FIELD OF THE INVENTION

The present invention is directed to additive manufacturing and the use of multicomponent thermoset resins in a material extrusion additive manufacturing process.

BACKGROUND OF THE INVENTION

Additive manufacturing has been used for many years. Fabricated parts have been produced using various printing techniques (e.g., three-dimensional or 3D printing techniques). For example, sheeting welding, wire welding, melting in powder beds or powder deposition via laser and electron beam melting, and injections using powder have all been used. These techniques have varying degrees of geometric complexity, but generally have few restrictions in comparison to conventional machining. Each type of technique has associated with it advantages and disadvantages, particularly with respect to solid state processing, fine grain structures, and mechanical properties.

Applicant has identified a number of deficiencies and problems associated with conventional additive manufacturing systems, which typically use metals or

thermoplastic polymers to form three dimensional structures. Through applied effort, ingenuity, and innovation, many of these identified problems have been solved by developing multicomponent thermoset solutions and their associated systems, methods, and apparatus that are included in embodiments of the present invention, many examples of which are described in detail herein. BRIEF SUMMARY OF THE INVENTION

Provided herein are an additive manufacturing apparatus for preparing a three- dimensional structure and associated methods, nozzle assemblies, and three-dimensional structures. The additive manufacturing apparatus may include (i) a first container configured to receive a first thermosetting resin component; (ii) a second container configured to receive a second thermosetting resin component; (iii) at least one pump fluidly connected to each of the first container and the second container; (iv) a nozzle assembly fluidly connected to the first container and the second container and configured to receive the first thermoset resin and the second thermoset resin, wherein the nozzle assembly includes a mixing assembly configured to combine the first thermosetting resin component and the second thermosetting resin component to form a multicomponent thermoset resin; and (v) a build platform configured to receive one or more layers of the multicomponent thermoset resin to form the three-dimensional structure, wherein the nozzle assembly is configured to extrude the multicomponent thermoset resin onto the build platform.

The device may operate generally according to a method comprising the following steps: (i) providing a first thermosetting resin component from a first container to a nozzle assembly, wherein the nozzle assembly includes a mixing assembly; (ii) providing a second thermosetting resin component from a second container to the nozzle assembly; (iii) combining the first thermosetting resin component and the second thermosetting resin component with the mixing assembly to create a multicomponent thermoset resin; (iv) extruding a first layer of the multicomponent thermoset resin from the nozzle assembly onto a build platform; (v) extruding a second layer of the

multicomponent thermoset resin from the nozzle assembly onto the build platform; and (vi) repeating step (v) until the three-dimensional structure is built. Further, some embodiments of the method of additive manufacturing may include the use of and removal of any support material from the completed three-dimensional structure. Steps (iv)-(vi) above may additionally include switching the additive manufacturing machine at each layer between producing structural multicomponent thermoset resin and producing support multicomponent thermoset resin as needed to shape the three-dimensional structure.

Moreover a resulting structure may be provided comprising one or more layers of a cured multicomponent thermoset resin, the structure may have an engineered three- dimensional shape, and wherein the multicomponent thermoset resin may comprise a combination of a first thermosetting resin component and a second thermosetting resin component.

A method for preparing a three-dimensional structure may be provided. The method may comprise providing a first thermosetting resin component from a first container to a nozzle assembly. The nozzle assembly may include a mixing assembly. The method may further include providing a second thermosetting resin component from a second container to the nozzle assembly. Embodiments of the method may include combining the first thermosetting resin component and the second thermosetting resin component with the mixing assembly to create a multicomponent thermoset resin. The method may further include extruding a first layer of the multicomponent thermoset resin from the nozzle assembly onto a build platform, and may include extruding a second layer of the multicomponent thermoset resin from the nozzle assembly onto the build platform.

In some embodiments of the method, the multicomponent thermoset resin may include a first ratio of the first thermosetting resin component and the second

thermosetting resin component. The method may further comprise providing the first thermosetting resin component from the first container to the nozzle assembly, and providing the second thermosetting resin component from the second container to the nozzle assembly. The method may further include combining the first thermosetting resin component and the second thermosetting resin component with the mixing assembly to create a support thermoset resin. The support thermoset resin may include a second ratio of the first thermoset resin and the second thermoset resin, and the first ratio may be different than the second ratio. The method may further include extruding a first layer of the support thermoset resin from the nozzle assembly onto a build platform, and extruding a second layer of the support thermoset resin from the nozzle assembly onto the build platform. The first layer of the multicomponent thermoset resin may be

substantially coplanar with the first layer of the support thermoset resin and the second layer of the multicomponent thermoset resin may be substantially coplanar with the second layer of the support thermoset resin. In some embodiments, the support thermoset resin may be configured to be removed from the multicomponent thermoset resin.

The first layer of the multicomponent thermoset resin may define a first planar area and the second layer of the multicomponent thermoset resin may define a second planar area, and the first planar area may be different than the second planar area. In some embodiments, the first planar area may be smaller than the second planar area. The method may further include extruding a support material coplanar with the first layer. The support material may comprise the first thermoset resin and the second thermoset resin.

In some embodiments, the second layer of multicomponent thermoset resin may be extruded before the first layer of multicomponent thermoset resin has fully cured. In some embodiments, at least the first layer of multicomponent thermoset resin may comprise a first portion having a first ratio of the first thermoset resin and the second thermoset resin and a second portion having a second ratio of the first thermoset resin and the second thermoset resin.

In some embodiments, one of the first thermosetting resin component and the second thermosetting resin component may include a catalyst. One of the first thermosetting resin component and/or the second thermosetting resin component may not include a catalyst.

Embodiments of the method may comprise providing a third thermosetting resin component from a third container to the nozzle assembly. The method may further comprise combining the first thermosetting resin component, the second thermosetting resin component, and the third thermosetting resin component with the mixing assembly to create the multicomponent thermoset resin. The method may include forming a support thermoset resin from at least two of the first thermosetting resin components, second thermosetting resin component, and third thermosetting resin component.

