3D printing components using dual light sources to control solidification locations

Abstract

An apparatus and method of forming a three-dimensional part includes filling a reservoir (26) with a volume of a curable resin (30) configured to undergo a first reaction to form a first product when exposed to a first wavelength of light (42) and a second reaction to form a second product when exposed to a second wavelength of light (62). The presence of the first product and the second product at a common location in the resin causes a third reaction that produces a solid polymer at the common location. The method further includes directing a first light source (34) of the first wavelength into the reservoir, directing a second light source (54) of the second wavelength into the reservoir such that the first light source and the second light source intersect at a first predetermined location (78) within the reservoir, and allowing the third reaction to form the solid polymer at the first predetermined location.

Description

Technical Field

[0001] This disclosure relates generally to 3D printing, and more specifically to 3D printed parts using dual light sources to control the solidification position. Background Technology

[0002] The statements in this section are provided only as background information in connection with this disclosure and may not constitute prior art.

[0003] Additive manufacturing (AM), also known as 3D printing, is a manufacturing technique currently used to produce prototypes and small batches of parts by systematically depositing and solidifying resin material in a spatially defined location, allowing parts to be gradually assembled and typically grown in one dimension. While many AM technologies exist, stereolithography (SLA) is one of the most commercially available types that utilizes ultraviolet (UV) curable resins.

[0004] UV-curable resins typically require a formulation that allows for rapid polymerization upon exposure to a specific wavelength of light, followed by immediate cessation of curing upon removal of that wavelength. These polymerization reactions are usually based on acrylate or methacrylate-functionalized polymers, which can be urethane, polyester, or polyether. In addition to the polymer, these formulations typically contain a photoinitiator (PI), which undergoes rapid bond breaking upon absorption of UV light to generate a catalyst and initiate polymerization. UV curing is generally rapid and can transform a liquid resin into a solid within a second.

[0005] For 3D printing using UV-cured resin, liquid resin is typically cured layer by layer. The desired prototype is usually generated in a CAD program that cuts the part into a series of substantially 2D cross-sectional layers of appropriate thickness. A UV laser rasterizes the surface of the printing liquid, causing the layer to solidify into the shape of the object's 2D cross-section. The solidified layer is then moved down a certain distance, fresh resin is wiped onto the surface, and the next 2D layer is cured on top of the previous one, but along the same plane as the first layer. As other layers cure, the solidified part continues to be lowered and immersed in a resin bath. When the part is finished, it is removed from the bath and rinsed to remove uncured resin. One variation of this method uses a digital light processing (DLP) system to project the entire layer onto the surface of the bath instead of using raster movement. Another variation involves using a transparent and semi-transparent window at the bottom of the bath, and then moving the part upwards from the bath instead of lowering it into the bath. In all these methods, the part is formed only along a fixed 2D plane within the resin (i.e., the resin is solidified), and the part is relocated relative to that 2D plane such that the next 2D cross-section of the part will be aligned with the 2D plane.

[0006] While useful for some applications, the typical 3D printing process can have several drawbacks. One such drawback is that if the support structure is not built into the 3D printed part, the part may flip or move within the resin. Additionally, resin may be wasted due to cleaning the finished part. Other drawbacks include the possibility that layer-by-layer methods may reduce part fidelity, part repositioning may limit print speed, the availability of typical resins may be limited to a variety of expensive, proprietary resins, and the durability of typical 3D printing resins may be less than expected.

[0007] This teaching addresses these problems in the 3D printing of parts, and includes fundamentally different devices and methods for controlling reaction sites and rates. Summary of the Invention

[0008] In one form, a method of forming a three-dimensional component includes filling a reservoir with a volume of curable resin configured to undergo a first reaction upon exposure to light of a first wavelength to form a first product and a second reaction upon exposure to light of a second wavelength to form a second product. The presence of the first and second products at a common location in the resin results in a third reaction that produces a solid polymer at the common location. The method further includes: directing a first light source of the first wavelength into the reservoir; directing a second light source of the second wavelength into the reservoir such that the first and second light sources intersect at a first predetermined location within the reservoir; and allowing the third reaction to form a solid polymer at the first predetermined location.

[0009] According to another embodiment, the method further includes: adjusting at least one of a first light source and a second light source such that the first light source and the second light source intersect at a second predetermined position within the resin; and allowing a third reaction to form a solid polymer at the second predetermined position.

[0010] According to another form, the second predetermined position is adjacent to the first predetermined position, such that the solidified material at the second predetermined position is bonded to the solidified material at the first predetermined position.

[0011] In another form, the first and second light sources are beam sources.

[0012] According to another form, at least one of the first and second light sources is a planar light source.

[0013] In another form, the other of the first and second light sources is a beam source.

[0014] In another form, the third reaction involves a cascade using a photoactive catalyst. The first reaction involves the photoactive catalyst being excited by light of a first wavelength, but a separate photoactivator is required to initiate the polymerization. The second reaction produces a second photoactivator.

[0015] In another form, the resin includes a catalyst that is activated by exposure to light of a first wavelength.

[0016] According to another form, the resin includes a catalyst that is activated by exposure to a combination of light of a first wavelength and a second wavelength.

[0017] In another embodiment, the first reaction includes a first catalyst configured to interact with and be activated upon exposure to light of the first wavelength. The first catalyst requires a second photogenerated reagent to form a final activator and initiate a curing cascade. The second reaction produces the second photogenerated reagent.

[0018] According to another embodiment, the third reaction comprises a light-mediated polymerization scheme utilizing a single catalyst. The first reaction comprises the activation of the catalyst upon exposure to light of a first wavelength. The second reaction comprises terminal functional group protection of the monomer or oligomer using a photoinstantaneous protecting group, which is disconnected upon irradiation with light of a second wavelength.

