Method for the layerwise construction of models

1. A method for building models in layers, wherein a particulate material is applied in layers in a build space and selectively hardened and these steps are repeated until a desired model is obtained, the particulate material comprises a particulate building material, characterized in that the particulate material comprises a spray-dried alkali silicate solution, the method includes a step of curing that is selectively activated by a solution containing water, and that a drying process is involved;

wherein the particulate material includes an inorganic curing agent; and

the inorganic curing agent is a latent curing agent, a synthetic silica, or a pyrogenic silicic acid.

2. The method of claim 1 , wherein the particulate building material includes sand.

3. The method of claim 2 , wherein the particulate material includes an auxiliary binder.

4. The method of claim 3 , wherein the auxiliary binder is a hydraulically setting binder including Portland cement, alumina cement and/or a hydraulic binder containing alumina.

5. The method of claim 1 , wherein the particulate material includes particles of the spray-dried alkali silicate solution.

6. The method of claim 1 , wherein the spray-dried alkali silicate solution is applied as a coating on the particulate building material.

7. The method of claim 1 , wherein the alkali silicate has a molar ratio M 2 O:SiO 2 of 1.6 to 3.8, wherein M is sodium, potassium, or both.

8. The method of claim 1 , wherein the particulate material contains a spray-dried alkali silicate fraction amounting to 2-18% by weight.

9. The method of claim 1 , wherein the inorganic curing agent is a latent curing agent and the proportion of the latent curing agent amounts to 5-90% by weight in relation to the solid binder.

10. The method of claim 1 , wherein the particulate material additionally includes refractory materials and/or fillers.

11. The method of claim 1 , wherein the solution for the selective hardening is applied with an ink jet print head.

12. The method of claim 1 , wherein the curing is accelerated by heat.

13. A solid body manufactured by a method claim 1 , characterized in that the solid body has a bending strength of greater than or equal to 220 N/cm 2 .

14. The method of claim 1 ,

wherein

the particulate building material includes sand;

the latent inorganic curing agent includes an amorphous silicon dioxide;

the particulate material includes a hydraulically setting binder including a Portland cement, an alumina cement, or a hydraulic binder containing alumina;

the alkali silicate has a molar ratio M 2 O:SiO 2 of 1.9 to 3.4, where M is sodium, potassium, or both;

the spray-dried alkali silicate is present in an amount of 3-10% by weight;

the particulate material includes a mixture of the spray-dried alkali silicate binder, the sand, and the amorphous silicon dioxide in a % by weight ratio of 1.5-15:80-98:0.2-8;

the solution contains 5-15 percent by weight of a sheet silicate to activate the selective hardening;

the solution for the selective hardening is applied with an ink jet print head using piezo technology; and

the curing is accelerated by heat.

15. A material system for building models in layers, wherein a particulate material is applied in layers in a build space and selectively hardened and these steps are repeated until a desired model is obtained, the material system comprises a particulate building material, characterized in that the material system further comprises a spray-dried alkali silicate solution, and that a polar solvent is used for selectively activating the hardening;

wherein the material system includes an inorganic curing agent; and

the inorganic curing agent is a latent curing agent, a synthetic silica, or a pyrogenic silicic acid.

16. A method for building models in layers, wherein a particulate material is applied in layers in a build space and selectively hardened and these steps are repeated until a desired model is obtained, the particulate material comprises a particulate building material, characterized in that the particulate material comprises a spray-dried alkali silicate solution, curing that is selectively activated by a solution containing water, and that a drying process is involved;

wherein the solution contains a sheet silicate.

17. A method for building models in layers, comprising the steps of:

applying a particulate material in layers in a build space, and selectively hardening the particulate material; wherein these steps are repeated until a desired model is obtained, wherein the particulate material comprises:

a particulate building material including a mixture of:

i) a spray-dried alkali silicate binder particles;

ii) a sand particles, and

iii) an amorphous silicon dioxide particles; and

the method includes a step of curing that is selectively activated by a solution containing water, and wherein a drying process is involved.

18. The method of claim 17 , wherein the spray-dried alkali silicate binder, the sand, and the amorphous silicon dioxide are present in the mixture in a % by weight ratio of 1.5-15:80-98:0.2-8.

19. A material system for building models in layers, wherein a particulate material is applied in layers in a build space and selectively hardened and these steps are repeated until a desired model is obtained, wherein the material system comprises:

a particulate building material including a mixture of:

i) a spray-dried alkali silicate binder particles

ii) a sand particles, and

iii) an amorphous silicon dioxide particles; and

a polar solvent for selectively activating the hardening.

20. The material system of claim 19 ,

wherein

the particulate building material includes sand;

the particulate material includes a latent inorganic curing agent including an amorphous silicon dioxide;

the particulate material includes a hydraulically setting binder including a Portland cement, an alumina cement, or a hydraulic binder containing alumina;

the alkali silicate has a molar ratio M 2 O:SiO 2 of 1.9 to 3.4, where M is sodium, potassium, or both;

the spray-dried alkali silicate is present in an amount of 3-10% by weight;

the material system includes a mixture of the spray-dried alkali silicate binder, the sand, and the amorphous silicon dioxide in a % by weight ratio of 1.5-15:80-98:0.2-8;

the solution contains 5-15 percent by weight of a sheet silicate to activate the selective hardening;

the material system includes a solution for the selective hardening including the polar solvent, wherein the solution is capable of being applied with an ink jet print head using piezo technology; and

the curing is accelerated by heat.