METHOD FOR PRODUCING A MOULDED BODY AND DEVICE

• US 20140227123A1
• Filed: 06/01/2012
• Published: 08/14/2014
• Est. Priority Date: 06/01/2011
• Status: Active Grant

• Current Assignee: Lithoz GmbH
• Original Assignee: Bam Bundesanstalt Fuer Materialforschung Und -Pruefung
• Inventors: Berger, Georg, Gnster, Jens, Gomes, Cynthia Morais
• Granted Patent: US 9,757,801 B2
• Time in Patent Office: Days
• US Class Current: 419/1
• CPC Class Codes: B22F 10/14 by jetting of binder onto a bed of metal powder
• CPC Class Codes: B22F 10/16 by embedding the binder within the powder bed
• CPC Class Codes: B22F 10/62 by chemical means
• CPC Class Codes: B22F 10/68 Cleaning or washing
• CPC Class Codes: B22F 12/222 for motion along a direction orthogonal to the plane of a layer
• CPC Class Codes: B22F 12/67 Blades
• CPC Class Codes: B22F 2003/1042 with support for articles to be sintered
• CPC Class Codes: B22F 2003/242 Coating
• CPC Class Codes: B22F 2202/11 Use of irradiation
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/003 Apparatus, e.g. furnaces in general F27B
• CPC Class Codes: B28B 1/001 Rapid manufacturing of 3D objects by additive depositing, agglomerating or laminating of material selective deposition modelling of metallic powder B22F10/00; rapid manufacturing of 3D objects in general and in particular of plastics B29C64/00
• CPC Class Codes: B28B 7/465 Applying setting liquid to dry mixtures
• 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 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: C04B 35/622 Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A method for producing a moulded body is proposed, comprising: applying a layer of particles and applying a binder and curing a moulded body; and a device for producing a metallic or ceramic moulded body, having a storage volume, which is configured for receiving a suspension of metallic or ceramic particles that are dispersed in a suspension fluid, a layer-forming application device, which is configured for removing an amount of suspension repeatedly from the storage volume and transferring it into a working volume and applying it there as a layer, a dehumidfying device, which is configured for dehumidifying the applied layer in the working volume, a binder application device, which is configured for applying a binder locally to the dehumidified layer in accordance with a layer model of the moulded body to be produced, in such a way that particles in the dehumidified layer are adhesively bonded locally to one another and optionally in addition to particles of at least one layer lying under the dehumidified layer, and a demoulding device, which is configured for demoulding the moulded body by detaching binder-free residual material from the particles bonded to another with the aid of the binder; and also a rapid prototyping method, comprising: producing a green body and sintering the green body.

Claims

1. A method for producing a molded article comprising:

applying a layer of particles and applying a binder, curing the shaped body.

27. The method of claim 1, wherein the method comprises the following steps:

i. forming a moulded body from a metallic or ceramic material by carrying out the following steps repeatedly;

i. applying a layer of a suspension of metallic or ceramic particles that have been dispersed in a suspension fluid, in a working volume; and

ii. dehumidifying the deposited layer in the working volume and local application to the dried layer and curing of a binding agent in accordance with a layer model of the moulded body to be produced, in such manner that particles in the dehumidified layer are adhesively bonded locally to each other and optionally also to particles in at least one layer below the dried layer; and

ii. demoulding the moulded body by detaching binder-free residual material from the particles bonded to each other with the aid of the binder.

28. The method according to claim 27, characterized in that the binder device is applied locally in a printing device.

29. The method according to claim 27, characterized in that the applied layer is heated during dehumidification.

30. The method according to claim 27, characterized in that the moulded body is produced as a porous moulded body.

31. The method according to claim 27, characterized in that curing the binder involves one or more steps from the following group of steps:

air-drying, supplying heat and irradiation with UV light.

32. The method according to claim 27, characterized in that demoulding is carried out at least partly in a liquid bath.

33. The method according to claim 27, characterized in that the moulded body is produced with a density of at least 60% v/v.

34. The method according to claim 27, characterized in that a green sheet is formed during application of the layer by the application of a suspension of ceramic particles.

35. The method according to claim 27, characterized in that an organic binder is used which is not soluble in water and/or not soluble in organic solvents after curing.

36. The method according to claim 27, characterized in that an inorganic binder is used.

37. The method according to claim 27, characterized in that the moulded body is sintered after demoulding.

38. The method according to claim 27, further comprising the step of:

locally applying corresponding to the layer model of the moulded body to be produced a liquid binder that alters the solubility of the green body, in such manner that the solubility of the moulded body is homogeneous and is different from that of the surrounding particulate material.

40. A method for producing a moulded body according to claim 1, wherein the moulded body is a green body and the method comprises:

(a) generating a layer of a suspension containing a binder that is laser-curable and/or laser-crosslinkable;

(b) curing and/or crosslinking the binder by local laser exposure; and

optionally repeating steps (a) and (b), wherein an additional layer is applied to a cured and/or crosslinked layer;

(c) washing out and/or dissolving components that have not been cured and/or crosslinked in a liquid medium to obtain the green body.

41. The method according to claim 40, wherein the layer is generated using a suspension in which the binder is contained, wherein the solid content of the suspension is selected from a polymer, a metal, a ceramic material or a mixture containing at least one polymer, one metal or one ceramic material.

42. The method according to claim 40, wherein the generation of the layer involves at least partial penetration of a binder into a dehumidified layer of a suspension that does not contain any binder.

43. The method according to claim 40, wherein the penetration of the binder is effected by spraying the dehumidified layer with the binder and/or by immersing the dehumidified layer in the binder or in a liquid containing the binder.

44. The method according to claim 40,

wherein the cured and/or crosslinked binder is not soluble in the liquid medium;

and

wherein the medium comprises water and/or an organic solvent; and

wherein the organic solvent is selected from the group consisting of acetone, cyclohexane, dioxane, n-hexane, n-octane, toluene, trichloroethanol, dimethyl ethyl ketone, isopropanol, ethyl alcohol, methyl ethyl ketone, and mixtures obtained therefrom.

45. The method according to claim 40,

wherein a density of the green body is at least 60% of the average material density of a solid portion of the suspension, when the density of the green body is defined as the quotient from a mass of the green body and a volume calculated on the basis of exterior contours of the green body;

and

wherein the dimensions of layer correspond to the dimension information of a layer model that is constructed one layer at a time.

2-26. -26. (canceled)

39. A device for producing a metallic or ceramic moulded body, comprising:

i. a storage volume that is configured to accommodate a suspension of metallic or ceramic particles that are dispersed in a suspension fluid,

ii. a layer-forming application device that is configured to repeatedly remove a quantity of suspension from the storage volume and transfer said quantity to a working volume, and to apply it there as a layer,

iii. a dehumidifier that is configured to dehumidify the applied layer in the working volume,

iv. a binding agent application device that is configured to apply a binder locally to the dehumidified layer in accordance with a layer model of the moulded body to be produced, in such manner that particles in the dehumidified layer are adhesively bonded locally to one another and optionally in addition to particles of at least one layer below the dehumidified film layer, and

v. a demoulding device that is configured to demould the moulded body by detaching the binder-free residual material from the particles bonded to each other with the aid of the binder.