Solid imaging system

• US 5,143,817 A
• Filed: 12/22/1989
• Issued: 09/01/1992
• Est. Priority Date: 12/22/1989
• Status: Expired due to Fees

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Lawton, John A., Fan, Roxy N.
• Primary Examiner(s): Hamilton, Cynthia
• Application Number:
  US07/455,473
• Time in Patent Office: 984 Days
• Field of Search: 430/269, 264/22, 264/138, 264/139, 264/160, 264/163, 264/40.1, 264/284, 264/293, 264/297.6, 264/299, 264/58, 264/212, 264/213, 264/239, 264/241, 264/253, 264/308, 264/313 , 264/316, 264/338, 425/174.4, 425/174.0, 425/89, 425/218, 425/174.5, 425/90, 425/93, 427/53.1, 427/54.1, 427/131, 427/164, 427/165, 427/169, 427/258, 427/270, 427/271, 427/299, 427/302, 427/355, 427/356, 427/358, 427/369, 427/402, 427/407.1 , 427/430.1, 427/56, 427/261, 427/403, 427/404, 427/406, 427/407, 427/413, 427/415, 427/422, 427/423, 427/428, 118/56, 118/261, 118/403, 118/404, 118/406, 118/407, 118/413, 118/415, 118/422, 118/423, 118/428
• US Class Current: 264/401
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29K 2995/0073 smooth
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing

Abstract

An apparatus and method for fabricating integral three-dimensional objects from successive layers of photoformable compositions by exposing the layers of the composition through a detachable flexible transparent film, one side of the film being in contact with the composition and the other side of the film with a rigid transparent plate, which guides and supports the film.

Claims

1. A method for quickly and accurately fabricating an integral three-dimensional object from successive solidified layers of a deformable and photoformable composition comprising the steps of:

(a) placing the composition in a vessel containing a substantially flat platform;

(b) positioning within the composition a tensioned, transparent, flexible and non-adherent film having a first and a second surface, the first surface being opposite and parallel to the second surface, the first surface being disposed in a way to prevent wetting of said first surface by the composition, and at least part of the second surface being disposed in a way to be in contact with the composition;

(c) securing on top of the film at a first position, a substantially flat, substantially rigid and substantially transparent plate having an upper and a lower planar surface, the upper surface being opposite and parallel to the lower surface, such that the lower planar surface of the plate is parallel to and in contact with the first surface of the film, the plate guiding the film to an original position so that the film becomes parallel and lies on top of the flat platform at a distance equal to the thickness of a layer;

(d) exposing imagewise the photoformable composition contained between the film and the platform to radiation through the transparent plate and through the transparent film, in order to form a solidified layer, with the requirement that the radiation is high enough to cause reasonable adherence between the solidified layer and the platform;

(e) removing the transparent plate from the first position on top of the platform to a second position away from the platform;

(f) peeling the film from the solidified layer, and from the unexposed deformable composition;

(g) causing the deformable composition to flow over the solidified layer;

(h) increasing the distance between the platform and the original position of the film by the thickness of a layer;

(i) repositioning the film within the composition as in step (b);

(j) resecuring the plate at the first position on top of the film, such that the lower planar surface of the plate is parallel to and in contact with the first surface of the film, the plate guiding the film such that it is parallel to and lying on top of the previously solidified layer at a distance equal to the thickness of a layer;

(k) exposing imagewise to radiation, through the transparent plate and through the transparent film, the photoformable composition contained between the film and the previously solidified layer in order to form a new solidified layer, with the requirement that the radiation is high enough to cause reasonable adherence between the newly solidified layer and the previously solidified layer;

(l) removing the transparent plate again from the first position on top of the platform to the second position away from the plate;

(m) peeling the film from the newly solidified layer and from the unexposed deformable composition; and

(n) repeating steps (g) through (m) until the integral three-dimensional object is formed.

2. A method as defined in claim 1, wherein the deformable composition is a liquid.

3. A method as defined in claim 1, wherein the deformable composition is a non-liquid.

4. A method as defined in claim 1, wherein the platform is movable in a way substantially normal to the transparent plate, when said plate is at the first position.

5. A method as defined in claim 4, wherein the step of removing the plate and the step of peeling the film are conducted simultaneously.