Some embodiments may comprise controlling the temperature within the nozzle assembly with at least two independent temperature control zones.

In some embodiments, a heating element may be provided proximate a downstream end of the mixing assembly. A cooling element may be provided proximate an upstream end of the mixing assembly.

In some embodiments, the first thermoset resin and the second thermoset resin are temperature controlled substantially continuously from the respective first resin container and second resin container to a downstream end of the nozzle assembly. In some embodiments, the mixing assembly may include a static mixer. In some embodiments, the mixing assembly may include a dynamic mixer.

The nozzle assembly may further comprise a nozzle configured to extrude the multicomponent thermoset resin perpendicular to a plane of the build platform. The nozzle assembly may be movable relative to the build platform. In some embodiments, the build platform may be movable relative to the nozzle assembly.

In some embodiments, the first layer may be substantially planar. The second layer may be substantially planar and wherein the first layer is substantially parallel to the second layer.

In some embodiments, the multicomponent thermoset resin may be thixotropic. Another embodiment may include an additive manufacturing apparatus for preparing a three-dimensional structure. The apparatus may include a first container configured to receive a first thermosetting resin component, a second container configured to receive a second thermosetting resin component, at least one pump fluidly connected to each of the first container and the second container, and a nozzle assembly fluidly connected to the first container and the second container and configured to receive the first thermoset resin and the second thermoset resin. The nozzle assembly may include a mixing assembly configured to combine the first thermosetting resin component and the second thermosetting resin component to form a multicomponent thermoset resin. The apparatus may further include a build platform configured to receive one or more layers of the multicomponent thermoset resin to form the three-dimensional structure. The nozzle assembly may be configured to extrude the multicomponent thermoset resin onto the build platform.

In some embodiments, the multicomponent thermoset resin may include a first ratio of the first thermosetting resin component and the second thermosetting resin component. The apparatus may be configured to combine the first thermosetting resin component and the second thermosetting resin component with the mixing assembly to create a support thermoset resin. The support thermoset resin may include a second ratio of the first thermoset resin and the second thermoset resin, and the first ratio may be different than the second ratio. The apparatus may be further configured to extrude the support thermoset resin from the nozzle assembly onto the build platform. The multicomponent thermoset resin may be substantially coplanar with the support thermoset resin. The support thermoset resin may be configured to be removed from the multicomponent thermoset resin. In some embodiments, the nozzle assembly may be configured to extrude a first layer of the multicomponent thermoset resin on the build platform, and the nozzle assembly may be configured to extrude a second layer of the multicomponent thermoset resin on the first layer. In some embodiments, the first layer of the multicomponent thermoset resin may define a first planar area and the second layer of the multicomponent thermoset resin may define a second planar area. The first planar area may be different than the second planar area. In some embodiments, the first planar area may be smaller than the second planar area. In some embodiments, the apparatus may be configured to extrude a support material coplanar with the first layer. In some embodiments, the support material may comprise the first thermosetting resin component and the second thermosetting resin component.

In some embodiments, one of the first thermosetting resin component and the second thermosetting resin component may include a catalyst. In some embodiments, one of the first thermoset resin and/or the second thermoset resin may not include a catalyst.

Some embodiments of the apparatus may be configured to provide a third thermoset resin from a third container to the nozzle assembly. In some embodiments, the apparatus may be configured to combine the first thermosetting resin component, the second thermosetting resin component, and the third thermosetting resin component with the mixing assembly to create the multicomponent thermoset resin. The apparatus may be further configured to form a support thermoset resin from at least two of the first thermosetting resin component, second thermosetting resin component, and third thermosetting resin component.

In some embodiments, the apparatus may comprise at least two independent temperature control zones configured to control the temperature within the nozzle assembly.

The apparatus may include a heating element proximate a downstream end of the mixing assembly. In some embodiments, the apparatus may include a cooling element proximate an upstream end of the mixing assembly.

In some embodiments, the apparatus may further comprise temperature control elements configured to control the temperature of the first thermoset resin and the second thermoset resin substantially continuously from the respective first resin container and second resin container to a downstream end of the nozzle assembly.

In some embodiments, the mixing assembly may include a static mixer. In some embodiments, the mixing assembly may include a dynamic mixer.

The nozzle assembly may further comprise a nozzle configured to extrude the multicomponent thermoset resin perpendicular to a plane of the build platform.

In some embodiments, the nozzle assembly may be movable relative to the build platform. In some embodiments, the build platform may be movable relative to the nozzle assembly.

In some embodiments, the multicomponent thermoset resin may be thixotropic.

In yet another embodiment, a nozzle assembly for an additive manufacturing apparatus may be provided. The nozzle assembly may include a first inlet configured to receive a first thermosetting resin component from a first container, a second inlet configured to receive a second thermosetting resin component from a second container, and a mixing assembly configured to combine the first thermoset resin and the second thermoset resin to form a multicomponent thermoset resin. The nozzle may be configured to extrude the multicomponent thermoset resin onto a build platform.

The multicomponent thermoset resin may include a first ratio of the first thermosetting resin component and the second thermosetting resin component. The nozzle assembly may be further configured to combine the first thermosetting resin component and the second thermosetting resin component with the mixing assembly to create a support thermoset resin. The support thermoset resin may include a second ratio of the first thermosetting resin component and the second thermosetting resin component, and the first ratio may be different than the second ratio. The nozzle may be further configured to extrude the support thermoset resin from the nozzle assembly onto the build platform. The multicomponent thermoset resin may be configured to be

substantially coplanar with the support thermoset resin.

In some embodiments, the support thermoset resin may be configured to be removed from the multicomponent thermoset resin.

