Indirect additive manufacturing process using amine-containing adhesive polymers
A method for binder jetting additive manufacturing of an object, the method comprising: (i) separately feeding a powder from which said object is to be manufactured and a solution comprising an adhesive polymer dissolved in a solvent into an additive manufacturing device, wherein said adhesive polymer is an amine-containing polymer having a molecular weight of at least 200 g/mole and is present in said solution in a concentration of 1-30 wt % to result in said solution having a viscosity of 2-25 mPa·s and a surface tension of 25-45 mN/m at room temperature; and (ii) dispensing selectively positioned droplets of said adhesive polymer, from a printhead of said additive manufacturing device, into a bed of said powder to bind particles of said powder with said adhesive polymer to produce a preform having a shape of the object to be manufactured.
1. A method for binder jetting additive manufacturing of an object, the method comprising:
(i) separately feeding a powder from which said object is to be manufactured and a solution consisting of an adhesive polymer dissolved in a solvent into an additive manufacturing device, wherein said adhesive polymer is an amine-containing polymer having a molecular weight of at least 200 g/mole and is present in said solution in a concentration of 1-30 wt % to result in said solution having a viscosity of 2-25 mPa·s and a surface tension of 25-45 mN/m at room temperature; and
(ii) dispensing selectively positioned droplets of said adhesive polymer, from a printhead of said additive manufacturing device, into a bed of said powder to bind particles of said powder with said adhesive polymer to produce a preform having a shape of the object to be manufactured.
2. The method of claim 1 , wherein said amine-containing polymer is a polyethyleneimine.
3. The method of claim 2 , wherein said polyethyleneimine is a branched polyethyleneimine.
4. The method of claim 3 , wherein said branched polyethyleneimine has the following structure:
wherein n is at least 1.
5. The method of claim 1 , wherein said solvent is aqueous-based.
6. The method of claim 1 , wherein said solvent is non-aqueous-based.
7. The method of claim 1 , wherein said dispensing step (ii) is followed by a curing step (iii) during which said solvent is removed.
8. The method of claim 7 , wherein said curing step is conducted at a temperature within a range of 50-250° C. for a period of time of 1-48 hours.
9. The method of claim 1 , wherein said dispensing step (ii) is followed by a sintering step in which particles in said preform are fused.
10. The method of claim 1 , wherein said powder is sinterable.
11. The method of claim 1 , wherein said powder has a metal oxide composition.
12. The method of claim 1 , wherein said powder has a metallic composition.
13. The method of claim 1 , wherein:
if said amine-containing polymer has a molecular weight of at least 200 g/mole and less than 1300 g/mole, the amine-containing polymer is present in said aqueous-based solution in a concentration of 2-30 wt %;
if said amine-containing polymer has a molecular weight of at least 1300 g/mole and less than 2000 g/mole, the amine-containing polymer is present in said aqueous-based solution in a concentration of 2-20 wt %;
if said amine-containing polymer has a molecular weight of at least 2000 g/mole and less than 5000 g/mole, the amine-containing polymer is present in said aqueous-based solution in a concentration of 2-17 wt %;
if said amine-containing polymer has a molecular weight of at least 5000 g/mole and less than 10,000 g/mole, the amine-containing polymer is present in said aqueous-based solution in a concentration of 1-15 wt %;
if said amine-containing polymer has a molecular weight of at least 10,000 g/mole and less than 100,000 g/mole, the amine-containing polymer is present in said aqueous-based solution in a concentration of 0.5-10 wt %; and
if said amine-containing polymer has a molecular weight of at least 100,000 g/mole and up to 1,000,000 g/mole, the amine-containing polymer is present in said aqueous-based solution in a concentration of 0.1-5 wt %.
14. The method of claim 1 , wherein said amine-containing polymer has a molecular weight of 200-2000 g/mole and is present in said aqueous-based solution in a concentration of 2-30 wt %.
15. The method of claim 1 , wherein said amine-containing polymer has a molecular weight of 200-2000 g/mole and is present in said aqueous-based solution in a concentration of 2-20 wt %.
16. The method of claim 1 , wherein said amine-containing polymer has a molecular weight of 500-2000 g/mole and is present in said aqueous-based solution in a concentration of 2-25 wt %.
17. The method of claim 1 , wherein said amine-containing polymer has a molecular weight of 500-1500 g/mole and is present in said aqueous-based solution in a concentration of 2-25 wt %.
18. The method of claim 1 , wherein said amine-containing polymer has a molecular weight of 500-1200 g/mole and is present in said aqueous-based solution in a concentration of 2-25 wt %.
19. The method of claim 1 , wherein said dispensing step (ii) is conducted at a binder saturation of 3-300%, wherein the binder saturation is the percentage of voidspace occupied by the aqueous solution of the adhesive polymer.
20. The method of claim 1 , wherein said dispensing step (ii) is conducted at a binder saturation of 3-90%.
21. The method of claim 1 , wherein said dispensing step (ii) is conducted at a binder saturation of 3-80%.