In one example, a powdered build material supply system for additive manufacturing includes a supply deck, a dispenser to dispense a ribbon of powdered build material on to the supply deck, and a spreader to spread powdered build material from the ribbon over a work area adjacent to the supply deck.

In one example, a powdered build material supply system for additive manufacturing includes a supply deck, a dispenser to dispense a ribbon of powdered build material on to the supply deck, and a spreader to spread powdered build material from the ribbon over a work area adjacent to the supply deck.

A method for producing a three-dimensional object by an additive manufacturing process includes introducing at least one manufacturing material fed in a flowable state from at least one feed-in opening of at least one feed-in needle into a supporting material. After being fed in, the at least one manufacturing material is cured, but it remains flexible or elastic after curing. The contour and/or position of at least one part of the three-dimensional object within the support material is detected by at least one sensor.

A method for producing a three-dimensional object by an additive manufacturing process includes introducing at least one manufacturing material fed in a flowable state from at least one feed-in opening of at least one feed-in needle into a supporting material. After being fed in, the at least one manufacturing material is cured, but it remains flexible or elastic after curing. The contour and/or position of at least one part of the three-dimensional object within the support material is detected by at least one sensor.

A method of selecting a scanning sequence of a laser beam in a selective laser solidification process, in which one or more objects are formed layer-by-layer by, repeatedly, depositing a layer of powder on a powder bed and scanning a plurality of laser beams over the deposited powder to selectively solidify the powder layers, wherein a gas flow is passed over the powder bed in a gas flow direction. The method including selecting a scanning sequence for the plurality of laser beams to include the simultaneous exposure of an upstream point together with a downstream point located downstream of a flow of debris carried from the upstream point by the gas flow, the downstream and upstream points selected for simultaneous exposure based upon the downstream point being within a maximum separation distance from the upstream point.

A method of selecting a scanning sequence of a laser beam in a selective laser solidification process, in which one or more objects are formed layer-by-layer by, repeatedly, depositing a layer of powder on a powder bed and scanning a plurality of laser beams over the deposited powder to selectively solidify the powder layers, wherein a gas flow is passed over the powder bed in a gas flow direction. The method including selecting a scanning sequence for the plurality of laser beams to include the simultaneous exposure of an upstream point together with a downstream point located downstream of a flow of debris carried from the upstream point by the gas flow, the downstream and upstream points selected for simultaneous exposure based upon the downstream point being within a maximum separation distance from the upstream point.

Methods to fabricate objects by 3D printing of poly-4-hydroxybutyrate (P4HB) and copolymers thereof have been developed. In one method, these objects are produced by continuous fused filament fabrication using an apparatus and conditions that overcome the problems of poor feeding of the filament resulting from the low softening temperature of the filament and heat creep along the fed filament. Methods using an apparatus including a heat sink, a melt tube, a heating block and nozzle, and a transition zone between the heat sink and heating block, with the melt tube extending through the heat sink, transition zone, and heat block to the nozzle are disclosed. 3D objects are also printed by fused pellet deposition (FPD), melt extrusion deposition (MED), selective laser melting (SLM), printing of slurries and solutions using a coagulation bath, and printing using a binding solution and polymer granules.

A tank assembly for a 3D printing system may include a membrane assembly that is releasably secured to a bottom rim of a tank sidewall of the tank assembly. The securing mechanism may include one or more of a friction-fit coupling and a magnetic coupling. The membrane assembly may include a frame, a radiation-transparent flexible membrane and a membrane securing member. A peripheral portion of the flexible membrane may be secured within a groove of the frame by the membrane securing member. The tank sidewall may include one or more components for supplying fresh resin to the tank assembly and one or more components for draining used resin from the tank assembly.

A tank assembly for a 3D printing system may include a membrane assembly that is releasably secured to a bottom rim of a tank sidewall of the tank assembly. The securing mechanism may include one or more of a friction-fit coupling and a magnetic coupling. The membrane assembly may include a frame, a radiation-transparent flexible membrane and a membrane securing member. A peripheral portion of the flexible membrane may be secured within a groove of the frame by the membrane securing member. The tank sidewall may include one or more components for supplying fresh resin to the tank assembly and one or more components for draining used resin from the tank assembly.

A three dimensional printing apparatus including a carrying plate, a transparent plate, an elastic film, and a bump is provided. The transparent plate is disposed on the carrying plate. The elastic film is disposed on the transparent plate. The bump is disposed between the elastic film and the carrying plate. An interface between the transparent plate and the elastic film is in communication with an external space through a fluid channel between each bump and the elastic film. An orthographic projection area of the bump on the transparent plate is not more than ¼ of a surface area of the transparent plate.