In some examples, a build material recycling system of a three-dimensional (3D) printer can include a build material transport system of the 3D printer, a build material recycling device of the 3D printer that includes a fluidizing membrane and is connected to the build material transport system, and a recycled build material hopper of the 3D printer connected, via the build material

Molded rubber objects may be molded and de-molded by defining both a desired final form for the molded rubber object and a tab extending from the final form of the molded rubber object using a cavity in a mold. Rubber pellets may be dispensed in predetermined amounts at desired location(s) within the cavity to provide the rubber needed to form the molded rubber object. Heat and pressure may be applied to the mold to cause the rubber pellets to fill the cavity defining both the desired final form of the molded rubber object and the tab. After the heat and pressure has been applied, a gripping device may grasp the tab and move the tab in a direction and with sufficient force to peel the rubber object from the mold cavity. If desired, the tab may be removed from the molded rubber object.

Molded rubber objects may be molded and de-molded by defining both a desired final form for the molded rubber object and a tab extending from the final form of the molded rubber object using a cavity in a mold. Rubber pellets may be dispensed in predetermined amounts at desired location(s) within the cavity to provide the rubber needed to form the molded rubber object. Heat and pressure may be applied to the mold to cause the rubber pellets to fill the cavity defining both the desired final form of the molded rubber object and the tab. After the heat and pressure has been applied, a gripping device may grasp the tab and move the tab in a direction and with sufficient force to peel the rubber object from the mold cavity. If desired, the tab may be removed from the molded rubber object.

An apparatus includes a platen and a dispensing system overlying the platen. The dispensing system includes a powder source. The dispensing system further includes a powder conveyor extending over the top surface of the platen, rings arranged coaxially along a longitudinal axis of the powder conveyor, and a cap plate extending along a length of the tube. The powder conveyor is configured to receive powder from the powder source. The powder conveyor is configured to move the powder. The rings form a tube surrounding the powder conveyor to contain the powder. Each concentric ring includes a ring opening. Each ring is configured to be independently rotatable. The cap plate includes a cap plate opening. The powder is dispensed from the tube through the ring opening and the cap plate opening when the ring opening and the cap plate opening are aligned.

A feedstock delivery system for injection molding includes a vessel unit that includes a vessel with an internal volume and an inlet for receipt of a feedstock. First and second dispensing units are alternatively connectable to the vessel unit and each include first and second ends, first and second valves, and a buffer chamber. The first end is connectable to the dispensing unit such that the buffer chamber is in communication with the internal volume of the vessel. The second end is connectable to an injection mold and defines an outlet of the feedstock delivery system. The outlet is in communication with the buffer chamber, and the buffer chamber is positioned between the first and second valves. The buffer chamber of the first dispensing unit defines a first chamber volume, and the buffer chamber of the second dispensing unit defines a second chamber volume greater than the first chamber volume.

An additive-manufacturing build-material container (201) comprises a reservoir to hold build material, an outlet opening in a top portion of the reservoir, an outlet tube structure including a longitudinal collection unit to collect build material from the bottom and guide the build material to the outlet opening at the top, upon application of a suction force at the other end thereof, and to guide the collected build material to the outlet opening at the top; and a vent opening in a top portion of the reservoir to admit gas from outside the reservoir into the reservoir to follow a gas flow path through the vent opening, through the reservoir and into said one end of the longitudinal collection tube; wherein on said gas flow path there is at least one turbulent-gas-flow-generation feature (237) to generate turbulent gas flow in a region that is within the reservoir and outside the longitudinal collection tube.

There is provided a 3D printing build material container (1). The container comprises a collapsible reservoir, (3) a relatively rigid reinforcement structure (4), a build material outlet structure (13) and a gas inlet structure (14). The reservoir is to hold build material (11). The reinforcement structure is to resist collapsing of at least one reinforced portion of the reservoir. The outlet structure is to allow build material to exit the reservoir. The inlet structure is to allow a gas to enter the reservoir.

There is provided a 3D printing build material container (31) comprising a reinforcement structure (34), a collapsible reservoir (33) to hold build material, a build material outlet structure (313), at least one first inlet structure (314, 316), and a second inlet structure (315). The reinforcement structure encloses an airtight space and the reservoir is disposed within the reinforcement structure. The build material outlet (313) structure is to allow build material to exit the reservoir. The at least one first inlet structure (314, 316) is to allow recycled build material to enter the reservoir and to selectively allow a gas to enter the reservoir. The second inlet structure (315) is to selectively allow a gas to enter a space between the reservoir and the reinforcement structure.

Measures for use in an additive manufacturing system. The temperature of at least one build material delivery hole in a printbed area of the system is measured. An emissivity of the at least one build material delivery hole is compared with a known emissivity of a build material being used in additive manufacturing by the system at the measured temperature. In response to the comparison indicating a difference in emissivity, it is determined that at least a portion of the at least one build material delivery hole is not covered by build material.

Method and apparatus for air flow regulation comprise a vertically oriented conduit, a sail assembly positioned in the conduit and moveable therewithin responsively to air flow through the conduit to regulate rate of air flow through the conduit and to stop air flow through the conduit upon air flow rate through the conduit exceeding a preselected value with a detector for sensing when the sail assembly has stopped air flow thought the conduit as a result of air flow rate exceeding said pre-selected value.