operation.

Abstract: A build material recovery system for a three-dimensional (3D) printer can include a selective solidification device to create a 3D object using build material, a build processing device to separate the 3D object from unfused build material, a material separating and conditioning device to condition the unfused build material, and a material storage device to store the conditioned build material.

Abstract: A build material recovery system for a three-dimensional (3D) printer can include a selective solidification device to create a 3D object using build material, a build processing device to separate the 3D object from unfused build material, a material separating and conditioning device to condition the unfused build material, and a material storage device to store the conditioned build material.

Abstract: A system for manufacturing three dimensional objects can include logic to apply a gas with at least one flow rate to a vessel of a three dimensional printer. The logic can also detect a permeability of a build material residing within the vessel, wherein the permeability is calculated based on a plurality of pressure values detected by a plurality of pressure sensors residing in the vessel, and apply the gas with a predetermined humidity level at a second flow rate to modify the permeability of the build material residing in the vessel. Furthermore, the logic can initialize manufacturing a three dimensional object with the build material in response to detecting the permeability of the build material is below a predetermined threshold.

Abstract: A system for manufacturing three dimensional objects can include logic to detect, for at least one vessel, a moisture content level corresponding to a build material residing in the at least one vessel. The logic can also adjust a humidity level and a temperature of a gas and a conditioning agent applied to the at least one vessel, wherein the humidity level and the temperature are based on the moisture content level and a temperature of the build material residing in the at least one vessel. Additionally, the logic can initialize manufacturing a three dimensional object with the build material from the at least one vessel in response to detecting the moisture content level of the build material residing in the at least one vessel is within a predetermined range.

Abstract: An example method to remove build material from a container is described. In that example a pulsed gas flow may be induced in a conduit to aspirate build material in pulses from the container.

Abstract: There is disclosed a method of cooling a bed of build material 12, 14 generated by additive manufacture. A container 10 containing a bed of build material may be provided, the bed having a hot region relative to ambient temperature. The container may be vibrated to fluidize unfused build material 12 in the container so as to cause convection of the unfused build material to cool the hot region. There is also disclosed a method of cooling a bed of build material 12, 14 including vibration when the temperature of a hot region in the bed of build material is higher than an unpacking threshold. There is also disclosed a cooling apparatus for cooling a bed of build material by vibration.

Abstract: An example of an apparatus is provided. The apparatus includes a build material transport path to transport a build material with air flow. The apparatus includes a humidifying element to receive the air flow and to add moisture to the air flow. The apparatus includes an inlet to introduce ambient air into the build material transport path to decrease moisture content in the air flow. The apparatus includes a valve to connect the humidifying element and the inlet to the build material transport path. The valve is to adjust an amount of ambient air introduced into the build material transport path. The apparatus includes a sensor to detect the moisture content in the air flow and to generate a signal to indicate the moisture content. The apparatus includes a processor to receive the signal to control the valve to maintain a moisture content in the air flow.

Abstract: In one example, a build material recovery system for additive manufacturing includes: a receiving station to receive a portable container containing a build material; a separator to remove build material from a stream of air; a first conduit to carry build material in the stream of air from the receiving station to the separator; a source of negative air pressure to pull the stream of air with the build material through the first conduit from the receiving station to the separator; a humidifier to add moisture to the stream of air; and a second conduit to carry build material from the separator to the receiving station.