The above object is solved by means of a method comprising the features as described herein as well as an extrusion device comprising the features as described herein. Further features and details of the invention follow from the depending claims, the description and the drawings. It goes without saying that features and details, which are described in connection with the method according to the invention, shall thereby also apply in connection with the extrusion device according to the invention and in each case vice versa, so that, with regard to the disclosure, reference is or can always be mutually made, respectively, to the individual invention aspects.

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 transport system, to the build material recycling device.

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 transport system, to the build material recycling device.

Certain examples relate to a material management station for use in an additive manufacturing process. In these examples a metering system is applied to measure the amount of build material transported into the material management station from refillable containers. Data describing the metered amount of build material is communicated over a data communication network and remotely compared to an allowance of usage stored in an administration system. Control messages are communicated to the material management station preventing or allowing further use of the build material in line with the allowance usage.

An example of an apparatus to transfer additive manufacturing build material from a container is disclosed. The example disclosed herein comprises a holding structure and a conduit. The holding structure comprises a fixation element to physically attach the holding structure to one or multiple sides of the container. The conduit may be couplable to a vacuum system through a vacuum open end to extract the build material. The holding structure receives and positions the conduit substantially vertically such that a build material extraction open end of the conduit is positioned towards the base of the container. The vacuum open end and the build material extraction open end are opposite open ends from the conduit.

The invention relates to a method and device for producing 3D moulded parts by means of a layer construction technique wherein a recoater is used which can coat in both directions of movement.

The invention relates to a method and device for producing 3D moulded parts by means of a layer construction technique wherein a recoater is used which can coat in both directions of movement.

The present invention relates to a method for changing material in an extrusion device comprising at least two supply devices for supplying feedstock for an extruder, comprising the following steps: identifying a change request for changing material in an extrusion device, predetermining a production stability for a time after the material of at least one supply device has been changed, comparing the predetermined production stability to a threshold value of stability, changing the material in at least one supply device depending on the result of comparison.

The present invention relates to a method for changing material in an extrusion device comprising at least two supply devices for supplying feedstock for an extruder, comprising the following steps: identifying a change request for changing material in an extrusion device, predetermining a production stability for a time after the material of at least one supply device has been changed, comparing the predetermined production stability to a threshold value of stability, changing the material in at least one supply device depending on the result of comparison.

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.