Interchangeable container with moveable side walls

1. A build container for a device for producing three-dimensional objects by layering, comprising: a build space on a building platform having a rectangular shape defining short sides and long sides of the build container, wherein the build space is adjustable in a height and is within the build container; wherein during a displacement of the building platform to adjust the height of the build space, a kinetic friction between constructed layers and at least two side walls is reduced or essentially avoided, the building platform and the at least two side walls being moved at the same speed, wherein the build container includes a drive engagement on each of the short sides for attaching to a Z-axis drive unit, and wherein the only movement of the build platform during building of the three-dimensional objects is a vertical movement.

2. The build container of claim 1 , wherein the at least two side walls includes 3 or 4 side walls.

3. The build container of claim 1 , wherein the at least two side walls of a build container are movable in the build direction.

4. The build container of claim 1 , wherein the at least two side walls are not rigid with respect to a particulate feedstock pressure and are supported via additional side walls.

5. The build container of claim 1 , wherein at least one of the at least two side walls is designed to be flexible in one direction.

6. The build container of claim 1 , wherein the at least two side walls are a segmented wall and/or a metallic wall and are designed to be flexible in one direction.

7. The build container of claim 1 , wherein a metal/plastic tribological pairing is used to reduce the friction effect.

8. The build container of claim 1 , wherein a supported belt, which is flexible in all directions, is used as at least one of the at least two of the side walls.

9. The build container of claim 1 , wherein a continuous belt is used as at least one of the at least two side walls.

10. The build container of claim 1 , wherein a finite belt is used as at least one of the at least two side walls and is tensioned by one or more springs or a weight force.

11. The build container of claim 1 , wherein the build container is capable of attaching to and then removing from a 3D printing device by engaging and disengaging the 3D printing device with the drive engagement, wherein the 3D printing device including a coater unit and a print head for constructing layers of particulate material and selectively printing a binder.

12. The build container of claim 3 , wherein the at least two side walls of the build container are displaceable relative to two fixed side walls.

13. The build container of claim 12 , wherein the at least two side walls of the build container are rigid with respect to a particulate feedstock pressure.

14. The build container of claim 5 , wherein the at least two side walls include four side walls that are designed to be flexible in one direction.

15. The build container of claim 6 , wherein the at least two side walls include three or four side walls.

16. The build container of claim 1 , wherein the build container includes an additional drive engagement positioned for attaching to an additional Z-axis drive unit on a different side of the build container.

17. A device for constructing three-dimensional objects comprising the build container of claim 1 , a coating device for applying a particulate feedstock material in layers over the build platform, and the Z axis drive unit on a side of the build container and attached to the build container by the drive engagement.

18. The device of claim 17 , wherein at least one roller bearing is used to reduce the kinetic friction.

19. The device of claim 17 , wherein the device includes a belt made of multiple materials and includes an antifriction layer.

20. The device of claim 17 , wherein a finite belt is wound up in an upper area of the build container.

21. The device of claim 17 , wherein the Z-axis drive unit is a lifting spindle.

22. A method for producing three-dimensional objects by layering comprising the steps of: constructing layers of a three-dimensional object with a coater for applying particulate material; wherein between a process of constructing two layers, a build platform is displaced to adjust a height of a build space within a build container, the build container is adjustable in height and have a plurality of side walls; wherein during a step of displacing the building platform, kinetic friction between the constructed layers and at least two side walls of the plurality of side walls is reduced or essentially avoided, wherein the building platform and the at least two side walls are moved at the same speed; wherein a Z-axis drive unit positioned on a side of the build container drives the build container in a vertical direction, wherein the Z-axis drive unit is attached to a drive engagement of the build container, and wherein the only movement of the build platform during building of the three-dimensional objects is the vertical movement.

23. The device of claim 22 , wherein the Z-axis drive unit is a lifting spindle.

24. The method of claim 22 , wherein the method comprises a step of selectively applying a binder material over a layer of particulate material.