Method for producing three-dimensional molded parts and regulating the moisture content in build material

Abstract

A method for producing three-dimensional molded parts by means of layering, the moisture content of the build material mixture being able to be regulated.

1 . A method for producing three-dimensional molded parts by means of layering comprising the steps of:
 a) applying an admixture including a particulate build material and one or multiple dissolved activators to a build space in a defined layer thickness with the aid of a coater;   b) selectively applying a binder fluid to the admixture by means of a print head;   c) polymerizing the binder fluid with the aid of at least one activator;   d) lowered by the build space by a distance of the layer thickness, or raising the coater by the distance of one layer thickness; and   e) repeating these steps until the desired molded part is produced;   wherein the one or more activators includes one or more humectants;   wherein the one or more humectants includes a phosphoric acid, a diphosphoric acid, a lactic acid, sodium chloride, calcium chloride, ammonium acetate, a salicylate, triacetin, glucose, sucrose, sorbitol, 1,2-propanediol, pentaerythritol, xylitol, or polyethylene glycol;   wherein the humectant aids in regulating a moisture content of the admixture.   
     
     
         2 . The method of  claim 1 , wherein the admixture includes water and/or the admixture in the coater includes liquid bridges between particles of the particulate build material. 
     
     
         3 . The method of  claim 2 , wherein the method includes a step of storing the admixture before introducing the admixture to the coater. 
     
     
         4 . The method of  claim 1 , wherein the particulate build material includes a sand. 
     
     
         5 . The method of  claim 1 , wherein the activator includes an acid. 
     
     
         6 . The method of  claim 5 , wherein the acid includes a sulfuric acid or a p-toluenesulfonic acid. 
     
     
         7 . The method of  claim 1 , wherein the particulate material has an average grain size of 100 μm to 500 μm. 
     
     
         8 . The method of  claim 3 , wherein
 the particulate build material includes a sand;   the activator includes an acid;   the acid includes sulfuric acid and p-toluenesulfonic acid; and   the particulate material has an average grain size of 100 μm to 500 μm.   
     
     
         9 . A method for producing three-dimensional molded parts by means of layering comprising the steps of:
 a) applying an admixture including a particulate build material and one or multiple dissolved activators to a build space in a defined layer thickness with the aid of a coater;   b) selectively applying a binder fluid to the admixture by means of a print head;   c) polymerizing the binder fluid with the aid of at least one activator, wherein the binder fluid includes 50 to 95 weight percent furfuryl alcohol;   d) lowered by the build space by a distance of the layer thickness, or raising the coater by the distance of one layer thickness; and   e) repeating these steps until the desired molded part is produced;   wherein the one or more activators includes one or more humectants that aids in regulating a moisture content of the admixture;   optionally, wherein the binder fluid includes a wetting agent, an adhesive, or a cross-linking agent.   
     
     
         10 . The method of  claim 9 , wherein the admixture includes water and/or the admixture in the coater includes liquid bridges between particles of the particulate build material. 
     
     
         11 . The method of  claim 10 , wherein the binder comprises the wetting agent, the adhesive, or the cross-linking agent. 
     
     
         12 . The method of  claim 10 , wherein the method includes a step of storing the admixture before introducing the admixture to the coater. 
     
     
         13 . The method of  claim 9 , wherein the particulate build material includes a sand. 
     
     
         14 . The method of  claim 9 , wherein the activator includes an acid, optionally wherein the acid includes a sulfuric acid or a p-toluenesulfonic acid. 
     
     
         15 . The method of  claim 9 , wherein the particulate material has an average grain size of 100 μm to 500 μm. 
     
     
         16 . The method of  claim 11 , wherein
 the method includes a step of storing the admixture before introducing the admixture to the coater.   the particulate build material includes a sand;   the activator includes an acid;   the acid includes sulfuric acid and p-toluenesulfonic acid; and   the particulate material has an average grain size of 100 μm to 500 μm.   
     
     
         17 . A device for the method of  claim 1 , wherein the device includes the coater and the print head. 
     
     
         18 . A device for the method of  claim 4 , wherein the device includes the coater and the print head. 
     
     
         19 . A molded body produced according to a method according to  claim 1 , wherein the moldable body is a casting mold and/or core in foundry processes or a mold and/or core for lamination processes,
 optionally wherein the foundry process is a concrete, mineral or reactive polymer casting process.   
     
     
         20 . A molded body produced according to a method according to  claim 4 , wherein the moldable body is a casting mold and/or core in foundry processes or a mold and/or core for lamination processes, optionally wherein the foundry process is a concrete, mineral or reactive polymer casting process.