6. A method as defined in claim 5, wherein the plate has a linear edge, and the removing step is conducted by a substantially horizontal translational motion of said plate, while the film is peeled around the linear edge.

7. A method as defined in claim 1 wherein the plate and the film are refractive index matched.

8. A method as defined in claim 6 wherein the plate and the film are refractive index matched.

9. A method as defined in claim 1 wherein an optical coupling fluid is placed between the plate and the film.

10. A method as defined in claim 6 wherein an optical coupling fluid is placed between the plate and the film.

11. A method as defined in claim 1 wherein at least part of the film is elastomeric.

12. A method as defined in claim 6 wherein at least part of the film is elastomeric.

13. A method as defined in claim 1 wherein the radiation is in the form of a laser beam.

14. A method as defined in claim 6 wherein the radiation is in the form of a laser beam.

15. A method as defined in claim 1 wherein the radiation is modified by a variable optical density photomask.

16. A method as defined in claim 6 wherein the radiation is modified by a variable optical density photomask.

17. A method as defined in claim 1 wherein the photoformable composition comprises plastisol.

18. A method as defined in claim 6 wherein the photoformable composition comprises plastisol.

33. An apparatus as defined in claim 17 wherein the photoformable composition comprises a plastisol.

19. An apparatus for quickly and accurately fabricating an integral three-dimensional object from successive solidified layers of a deformable and photoformable composition comprising an assembly of:

imaging means for imagewise exposing to radiation each of the successive layers of the photoformable composition; and

a coating station comprising,

a vessel for containing the composition;

a substantially flat platform disposed within the vessel;

a transparent, flexible and non-adherent film supported under tension over the platform, the film having a first and a second surface, the first surface being opposite and parallel to the second surface, the film intended to be operable within the composition in a manner preventing wetting of the first surface by the composition, and allowing at least part of the second surface to be in contact with the composition;

a substantially flat, substantially rigid and substantially transparent plate secured at a first position on top of the film, the plate having an upper and a lower planar surface, the upper surface being at the opposite side of and parallel to the lower surface, such that the lower planar surface of the plate is also parallel to and in contact with the first surface of the film, the plate guiding the film to be on top and parallel to the flat platform;

placement means for controllably varying the distance between the second surface of the film and the platform in order to allow the successive layers of the photoformable composition to be formed under said second surface and be solidified by the imagewise exposure to radiation provided by the imaging means;

means for removing the plate from its first position to a second position;

means for causing the deformable composition to flow over the solidified layer; and

means for peeling the film.

20. An apparatus as defined in claim 19, wherein the deformable composition is a liquid.

21. An apparatus as defined in claim 19, wherein the deformable composition is a non-liquid.

22. An apparatus as defined in claim 19, wherein the imaging means comprises:

radiation means for providing a radiation beam, the radiation beam having an intensity;

deflection means for controllably deflecting the radiation beam;

modulation means positioned between the radiation means and the deflection means for modulating the intensity of the radiation beam; and

computer means for storing graphic data corresponding to the shape of the rigid object, the computer means being also coupled to the modulation means, the deflection means and the placement means, in order to control said modulation means, deflection means and placement means according to the graphic data.

23. An apparatus as defined in claim 19, wherein the radiation beam comprises a laser beam.

24. An apparatus as defined in claim 19, wherein the placement means is connected to the platform and provides movement to the platform in a substantially vertical direction.

25. An apparatus as defined in claim 23, wherein the means for removing the plate provides a substantially translational motion to the plate.

26. An apparatus as defined in claim 19 wherein the plate and the film are refractive index matched.

27. An apparatus as defined in claim 24 wherein the plate and the film are refractive index matched.

28. An apparatus as defined in claim 19 further comprising an optical coupling fluid placed between the plate and the film.

29. An apparatus as defined in claim 24 further comprising an optical coupling fluid placed between the plate and the film.

30. An apparatus as defined in claim 19 wherein at least part of the film is elastomeric.

31. An apparatus as defined in claim 24 wherein at least part of the film is elastomeric.

32. An apparatus as defined in claim 19, wherein the imaging means comprises a variable optical density photomask.

34. An apparatus as defined in claim 22 wherein the photoformable composition comprises a plastisol.