In some embodiments, the nozzle assembly may be configured to extrude a first layer of the multicomponent thermoset resin on the build platform, and the nozzle assembly may be configured to extrude a second layer of the multicomponent thermoset resin on the first layer. In some embodiments, the first layer of the multicomponent thermoset resin may define a first planar area and the second layer of the multicomponent thermoset resin may define a second planar area. The first planar area may be different than the second planar area. In some embodiments, the first planar area may be smaller than the second planar area. In some embodiments, the nozzle may be further configured to extrude a support material coplanar with the first layer. The support material may comprise the first thermoset resin and the second thermoset resin.

In some embodiments, one of the first thermoset resin and the second thermoset resin may include a catalyst. In some embodiments, one of the first thermoset resin and the second thermoset resin does not include a catalyst.

In some embodiments, the nozzle assembly may be configured to receive a third thermosetting resin component from a third container. The nozzle assembly may be further configured to combine the first thermosetting resin component, the second thermosetting resin component, and the third thermosetting resin component with the mixing assembly to create the multicomponent thermoset resin. In some embodiments, the nozzle assembly may be further configured to form a support thermoset resin from at least two of the first thermosetting resin component, second thermosetting resin component, and third thermosetting resin component.

In some embodiments, the nozzle assembly may include at least two independent temperature control zones configured to control the temperature within the nozzle assembly.

In some embodiments, the nozzle assembly may further comprise a heating element proximate a downstream end of the mixing assembly. In some embodiments, the nozzle assembly may further comprise a cooling element proximate an upstream end of the mixing assembly.

In some embodiments, the mixing assembly may include a static mixer. In some embodiments, the mixing assembly may include a dynamic mixer.

In some embodiments, the nozzle assembly may further comprise a nozzle configured to extrude the multicomponent thermoset resin perpendicular to a plane of the build platform. The nozzle assembly may be movable relative to the build platform. The build platform may be movable relative to the nozzle assembly.

In some embodiments, the multicomponent thermoset resin may be thixotropic.

In another embodiment, a structure may be provided comprising one or more layers of a cured multicomponent thermoset resin. The structure may have an engineered three-dimensional shape, and the multicomponent thermoset resin may comprise a combination of a first thermosetting resin component and a second thermosetting resin component.

In some embodiments, a first layer of the multicomponent thermoset resin may define a first planar area and a second layer of the multicomponent thermoset resin may define a second planar area. The first planar area may be different than the second planar area. In some embodiments, the first planar area may be smaller than the second planar area.

A second layer of multicomponent thermoset resin may be extruded onto a first layer of multicomponent thermoset resin before the first layer of multicomponent thermoset resin has fully cured.

In some embodiments, at least a first layer of multicomponent thermoset resin may comprise a first portion having a first ratio of the first thermosetting resin component and the second thermosetting resin component and a second portion having a second ratio of the first thermosetting resin component and the second thermosetting resin component.

One of the first thermosetting resin component and the second thermosetting resin component may include a catalyst. One of the first thermosetting resin component and/or the second thermosetting resin component may not include a catalyst.

In some embodiments, the structure may comprise a third thermosetting resin component.

In some embodiments, the cured multicomponent thermoset resin may be configured to be cured via heating.

In some embodiments, at least one of the one or more layers may be substantially planar. A second layer may be substantially planar and a first layer may be substantially parallel to the second layer.

In some embodiments, the multicomponent thermoset resin is thixotropic. BRIEF DESCRIPTION OF THE FIGURES

Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

FIG. 1 shows a block diagram of an additive manufacturing system in accordance with some embodiments of the present invention;

FIG. 2 shows an illustration of an additive manufacturing system in accordance with some embodiments of the present invention;

FIG. 3 shows an additive manufacturing system in accordance with some embodiments of the present invention;

FIG. 4 shows a manifold used in an additive manufacturing system in accordance with some embodiments of the present invention;

FIG. 5 shows a side view of a nozzle assembly performing additive

manufacturing onto a build platform in accordance with some embodiments of the present invention;

FIG. 6 shows a cross-sectional view of a nozzle assembly having a static mixer in accordance with some embodiments of the present invention;

FIG. 7 shows a cross-sectional view of a nozzle assembly having a static mixer in accordance with some other embodiments of the present invention; and

FIG. 8 shows a cross-sectional view of a nozzle assembly having a dynamic mixer in accordance with some other embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The presently disclosed subject matter will now be described more fully hereinafter. However, many modifications and other embodiments of the presently disclosed subject matter set forth herein will come to mind to one skilled in the art to which the presently disclosed subject matter pertains having the benefit of the teachings presented in the foregoing descriptions. Therefore, it is to be understood that the presently disclosed subject matter is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Disclosed herein are advantageous apparatus, processes, and materials for use in additive manufacturing processes that utilize a multicomponent thermoset resin. The products of these processes and apparatus comprise the cured or partially cured thermoset resin(s) and they have three-dimensional, engineered shapes. The use of thermoset resins in additive manufacturing provides several advantages. The curing of these resins can be accomplished without the addition of significant heat, as the curing process includes a chemical cross-linking. Accordingly, the processes described herein can use less energy and, therefore, can have lower economic cost and environmental impact than processes that rely solely on conductive or convective thermal energy for melting and solidification. Importantly, because sintering or melting is not required, the three-dimensional structures prepared by these processes are not subjected to the thermal stress generated during typical sintering or melting. As such, the integrity of the three-dimensional structures will not be compromised as a result of such stress.

However, it is not straightforward that a thermosetting resin or a multicomponent thermosetting resin can be used in place of a thermoplastic because the thermosetting resin will need to have flow and curing of the resin to be occurring simultaneously but at different rates. The ability to control the rates of these two processes are provided by the apparatus and methods described herein. The rate of crosslinking of the resin can be adjusted by the molar density of crosslinkable moieties, the type of catalyst, the amount of catalyst, the molecular weight of the thermosetting resin and the polydispersity, i.e., the degree of branching of the polymeric chains making up the thermosetting resin. The flow of the thermosetting resin can be adjusted by changing the molecular weight of the thermosetting resin, changing the degree of branching of the polymeric chains making up the thermosetting resin, adding viscosifiers or viscosity reducers to the thermosetting resin. It is therefore disclosed herein that the flow and cross-linking can be independently controlled.