[0019] According to another form, the third reaction includes a cascade that uses a photoinstantaneous protecting group to protect the terminal monomer or oligomer functional groups. The first reaction involves the photoinstantaneous protecting group undergoing a conformational change upon irradiation with light of a first wavelength, but a separate photoactivator is required to completely break the linkage and expose the active end for polymerization. The second reaction produces the separate photoactivator.

[0020] In another form, the third reaction involves a cascade using a photoactive catalyst. The first reaction involves the photoactive catalyst being activated by light of a first wavelength, but a separate photogenerated reagent is required to initiate polymerization at a rate rapid enough to overcome the inhibition of external inhibitors. The second reaction produces the photogenerated reagent.

[0021] In another form, a method of forming a component includes: filling a reservoir with a curable resin comprising a first photoactive material and a second photoactive material; directing a first light source of a first wavelength into the reservoir; directing a second light source of a second wavelength into the reservoir such that the first light source and the second light source intersect at a predetermined position within the reservoir; and causing the first photoactive material and the second photoactive material to react to solidify the resin at the predetermined position.

[0022] In another form, an apparatus for 3D printed articles includes a reservoir, a volume of resin disposed within the reservoir, a first light source, a second light source, and a controller. The resin is configured to undergo a first reaction upon exposure to light of a first wavelength to form a first product and a second reaction upon exposure to light of a second wavelength to form a second product. The presence of the first and second products at a common site in the resin induces a third reaction, which produces a solid polymer at said common site. The first light source is configured to emit light of the first wavelength. The second light source is configured to emit light of the second wavelength. The controller is configured to selectively operate the first and second light sources such that light from the first light source intersects with light from the second light source at a predetermined location within the resin.

[0023] In another form, the first and second light sources are beam sources.

[0024] According to another form, at least one of the first and second light sources is a planar light source.

[0025] In another form, the other of the first and second light sources is a beam source.

[0026] Other application areas will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0027] To better understand this disclosure, various forms of the disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0028] Figure 1 A perspective view of an additive manufacturing apparatus according to the teachings of this disclosure;

[0029] Figure 2 A perspective view of an additive manufacturing apparatus of a second construction based on the teachings of this disclosure;

[0030] Figure 3 It is based on the teachings of this disclosure for use with Figure 1 or Figure 2 The chemical formula of the first resin polymerized and used in additive manufacturing equipment;

[0031] Figure 4 It is based on the teachings of this disclosure and can be used for Figure 1 or Figure 2 The chemical formula for the polymerization of the second resin used in additive manufacturing equipment;

[0032] Figure 5 It is possible to do so based on the teachings of this disclosure. Figure 1 or Figure 2The chemical formula for the polymerization of the third resin used in additive manufacturing equipment;

[0033] Figure 6 It is possible to do so based on the teachings of this disclosure. Figure 1 or Figure 2 The chemical formula for the polymerization of the fourth resin used in additive manufacturing equipment;

[0034] Figure 7 It is possible to do so based on the teachings of this disclosure. Figure 1 or Figure 2 The chemical formula for the polymerization of the fifth resin used in additive manufacturing equipment; and

[0035] Figure 8 Is using Figure 1 or Figure 2 A flowchart of a method for forming three-dimensional parts using additive manufacturing equipment.

[0036] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Detailed Implementation

[0037] The following description is merely exemplary in nature and is not intended to limit this disclosure, its application, or its uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0038] refer to Figure 1 An additive manufacturing apparatus 10 is shown. The additive manufacturing apparatus 10 includes a first optical device 14, a second optical device 18, a control module 22, and a reservoir 26 filled with resin 30. The resin 30 is a liquid material that is typically configured to solidify only at the locations in the reservoir where both a first wavelength of light and a second wavelength of light are present. The resin 30 is described in more detail below. The reservoir 26 is a container with multiple walls configured to hold a volume of resin 30 therein. In the provided example, while the reservoir 26 is generally cubic in shape, it can also be any suitable shape, including polygonal or cylindrical. The reservoir 26 can be made of any suitable material, such as glass or plastic. At least one side of the reservoir 26 is configured to allow light from the first optical device 14 to enter the reservoir 26, and at least one side of the reservoir 26 is configured to allow light from the second optical device 18 to enter the reservoir 26, as explained below. In the example provided, although the reservoir 26 is made of glass or transparent polycarbonate, other configurations may be used.

[0039] The first optical device 14 includes a first light source 34 and a first positioning device 38. The first light source 34 is typically configured to emit light of a first wavelength. Alternatively, the first light source 34 may be configured to emit light within a first predetermined wavelength range. The first light source 34 may be any suitable light source capable of limiting the emitted wavelength range to a single wavelength or the first predetermined wavelength range. In one example, the first light source 34 is a laser with a specific spectral range. In another example, the first light source 34 produces light across a wide wavelength range, but includes a filter (not specifically shown) that limits the emission of light from the first light source 34 such that the first light source 34 emits only light of the first wavelength or light within a first predetermined wavelength range narrower than the wide range. The first wavelength or the first predetermined wavelength range may be within or outside the visible spectrum. For ease of description herein, the first wavelength and the first predetermined wavelength range are generally referred to herein as first type of light or first light. In the provided example, although the first light source 34 is a beam source emitting first light as a first beam 42, other configurations may be used.

