Three-dimensional structured printing
View Patent ↗A process for forming a three-dimensional article in sequential layers in accordance with a digital model of the article. The process comprises the steps of defining a layer of powder material, applying a liquid reagent to the powder layer in a pattern corresponding to the digital model, and repeating these steps to form successive layers. The powder comprises a first reactive component and the liquid includes a second active component capable of reacting with the first reactive component so that the article is built up in layers.
1. A process for forming a three-dimensional article in sequential cross-sectional layers in accordance with a model of the article, the process comprising the steps of:
(i) defining a layer of powder material comprising a first reactive component;
(ii) applying to the layer in a pattern corresponding to a respective cross-sectional layer of the model a liquid reagent comprising a second reactive component wherein the second reactive component includes an oxetane and a photoinitiator;
(iii) irradiating the layer with electromagnetic radiation to cause the first reactive component to chemically react with itself or with the second reactive component to form a new chemical component and optionally to cause the second reactive component to cure and fill in gaps between the powder; and
(iv) repeating steps (i) to (iii) to form successive layers;
and wherein substantially void-free regions are formed in the article where the liquid reagent has been applied to the powder.
2. A process as claimed in claim 1 , wherein the liquid reagent additionally comprises a viscosity lowering diluent.
3. A process as claimed in claim 1 , wherein the model is a digital model.
4. A process as claimed in claim 1 , wherein the article is irradiated, pixel by pixel, line by line or layer by layer, either randomly or clustered.
5. A process as claimed in claim 4 , wherein the article is irradiated after several layers have been formed.
6. A process as claimed in claim 4 , wherein the article is irradiated after all the layers have been formed.
7. A process as claimed in claim 4 , wherein the irradiating step employs UV radiation.
8. A process as claimed in claim 1 , wherein the liquid reagent is applied through a plurality of nozzles.
9. A process as claimed in claim 8 , wherein the nozzles form part of an inkjet printer or a device including a set of nozzles equivalent to an inkjet print head.
10. A process as claimed in claim 9 , wherein the nozzles operate on a piezo inkjet system.
11. A process as claimed in claim 10 , wherein the size of the nozzle openings is in the range 0.01 to 100 μm and/or the size of the applied droplets is in the range 0.1 to 200 μm.
12. A process as claimed in claim 1 , wherein the first reactive component comprises a reactive organic or organometallic polymer, oligomer or monomer and the second reactive component further comprises a curable resin.
13. A process as claimed in claim 12 , wherein the powder material further contains an organic or inorganic filler, a pigment, nanoparticles, a dye and/or a surfactant.
14. A process as claimed in claim 2 , wherein the viscosity of the liquid reagent is 2-30 cps at room temperature.
15. A process as claimed in claim 2 , wherein the diluent is reactive.
16. A process as claimed in claim 1 , wherein the thickness of the applied powder layer is in the range of 1.0 to 30 μm.
17. A process for forming a three-dimensional article in sequential cross-sectional layers in accordance with a model of the article, the process comprising the steps of:
(i) defining a layer of powder material comprising a first reactive component;
(ii) applying to the layer in a pattern corresponding to a respective cross-sectional layer of the model a liquid reagent comprising a second reactive component and colloidal or nano-particles of ceramics, organic micro-particles, metals and alloys wherein the second reactive component includes an oxetane and a photoinitiator;
(iii) irradiating the layer with electromagnetic radiation to cause the first reactive component to chemically react with itself or with the second reactive component to form a new chemical component and optionally to cause the second reactive component to cure and fill in gaps between the powder; and
(iv) repeating steps (i) to (iii) to form successive layers; and wherein substantially void-free regions are formed in the article where the liquid reagent has been applied to the powder.
18. A process as claimed in claim 17 , wherein the liquid reagent additionally comprises a viscosity lowering diluent.
19. A process as claimed in claim 17 , wherein the viscosity of the liquid reagent is 2-20 cps at room temperature.
20. A process as claimed in claim 17 , wherein the electromagnetic radiation is selected from the group consisting of TV light, microwave radiation, visible light, and laser beam.