Typical additive manufacturing machines, for example, as shown in U.S. Patent No. 5, 121,329 and U.S. Patent No. 5,340,433, do not anticipate using multicomponent, thermosetting resins for material extrusion. These systems are designed for thermoplastic materials. As such, the speed at which a part can be fabricated is limited by the heat transfer out of the thermoplastic material once it is placed on the build platform and thermoplastics are known to be thermal insulators. This characteristic of thermoplastics slows the fabrication of the part. When a multicomponent thermosetting resin formulation is used to fabricate the part, heat transfer out of the part is no longer a limitation. Instead, in some embodiments of the present invention, the speed of part fabrication is controlled by the rate of chemical crosslinking and the greatest speed can be achieved by in-line mixing of the components of the thermosetting resin formulation. An efficient way to achieve in-line mixing of the components of the thermosetting resin formulation is through the use of a static mixer in accordance with embodiments discussed herein. Additionally, any residual heat in the thermosetting resin formulation accelerates the chemical crosslinking reaction while on the build platform.

Another limitation of the apparatus described in U.S. 5, 121,329 and U.S.

5,340,433 is that the melt is pushed out of the extruder tip by force applied to a thermoplastic strand. Because of this design, the material that can be used in this apparatus must have sufficient mechanical stiffness to push out molten polymer from the extruder tip. This requirement restricts the selection of thermoplastic materials that can be used. In contrast, any pumpable thermosetting resin formulation can be used in the device described in embodiments of the present invention.

U.S. Patents 5, 121,329 and 5,340,433 disclose using more than one thermoplastic material. However neither of these patents anticipates mixing these components. Figure 6 of US 5,121,329 shows the design for an extruder tip to apply two thermoplastics sequentially. That figure specifically calls out a check valve to prevent mixing of the two components and the design of the melt flow channels prevents any turbulent mixing from occurring. Likewise, Figure 7 of U.S. 5,121,329 describes a manifold for extruding multiple thermoplastic materials in discrete layers. No mixing of these layers is anticipated.

Moreover, extrusion devices of additive manufacturing devices typically extrude material into layers perpendicular to their direction of travel. As such, conventional additive manufacturing devices, methods, and materials are not necessarily combinable with conventional molding or casting devices (e.g., the material should be of sufficiently low viscosity to be extruded into a layer perpendicular to the nozzle). The subject matter disclosed herein addresses these shortcomings and more. In some embodiments, the subject matter disclosed herein is directed to combining multiple resins via a nozzle assembly to produce a multicomponent thermoset resin. The multicomponent thermoset resins disclosed herein may be generally thixotropic to allow mixing in the nozzle assembly and extrusion onto the build platform, while ensuring the multicomponent thermoset resin maintains a predetermined form when extruded onto a build platform in the interval of time between leaving the nozzle and when sufficient cure occurs to maintain the form. One or more liquid, resins, along with a desired combination of additives, solvents, catalyzing agents, thixotropic agents, and any other desired additive, collectively forming a component resin, may each be stored in a separate container for combination with one another in the additive manufacturing process. Two or more component resins may be pumped or otherwise driven from the respective containers to a mixing assembly. In some embodiments, the mixing assembly may be included in a nozzle assembly of an additive manufacturing apparatus. In order to facilitate the mixing of the component resins, one or more temperature control devices may be placed in any area of the additive manufacturing apparatus, as detailed herein. In some embodiments, the multicomponent thermoset resin cures via chemical cross-linking such that minimal or no thermal energy is added to the system.

As used herein the term "additive manufacturing" refers to any process of joining materials to make objects by depositing layer upon deposited layer. Each layer will have the desired dimensions and shape such that together the layers form a three-dimensional, engineered structure.

As used herein, the term "thermoset" or "thermosetting" refers to a property of a polymer precursor or polymer made from such precursor where the polymer once crosslinked is irreversibly cured. The cure may be induced through a chemical reaction that leads to formation of covalent or ionic bonds that were not present prior to cure.

As used herein, the term "thermoset resin" or "thermosetting resin" refers to precursor materials that will form a thermoset polymer when induced to polymerize and to crosslink as described herein. Thermoset resins are distinguishable from thermoplastic powders and resins, which are known in the art. Thermosetting resins are chemically distinct from thermoplastic resins and can be contrasted with thermoplastic polymers which are commonly produced in pellets and shaped into their final product form by melting and pressing or injection molding.

As used herein, the term "curing" refers to the chemical crosslinking within the resin and between different layers of resin. Other chemical changes may be occurring at the same time that crosslinking is occurring. The term "crosslinking" refers to the formation of covalent or ionic bonds between thermoset resin monomers, oligomers, or polymers and polymers formed therefrom. Such chemical changes are distinguished from a physical change such as melting. In thermoset polymers, unlike thermoplastic polymers, the curing is considered irreversible. Curing and the term "cure" refer to "partial" or "full" curing. As used herein, the term "partial" or "partially" cure, cured or curing refers to an amount of chemical crosslinking within the resin and between different layers of resin to form covalent bonds between the resin molecules and layers. As used herein, the term "full" or "fully" cure, cured or curing refers to an amount of chemical crosslinking within the resin and between different layers of resin to form covalent bonds between the resin molecules and layers such that subjecting the resin to additional heat or energy does not provide appreciably more of the same type of covalent bonding. Accordingly, the term "fully" does not imply that all of the crosslinking moieties must be covalently bonded.

