Process for producing a three dimensional object from particles, as well as product produced thereby
Generative processes for production of a three dimensional object comprised of particles are increasingly employed in the manufacture of casting molds and casting cores. Therein the casting mold is constituted of sand particles, which are joined using a binder material. The task of the present invention is comprised therein, of providing an alternative layer building-up process for production of a three dimensional object, which achieves sufficient casting stability, without suffering intolerable quality degradation due to evolution of off-gases from binder material during casting. This task is solved by a process employing particles, which are comprised of a mono- or polyvalent, water and/or alcohol soluble metals salt.
1 - 6 . (canceled)
7 . A process for producing a three dimensional object comprising the following steps:
a. applying a layer of particles comprised of at least a mono- or polyvalent water and/or alcohol soluble metal salt upon a target surface,
b. spraying a select part of the layer, corresponding to a cross section of the object, with a liquid stream containing water and/or alcohol, so that the particles are joined in the selected part,
c. repeating steps a and b so that the joined parts of the adjacent layers combine to form the object.
8 . A process according to claim 7 , wherein at least one metal salt having crystal water and/or at least one metal salt having condensable anions is employed in step a.
9 . A three dimensional object produced by a process comprising the following steps:
a. applying a layer of particles comprised of at least a mono- or polyvalent water and/or alcohol soluble metal salt upon a target surface,
b. spraying a select part of the layer, corresponding to a cross section of the object, with a liquid stream containing water and/or alcohol, so that the particles are joined in the selected part,
c. repeating steps a and b so that the joined parts of the adjacent layers combine to form the object.
10 . The three dimensional object according to claim 9 , wherein the object is a casting mold or casting core.
11 . The three dimensional object according to claim 9 , wherein the object is a tool or an insert for a plastic or ceramic mold.
12 . A process for casting metal, comprising
a. forming a casting mold by a process comprising (i) applying a layer of particles comprised of at least a mono- or polyvalent water and/or alcohol soluble metal salt upon a target surface, (ii) spraying a select part of the layer, corresponding to a cross section of the object, with a liquid stream containing water and/or alcohol, so that the particles are joined in the selected part, and (iii) repeating steps a and b so that the joined parts of the adjacent layers combine to form a green casting mold,
b. heating the casting mold to form a brown casting mold, and
c. casting a molten metal into said casting mold.