Method for fabricating an integral three-dimensional object from layers of a photoformable composition

• US 5,122,441 A
• Filed: 10/29/1990
• Issued: 06/16/1992
• Est. Priority Date: 10/29/1990
• Status: Expired due to Term

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Adams, Jerome T., Lawton, John A.
• Primary Examiner(s): McCamish, Marion E.
• Assistant Examiner(s): Duda, Kathleen
• Application Number:
  US07/604,982
• Time in Patent Office: 596 Days
• Field of Search: 430/22, 430/269, 430/320, 430/321, 430/396, 430/394, 156/58, 156/59, 264/1.4, 264/1.7, 264/22, 425/174, 425/174.4, 427/54.1
• US Class Current: 430/320
• CPC Class Codes: B29C 64/129 characterised by the energy source therefor, e.g. by global irradiation combined with a mask
• 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 semi-permeable film that allows creation of release coatings on the side of said film facing said composition.

Claims

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

a) positioning a substantially transparent, composition-inert, composition-impermeable, semi-permeable film, said film being permeable to an imaging atmosphere and having a first surface and a second surface, such that said first surface is, at least partially, in contact with said imaging atmosphere, and said second surface is, at least partially, in contact with the photoformable composition;

b) contacting an interface of said composition with a composition atmosphere;

c) allowing said imaging atmosphere to permeate through said film and partially into a photoformable-composition-layer;

d) exposing said photoformable-composition-layer to radiation imagewise through said film making a photoformed layer and a deformable-composition-release-coating;

e) sliding said film relative to said photoformed layer in order to separate said film from said photoformed layer;

f) positioning said film in such a way as to form a photoformable-composition-layer between said previously made photoformed layer and said film second surface; and

g) repeating steps c-f until said layers of the integral three-dimensional object are formed.

2. A method for fabricating an integral three-dimensional object as recited in claim 1 wherein said film has molecular weight cutoff pores and said film does not substantially wet said composition.

3. A method for fabricating an integral three-dimensional object as recited in claim 1 wherein said film has expandable pores and said film does not substantially wet said composition.

4. A method for fabricating an integral three-dimensional object as recited in claim 1 wherein said film is elastomeric and does not substantially wet said composition.

5. A method for fabricating an integral three-dimensional object as recited in claim 4 wherein said film is a fluoroelastomer.

6. A method for fabricating an integral three-dimensional object as recited in claim 1 wherein both said imaging atmosphere and said composition atmosphere are air.

7. A method for fabricating an integral three-dimensional object as recited in claim 1 wherein said imaging atmosphere comprises oxygen in a concentration higher than that normally found in air.

8. A method for fabricating an integral three-dimensional object as recited in claim 1 wherein said composition atmosphere comprises an inert gas in a concentration higher than that normally found in air.

9. A method for fabricating an integral three-dimensional object from successive layers of a photoformable composition comprising the steps of:

a) positioning a substantially transparent, composition-inert, composition-impermeable, semi-permeable film, said film being permeable to an imaging atmosphere and having a first surface and a second surface, with said second surface at least partially in contact with the photoformable composition in a vat;

b) holding said film to a substantially flat shape with a tenter frame such that a substantially sharp change in shape of said film is formed at an edge of said tenter frame;

c) contacting said film first surface, at least partially, with said imaging atmosphere,

d) contacting an interface of said composition with a composition atmosphere;

e) forming a photoformable-composition-layer between a platform and said film second surface;

f) allowing said imaging atmosphere to permeate through said film and partially into said photoformable-composition-layer;

g) exposing said photoformable-composition-layer to radiation imagewise through said film, thus making a deformable-composition-release-coating and a photoformed layer that is substantially adhered to said platform, or to a previously photoformed layer;

h) sliding said tenter frame and film relative to said photoformed layer past said substantially sharp change in shape in order to separate said film from said photoformed layer;

i) positioning said tenter frame and film forming a photoformable-composition-layer between said film and said previously photoformed layer; and

j) repeating steps g-i until said layers of the integral three-dimensional object are formed.