[0040] The first positioning device 38 typically oriented the first light source 34 such that the first light source 34 can emit first light into the storage container 26. The first positioning device 38 is configured to adjust the position of the first light passing through the storage container 26 so that the first light can be guided to a desired position within the storage container 26. In the provided example, the first positioning device 38 includes a vertical track 46 and a horizontal track 50. Additional vertical and / or horizontal tracks or supports (not shown) may be used to improve stability. The first light source 34 is mounted to the first positioning device 38 such that the vertical track 46 allows the first light source 34 to move vertically (i.e., along the Z-axis as shown), while the horizontal track 50 allows the first light source to move horizontally (i.e., along the Y-axis as shown). In the provided example, although the first light source 34 emits the first beam 42 along the Y-direction, other configurations may be used.

[0041] In an alternative configuration not specifically shown, the first positioning device 38 may adjust the angle and / or focus of the light emitted from the first light source 34, such that the first light can pass through the reservoir 26 at different angles and enter the reservoir 26. Therefore, the first positioning device 38 may alternatively or additionally include a mirror (not shown) and / or a lens (not shown) and / or a motor (not shown), which is configured to pivot the first light source 34 to adjust the focus and / or adjust the angle at which the emitted light enters the reservoir 26.

[0042] The second optical device 18 includes a second light source 54 and a second positioning device 58. The second light source 54 is typically configured to emit light of a second wavelength. Alternatively, the second light source 54 may be configured to emit light within a second predetermined wavelength range. In the provided example, the second wavelength and the second predetermined wavelength range are different from the first wavelength and the first predetermined wavelength range and do not overlap in the electromagnetic spectrum. The second light source 54 can be any suitable light source capable of limiting the emitted wavelength range to a single wavelength or a second predetermined wavelength range. In one example, the second light source 54 is a laser with a specific spectral range. In another example, the second light source 54 produces light across a wide wavelength range but includes a filter (not specifically shown) that limits the emission of light from the second light source 54 such that the second light source 54 emits only light of the second wavelength or light within a second predetermined wavelength range narrower than the wide range. The second wavelength or the second predetermined wavelength range may be within the visible spectrum or may be outside the visible spectrum. For ease of description herein, the second wavelength and the second predetermined wavelength range are generally referred to herein as a second type of light or second light. In the provided example, although the second light source 54 is a beam source emitting second light as a second beam 62, other configurations may be used.

[0043] The second positioning device 58 typically oriented the second light source 54 such that the second light source 54 can emit second light into the storage container 26. The second positioning device 58 is configured to adjust the position of the second light passing through the storage container 26 so that the second light can be guided to a desired position within the storage container 26. In the provided example, the second positioning device 58 includes a vertical track 66 and a horizontal track 70. The second light source 54 is mounted to the second positioning device 58 such that the vertical track 66 allows the second light source 54 to move vertically (i.e., along the Z-axis as shown), while the horizontal track 70 allows the second light source to move horizontally (i.e., along the X-axis as shown). In the provided example, although the second light source 54 emits the second beam 62 along the X-direction, other configurations can be used.

[0044] In an alternative configuration not specifically shown, the second positioning device 58 can adjust the angle and / or focus of the light emitted from the second light source 54, allowing the second light to pass through the reservoir 26 at different angles. Therefore, the second positioning device 58 may alternatively or additionally include a mirror (not shown) and / or a lens (not shown) and / or a motor (not shown), configured to pivot the second light source 54 to adjust the focus and / or adjust the angle at which the emitted light enters the reservoir 26.

[0045] Returning to the provided example, the first positioning device 38 and the second positioning device 58 are configured such that the first light and the second light intersect at a desired location within the resin 30 in the reservoir 26. In the provided example, the first positioning device 38 positions the first light source 34 such that the first light enters the reservoir 26 through a first side of the reservoir 26, while the second positioning device 58 positions the second light source 54 such that the second light enters the reservoir 26 through a second side or a different side of the reservoir 26. In an alternative configuration not specifically shown, the first positioning device 38 and the second positioning device 58 may be configured such that the first light and the second light enter the reservoir 26 through the same side, but at different angles relative to the reservoir 26.

[0046] Control module 22 is electrically communicated with and configured to control the operation of the first positioning device 38, the second positioning device 58, the first light source 34, and the second light source 54. Control module 22 is configured to receive input data representing a three-dimensional part. In one example, control module 22 may receive data in the form of a three-dimensional computer model of the part and may convert the three-dimensional model into appropriate X, Y, and Z coordinates. In an alternative example, control module 22 may receive data in the form of X, Y, and Z coordinates of points of the three-dimensional part, or other data derived from the three-dimensional computer model. An example of data derived from the three-dimensional model includes a two-dimensional cross-section of the three-dimensional part. The X, Y, and Z coordinates of the three-dimensional part correspond to the X, Y, and Z coordinates within the resin 30 in reservoir 26. In the provided example, although corner 74 of reservoir 26 represents the zero position or origin (0, 0, 0) of the X, Y, and Z coordinates, the coordinate system can be arranged in any suitable manner and its zero position does not need to be at corner 74 of reservoir 26.

[0047] In the provided example, control module 22 is configured to output control signals to first positioning device 38 to move first light source 34 in the Y and Z directions, such that the first light passes through the X, Y, and Z coordinates of the three-dimensional part. Control module 22 is configured to output control signals to second positioning device 58 to move second light source 54 in the X and Z directions, such that the second light passes through the X, Y, and Z coordinates of the three-dimensional part. Control module 22 is configured to control first light device 14 and second light device 18 such that the first light and the second light intersect within resin 30 at predetermined X, Y, and Z coordinates (e.g., the position of intersection 78 shown).

[0048] The resin 30 and its chemical properties are described in more detail below; however, resin 30 is typically configured to solidify at the location where both the first and second light rays are present (i.e., the intersection 78 of the first and second light rays). Control module 22 can then adjust the positioning of the first light source 34 and the second light source 54 such that subsequent intersections of the first and second light rays correspond to different X, Y, and Z coordinates, until the first and second light rays have intersected at all desired coordinates of the three-dimensional part, thus solidifying resin 30 into the three-dimensional part. Subsequent intersections of the first and second light rays can be adjacent to previous intersections, allowing newly solidified material to bond to previously solidified material.

