Manufacturing method and manufacturing apparatus

1. An additive manufacturing method in which regions of successively deposited layers of granular construction material are bound together so as to form a three-dimensional structure of bound material extending through and between the layers, the method comprising repetitively:

depositing a first granular construction material as a layer into a build region;

selectively binding regions of the first granular construction material together to form bound regions within the layer;

removing unbound granular construction material from the layer so as to provide at least one void in the layer;

depositing a second granular construction material into the build region so as to fill the at least one void;

selectively binding regions of the second granular construction material together to form bound regions within the layer,

wherein the second granular construction material is different from the first granular construction material,

wherein the first granular material has a different solubility than the second granular material, the different solubility being with regard to a polar or non-polar solvent; and

applying the solvent to the three-dimensional structure to separate a portion of the structure formed from the first granular construction material from a portion of the structure formed from the second granular construction material.

2. The method of claim 1 , further comprising:

smoothing the deposited second granular construction material to a uniform thickness before selectively binding regions of the second granular construction material together.

3. The method of claim 1 , further comprising:

smoothing the deposited first granular construction material to a uniform thickness before selectively binding regions of the first granular construction material together.

4. The method of claim 1 , wherein removing unbound granular construction material from the layer comprises applying suction to the layer.

5. The method of claim 1 , applying the solvent to the three-dimensional structure includes applying the solvent to dissolve the portion of the structure formed from one of the first granular construction material or the second granular construction material but not portions of the structure formed from the other of the first granular construction material or the second granular construction material.

6. The method of claim 1 , wherein

the deposition of the first granular construction material occurs in a pass of a deposition unit for depositing the granular construction material over the build region in a first direction at a first position in a second dimension that is transverse to the first direction, and

the deposition of the second granular construction material occurs in a pass of a deposition unit for depositing the second granular construction material over the print region in a second direction opposite to the first direction at the first position in the second dimension after the pass of the deposition unit for depositing the first granular construction material in the first direction at the first position in the second dimension and before the deposition unit for depositing the first granular construction material moves to another position in the second dimension.

7. The method of claim 1 , wherein

binding the first granular construction material occurs in a pass of a binding unit for binding the first granular material over the print region in a first direction at a first position in a second dimension that is transverse to the first direction, and

binding the second granular construction material occurs in a pass of a binding unit for binding the second granular construction material over the print region in a second direction opposite to the first direction at the first position in the second dimension after the pass of the deposition unit for depositing the first granular construction material in the first direction at the first position in the second dimension and before the deposition unit for depositing the first granular construction material moves to another position in the second dimension.

8. The method of claim 1 , wherein removing unbound granular construction material provides removed granular construction material, and the removed granular construction material is collected after removal.

9. The method of claim 1 , wherein the selective binding is performed for the first and second granular construction materials by selective application of a liquid binder using an ink-jet method.

10. The method of claim 1 , further comprising:

dissolving at least a portion of bound regions of the first granular construction material; and

sintering bound regions of the second granular construction material.

11. The method of claim 1 , further comprising:

dissolving at least a portion of bound regions of the second granular construction material; and

sintering bound regions of the first granular construction material.

12. The method of claim 1 , further comprising:

dissolving at least a portion of a bound region of the first granular construction material; and

after dissolving the portion of the bound region of the first granular construction material, sintering a bound region of the second granular construction material.

13. The method of claim 1 , further comprising:

dissolving at least a portion of a bound region of the second granular construction material; and

after dissolving the portion of the bound region of the second granular construction material, sintering a bound region of the first granular construction material.

14. An additive manufacturing method in which regions of successively deposited layers of granular construction material are bound together so as to form a three-dimensional structure of bound material extending through and between the layers, the method comprising repetitively:

depositing a first granular construction material as a layer into a build region;

selectively binding regions of the first granular construction material together to form bound regions within the layer;

removing unbound granular construction material from the layer so as to provide at least one void in the layer;

depositing a second granular construction material into the build region so as to fill the at least one void;

selectively binding regions of the second granular construction material together to form bound regions within the layer,

wherein the second granular construction material is different from the first granular construction material, wherein

the deposition of the first granular construction material occurs in a pass of a deposition unit for depositing the granular construction material over the build region in a first direction and

the deposition of the second granular construction material occurs in a pass of a deposition unit for depositing the second granular construction material over the print region in a second direction opposite to the first direction; and

applying a solvent to the three-dimensional structure to separate a portion of the structure formed from the first granular construction material from a portion of the structure formed from the second granular construction material.

15. The method of claim 14 , wherein the pass of the deposition unit for depositing the first granular construction material occurs in the first direction at a first position in a second dimension that is transverse to the first direction, and the pass of the deposition unit for depositing the second granular construction material occurs in the second direction at the first position in the second dimension after the pass of the deposition unit for depositing the first granular construction material in the first direction at the first position in the second dimension and before the deposition unit for depositing the first granular construction material moves to another position in the second dimension.

16. The method of claim 15 , wherein a smoothing blade smooths the first granular construction material before the pass of the deposition unit for depositing the second granular construction material.

17. The method of claim 16 , wherein a suction unit creates the at least one void after the smoothing blade smooths the first granular construction material and before the pass of the deposition unit for depositing the second granular construction material.

18. An additive manufacturing method in which regions of successively deposited layers of granular construction material are bound together so as to form a three-dimensional structure of bound material extending through and between the layers, the method comprising repetitively:

depositing a first granular construction material as a layer into a build region;

selectively binding regions of the first granular construction material together to form bound regions within the layer;

removing unbound granular construction material from the layer so as to provide at least one void in the layer;

depositing a second granular construction material into the build region so as to fill the at least one void;

selectively binding regions of the second granular construction material together to form bound regions within the layer,

wherein the second granular construction material is different from the first granular construction material, wherein

binding the first granular construction material occurs in a pass of a binding unit for binding the first granular material over the print region in a first direction and

binding the second granular construction material occurs in a pass of a binding unit for binding the second granular construction material over the print region in a second direction opposite to the first direction; and

applying a solvent to the three-dimensional structure to separate a portion of the structure formed from the first granular construction material from a portion of the structure formed from the second granular construction material.

19. An additive manufacturing method in which regions of successively deposited layers of granular construction material are bound together so as to form a three-dimensional structure of bound material extending through and between the layers, the method comprising repetitively:

depositing a first granular construction material as a layer into a build region;

selectively binding regions of the first granular construction material together to form first bound regions within the layer;

removing unbound granular construction material from the layer so as to provide at least one void in the layer;

depositing a second granular construction material into the build region so as to fill the at least one void;

selectively binding regions of the second granular construction material together to form second bound regions within the layer; and

selectively binding further regions of unbound first granular construction material or unbound second granular construction material to form third bound regions within the layer, the third bound regions having a weaker binding than the first bound regions and the second bound regions,

wherein the second granular construction material is different from the first granular construction material.