The term "structure" or "three-dimensional structure" and the like as used herein refer generally to intended or actually fabricated three-dimensional configurations, objects, or parts that are fabricated and intended to be used for a particular purpose. Such structures, etc. may, for example, be designed with the aid of a three-dimensional CAD system. The shapes are engineered, meaning that they are particular shapes designed and manufactured according to specification in the desired shape as contrasted with random shapes. The structures will be comprised of layers as described herein. In contrast, structures formed from other methods, such as molding, will not contain such layers. A "plurality" of structures refers to two or more of such structures that are substantially identical. As used herein, the term "substantially" implies that the structures are identical in all respects but are allowed to have minor topological imperfections.

As used herein a "single layer" of thermoset resin can be any amount of material applied in any fashion that is crosslinked, partially or fully, prior to the addition of any new material (the next layer) proximate to the cured material. Therefore, in embodiments, a single layer may be defined by multiple individual layers of material if all those layers are extruded together. Additive manufacturing systems build the solid part one layer at a time. Typical layer thicknesses range from about 0.001-10.00 mm. However, depending on the build design, the layer may be thicker or thinner as practicable. The thickness can be adjusted depending on the process parameters, including the cure time, the total number of layers that make up the structure, the speed in which the structure is being built, and the resolution of the features of the part.

As used herein, the term "contacting" includes applying, spreading, filling dumping, dropping and the like such that the resins are in position for the processes described herein to proceed.

Additive Manufacturing Processes and Devices

Additive manufacturing is defined by the American Society for Testing and Materials (ASTM) as the "process of joining materials to make objects from 3D model data, usually deposit layer upon deposit layer, as opposed to subtractive manufacturing methodologies, such as traditional machining and casting." As referred herein as

"additive manufacturing," there are a number of processes for creating a digital model and producing a three-dimensional solid object of virtually any shape from that model. These processes are named 3D printing, rapid prototyping, fused-filament, additive manufacturing, and the like. Additive manufacturing is, therefore, a method for forming three-dimensional articles through successive joining of chosen parts of resin layers resting on a substrate (e.g., a build platform).

As disclosed herein, embodiments of the present invention may use additive manufacturing technology to provide low cost product assembly and the building of any number of products with engineered, complex shapes/geometries, complex material compositions and designed property gradients has been expanded to multicomponent thermoset resins as the material for the build.

In some embodiments of the additive-manufacturing process, a model, such as a design model, of the component may be defined in any suitable manner. For example, the model may be designed with computer aided design (CAD) software. The model may include 3D numeric coordinates of the entire configuration of the component including both external and internal surfaces of an airfoil, platform and dovetail. The model may include a number of successive 2D cross-sectional slices that together form the 3D component.

3D design files may be created using Computer Assisted Design (CAD) software, such as SolidWorks™, to generate a digital representation of a 3D object. The STL (Standard Tessellation Language) file format may be used for storing such CAD files. This CAD file, in other words the digital representation of the 3D object, may

subsequently be converted into a series of contiguous 2D cross sections, representing sequential cross-sectional slices of the 3D object. These 2D cross sections may be referred to as 2D contour data. The 2D contour data can be directly input into a 3D printer in order for the printer to print the 3D object. Conversion of a 3D design file into 2D cross-sectional data may be carried out by dedicated software.

As such, embodiments of the present additive manufacturing system may be used to print or otherwise build three-dimensional ("3D") parts from digital representations of the 3D parts (e.g., AMF and STL format files) using one or more additive manufacturing techniques. Examples of commercially available additive manufacturing techniques include powder bed fusion, direct energy deposition, extrusion-based techniques including extrusion deposition or fused deposition modeling, jetting, selective laser sintering, powder/binder jetting, electron-beam melting, and stereolithographic processes.

Extrusion based techniques may involve extruding a liquid resin from a nozzle onto a substrate, such that the liquid hardens quickly to form a layer or a portion of a layer of cured polymer. Conventional thermoplastic extrusion systems melt a solid thermoplastic and extrude the then molten thermoplastic into layers, which re-solidify as a plastic product. Embodiments of the present invention may form and cure a

multicomponent thermoset resin material into one or more polymer layers. The three- dimensional structure may be formed on a build platform, which may be a releasable substrate, by consecutively forming and crosslinking planar layers of polymer in an iterative extrusion process. In some alternative embodiments, three-dimensional structures may be extruded in three dimensions by extruding a plurality of three- dimensional filaments. To support the three-dimensional structure during construction, support material may be formed between portions of the polymer layers and the build platform. In some embodiments, the support material may be a second polymeric material that may be broken away from the three-dimensional structure after the extrusion process is complete. Embodiments of the present invention form the support material from different combinations of component resins, as detailed herein.

For all of these techniques, some embodiments may initially slice the digital representation of the 3D part into multiple horizontal layers. For each sliced layer, a tool path may be generated, which provides instructions for the particular additive

manufacturing system to print the given layer.

Before a printing cycle is executed, some embodiments appropriately configure the temperature control and pumping parameters on the basis of the object being printed. For example, different thermoset resins may require different heat settings in order to achieve the required curing/solidity/rigidity, while simultaneously allowing the component resins to have the correct viscosity to mix properly in the mixing assembly. As further described herein, the multicomponent thermoset resin may be substantially thixotropic in order to facilitate mixing. Different parameter settings may also be associated with different build algorithms used to print features such as hatching and/or to print specific geometric structures such as meshes. Those of ordinary skill in this field are familiar with the performance and capabilities of such printers and can configure the 3D printer with the most appropriate parameter settings, to ensure that printed objects satisfy the required specifications.

Some systems for additive manufacturing are known in the art, e.g., in the following non-limiting list of US patent publications: 5,597,589; 5,730,925; 7,047,098; 7,048,53020140277669; 20140314609; 20140255666; 20140156053; 20130316081; 20130186514; 20120329659; 20130001834; 20120201960; 20080206383; and

WO2004/056512, each of which is incorporated by herein reference in its entirety.

