Manufacture of three dimensional objects from thermosets
Provided herein is a method for creating a three dimensional (3D) object from reactive components that form a thermoset product. In one embodiment, a method includes providing first and second reactive components that are effective to form the thermoset product. In one embodiment, the thermoset product includes a urethane and/or urea-containing polymer. In one embodiment, the first reactive component includes an isocyanate and the second reactive component includes a polyol having at least one terminal hydroxyl group, a polyamine having at least one amine that includes an isocyanate reactive hydrogen, or a combination of the polyol and the polyamine. In one embodiment, the first reactive component includes a prepolymer, and optionally the ratio of viscosity of the first and second reactive components is from 1:3 to 3:1. Also provided is a 3D object that includes a completely reacted thermoset product, and a thermoset system that includes a first and a second reactive component.
1. A method of creating a three dimensional (3D) object from reactive components that form a thermoset product using extruded thermoset printing comprising:
(a) providing first and second reactive components that are effective to form a thermoset product having a predetermined layer resolution during the method;
(b) introducing the first and second reactive components into a mixing chamber where mixing occurs to form a mixture,
wherein
the first and second reactive components have a residence time in the mixing chamber effective to form a partially reacted thermoset product in the mixing chamber and result in the predetermined layer resolution upon exiting the mixing chamber, and
the first and second reactive components have a residence time in the mixing chamber insufficient to completely react;
(c) extruding the partially reacted thermoset product out of the mixing chamber through an extrusion nozzle and onto a substrate; and
(d) moving the extrusion nozzle and/or the substrate to form a 3D object having a predetermined shape resolution,
wherein the ratio of viscosity of the first reactive component to viscosity of the second reactive component is from 1:3 to 3:1.
2. The method of claim 1 wherein the thermoset product comprises a urethane and/or urea-containing polymer.
3. The method of claim 2
wherein the first reactive component comprises an isocyanate,
wherein the second reactive component comprises a polyol comprising at least one terminal hydroxyl group, a polyamine comprising at least one amine that comprises an isocyanate reactive hydrogen, or a combination of the polyol and the polyamine.
4. The method of claim 1 , wherein the first reactive component comprises an isocyanate prepolymer and the second reactive component comprises a polyol and/or amine prepolymer.
5. The method of claim 4 , wherein the isocyanate prepolymer has from greater than 0.1% to less than 8.5% unreacted isocyanate groups and the polyol and/or polyamine prepolymer has from greater than 1% to less than 8.5% alcohol and/or amine groups.
6. The method of claim 1 wherein the first and second reactive components comprise at least one additive selected from a catalyst, a chain extender, a curing agent, a surfactant, a pigment, a dye, a rheology modifier, a filler, or a combination thereof.
7. The method of claim 1 wherein the first and second reactive components each comprise a viscosity of at least 60 centipoise (cP).
8. The method of claim 7 wherein the first and second reactive components each comprise a viscosity from 500 cp to 500,000 cP.
9. The method of claim 1 wherein the partially reacted thermoset product comprises a viscosity below 3,000,000 cP upon exiting the mixing chamber.
10. The method of claim 1 wherein the partially reacted thermoset product does not increase pressure present in the mixing chamber by more than 20% in 5 minutes.
11. The method of claim 1 wherein the partially reacted thermoset product is not thixotropic.
12. The method of claim 1 wherein the extrusion nozzle has an inner diameter at the tip of 0.01 to 2 mm.
13. The method of claim 1 wherein the substrate comprises a previously formed and partially reacted thermoset product, or a previously formed and completely reacted thermoset or thermoplastic product, or a metal product.
14. The method of claim 1 wherein the 3D object comprises a foam thermoset product.
15. The method of claim 1 further comprising providing one or more additional reactive components, wherein the one or more additional reactants are introduced into the mixing chamber.
16. The method of claim 1 , wherein the spread of a layer after deposition on the substrate or on another layer is such that the height of the layer decreases by no greater than 50% of the height of the layer when extruded.
17. The method of claim 1 , wherein the reactive components have a flow rate through the mixing chamber such that the flow rate of the partially reacted thermoset product is reduced by no greater than 20% at constant pumping pressure and/or load for at least 10 minutes.