Process for producing a component
The present invention relates to a slip-based process for producing a component which provides the use of a washout agent for removing excess material, and a device for carrying out the process according to the invention.
1 . A process for producing a three-dimensional component by additive manufacturing, comprising the steps of:
a) depositing a slip comprising powder particles to obtain a slip layer;
b) reducing the moisture content of the slip layer;
c) depositing a binder on the powder layer according to a cross-section of the desired component;
d) contacting said powder bed with a liquid cleaning medium to obtain the desired component
e) repeating steps a) to c) to obtain a powder bed with the component embedded therein;
characterized in that a washout agent is selectively deposited at least partially onto the regions not wetted with the binder.
2 . The process according to claim 1 , characterized in that said washout agent is deposited separately from the slip.
3 . The process according to claim 1 , characterized in that said washout agent is selected from the group consisting of substances that are swellable in said liquid cleaning medium; substances that will develop gas upon contacting said liquid cleaning medium; from hydrophilization agents, and mixtures thereof.
4 . The process according to claim 1 , characterized in that said liquid cleaning medium is selected from the group consisting of water, alcohols, acetone, and mixtures thereof.
5 . The process according to claim 1 , characterized in that said washout agent is selected from the group consisting of starches, modified celluloses, casein, glycols, alginates, polysaccharides, dextrans, crosslinked polymers, sodium hydrogencarbonate, citric acid, tartaric acid, and sorbitan fatty acid esters.
6 . The process according to claim 1 , characterized in that said process further includes one or more drying steps for drying the slip.
7 . The process according to claim 1 , characterized in that said slip contains powder particles selected from the group consisting of the oxides, carbides and nitrides of metals and non-metals.
8 . The process according to claim 1 , characterized in that said binder is selected from the group consisting of resins, polysaccharides, polyvinyl alcohol, cellulose and cellulose derivatives, lignin sulfonates, polyethylene glycol, polyvinyl derivatives, polyacrylates, and mixtures thereof.
9 . A device for carrying out a process according to claim 1 , characterized in that said device includes a slip depositing device, a binder depositing device, and a washout agent depositing device.
10 . The device according to claim 9 , characterized in that the slip depositing device is a die or a doctor blade.
11 . The device according to claim 9 , characterized in that said binder depositing device and/or said washout agent depositing device is a die and/or a printing head.
12 . The process according to claim 5 , wherein the crosslinked polymer comprises crosslinked polyvinylpyrrolidone.
13 . The process according to claim 7 , wherein the non-metals comprise silicon carbide particles.