Stereolithography method and machine for the production of a three-dimensional object

Stereolithography method for producing a three-dimensional object through the superimposition of a plurality of layers on one another, comprising the following operations:

• a. application of a base substance (2) to a supporting surface (3) through at least a nozzle (6) which is moved along an X-axis and a Y-axis being parallel to the supporting surface (3) and orthogonal to each other, the nozzle (6) is moved with a Cartesian movement with respect to the supporting surface (3) according to two axes X and Y which are parallel to the supporting surface (3) and orthogonal to each other, said base substance (2) being liquid or pasty and being suitable for solidification through exposure to predefined radiation (4) produced by means of an emitting unit that is a laser or a DLP, a DMD, an LCD, or in general a dot matrix projection device;
• b. selective irradiation of said base substance (2) having a predefined thickness and being in contact with said supporting surface (3) through said predefined radiation (4), in such a way as to obtain a solidified layer (2b);
• the selective irradiation is carried out by directing the selective radiation only onto areas corresponding to a volume of said three-dimensional object to be obtained;
• c. separation of said solidified layer (2b) from said supporting surface (3) through a movement intended to move them away from each other;
• wherein:
• said supporting surface (3) belongs to a first laminar element (51) and to a second laminar element (52);
• said application of said base substance (2) to said supporting surface (3) is carried out by depositing a single layer (2a) of said base substance (2) so that it comes into contact with said second laminar element (52) while the second laminar element (52) is temporarily stationary, wherein said single layer (2a) has a thickness at least corresponding to said predefined thickness, said depositing being carried out selectively only on the areas corresponding to the volume of said three-dimensional object and without depositing said base substance (2) on one or more areas not belonging to the three-dimensional object to be obtained said selective irradiation is carried out on said first laminar element (51) only onto the areas corresponding to the volume of said three-dimensional object to be obtained and at the same time as said application of operation of applying said base substance (2) to said second laminar element (52), the application of said base substance (2) to said first laminar element (51) having been performed before said application of said base substance (2) to said second laminar element (52);
• and
• the minimum amount of base substance (2) to be deposited in excess with respect to each perimeter point of each single layer to be solidified is from 1 to 2 times the largest diameter of the ellipsoid of the intersection of the laser spot in such specific point of the plane, for each X or Y axis;
• if a DMD, an LCD, or in general a dot matrix projection device is used, according to the XY plan, the minimum amount of base substance (2) that has to be deposited in excess with respect to each perimeter point of each single layer to be solidified must be equal to a quantity of base substance (2) covering the linear dimension of the definition pixel of the DLP, of the DMD, of the LCD or of any other device of dot matrix projection, for each X or Y axis.

Stereolithography method for producing a three-dimensional object through the superimposition of a plurality of layers on one another, comprising the following operations:

• a. application of a base substance (2) to a supporting surface (3) through at least a nozzle (6) which is moved with respect to the supporting surface (3), said base substance (2) being liquid or pasty and being suitable for solidification through exposure to predefined radiation (4);
• b. selective irradiation of said base substance (2) having a predefined thickness and being in contact with said supporting surface (3) through said predefined radiation (4), in such a way as to obtain a solidified layer (2b);
• the selective irradiation is carried out by directing the selective radiation only onto areas corresponding to a volume of said three-dimensional object to be obtained;
• c. separation of said solidified layer (2b) from said supporting surface (3) through a movement intended to move them away from each other;
• wherein:
• said supporting surface (3) belongs to a first laminar element (51) and to a second laminar element (52);
• said application of said base substance (2) to said supporting surface (3) is carried out by depositing a single layer (2a) of said base substance (2) so that it comes into contact with said second laminar element (52) while the second laminar element (52) is temporarily stationary, wherein said single layer (2a) has a thickness at least corresponding to said predefined thickness, said depositing being carried out selectively only on the areas corresponding to the volume of said three-dimensional object and without depositing said base substance (2) on one or more areas not belonging to the three-dimensional object to be obtained said selective irradiation is carried out on said first laminar element (51) only onto the areas corresponding to the volume of said three-dimensional object to be obtained and at the same time as said application of operation of applying said base substance (2) to said second laminar element (52), the application of said base substance (2) to said first laminar element (51) having been performed before said application of said base substance (2) to said second laminar element (52);
• and
• the nozzle (6) is moved on the supporting surface (3) according to only one axis X and width of the nozzle (6) according to an Y-axis is at least equal to the width of the area of the supporting surface (3) which can be irradiated.