Method for the layered construction of models

• US 20060237159A1
• Filed: 06/14/2004
• Published: 10/26/2006
• Est. Priority Date: 06/17/2003
• Status: Active Grant

• Current Assignee: Exone GMBH (Desktop Metal, Inc.)
• Original Assignee: Voxelet GmbH
• Inventors: Hochsmann, Rainer
• Granted Patent: US 8,020,604 B2
• Time in Patent Office: Days
• US Class Current: 164/23
• CPC Class Codes: B22C 9/02 Sand moulds or like moulds for shaped castings
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

Described is a procedure for layered composition of models, whereby at least a first material is applied to an assembly platform, followed by selective application of a second material layer; these two application steps are repeated until the required model is achieved and both materials form a solid structure in an appropriate mixture ratio. The first material comprises a moulding sand; the first and/or second material comprises a bonding agent encompassing a salt-crystal binder and/or protein binder.

Claims

1. A procedure for layered composition of models, comprising the steps of:

applying at least a first material layer that includes a moulding sand and optionally a bonding agent that includes a salt-crystal binder, a protein binder, or both to an assembly platform, and applying a second material layer that includes a moulding sand and optionally a bonding agent that includes a salt-crystal binder, a protein binder, or both; and

repeating these two application steps until the required model is achieved and both materials form a solid structure in an appropriate mixture ratio, the first material layer, the second material layer or both comprises a bonding agent comprising a salt-crystal binder, a protein binder, or both.

2. A procedure according to claim 1, whereby the bonding agent is mixed into the material of the first material layer.

3. A procedure according to claim 1, whereby the first material layer includes a mixture comprising a solvent, the bonding agent and moulding sand.

4. A procedure according to claim 3, whereby the moulding sand is coated with the bonding agent.

5. A procedure according to claim 1, whereby the bonding agent is mixed into the material of the second material layer.

6. A procedure according to claim 1, whereby the first material layer comprises moulding sand and bonding agent, which is selectively contacted with a solvent.

7. A procedure according to claim 6, whereby the solevent essentially comprises water.

8. A procedure according to claim 1, whereby the solvent is applied by means of droplet generation.

9. A procedure according to claim 1, whereby the solvent is applied by means of screen printing or spraying through a template.

10. A procedure according to claim 1, whereby the solvent is removed by drying after an appropriate reaction time has elapsed.

11. A procedure according to claim 1, whereby the moulding sand comprises quartz sand, zircon sand, olivine sand and/or fireclay sand.

12. A procedure according to claim 1, whereby the bonding agent comprises magnesium sulphate, sodium polyphosphate and/or proteins.

14. The procedure of claim 1, whereby the model is metal casting mould

13. (canceled)

15. A procedure for layered composition of a metal casting mould, comprising the steps of:

a) mixing solid particles of a bonding agent comprising a salt-crystal, a protein or a combination thereof, with a sand that comprises quartz sand, zircon sand, olivine sand, fireclay sand or a combination thereof, to form a bonding agent/sand admixture,

b) applying a thin layer of the bonding agent/sand admixture to and assembly field of an assembly platform;

c) selectively applying a solvent to the bonding agent/sand admixture in required areas;

d) lowering the assembly platform; and

e) repeating at least steps (a)-(c) for applying an additional layer.

16. The procedure of claim 15, characterized in that the solvent is water and is applied in a sufficient dose so that it is capable of bonding particles of sand within a layer to each other, to underlying sand particles that may be present;

and the moulding sand comprises quartz sand zircon sand, olivine sand, fireclay sand or a combination thereof; and

17. The procedure of claim 15, characterized in that the sand includes a quartz sand and the bonding agent includes a salt-crystal binder.

19. A metal casting mould including a plurality of layers of a bonding agent/sand admixture comprising a salt-crystal, a protein or a combination thereof, with a sand that comprises quartz sand, zircon sand, olivine sand, fireclay sand or a combination thereof, prepared according to the method of claim 15.

20. A procedure for layered composition of a metal casting mould, comprising the steps of:

a) mixing solid particles of a bonding agent comprising a salt-crystal, a protein or a combination thereof, with a sand that comprises quartz sand, zircon sand, olivine sand, fireclay sand or a combination thereof to form a bonding agent/sand admixture,

b) applying a thin layer of the bonding agent/sand admixture to an assembly field of an assembly platform;

c) selectively applying water, in a sufficient dose so that it is capable of bonding particles of sand within a layer to each other, to underlying sand particles that may be present, to the bonding agent/sand admixture in required areas for reacting it with the bonding agent/sand admixture;

d) drying the water;

e) lowering the assembly platform; and

f) repeating at least steps (a)-(d) for applying an additional layer.

21. The procedure of claim 20, further characterized by a step of recycling the sand from the resulting mould.