[0049] For further reference Figure 2 The diagram illustrates a second configuration of the additive manufacturing apparatus 10'. Except as otherwise shown or described herein, the additive manufacturing apparatus 10' is similar to additive manufacturing apparatus 10 (…). Figure 1 Therefore, similar elements are indicated by similar but apostrophe-marked reference numerals, and only the differences are described in detail herein. In the provided example, the first light source 34' is a planar light source that emits the first light as the first light plane 210, rather than Figure 1 The light source is a beam of light. The first light plane 210 enters and passes through the resin 30' as a plane of light with a first wavelength or a first predetermined wavelength range. In the provided example, the first positioning device 38' includes only a vertical track 46' because the first plane 210 extends across the entire width of the reservoir 26' in the horizontal direction, but other configurations can be used. In the provided example, although the first light source 34' emits the first plane 210 along the X direction, other configurations can be used.

[0050] In the provided example, the second light source 54′ is similar to the second light source 54 ( Figure 1 And emits a second beam 62'. The second positioning device 58' is configured to position the second light source 54' such that the second beam 62' passes through the first plane 210 at an angle relative to the first plane 210, such that the first light and the second light intersect at a predetermined position (e.g., intersection point 78'). In the provided example, although the second beam 62' is perpendicular to the first plane 210, other configurations can be used. In the provided example, the second positioning device 58' includes two horizontal rails 214, 218, which are configured to move the second light source 54' in the X and Y directions, and the second beam 62' is emitted along the Z direction, but other configurations can be used. Similar to control module 22 ( Figure 1 The control module 22′ is configured to control the operation of the first optical device 14′ and the second optical device 18′.

[0051] In another example not specifically shown, the additive manufacturing apparatus may include more than one first optical device 14 or 14' and / or more than one second optical device 18 or 18'. Additional optical devices (not shown) may be configured to provide multiple intersection points of two wavelengths (or two predetermined wavelength ranges) of light within the resin 30. Thus, multiple points in the resin 30 corresponding to the three-dimensional model can be simultaneously solidified. In another example not specifically shown, the first light source may be similar to a first light source 34' (…). Figure 2 The first planar light source can be used to solidify the two-dimensional cross-section of the resin in one step. The second light source can then be moved upwards to correspond to the next two-dimensional cross-section layer of the part, and the second light source can project the next two-dimensional cross-section into the resin.

[0052] Therefore, the additive manufacturing apparatus of this disclosure (e.g., 10 or 10') allows for the formation of parts by solidifying resin in a reservoir without moving the reservoir or the entire three-dimensional part within the reservoir during the molding process.

[0053] Resin 30 may be any suitable resin configured to solidify only at the point where the first and second light intersect. Resin 30 is generally configured to undergo a first reaction when exposed to the first light and a second reaction when exposed to the second light, and to undergo a substantially irreversible reaction when exposed to both the first and second light to polymerize and solidify.

[0054] For further reference Figure 3 Resin 30 may include a photoactive catalyst 310, an auxiliary agent 314, and a plurality of monomers 318. In the provided example, resin 30 also includes an inhibitor 320 configured to inhibit the polymerization of monomer 318. The auxiliary agent 314 may include a second catalyst, a photoactive agent, or a co-catalyst. Alternatively, monomer 318 may be an oligomer. Resin 30 may also include additional inactive components. One such additional inactive component may be a solvent (not shown) configured to help control the viscosity of resin 30. In this example, resin 30 is configured such that the polymerization reaction is a cascade using a photoactive catalyst.

[0055] In this example, when catalyst 310 is exposed to first light 322 (i.e., light of a first wavelength or within a first predetermined wavelength range), catalyst 310 undergoes a first reaction, wherein the product is the activated form of the catalyst (i.e., cat*326). In the provided example, the first reaction is shown as an irreversible reaction, but in some configurations, the first reaction may be a reversible reaction. In the provided example, catalyst 310 does not react or otherwise become activated when exposed to second light 330 (i.e., light of a second wavelength or within a second predetermined wavelength range). When the first light 322 is removed from resin 30, the production of activated catalyst (cat*326) ceases. In the provided example, the reaction from catalyst 310 to cat*326 can occur in microseconds or less.

[0056] When auxiliary reagent 314 is exposed to the second light, it undergoes a second reaction in which the product is the activated form of the auxiliary reagent (i.e., reag*334). In the provided example, the second reaction is shown as irreversible, but in some configurations, it may be reversible. In the provided example, auxiliary reagent 314 does not react or otherwise become activated when exposed to the first light 322. When the second light 330 is removed from the resin 30, the production of the activated auxiliary reagent (reag*334) ceases. In the provided example, the reaction from auxiliary reagent 314 to reag*334 can occur in microseconds or less.

[0057] Then, in the presence of an activated auxiliary agent (reag*344), the activated catalyst (cat*326) can catalyze the polymerization of monomer 318 in an irreversible reaction at a rate that overcomes the inhibition of inhibitor 320. During the polymerization of monomer 318, monomer 318 can continue to crosslink and bond to form a solid polymer until the first light 322 or the second light 330 is removed. Upon removal of the first light 322, the generation of cat*326 ceases, and inhibitor 320 inhibits further polymerization. Upon removal of the second light 330, the generation of reag* ceases, and inhibitor 320 inhibits further polymerization. Upon removal of both the first light 322 and the second light 330, the generation of cat* and reag* ceases, and inhibitor 320 inhibits further polymerization. In the provided example, neither catalyst 310 nor auxiliary agent 314 can directly catalyze the polymerization of monomer 318. In the provided example, neither cat*326 nor reag*334 can catalyze the polymerization of monomer 318 alone in the absence of the other. Therefore, resin 30 can be configured such that the reaction occurs faster than the inhibitor diffusion limit only when the photon flux of both the first light 322 and the second light 330 is appropriate, resulting in a polymer solidification at the location where the photon flux is sufficient.