Turning to FIG. 1, an example block diagram of a system in accordance with some embodiments of the present invention is shown. As shown in FIG. 1, an additive manufacturing apparatus 100 may have two or more resin containers 105 for storing each of the component resins. The resin containers 105 may be fluidly connected to a nozzle assembly 110 via one or more conduits 130, 135 and/or pump 115. The nozzle assembly 110 may include the mixing assembly 120 and an extrusion nozzle 125. The mixing assembly 120 may combine the component resins into the multicomponent thermoset resin and the nozzle 125 may extrude the multicomponent thermoset resin onto the build platform 140. The mixing assembly 120 may be configured to allow the desired total mass flow of the multicomponent thermosetting resin to print the three-dimensional structure at the desired speed. Moreover, the resin containers 105; conduits 130, 135; and/or nozzle assembly 110 may include one or more independently controllable heating or cooling elements to assist with the transport, mixing, curing, and extrusion of the multicomponent thermoset resin.

A control module 150 may be coupled to the resin containers 105; conduits 130,

135; drive systems 145; and/or nozzle assembly 110 to facilitate the additive

manufacturing process. The control module 150 may be further connected to a communications module 155, which may facilitate interaction between the additive manufacturing machine and external devices, as detailed herein. A computer 157, which may be separate or integrated with the additive manufacturing device, may transfer a specification of the desired product to an additive manufacturing device which performs the additive manufacturing techniques according to the specification in order to create the 3D product. While not required in all aspects, the additive manufacturing device can include processors that interpret the specification, and control other elements which apply the materials using robots, printers, lasers or the like to add the materials as layers or coatings to produce the 3D product.

With reference to FIG. 2, a simplified illustration of an additive manufacturing apparatus 100 is shown. In some embodiments, as detailed herein, the additive manufacturing apparatus 100 may include two or more resin containers 105. In some embodiments, the two or more resin containers 105 may be disposed in substantially the same housing or enclosure. The resin containers 105 may include a resin chamber 107 for storing the component resins. One or more of the resin containers 105 may include a temperature control device 109 for monitoring and/or controlling the temperature of the resin chambers 107. In some embodiments the temperature control device 109 may include a heater for warming the resin in the resin chamber 107. In some embodiments, the temperature control device 109 may include a cooler for cooling the resin. In some further embodiments, the temperature control device 109 may be configured to heat and cool the resin in the resin chamber 107 as needed, as discussed in greater detail herein. The materials of construction for the resin chamber 107 should be compatible with the resin they contain.

With continuing reference to FIG. 2, the two or more resin containers 105 may be connected to the nozzle assembly 110 via one or more conduits 130, 135. In some embodiments, the resin containers 105 may be integrally formed with the nozzle assembly 110. In some other embodiments, as shown in FIG. 2, the containers 105 may be separately formed and connected via the conduits 130, 135. Resin may be pumped to the nozzle assembly 110 via one or more pumps 115. The ratio of the thermosetting resin components may be controlled by the mass flow of resin from pumps (e.g., the pumps 115 shown in FIGS. 1-2). The type of pump to be used in this invention is not limited. As examples, depending on the characteristics of the component resins, these pumps might be peristaltic pumps, pressure pumps, screw pumps or gear pumps.

In some embodiments, the pumps 115 may be positioned in line between one or more of the resin containers 105 and the nozzle assembly 110. Additionally or alternatively, a positive pressure may be applied to the resin containers 105 by one or more pumps (e.g., air compressors, mechanical pumps, compressed air, etc.) to drive the resin toward the nozzle assembly 110. Similarly, a negative pressure may be applied to the nozzle assembly to draw the resin from the resin containers 105 into the nozzle assembly. The conduits 130, 135 may include heating and/or cooling elements. For example, the conduits 130, 135 may be clad in a heat transfer medium (e.g., a water chamber) and the medium may be circulated along the conduit via a heating or cooling system. Moreover, any additional or alternative heating or cooling system may be applied to the conduits 130, 135.

The conduits 130, 135 may terminate at the mixing assembly 120 of the nozzle assembly 110. The mixing assembly 120 may be configured to combine the component resins from each of the resin containers 105 into a multicomponent thermoset resin. In some embodiments, the mixing assembly may include a static mixer 160 to mix the resins in a simple, robust, and cost-effective manner. As described in further detail below, the static mixer 160 may include one or more curved or straight surfaces, plates, orifice holes, protrusions, or any other mixing device to combine the component resins. The static mixer 160 may use the pressure applied to the resins by the pumping system to generate the multicomponent thermoset resin without requiring additional motors or moving pieces. In some alternative embodiments, a moving, dynamic mixer may additionally or alternatively be used.

As described in further detail below, the mixing chamber may include a heating and/or cooling system 165 comprising one or more heating or cooling elements for maintaining a desired temperature throughout the mixing process. Once the

multicomponent thermoset resin reaches the downstream end of the mixing assembly 120, the multicomponent thermoset resin is extruded from the nozzle assembly 1 10 by a nozzle 125. The pressure applied to the resins by the pumping system may supply the pressure to extrude the multicomponent thermoset resin through the nozzle 125.

With reference to FIG. 3, an embodiment of the additive manufacturing apparatus 100 is shown. The apparatus may include two or more extruder heads 225 coupled to a nozzle assembly 1 10 via one or more pipes 235 and/or connectors (e.g., elbow joints 230). In one example embodiment, the pipe may be a 1/4 inch pipe 235 connected to a 10-32 male thread to 1/4 inch push-to-fit pipe elbow 230. The depicted extruders are positive displacement pumps including the extruder heads 225 and extruder barrels 265. The extruder heads 225 may force the resin into the pipes from the barrels 265. In some embodiments, one or more of the pumps may be velocity pumps.

The depicted nozzle assembly 1 10 includes a manifold 220 for receiving the resin components through the respective pipes 235 and connecting the pipes to the mixing chamber 120. In some embodiments, the mixing chamber 120 may be a static mixer (e.g., static mixer 160 shown in FIG. 2). The mixing chamber 120 may be coupled to the manifold 220 by a threaded collar 250. The nozzle assembly 1 10 may further include a nozzle 125 disposed at a downstream end of the mixing chamber 120.

