Method and device for conveying particulate material during the layer-wise production of patterns
The present invention relates to a method for conveying particulate material during the manufacture of patterns in layers, wherein powder is conveyed out of a reservoir into a spreader unit and, if applicable, excess powder fed to the spreader unit is again conveyed back into the reservoir and wherein this conveying takes place in a closed conveying circuit.
1. A method comprising:
forming three dimension objects comprising the steps of:
1) providing a device for conveying particulate material comprising:
a) a reservoir;
b) a spreader unit; and
c) a plurality of particulate material conveying systems including a first particulate material conveying system having a screw conveyor and a second particulate material conveying system having a screw conveyor;
2) forming a first layer of the three dimension object by a layer forming step comprising:
a) conveying the particulate material out of the reservoir into the spreader unit with at least the first particulate material conveying system;
b) spreading the particulate material unit unto a build platform with the spreader; and
c) conveying excess particulate material that was fed to the spreader unit back into the reservoir after the step of spreading; and
3) forming a second layer of the three dimensional object by a layer forming step by repeating steps 2 a , 2 b and 2 c;
wherein the steps 2 a and 2 c of conveying takes place in a closed conveying circuit that includes the plurality of particulate material conveying systems.
2. The method of claim 1 , wherein the step of conveying the excess particulate material back into the reservoir takes place using a bypass opening in the particulate material conveying system.
3. The method according to claim, wherein the step 2 a of conveying the particulate material takes place via low pressure.
4. The method according to claim 1 , wherein the closed conveying circuit conveys the excess particulate material back into the reservoir after a coating process.
5. The method of claim 1 , wherein the device for conveying particulate material includes an ejection system.
6. The method of claim 1 , wherein the reservoir is arranged below the spreader unit in a vertical direction, when viewed in a direction at a right angle to a coating direction, at least during a filling process.
7. The method of claim 1 , wherein at least one of the plurality of particulate material conveying systems comprises at least one conveyor belt, and
wherein the device for conveying particulate material includes a junction for introducing anew powder material into the reservoir.
8. The method of claim 1 , wherein the step 2 a of conveying the particulate material out of the reservoir into the spreader further employs the second particulate material conveying system, and
wherein the device for conveying particulate material includes a junction for introducing a new powder material into the reservoir.
9. The method of claim 1 , wherein at least one of the particulate material conveying systems comprises a suction device for low pressure conveying, and
wherein the device for conveying particulate material includes a junction for introducing anew powder material into the reservoir.
10. The method of claim 5 , wherein the ejection system comprises two covers comprising slits, and
wherein the device for conveying particulate material includes a junction for introducing anew powder material into the reservoir.