[0058] A non-limiting example of catalyst 310 and auxiliary reagent 314 is wherein both catalyst 310 and auxiliary reagent 314 are radical photoinitiators, which are either type I photoinitiators (such as 2-methyl-4′-(methylthio)-2-morpholinophenylacetone) or type II photoinitiators (such as benzoin methyl ether) and donor molecules (such as 2-propanol) systems. In this particular example, the first light 322 may be in the UV-C wavelength range (e.g., 100 nm–290 nm), and the second light 330 may be in the UV-B to UV-A wavelength range (e.g., 290 nm–400 nm), but other configurations may be used. In this particular example, monomer 318 may be a molecule characterized by terminal acrylate, vinyl, ketone, or aldehyde functional groups, such as trimethylolpropane propoxylated triacrylate or diallyl maleate, and inhibitor 320 may be monomethyl ether quinone, but other configurations may be used.

[0059] For further reference Figure 4 The diagram illustrates the chemical reactions of resin 30 in different configurations. In such configurations, resin 30 may include a photoactive catalyst 410 and a plurality of monomers 414. Alternatively, monomers 414 may be oligomers. Resin 30 may also include additional inactive components. One such additional inactive component may be a solvent (not shown) configured to help control the viscosity of resin 30. In this example, catalyst 410 is configured such that when exposed to first light 418 (i.e., light of a first wavelength or a first predetermined wavelength range) but not to second light 422 (i.e., light of a second wavelength or a second predetermined wavelength range), catalyst 410 does not enter its activated state (i.e., cat*426). In other words, catalyst 410 undergoes a first reaction when exposed to first light 418, wherein the product may be catalyst 410 or an intermediate product (not shown) other than cat*426. Similarly, when exposed to second light 422 but not to first light 418, catalyst 410 does not enter its activated state (i.e., cat*426). In other words, catalyst 410 undergoes a second reaction when exposed to second light 422, wherein the product may be catalyst 410 or an intermediate product (not shown) other than CAT 426. In the provided example, the first and second reactions are shown as irreversible reactions, but in some configurations, the first and / or second reactions may be reversible reactions.

[0060] When both first light 418 and second light 422 are present, catalyst 410 reacts, resulting in an activated catalyst (i.e., cat*426). Removal of either first light 418 or second light 422 causes the production of cat*426 to cease. In the provided example, the reaction from catalyst 410 to cat*426 can occur in microseconds or less. cat*426 can then catalyze the polymerization of monomer 414 in an irreversible reaction. During the polymerization of monomer 414, the monomer can continue to crosslink and bond to form a solid polymer until either first light 418 or second light 422 is removed.

[0061] A non-limiting example of catalyst 410 is a two-stage photobase generator that produces a suitable base upon absorbing photons of two different wavelengths. In this example, the first light 418 may be in the UV-A to visible wavelength range (e.g., 315 nm–600 nm), and the second light 422 may be in the UV-C to UV-A wavelength range (e.g., 200 nm–350 nm), although its wavelength may not be the same as the first light 418, but other configurations may be used. In this example, monomer 414 may be an unsaturated terminal functional group (e.g., vinyl or acrylate), wherein the backbone may be a polyurethane, polyester, or the like, and the comonomer is a highly branched monomer (or oligomer) having terminal alcohol or thiol functional groups, such as pentaerythritol tetra(3-mercaptopropionate), i.e., “PETMP”, but other configurations may be used.

[0062] For further reference Figure 5 The diagram illustrates the chemical reactions of different configurations of resin 30. In such configurations, resin 30 may include a photoactive catalyst 510, a photoactivator 514, and a plurality of monomers 516. Alternatively, monomers 516 may be oligomers. Resin 30 may also include additional inactive components. One such additional inactive component may be a solvent (not shown) configured to help control the viscosity of resin 30. In this example, when catalyst 510 is exposed to a first light 518 (i.e., light of a first wavelength or a first predetermined wavelength range), catalyst 510 undergoes a first reaction, wherein the product is the activated form of the catalyst (i.e., cat*522). In the provided example, the first reaction is shown as an irreversible reaction, but in some configurations, the first reaction may be a reversible reaction. In the provided example, catalyst 510 does not react or otherwise become activated when exposed to a second light 526 (i.e., light of a second wavelength or a second predetermined wavelength range). When the first light 518 is removed from resin 30, the production of activated catalyst (cat*522) ceases. In the example provided, the reaction from catalyst 510 to cat*522 can occur in microseconds or even faster.

[0063] When activator 514 is exposed to second light 526, activator 514 undergoes a second reaction, in which the product is the activated form of the activator (i.e., act*530). In the provided example, the second reaction is shown as irreversible, but in some configurations, the second reaction may be reversible. In the provided example, activator 514 does not react or otherwise become activated when exposed to first light 518. The generation of act*530 ceases when the second light 526 is removed from resin 30. In the provided example, the reaction from activator 514 to act*530 can occur in microseconds or less.

[0064] Catalyst 522 can then catalyze the polymerization of monomer 516 in an irreversible reaction in the presence of activator 530. During the polymerization of monomer 516, monomer 516 can continue to crosslink and bond to form a solid polymer until the first light 518 or the second light 526 is removed. In the provided example, neither catalyst 510 nor activator 514 can directly catalyze the polymerization of monomer 516. In the provided example, neither cat*522 nor act*530 can catalyze the polymerization of the monomer alone in the absence of the other.

