Stereolithographic supports

• US 6,797,351 B2
• Filed: 04/09/2003
• Issued: 09/28/2004
• Est. Priority Date: 01/28/2000
• Status: Expired due to Term

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Inventors: Kulkarni, Rajeev B., Manners, Chris R.
• Primary Examiner(s): Thomas, Alexander S.
• Application Number:
  US10/410,073
• Publication Number:
  US 20030178750A1
• Time in Patent Office: 538 Days
• Field of Search: 428/43, 425/174, 425/174.4, 425/447
• US Class Current: 428/43
• CPC Class Codes: B29C 64/129 characterised by the energy source therefor, e.g. by global irradiation combined with a mask
• CPC Class Codes: B29C 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y10T 428/15 Sheet, web, or layer weakened to permit separation through thickness

Abstract

An improved stereolithographic process for forming three-dimensional objects using an improved support structure and the improved support structure is described. The support structure is formed by using differential curing of the liquid media material to form solid supports with weak points at selected locations to facilitate support removal from a three-dimensional object and minimize post-processing.

Claims

1. A stereolithographic part formed by selective stimulation of a liquid medium to a solid state comprising:

(a) at least one support structure with an intermediate region connecting opposing interfacing regions, the interfacing regions contacting the part at interfacing boundaries;

(b) the intermediate region having a first solid cure depth; and

(c) the interfacing regions having a second solid cure depth, the second solid cure depth being sufficiently less than the first solid cure depth to create weak points where the support structure is easily separable from the part.

2. The part according to claim 1 wherein the interfacing regions further comprise up-facing interfacing regions and down-facing interfacing regions.

3. The part according to claim 2 wherein the part has a third solid cure depth greater than the second solid cure depth.

4. The part according to claim 3 wherein the support structure further comprises vertically oriented strands.

5. The part according to claim 4 wherein the strands each have the opposing interfacing regions connected to an object interfacing side.

6. The part according to claim 5 wherein the strands each have an object non-interfacing side orthogonally intersecting the object interfacing side.

7. The part according to claim 6 wherein adjacent vertically oriented strands are connected and reinforced with at least one projection extending therebetween.

8. The part according to claim 5 wherein the object non-interfacing side and the object intersecting side are graphically patterned triangles.

9. The part according to claim 2 wherein the support structure is reinforced with triangular braces.

10. The part according to claim 1 wherein the support structure to reinforce the part includes gussets.

11. The part according to claim 10 wherein the gussets are formed from horizontal strips and angular strips connected to the part, the strips being separated by spaces to facilitate drainage of the liquid medium during part generation.