Three-dimensional printing system with improved optical path

1. A three-dimensional printing system for fabricating a three-dimensional article comprising:

a resin vessel for containing resin and including:

a vessel body defining a central opening; and

a transparent sheet that closes the central opening, the transparent sheet at least partially formed from a cast polypropylene (CPP) film;

a support plate for supporting the resin vessel;

a light engine configured to project pixelated light through the rigid transparent central portion of the support plate and through the transparent sheet and to a build plane within the resin;

a build tray defining a support surface for supporting the three-dimensional article to be at least partially submerged in the resin;

a motorized support configured to align and adjust a vertical position of the build tray; and

a controller for controlling the light engine and the motorized support for fabricating the three-dimensional article,

wherein the transparent sheet is a multilayer film including CPP and at least one other polymer layer that is not CPP.

2. The three-dimensional printing system of claim 1 wherein the support plate includes a plate body that defines a central opening closed by a rigid transparent plate, the rigid transparent plate includes a rigid transparent central portion of the support plate for supporting the transparent sheet.

3. The three-dimensional printing system of claim 1 wherein the controller is configured to:

(1) operate the motorized support to position a lower surface of the build tray or the three-dimensional article at the build plane;

(2) operate light engine to selectively solidify a layer of resin onto the lower surface of the build tray or the three-dimensional article;

(3) repeat (1) and (2) to complete fabrication of the three-dimensional article.

4. The three-dimensional printing system of claim 1 wherein the transparent sheet has a thickness within a range of 25 microns to 200 microns.

5. The three-dimensional printing system of claim 1 wherein the transparent sheet has a thickness within a range of 50 microns to 150 microns.

6. The three-dimensional printing system of claim 1 wherein the at least one other polymer layer that is not CPP includes silicone.

7. The three-dimensional printing system of claim 1 wherein transparent sheet includes at least one layer of silicone and two layers of CPP.

8. A method of manufacturing a three-dimensional article comprising:

providing a three-dimensional printing system including:

a resin vessel for containing resin and including:

a vessel body defining a central opening; and

a transparent sheet that closes the central opening, the transparent sheet at least partially formed from a cast polypropylene (CPP) film;

a support plate for supporting the resin vessel;

a light engine configured to project pixelated light through the rigid transparent central portion of the support plate and through the transparent sheet and to a build plane within the resin;

a build tray defining a support surface for supporting the three-dimensional article to be at least partially submerged in the resin; and

a motorized support configured to align and adjust a vertical position of the build tray;

operating the motorized support to position a lower surface of the build tray or the three-dimensional article at the build plane;

operating the light engine to selectively solidify a layer of resin onto the lower surface of the build tray or the three-dimensional article; and

repeating (1) and (2) to complete manufacture of the three-dimensional article;

wherein the transparent sheet is a multilayer film including CPP and at least one other polymer layer that is not CPP.

9. The method of claim 8 wherein the support plate includes a plate body that defines a central opening closed by a rigid transparent plate, the rigid transparent plate includes a rigid transparent central portion of the support plate for supporting the transparent sheet.

10. The method of claim 8 wherein the transparent sheet has a thickness within a range of 25 microns to 200 microns.

11. The method of claim 8 wherein the transparent sheet has a thickness within a range of 50 microns to 150 microns.

12. The method of claim 8 wherein the at least one other polymer layer that is not CPP includes silicone.

13. The method of claim 8 wherein transparent sheet includes at least one layer of silicone and two layers of CPP.

14. A three-dimensional printing system for fabricating a three-dimensional article comprising:

a resin vessel for containing resin and including:

a vessel body defining a central opening that is closed by a rigid support plate; and

a transparent sheet supported over the rigid support plate, the transparent sheet is a multilayer film including a cast polypropylene (CPP) layer and at least one other polymer layer, the transparent sheet having a thickness in a range of 25 microns to 200 microns;

a support plate for supporting the resin vessel;

a light engine configured to project pixelated light through the rigid transparent central portion of the support plate and through the transparent sheet and to a build plane within the resin;

a build tray defining a support surface for supporting the three-dimensional article to be at least partially submerged in the resin;

a motorized support configured to align and adjust a vertical position of the build tray; and

a controller for controlling the light engine and the motorized support for fabricating the three-dimensional article.

15. The three-dimensional printing system of claim 14 wherein the at least one other polymer layer that is not CPP includes silicone.

16. The three-dimensional printing system of claim 14 wherein transparent sheet includes at least one layer of silicone and two layers of CPP.