[0065] A non-limiting example of catalyst 510 is a switchable photobase characterized by protecting the azobenzene moiety of the side amine base in a stationary cis conformation. In this example, upon irradiation with a first light 518, the azobenzene fragment undergoes a cis / trans conformational change to produce cat*522, thereby exposing the active side base. In this example, the first light 518 may be a wavelength of approximately 350 nm, but other configurations may be used. In this example, the activator 514 may be a haloalkane initiator, such as ethyl α-bromophenyl acetate, and the second light 526 may be a wavelength of approximately 250 nm, but other configurations may be used. In this example, the monomer 516 may be a branched monomer having terminal acrylate or vinyl functional groups, such as trimethylolpropane propoxylated triacrylate, or an oligomer having a polyurethane, polyether, or polyvinyl backbone, but other configurations may be used.

[0066] For further reference Figure 6The diagram illustrates the chemical reactions of resin 30 in different configurations. In such configurations, resin 30 may include a photoactive catalyst 610 and a plurality of monomers, some of which may be protected monomers 614. Alternatively, the protected monomers 614 may be protected oligomers. Resin 30 may also include additional inactive components. One such additional inactive component may be a solvent (not shown) configured to help control the viscosity of resin 30. The protected monomers 614 include monomers 618 attached to a photoinstantaneously protective group 622. In this example, resin 30 may be configured such that the polymerization reaction is a light-mediated polymerization scheme using a single photoactive catalyst. The photoactive catalyst 610 is activated in the first reaction when exposed to first light 626 (i.e., light of a first wavelength or a first predetermined wavelength range), such that the product is the activated form of the catalyst (i.e., cat*630). In the provided example, the first reaction is shown as an irreversible reaction, but in some configurations, the first reaction may be a reversible reaction. In the provided example, the photoactive catalyst 610 does not react or otherwise become activated when exposed to the second light 634 (i.e., light of a second wavelength or within a second predetermined wavelength range). The generation of the activated catalyst (cat*630) ceases when the first light 626 is removed from the resin 30. In the provided example, the reaction from catalyst 610 to cat*630 can occur in microseconds or less.

[0067] The photostable protecting group 622 provides terminal functional group protection for monomer 618. When the protected monomer 614 is exposed to the second light 634, the photostable protecting group 622 disconnects from monomer 618 in the second reaction. In the provided example, the second reaction is shown as an irreversible reaction, but in some configurations, the second reaction may be reversible. The disconnection of the photostable protecting group 622 from monomer 618 ceases when the second light 634 is removed from resin 30. In the provided example, monomer 618 does not polymerize in the absence of an activated catalyst (i.e., cat*630). The presence of cat*630 and the deprotected monomer 618 leads to the polymerization of monomer 618. During the polymerization of monomer 618, monomer 618 may continue to crosslink and bond to form a solid polymer until the first light 626 or the second light 634 is removed.

[0068] A non-limiting example of a photoinstability-protected monomer 614 is a branched thiol, such as pentaerythritol tetra(3-mercaptopropionate) (“PETMP”), which is protected with a thiol-appropriate photoactive protecting group (such as o-nitrobenzyl or 9-phenylthioxanthyl). In the 9-phenylthioxanthyl example, the second light 634 may be in the UV-B region (e.g., 290 nm–320 nm), or typically in the UV region (e.g., 200 nm–400 nm), with a wavelength different from the first light 626, but other configurations may be used. In this example, the catalyst 610 may be a switchable photobase characterized by protecting the azobenzene moiety of the side amine base in a stationary cis conformation. In this example, upon irradiation with the first light 626, the azobenzene fragment undergoes a cis / trans conformational change to produce cat*630, thereby exposing the active amine base. In this example, the first light 626 may be a wavelength of approximately 350 nm, but other configurations may be used. In this example, the released monomer 618 may be a thiol-terminated monomer as described above, and the second comonomer (not shown) may be a vinyl or acrylate-terminated monomer or oligomer, such as diallyl maleate or 1,4-bis(acryloyl)piperazine, but other configurations may be used.

[0069] For further reference Figure 7The diagram illustrates the chemical reactions of different configurations of resin 30. In such configurations, resin 30 may include an activator precursor 710 and a plurality of monomers, some of which may be protected monomers 714. Alternatively, the protected monomers 714 may be protected oligomers. Resin 30 may also include additional inactive components. One such additional inactive component may be a solvent (not shown) configured to help control the viscosity of resin 30. The protected monomers 714 include monomers 718 attached to a photostable protecting group 722. In this example, resin 30 may be configured such that the polymerization reaction is a cascade using the protection of the terminal monomer functional groups via the photostable protecting group 722. When the protected monomers 714 are exposed to a first light 726 (i.e., light of a first wavelength or a first predetermined wavelength range), the photostable protecting group 722 does not disconnect from monomers 718. Instead, the photostable protecting group 722 undergoes an activation step in the first reaction (indicated by M-PPG*730). In the provided example, the first reaction is shown as irreversible, but in some configurations, the first reaction may be reversible. Activation of the photoinstantaneous protecting group 722 ceases when the first light 726 is removed from resin 30. The photoinstantaneous protecting group 722 does not undergo activation in the presence of the second light 734 (i.e., light of a second wavelength or within a second predetermined wavelength range). In the provided example, the reaction from the protected monomer 714 to M-PPG*730 can occur in milliseconds or less. In the provided example, neither the protected monomer 714 nor the activated protected monomer M-PPG*730 can be directly polymerized.

