STEREOLITHOGRAPHY METHOD FOR PRODUCING A THREE-DIMENSIONAL OBJECT, COMPRISING A MOVEMENT ACCORDING TO WHICH A SUPPORTING SURFACE FOR SAID OBJECT INTERMITTENTLY APPROACHES THE BOTTOM OF A CONTAINER, AND STEREOLITHOGRAPHY MACHINE USING SAID METHOD

• US 20150123319A1
• Filed: 07/15/2013
• Published: 05/07/2015
• Est. Priority Date: 07/16/2012
• Status: Active Grant

• Current Assignee: Dws S.R.L.
• Original Assignee: Dws S.R.L.
• Inventors: Fortunato, Roberto, Zenere, Sergio
• Granted Patent: US 9,782,931 B2
• Time in Patent Office: Days
• US Class Current: 264/401
• CPC Class Codes: B29C 64/124 using layers of liquid which are selectively solidified
• 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 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 64/232 for motion along the axis orthogonal to the plane of a layer
• CPC Class Codes: B29C 64/264 Arrangements for irradiation
• CPC Class Codes: B29C 64/30 Auxiliary operations or equipment
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes

Abstract

The invention is a method for producing a three-dimensional object in layers through stereolithography, comprising the following operations: moving a supporting surface (6a, 7a) near the bottom (2a) of a container (2) containing a liquid substance (3), so as to arrange it in a predefined operating position (17); selectively irradiating a layer (6) of liquid substance (3) with pre-defined radiation (4), in such a way as to solidify it against the supporting surface (6a, 7a). The approaching movement (11) comprises a plurality of approaching moves (12, 12a, 12b, 12c) having corresponding predefined lengths (13, 13a, 13b, 13c), spaced by corresponding intermediate stops (14, 14a, 14b) for corresponding predefined time intervals (15, 15a, 15b), the intermediate stops (14, 14a, 14b) being carried out when the supporting surface (6a, 7a) is at least partially immersed in the liquid substance (3).

Claims

1. A method for producing a three-dimensional object in layers of using a stereolithography machine, said stereolithography machine comprising:

a container for containing a liquid substance suited to be solidified through exposure to predefined radiation;

a device for emitting said predefined radiation, suited to selectively irradiate a layer of said liquid substance having a predefined thickness and arranged adjacent to a bottom of said container in order to solidify said liquid substance;

a supporting surface for a solidified layer, facing the bottom of said container; and

an actuator suited to move said supporting surface with respect to said bottom at least according to a direction perpendicular to said bottom;

said method comprising the following steps;

moving said supporting surface near said bottom through a mutual positioning movement, in such a way as to arrange said supporting surface in contact with said layer of liquid substance in a predefined operating position; and

with said supporting surface in said operating position, selectively irradiating said layer in such a way as to solidify said layer,

wherein said positioning movement comprises a plurality of approaching moves having corresponding predefined lengths, spaced by corresponding intermediate stops for corresponding predefined time intervals, said intermediate stops being carried out when said supporting surface is at least partially immersed in said liquid substance.

2. The method according to claim 1, wherein a value of at least one parameter selected among the lengths of said approaching moves, a number of said intermediate stops (14, 14a, 14b) and the corresponding time intervals is determined before starting said positioning movement.

3. The method according to claim 2, wherein the values of said selected parameters are calculated as a function of a surface area of said supporting surface.

4. The method according to claim 3, wherein the values of said selected parameters are calculated as a function of a ratio between said surface area and a perimeter of said supporting surface.

5. The method according to claim 1, wherein calculation of said selected parameters comprises the following steps:

dividing said surface area of said supporting surface into a plurality of cells;

assigning each cell a weight proportional to a number of cells adjacent to said cell;

summing up said weights in order to obtain a shape parameter; and

calculating the values of said selected parameters according to said shape parameter.

6. The method according to claim 1, wherein the approaching moves following a first one of said intermediate stops have respective lengths that are equal to each other.

7. The method according to claim 1, wherein said supporting surface belongs to said solidified layer of said three-dimensional object.

8. The method according to claim 1, wherein said supporting surface belongs to a modeling plate belonging to said actuator.

9. The method according to claim 1, wherein a last one of said approaching moves moves said supporting surface beyond said operating position, and wherein said positioning movement ends with a receding move of said supporting surface away from said bottom.

10. A stereolithography machine comprising:

said container for containing said liquid substance suited to be solidified through exposure to said predefined radiation;

said device for emitting said predefined radiation, suited to selectively irradiate said layer of said liquid substance having said predefined thickness and arranged adjacent to the bottom of said container in order to solidify said liquid substance;

said actuator suited to move said solidified layer with respect to said bottom according to said direction perpendicular to said bottom; and

,

a logic control unit operatively connected to said device and to said actuator,

wherein said logic control unit is a programmable device loaded with the IT programming product according to claim 12.

12. An IT programming product comprising a data support provided with software portions configured so that, when executed on a programmable device, said software portions configure said programmable device to control a stereolithography machine according to the method claimed in claim 1.

11. (canceled)