Method for regulating temperature at a resin interface in an additive manufacturing process

1. A method for additive manufacturing comprising:

selecting a target bulk resin temperature less than a heat deflection temperature of a resin in a photocured state by a set temperature buffer;

at a reservoir volume of the resin in a liquid state and arranged over a build window, heating the reservoir volume toward the target bulk resin temperature;

selectively heating regions of an interface layer of the resin to bring a temperature across the interface layer toward a target reaction temperature of the resin, the interface layer of the resin interposed between an upper surface of the build window and a preceding layer of a build, and the target reaction temperature of the resin greater than the target bulk resin temperature; and

during a build cycle:

detecting a first temperature of the reservoir volume;

comparing the first temperature to the target bulk resin temperature;

detecting a second temperature of the interface layer;

comparing the second temperature to the target reaction temperature; and

in response to the first temperature being proximal the target bulk resin temperature and in response to the second temperature being proximal the target reaction temperature, selectively photocuring a volume of the resin in the interface layer through the build window to form a photocured resin layer of the build.

2. The method of claim 1 :

further comprising:

at a build chamber containing a gaseous environment above the reservoir volume and the build window, heating the gaseous environment toward a target chamber temperature; and

detecting a third temperature of the gaseous environment and comparing the third temperature to the target chamber temperature; and

wherein selectively photocuring the volume of the resin in the interface layer to form the photocured resin layer of the build comprises, in response to the first temperature being proximal the target bulk resin temperature, in response to the second temperature being proximal the target reaction temperature, and in response to the third temperature being proximal the target chamber temperature, selectively photocuring the volume of the resin in the interface layer to form the photocured resin layer of the build.

3. The method of claim 2 , wherein the target chamber temperature is less than the heat deflection temperature of the resin in the photocured state.

4. The method of claim 1 , wherein the target bulk resin temperature corresponds to a target viscosity of the resin in the liquid state.

5. The method of claim 1 , wherein the target reaction temperature is greater than the target bulk resin temperature and corresponds to a target crosslinking density of the resin in the photocured state.

6. The method of claim 1 :

further comprising:

melting a quantity of the resin provided in a solid state into the resin in the liquid state; and

detecting a phase change of the quantity of the resin from the solid state to the liquid state;

wherein, at the reservoir volume, heating the reservoir volume toward the target bulk resin temperature comprises, in response to detecting the phase change, heating the reservoir volume toward the target bulk resin temperature; and

wherein selectively heating regions of the interface layer comprises, in response to detecting the phase change, selectively heating regions of the interface layer of the resin toward the target reaction temperature.

7. The method of claim 6 , wherein detecting the phase change of the quantity of the resin from the solid state to the liquid state comprises detecting the phase change of the quantity of the resin from the solid state to the liquid state via a visual light image sensor.

8. The method of claim 1 , wherein detecting the second temperature of the interface layer comprises detecting the second temperature of the interface layer via a thermal image sensor arranged below the build window and defining a field of view aligned with the build window.

9. The method of claim 1 , wherein selectively heating regions of the interface layer comprises selectively heating regions of the interface layer via an infrared projector defining a projection area aligned with the build window.

10. The method of claim 9 :

further comprising:

detecting a temperature distribution across the interface layer via a thermal image sensor arranged below the build window and defining a field of view aligned with the build window;

accessing a first layer geometry for the build cycle;

calculating a first target temperature distribution based on the first layer geometry; and

calculating an infrared light projection predicted to heat the interface layer to the first target temperature distribution; and

wherein selectively heating regions of the interface layer via the infrared projector comprises projecting the infrared light projection toward the interface layer.

11. The method of claim 10 , wherein calculating the first target temperature distribution based on the first layer geometry comprises calculating the first target temperature distribution, wherein regions of the interface layer coinciding with the first layer geometry define the target reaction temperature.

12. The method of claim 10 , wherein calculating the first target temperature distribution based on the first layer geometry comprises calculating the first target temperature distribution, wherein edges of the first layer geometry define the target reaction temperature.

13. The method of claim 1 , further comprising:

accessing a first layer geometry for the build cycle;

calculating a replacement volume of the resin based on the first layer geometry approximating the volume of the resin;

at a resin dispenser subsystem, preheating the replacement volume toward a third temperature proximal the target bulk resin temperature; and

in response to selectively photocuring the volume of the resin, dispensing the replacement volume into the reservoir volume via the resin dispenser subsystem.

14. The method of claim 1 , further comprising detecting the first temperature of the reservoir volume via a thermal image sensor defining a field of view incident a surface of the reservoir volume.

15. The method of claim 1 , further comprising post-curing the photocured resin layer of the build via an infrared projector defining a projection area aligned with the build window.

16. A method for additive manufacturing comprising:

at a build chamber containing a gaseous environment above a reservoir volume of a resin in a liquid state, heating the gaseous environment toward a target chamber temperature less than a heat deflection temperature of the resin in a photocured state;

selectively heating regions of an interface layer of the resin to bring a temperature across the interface layer toward a target reaction temperature of the resin, the interface layer of the resin interposed between an upper surface of the build window and a preceding layer of a build, and the target reaction temperature of the resin greater than the target chamber temperature and different from the heat deflection temperature of the resin in the photocured state; and

during a build cycle:

detecting a first temperature of the gaseous environment;

comparing the first temperature to the target chamber temperature;

detecting a second temperature of the interface layer;

comparing the second temperature to the target reaction temperature; and

in response to the first temperature being proximal the target chamber temperature and in response to the second temperature being proximal the target reaction temperature, selectively photocuring a volume of the resin through the build window to form a photocured resin layer of the build.

17. The method of claim 16 , wherein the target reaction temperature

corresponds to a target crosslinking density of the resin in the photocured state.

18. The method of claim 16 , further comprising pressurizing the build chamber toward a target chamber pressure predicted to prevent off-gassing of the resin in the reservoir volume.

19. A method for additive manufacturing comprising:

at a reservoir volume of a resin in a liquid state and arranged over a build window, heating the reservoir volume toward a target bulk resin temperature less than a heat deflection temperature of the resin in a photocured state by a set temperature buffer;

selectively heating regions of an interface layer of the resin to bring a temperature across the interface layer toward a target reaction temperature of the resin, the interface layer of the resin interposed between an upper surface of the build window and a preceding layer of a build, and the target reaction temperature of the resin greater than the target bulk resin temperature; and

during a build cycle:

detecting when a first temperature of the reservoir volume is proximal to the target bulk resin temperature;

detecting when a second temperature across the interface layer is proximal to the target reaction temperature; and

in response to detecting the first temperature as being proximal to the target bulk resin temperature and in response to detecting the second temperature as being proximal to the target reaction temperature, selectively photocuring a volume of the resin through the build window to form a photocured resin layer of the build.

20. The method of claim 19 , wherein the target bulk resin temperature corresponds to a target viscosity of the resin in the liquid state.