[0070] When the activator precursor 710 is exposed to the second light 734, it undergoes a second reaction, resulting in an activator (i.e., act*738). In the provided example, the second reaction is shown as irreversible, but in some configurations, the second reaction may be reversible. In the provided example, the activator precursor 710 does not react or otherwise become activated when exposed to the first light 726. The production of act*738 ceases when the second light 734 is removed from the resin 30. In the provided example, the reaction from the activator precursor 710 to act*738 can occur in microseconds or less.

[0071] Act*738 causes an irreversible reaction with M-PPG*730 to strip the photoinstantaneous protecting group 722 from monomer 718. In the provided example, if the photoinstantaneous protecting group 722 is not in its activated state, act*738 will not strip the photoinstantaneous protecting group 722. In the event of deprotection of monomer 718, irreversible polymerization of monomer 718 may occur. During the polymerization of monomer 718, monomer 718 may continue to crosslink and bond to form a solid polymer until the first light 726 or the second light 734 is removed, at which point no further deprotected monomers are produced.

[0072] A non-limiting example of the protected monomer 714 is a branched thiol monomer or oligomer, such as pentaerythritol tetra(3-mercaptopropionate) (“PETMP”), which is protected with a photoinstable protecting group (such as a 2-benzylbenzoic acid group) that undergoes excitation or activation upon absorption of the first light 726. The first light 726 may be in the UV wavelength region, and in the provided example, may be approximately 300 nm, but other configurations may be used. In this example, the activator 710 may be a photoalkalizing agent capable of generating an electron donor (such as cyclohexylamine), but other configurations may be used. An example of this type of molecule is cyclohexylamine protected with 4,3',5'-trimethoxybenzocarbamate, but other configurations may be used. In this example, the second light 734 may be in the UV to visible wavelength region, but unlike the first light 726, such as approximately 350 nm, but other configurations may be used. In this example, a comonomer (not shown), such as an acrylate or olefin-terminated monomer or oligomer, may be present, but other configurations may be used.

[0073] Therefore (and see also) Figure 8 Additive manufacturing equipment (e.g., additive manufacturing equipment 10 or 10') can be used to rapidly and accurately form three-dimensional objects from resin. While the process has been described in more detail above, it typically includes: filling a reservoir with resin 30; inputting data representing the coordinates of the three-dimensional part into a controller; operating a light source such that two different wavelengths of light intersect at at least one first predetermined location in the resin; allowing the resin to solidify at the first predetermined location; and then repeating the operation of the light source such that the two different wavelengths of light intersect at subsequent locations to solidify the resin at those subsequent locations, until the entire three-dimensional part is solidified in the reservoir.

[0074] While some specific examples of the chemical composition of the resin have been described above, other chemicals and / or light wavelengths can be used to achieve the desired reaction while limiting dark curing (i.e., polymerization when neither light nor light is present).

[0075] The description in this disclosure is merely exemplary in nature, and therefore any modifications that do not depart from the spirit and scope of this disclosure are intended to be within its scope. Such modifications should not be considered as departing from the spirit and scope of this disclosure.

[0076] Although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, and / or segment from another. Unless the context clearly indicates otherwise, terms such as “first,” “second,” and other numerical terms, as used herein, do not imply order or sequence. Therefore, without departing from the teachings of exemplary embodiments, a first element, component, region, layer, or segment may be referred to as a second element, component, region, layer, or segment. Furthermore, an element, component, region, layer, or segment may be referred to as a “second” element, component, region, layer, or segment, without referring to it as a “first” element, component, region, layer, or segment.

[0077] For ease of description, this document uses spatial relative terms such as “inner,” “outer,” “below,” “below,” “down,” “above,” and “up” to describe the relationship between one element or feature as shown in the figures and one or more other elements or features. In addition to the orientations depicted in the figures, spatial relative terms may be intended to cover different orientations of the device during use or operation. For example, if the device in the figures is flipped, an element described as “below” or “below” other elements or features would be oriented “above” other elements or features. Thus, the exemplary term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or otherwise), and the spatial relative descriptors used herein are interpreted accordingly.

[0078] In this application, which includes the following definitions, the term "module" or "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed-signal analog / digital discrete circuit; digital, analog, or mixed-signal analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or grouped) that executes code; memory circuitry (shared, dedicated, or grouped) that stores code executed by the processor circuitry; other suitable hardware components that provide the described functionality; or combinations of some or all of the foregoing, such as in a system-on-a-chip.

[0079] A module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that connect to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module in this disclosure may be distributed among multiple modules connected via the interface circuits. For example, multiple modules may allow load balancing. In another example, a server (also referred to as a remote or cloud) module may perform certain functionalities on behalf of a client module.

[0080] The term "code," as used above, can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuitry" covers a single processor circuitry that executes some or all of the code from multiple modules. The term "grouped processor circuitry" covers a processor circuitry that, in conjunction with additional processor circuitry, executes some or all of the code from one or more modules. References to multiple processor circuitry cover multiple processor circuitry on a discrete die, multiple processor circuitry on a single die, multiple cores of a single processor circuitry, multiple threads of a single processor circuitry, or a combination of the above. The term "shared memory circuitry" covers a single memory circuitry that stores some or all of the code from multiple modules. The term "grouped memory circuitry" covers a memory circuitry that, in conjunction with additional memory, stores some or all of the code from one or more modules.

[0081] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not cover transient electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium can therefore be considered tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media include non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog magnetic tape or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0082] The apparatus and methods described in this application can be implemented, in part or in whole, by a dedicated computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. Function blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a technician or programmer.