In some embodiments, with continued reference to FIG. 3, the nozzle assembly 1 10 may be mounted to a runner plate 245 or similar support structure, for example, by a clamp 240 or other attachment mechanism such as bolts, screws, pins, French cleats, notches, welding, adhesives, or the like. The additive manufacturing apparatus 100 may contain heating and/or components in the extruder heads 225, pipes 235, joints 230, and nozzle assembly 1 10 as described herein.

FIG. 4 shows a cross-sectional view of the manifold 220 having a first flow channel 255 for one part of the multicomponent thermoset resin to travel through and a second flow channel 260 for a second part of the multicomponent thermoset resin. The manifold 220 may receive the first and second components from the pipes 235 and direct the components separately into the mixing chamber 120 (e.g., static mixer). In some embodiments, the manifold may at least partially combine the components prior to entering the mixing chamber.

Turning to FIG. 5, the nozzle 125 may extrude the multicomponent thermoset resin into sequential layers on the build platform to form the three-dimensional structure. Either or both the build platform 140 and the nozzle 125 may be connected to a drive system for positioning the two relative to one another to form the three-dimensional structure. For example, the nozzle assembly 1 10 may be connected to a rail 170, on which it may travel to control the extrusion. One or more rails, tracks, and/or conveyor systems may be used to form each dimension of the three-dimensional shape. In some embodiments, the entire nozzle assembly 1 10 may be moved and operated by the drive system. In some alternative embodiments, the mixing assembly 120 may remain stationary. For example, in some embodiments, the nozzle 125 or nozzle assembly 1 10 may move in three dimensions to form the three-dimensional structure on a stationary build platform 140. In some alternative embodiments, the build platform 140 may move in three dimensions to form the three-dimensional structure from a stationary nozzle assembly 1 10. Both the nozzle 125 or nozzle assembly 1 10 and the build platform 140 may be configured to move. For example, the build platform may move along a vertical, Z-Axis (e.g., the Z-Axis shown in FIG. 5) while the nozzle 125 or nozzle assembly 1 10 moves along an X- and Y-axis (e.g., the X-Axis and Y-Axis shown in FIG. 5). Any of the build platform 140, nozzle 125, and nozzle assembly 1 10 may move in any desired direction or combination of directions for the additive manufacturing process (e.g., the build platform may move along the X, Y, Z, X and Y, Y and Z, X and Z, or X Y and Z axes; the nozzle assembly may move along the X, Y, Z, X and Y, Y and Z, X and Z, or X Y and Z axes). In some embodiments one of the build platform and nozzle assembly may move along the X, Y, and Z axes to collectively move along all three axes.

As discussed herein, the additive manufacturing apparatus may extrude layers of multicomponent thermoset resin onto the build platform. In some embodiments, forming the three-dimensional structure may include depositing the multicomponent thermoset resin at a location where no lower layer of resin is available to support the new layer (e.g., the three-dimensional structure has an overhang). In such instances, some embodiments of the present invention may apply a support material beneath the overhanging layer to provide temporary support during the manufacturing process. For example, as shown in FIG. 5, a first layer 200 may include a portion of structural multicomponent thermoset resin 210 and a portion of support material 215. The second layer 205 may then be formed atop the support material 215 for the formation process, but may be removed after manufacturing. In this manner, the support layer 215 may allow overhanging portions of the three-dimensional structure to be manufactured. The additive manufacturing device may form multiple layers of support material and may form layers entirely of support material as necessary to produce the desired three- dimensional structure.

As discussed herein, the structure material (e.g., the structure material 210) and the support material (e.g., the support material 215) may be formed with the same resins and/or from the same nozzle assembly. For example, each of the same two or more component resins may be combined to form both the structural multicomponent thermoset resin and the support multicomponent thermoset resin. Different proportions of each resin and additional additives may be used to maintain the strength of the structural material while allowing the support material to be broken away and/or dissolved from the structural material after manufacturing. In some embodiments, three or more resin containers may be used, in which one or more of the containers may be used to form the structural multicomponent thermoset resin and one or more of the containers may be used to form the support multicomponent thermoset resin.

In some embodiments the nozzle assembly 110 may mix and deposit both the structural and the support material. In such embodiments, the machine (e.g., via control module 150 shown in FIG. 1) may change the proportions of the respective resins between the structural formulation and the support formulation to switch between material types. In some embodiments, the additive manufacturing machine will anticipate a switch in material type and begin feeding the new formulation such that the new formulation reaches the nozzle (e.g., the nozzle 125 shown in FIG. 5) when needed. In some embodiments, the machine may discard a changeover section of multicomponent thermoset resin, in which the concentrations of the respective resins have not yet reached a steady state. In some alternative embodiments, separate nozzles may be used for the structural and support materials. Moreover, multiple formulations of structural multicomponent thermosetting resin may be used. For example, a stronger formulation may be utilized to form a skeleton of the three dimensional structure, and a more cost effective formulation may be used for the remainder of the structure. In some

embodiments, three or more different multicomponent thermoset resins (e.g., a support resin and a plurality of structural resins) may be produced from the two or more component resin.

Turning to FIGS. 6-7, embodiments of the nozzle assembly 110 are shown having static mixers 260, 360 configured to mix the component resins. For example, the static mixer 260 shown in FIG. 6 has a first series of slats 265 and a second series of slats 270 crisscrossing along the length of the mixing chamber. The first series of slats 265 are positioned in a first half of the mixing assembly 120 and the second series of slats 270 are positioned in a second half of the mixing assembly with the first and second halves being divided vertically along the length of the mixing assembly. Similarly, with reference to FIG. 7, a second configuration of a static mixer 360 is shown. In the embodiment of FIG. 7, alternating slats 365 are spaced along the length of the mixing assembly 120. In some embodiments, the nozzle 125 may include a space 127 between the last mixing element and the extrusion outlet to reduce or eliminate inertial flow memory characteristics of the multicomponent thermoset resin. The space 127 may be separately heated and/or cooled as detailed herein.

