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 additive manufacturing, the method comprising:
forming a printing mixture, the printing mixture comprising one or more polymers and one or more solvents;
disposing a volume of the printing mixture into a yield-stress support bath; and
allowing the printing mixture to partially coagulate in the yield-stress support bath.
2. The method of claim 1 , wherein the allowing the printing mixture to partially coagulate in the yield-stress support bath forms an intermediate article.
3. The method of claim 2 , further comprising:
exposing the intermediate article to a post-treatment coagulation solution to cause the intermediate article to further coagulate, forming a finished article.
4. The method of claim 3 , wherein the intermediate article and finished article are formed free of printed support structures.
5. The method of claim 1 , further comprising:
dissolving the one or more polymers in the one or more solvents to form the printing mixture.
6. The method of claim 1 , further comprising:
disposing a rheological additive material into one or more second solvents or a solvent/non-solvent mixture; and
allowing the mixture of the rheological additive material with the one or more second solvents or the solvent/non-solvent mixture to become at least partially solid-like, forming the yield-stress support bath.
7. The method of claim 1 , wherein said disposing the printing mixture into the yield-stress support bath is carried out by an apparatus comprising a nozzle, the nozzle being dimensioned and configured to reduce or eliminate nozzle movement-induced liquefaction of the yield-stress support bath during said disposing.
8. The method of claim 7 , wherein the apparatus further comprises a computing device operable to guide movement of the nozzle during said disposing.
9. The method of claim 1 , wherein the additive manufacturing is carried out at about room temperature.
10. A method for three-dimensional printing, the method comprising:
providing a printing mixture, the printing mixture comprising at least one polymer and at least one solvent;
disposing at least a portion of the printing mixture into a rheologically stabilized solution; and
allowing the printing mixture to partially solidify in the rheologically stabilized solution.
11. The method of claim 10 , wherein the allowing the printing mixture to partially solidify in the rheologically stabilized solution forms an
intermediate article.
12. The method of claim 11 , further comprising:
exposing the intermediate article to a post-treatment coagulation solution or alternative solidification stimuli to fully solidify the intermediate part, forming a finished article.
13. The method of claim 10 , further comprising:
mixing a rheological additive with at least one other solvent or a solvent/non-solvent mixture to form the printing mixture.
14. The method of claim 13 , further comprising:
allowing the mixture of the rheological additive and the at least one other solvent or the solvent/non-solvent mixture to become at least partially solid-like, forming the rheologically stabilized solution.
15. A method for additive manufacturing, the method comprising:
forming a printing mixture comprising a crosslinking material and a solvent;
causing a printing nozzle to travel along a path through a yield-stress support bath, the printing nozzle being dimensioned and configured to reduce or eliminate nozzle movement-induced liquefaction of the yield-stress support bath during the travel of the printing nozzle along the path through the yield-stress support bath; and
disposing, via the printing nozzle, one or more portions of the printing mixture into the yield-stress support bath at one or more points along the path to form an intermediate article within the yield-stress support bath.
16. The method of claim 15 , further comprising:
allowing the printing mixture to partially coagulate in the yield-stress support bath to form the intermediate article.
17. The method of claim 16 , further comprising:
exposing the intermediate article to a post-treatment coagulation solution to cause the intermediate article to further coagulate, forming a finished article.
18. The method of claim 15 , further comprising:
dissolving one or more portions of the crosslinking material in the solvent to form the printing mixture.
19. The method of claim 15 , further comprising:
disposing a rheological additive material into a second solvent or a solvent/non-solvent mixture; and
allowing the mixture of the rheological additive material with the second solvent or the solvent/non-solvent mixture to become at least partially solid-like, forming the yield-stress support bath.
20. The method of claim 15 , wherein the additive manufacturing is carried out at about room temperature.