10. A method for fabricating an integral three-dimensional object from successive layers of a photoformable composition comprising the steps of:

a) positioning a substantially transparent, composition-inert, composition-impermeable, semi-permeable film, said film being permeable to a deformable-coating-mixture and having a first surface and a second surface, with said second surface at least partially in contact with the photoformable composition in a vat;

b) holding said film to a substantially flat shape with a tenter frame such that a substantially sharp change in shape of said film is formed at an edge of said tenter frame;

c) contacting said film'"'"'s first surface, at least partially, with said deformable-coating mixture which in turn is in contact with an imaging atmosphere capable of dissolving in said deformable-coating-mixture;

d) contacting an interface of said photoformable composition with a composition atmosphere;

e) allowing said deformable-coating-mixture and said dissolved imaging atmosphere to permeate through said film forming a permeated-deformable-release-coating between said film and said composition,

f) forming a photoformable-composition-layer between said permeated-deformable-release-coating and a translatable platform, said platform adapted to be translated in a direction substantially normal to said second surface of said film;

g) exposing said photoformable-composition-layer to radiation imagewise through said film, deformable-coating-mixture, and permeated-deformable-release-coating creating a deformable-composition-release-coating and a photoformed layer that is substantially adhered to said platform, or to a previously photoformed layer;

h) sliding said tenter frame, film, and deformable-coating-mixture relative to said photoformed layer past said substantially sharp change in shape in order to separate said film from said photoformed layer;

i) positioning said tenter frame, film, deformable coating mixture, and permeated deformable release coating such that a photoformable-composition-layer is created between said permeated-deformable-release-coating and said previous photoformed layer; and

j) repeating steps g-i until said layers of the integral three-dimensional object are formed.

11. A method for fabricating an integral three-dimensional object from successive layer of a photoformable composition comprising the steps of:

a) positioning a substantially transparent, composition-inert, composition-impermeable, semi-permeable film, said film being permeable to a deformable-coating mixture and having a first surface and a second surface, with said second surface at least partially in contact with the photoformable composition in a vat;

b) securing in a frame said film such that said film'"'"'s first surface is disposed against a first surface of a transparent plate, said plate'"'"'s first surface having a recess disposed at an edge thereof;

c) introducing said deformable-coating-mixture between said plate and said film;

d) contacting an interface of said photoformable composition with a composition atmosphere;

e) allowing said deformable-coating-mixture to permeate through said film forming a permeated-deformable-release-coating between said film and said composition;

f) drawing said deformable-coating-mixture from between said film and said plate such that said film and said permeated-deformable-release coating substantially conforms to said plate'"'"'s first surface and such that a substantially sharp change in shape of said film is formed at said edge of said plate'"'"'s first surface;

g) forming a photoformable-composition-layer between a translatable platform and said permeated-deformable-release-coating, said platform adapted to be translated in a direction substantially normal to said first surface of said plate;

exposing said photoformable-composition-layer to radiation imagewise through said plate, deformable-coating-mixture, film, and permeated deformable release coating such that portions of a photoformed layer are substantially adhered to said platform, or a previously photoformed layer;

i) sliding said frame, plate, film, and deformable coating mixture relative to said photoformed layer past said edge of said plate and past said substantially sharp change in shape of said film while replenishing said deformable-coating-mixture between said film and said plate;

j) drawing said deformable-coating-mixture from between said film and said plate such that said film and said permeated-deformable-release-coating substantially conforms to said plate'"'"'s first surface;

k) positioning said frame, plate, film, deformable-coating-mixture, and permeated-deformable-release-coating such that a photoformable-composition-layer is formed between said permeated-deformable-release-coating and said previously photoformed layer; and

l) repeating steps h-k until said layers of the integral three-dimensional object are fabricated.

12. A method for fabricating an integral three-dimensional object from successive thin layers of a photoformable composition comprising the steps of:

a) position a substantially inert, transparent, and composition-impermeable, semi-permeable film, said film being permeable to a deformable-coating-mixture and having a first surface and a second surface, such that said first surface is partially adhered to a surface of a porous plate, having an edge, and said second surface is, at least partially, in contact with the photoformable composition;

b) filling the pores of said porous plate with said deformable-coating-mixture and wetting said film first surface with said deformable-coating-mixture;

c) allowing said deformable-coating-mixture to permeate through said film forming a permeated-deformable-release-coating between said film and said photoformable composition;

d) forming a photoformable-composition-layer between said permeated deformable release coating and a translatable platform, said platform adapted to be translated in a direction substantially normal to said surface of said porous plate;

e) exposing said photoformable-composition-layer to radiation imagewise through said porous plate, film, deformable-coating-mixture and permeated-deformable-release-coating such that portions of a photoformed layer are substantially adhered to said platform, or a previously photoformed layer;

f) sliding said porous plate, film, and deformable-coating-mixture relative to said photoformed layer past said edge of said plate;

g) positioning said porous plate, film, deformable-coating-mixture, and permeated-deformable-release-coating making a photoformable-composition-layer between said permeated-deformable-release-coating and said previous photoformed layer; and

h) repeating steps e-g until said layers of the integral three-dimensional object are fabricated.