Methods and apparatuses for freeform additive manufacturing of engineering polymers
A polymer three-dimensional (3D) printing methodology is disclosed for freeform fabrication of polymeric structures under ambient conditions without the use of printed support structures. The build material can be dissolved in a suitable solvent for 3D printing. The polymer solution can be printed in (e.g., continuously printed using a moving dispensing nozzle) a yield-stress support bath to form an intermediate article. The intermediate article may be liquid or only partially coagulated after being printed into the yield-stress support bath. The yield-stress support bath may be at least partially disposed within a container, and the container may be immersed in a post-treatment coagulation solution to remove some or all of the solvent, causing the build material to fully solidify to form a finished article from the intermediate article.
1. A method for three-dimensional printing of a finished article, the method comprising:
dispensing a mixture of a polymeric material and a solvent into a yield-stress support bath;
allowing the mixture to only partially coagulate, forming an intermediate article; and
exposing the intermediate article to a post-treatment coagulation solution to fully solidify the intermediate part, forming the finished article.
2. The method of claim 1 , further comprising:
dissolving the polymeric material in the solvent to form the mixture of the polymeric material and the solvent.
3. The method of claim 1 , wherein the polymeric material is a first polymeric material and the solvent is a first solvent, the method further comprising:
mixing a rheological additive material with a second solvent, a mixture of solvents, or a solvent/non-solvent mixture; and
allowing the mixture of the rheological additive material with the second solvent, the mixture of solvents, or the solvent/non-solvent mixture to become at least partially solid-like, forming the yield-stress support bath.
4. The method of claim 1 , wherein at least one of the dispensing, the allowing, or the exposing is carried out by an apparatus comprising one or more of a reservoir configured to contain a supply of the mixture of the polymeric material and the solvent, a nozzle, and a computing device.
5. The method of claim 4 , wherein the nozzle is configured and dimensioned to reduce or eliminate nozzle movement-induced liquefaction of the yield-stress support bath.
6. The method of claim 4 , wherein the apparatus is configured to communicate the mixture of the polymeric material and the solvent from the reservoir, through the nozzle, and into the yield-stress support bath.
7. The method of claim 6 , wherein the computing device is configured to guide the movement of the nozzle during the dispensing such that a first portion of the supply of the mixture of the polymeric material and the solvent can be dispensed in a first portion of the yield-stress support bath and a second portion of the supply of the mixture of the polymeric material and the solvent can be dispensed in a second portion of the yield-stress support bath.
8. The method of claim 1 , wherein the intermediate article and finished article are formed free of printed support structures.
9. A method for three-dimensional printing of a finished article, the method comprising:
dissolving a polymeric material in a solvent to form a mixture of the polymeric material and the solvent;
dispensing the mixture of the polymeric material and the solvent into a yield-stress support bath;
allowing the mixture to only partially solidify, forming an intermediate article; and
exposing the intermediate article to a post-treatment coagulation solution or alternative solidification stimuli to fully solidify the intermediate part, forming the finished article.
10. The method of claim 9 , wherein the polymeric material is a first polymeric material and the solvent is a first solvent, the method further comprising:
mixing a rheological additive material with a second solvent, a mixture of solvents, and/or a solvent/non-solvent mixture, any of which can include the first solvent; and
allowing the mixture of the rheological additive material with a second solvent, a mixture of solvents, and/or a solvent/non-solvent mixture to become at least partially solid-like, forming the yield-stress support bath.
11. The method of claim 10 , wherein the dispensing is carried out by an apparatus comprising a reservoir configured to contain a supply of the mixture of the polymeric material and the solvent, a nozzle, and a computing device, the apparatus configured to carry out at least one of the dispensing, the allowing, and the exposing.
12. The method of claim 11 , wherein the apparatus is configured to communicate the mixture of the polymeric material and the solvent from the reservoir, through the nozzle, and into the yield-stress support bath.
13. The method of claim 12 , wherein the computing device is configured to guide the movement of the nozzle during the dispensing such that a first portion of the supply of the mixture of the polymeric material and the solvent can be dispensed in a first portion of the yield-stress support bath and a second portion of the supply of the mixture of the polymeric material and the solvent can be dispensed in a second portion of the yield-stress support bath.
14. The method of claim 10 , wherein the three-dimensional printing is carried out at about room temperature.
15. The method of claim 10 , wherein the intermediate article and finished article are formed free of printed support structures.
16. A method for forming a yield-stress support bath for three-dimensional printing of a finished article, the method comprising:
mixing a rheological additive material with a solvent, a mixture of solvents, and/or a solvent/non-solvent mixture to form a support mixture;
allowing the mixture of the rheological additive, solvent, mixture of solvents, and/or solvent/nonsolvent mixture to become at least partially solid, forming the yield-stress support bath.
17. The method of claim 16 , wherein the solvent is a first solvent, the method further comprising:
mixing a polymeric material and a second solvent to form a print mixture;
disposing said print mixture into a bath of the support mixture;
allowing the printing mixture to only partially coagulate, forming an intermediate article; and
exposing the intermediate article to a post treatment coagulation solution to fully solidify the intermediate part, forming the finished article,
wherein the three-dimensional printing is carried out at about room temperature, and
wherein the intermediate article and finished article are formed free of printed support structures.
18. The method of claim 17 , wherein at least one of the disposing, the allowing, and the exposing is carried out by an apparatus comprising a reservoir configured to contain a supply of the mixture of the polymeric material and the solvent, a nozzle, and a computing device,
wherein the apparatus is configured to communicate the mixture of the polymeric material and the solvent from the reservoir, through the nozzle, and into the yield-stress support bath.
19. The method of claim 18 , wherein the computing device is configured to guide the movement of the nozzle during the dispensing such that a first portion of the supply of the mixture of the polymeric material and the solvent can be dispensed in a first portion of the yield-stress support bath and a second portion of the supply of the mixture of the polymeric material and the solvent can be dispensed in a second portion of the yield-stress support bath.
20. The method of claim 18 , wherein the nozzle is configured and dimensioned to reduce or eliminate nozzle movement-induced liquefaction of the yield-stress support bath.