[0083] A computer program includes processor-executable instructions stored on at least one non-transitory tangible computer-readable medium. A computer program may also include or depend on stored data. A computer program may encompass a basic input / output system (BIOS) for interacting with the hardware of a special-purpose computer, device drivers for interacting with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0084] Computer programs may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language) or XML (Extensible Markup Language); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code executed by an interpreter; and (v) source code compiled and executed by a just-in-time (JIT) compiler, etc. As an example only, source code can be written using syntax from languages ​​including: C, C++, C#, Objective C, Haskel, Go, SQL, R, Lisp, etc. Fortran, Perl, Pascal, Curl, OCaml, HTML5, Ada, ASP (active server-side page), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby Visual Lua and

[0085] The elements described in the claims are not intended to be means plus function elements in the sense of 35 USC §112(f), unless an element is explicitly described using the phrase “means for…” or in the case of a method claim using the phrase “operation for…” or “steps for…”.

Claims

1. A method for forming a three-dimensional part, the method comprising: A reservoir is filled with a certain volume of curable resin, which is configured to undergo a first reaction to form a first product when exposed to light of a first wavelength and a second reaction to form a second product when exposed to light of a second wavelength, wherein the presence of the first product and the second product at a common site in the resin results in a third reaction, which produces a solid polymer at the common site. The first light source of the first wavelength is directed into the storage device; The second light source of the second wavelength is guided into the storage device such that the first light source and the second light source intersect at a first predetermined position within the storage device; as well as The third reaction is allowed to form the solid polymer at the first predetermined location; Wherein, one of the first product and the second product is a photoinstable protected monomer, and the third reaction includes the reaction of the photoinstable protected monomer with the other of the first product and the second product to form the solid polymer.

2. The method of claim 1, further comprising: Adjust at least one of the first light source and the second light source such that the first light source and the second light source intersect at a second predetermined position within the resin in the reservoir; as well as The third reaction is allowed to form the solid polymer at the second predetermined location.

3. The method of claim 2, wherein the second predetermined position is adjacent to the first predetermined position, such that the solidified material at the second predetermined position bonds to the solidified material at the first predetermined position.

4. The method of claim 1, wherein the first light source and the second light source are beam light sources.

5. The method of claim 1, wherein at least one of the first light source and the second light source is a planar light source.

6. The method of claim 5, wherein the other of the first light source and the second light source is a beam light source.

7. The method of claim 1, wherein the third reaction comprises a cascade using a photoactive catalyst, the first reaction comprising the photoactive catalyst being excited by light of the first wavelength but requiring a separate photogenerating agent to initiate polymerization, wherein the second reaction produces a second photogenerating agent.

8. The method of claim 1, wherein the resin comprises a catalyst activated by exposure to light of the first wavelength.

9. The method of claim 1, wherein the resin comprises a catalyst activated by exposure to a combination of light of the first wavelength and the second wavelength.

10. The method of claim 1, wherein the first reaction comprises a first catalyst configured to interact with light of the first wavelength and to be activated when exposed to light of the first wavelength, the first catalyst requiring a second photogenerated reagent to form a final activator and initiate a curing cascade, wherein the second reaction produces the second photogenerated reagent.

11. The method of claim 1, wherein the third reaction comprises light-mediated polymerization using a single catalyst, wherein the first reaction comprises the catalyst being activated when exposed to light of the first wavelength, and wherein the second reaction comprises terminal functional group protection of the monomer or oligomer using a photoinstantaneous protecting group, the photoinstantaneous protecting group being disconnected when irradiated by light of the second wavelength.

12. The method of claim 1, wherein the third reaction comprises a cascade of protecting the functional groups at the ends of the monomer or oligomer with a photoinstantaneous protecting group, wherein the first reaction comprises the photoinstantaneous protecting group being activated when irradiated with light of the first wavelength, but requiring a separate photogenerating agent to completely disconnect the connection and expose the active end for polymerization, wherein the second reaction generates the separate photogenerating agent.

13. The method of claim 1, wherein the third reaction comprises a cascade using a photoactive catalyst, the first reaction comprising the photoactive catalyst being activated by light of the first wavelength, but requiring a separate photogenerating agent to initiate polymerization at a rate sufficient to overcome the inhibition of external inhibitors, wherein the second reaction generates the photogenerating agent.

14. A method of forming a component, comprising: The reservoir is filled with a curable resin comprising a first photoactive substance and a second photoactive substance, wherein one of the first photoactive substance and the second photoactive substance is a photoinstable protected monomer. The first light source of the first wavelength is directed into the storage device; A second light source of a second wavelength is guided into the storage device such that the first light source and the second light source intersect at a predetermined position within the storage device; as well as The first and second photoactive substances are reacted to solidify the resin at the predetermined location.

15. An apparatus for 3D printed articles, the apparatus comprising: Storage container; A certain volume of resin is disposed within the reservoir, the resin being configured to undergo a first reaction to form a first product when exposed to light of a first wavelength and a second reaction to form a second product when exposed to light of a second wavelength, wherein the presence of the first product and the second product at a common site in the resin results in a third reaction, the third reaction producing a solid polymer at the common site; A first light source is configured to emit light of the first wavelength; A second light source is configured to emit light of the second wavelength; as well as A controller configured to selectively operate the first light source and the second light source such that light from the first light source intersects with light from the second light source at a predetermined position within the resin; Wherein, one of the first product and the second product is a photoinstable protected monomer, and the third reaction includes the reaction of the photoinstable protected monomer with the other of the first product and the second product to form the solid polymer.

16. The device of claim 15, wherein the first light source and the second light source are beam light sources.

17. The device of claim 15, wherein at least one of the first light source and the second light source is a planar light source.

18. The device of claim 17, wherein the other of the first light source and the second light source is a beam light source.

Images