In some alternative embodiments, with reference to FIG. 8 the mixing assembly 120 may include a dynamic mixer 460 that mechanically mixes the component resins. The dynamic mixer 460 may include stirrer blade 465 or other mixing device that may be driven (e.g., on a shaft 470) to produce the multicomponent thermoset resin. In some embodiments, the dynamic mixer 460 may also be the pump that draws the resins from the containers (e.g., the resin containers 105 shown in FIGS. 1-2). Moreover, some embodiments may utilize a combined static and dynamic mixing system.

With continued reference to FIGS. 6-8, the nozzle assembly may include a heater and/or cooler system, which may include one or more independently controllable heating and/or cooling elements 175-181. Each heating and/or cooling element 175-181 may be used to assist with the transport, mixing, curing, and extrusion of the multicomponent thermoset resin. For example, an upstream end of the mixing assembly 110 may be cooled to promote mixing and maintain a lower viscosity of the component resins. A downstream end of the mixing assembly 110 may be configured to heat the thermoset resin to promote fast curing after the resin is extruded. Similarly the space 127 and nozzle 125 may be independently heated and/or cooled with additional elements (e.g., elements 180, 181). For example, the mixing chamber 120 may be divided into zones (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 zones) (e.g., the zones 175-181) with each zone being independently controllable. Moreover, the static mixing components 160, 260, 360 may include internal channels to allow heat transfer fluid to be pumped through the elements thereby providing for additional heating or cooling during the mixing process.

In some embodiments, the resins may be temperature controlled during their entire transport in the additive manufacturing machine. Each component from the resin containers (e.g., resin containers 105 shown in FIGS. 1-2) to the nozzle 125 may be independently temperature controlled to facilitate the processing of the multicomponent thermoset resins. Further heating the polymer after curing may unnecessarily stress the three-dimensional structure. As such, heating may preferably be applied within the nozzle assembly 110 prior to fully curing.

The device may operate generally according to a method comprising the following steps: (i) providing a first thermosetting resin component from a first container to a nozzle assembly, wherein the nozzle assembly includes a mixing assembly; (ii) providing a second thermosetting resin component from a second container to the nozzle assembly; (iii) combining the first thermosetting resin component and the second thermosetting resin component with the mixing assembly to create a multicomponent thermoset resin; (iv) extruding a first layer of the multicomponent thermoset resin from the nozzle assembly onto a build platform; (v) extruding a second layer of the

multicomponent thermoset resin from the nozzle assembly onto the build platform; and (vi) repeating step (v) until the three-dimensional structure is built. Further, some embodiments of the method of additive manufacturing may include removing any support material from the completed three-dimensional structure. Steps (iv)-(vi) above may additionally include switching the additive manufacturing machine at each layer between producing structural multicomponent thermoset resin and producing support multicomponent thermoset resin as needed to shape the three-dimensional structure. Multicomponent Thermoset Resins

Useful multicomponent thermoset resins for use in some embodiments disclosed herein include any known thermoset resins. Such resins may be preferably in liquid form and may preferably be made thixotropic. Thixotropic liquids may experience a decrease in viscosity as a function of shear rate. In some embodiments, the resulting

multicomponent thermoset resin may have about a 1000 centipoise viscosity.

The ratio of the thermosetting resin components may be controlled by the mass flow of resin from pumps (e.g., the pumps 115 shown in FIGS. 1-2). The type of pump to be used in this invention is not limited. As examples, depending on the characteristics of the component resins, these pumps might be peristaltic pumps, pressure pumps, screw pumps or gear pumps. The materials of construction for the pumps must be compatible with the resin they contain. The mass ratio of a first thermosetting resin component to a second thermosetting resin component can be as high as 1000: 1 or greater. In some embodiments, the mass ratio may be 10: 1 or less.

In some embodiments, the component resins may include an acrylic monomer. In a preferred embodiment, two acrylic monomers may be combined to form the multicomponent thermosetting resin. Useful resins may additionally or alternatively be selected from thermoset resins known in the art including at least one resin selected from epoxy amines, polymethylene diisocyanates (PMDI), polyurethane resins, polyimide resins; isocyanate resins; (meth)acrylic resins; phenolic resins; vinylic resins; styrenic resins; polyester resins; melamine resins; vinylester resins; maleimide resins; and mixtures thereof. The resins that have been named are intended to be examples of classes without limiting the range of materials that may be used. Precursors that include resorcinol, tannin, lignin, epoxies, urethanes, polyesters, or melamine are also encompassed.

The resins described herein, including those known in the art, can contain a catalyst. The type of catalyst will be chosen based on the crosslinking moieties on the thermosetting resin and is well within the skill of those in this field. Non-limiting examples include the following. For example, the crosslinking of isocyanate moieties can be catalyzed with dimethylaminopyridine or dibutyl tin oxide. The crosslinking of resole phenol formaldehyde resins can be catalyzed with sodium hydroxide, potassium hydroxide or salts of ethylenediamine-sulfonic acid. The crosslinking of novolac phenol formaldehyde resins can be catalyzed with boric acid, oxalic acid or sulfamic acid.

Thermosetting epoxy resins can be catalyzed with tributylamine, cis-5-Norbornene-endo- 2,3-dicarboxylic anhydride, or oxalic acid. Certain resins that are composed of polycarboxic acid with polyols, crosslink by esterification reactions and these

esterification reactions can be catalyzed with sodium hypophosphite. In some

embodiments at least one of the two or more resin components that form the

multicomponent thermosetting resin may include a catalyst. In some further

embodiments, all of the two or more resin components that form the multicomponent thermosetting resin may include a catalyst.

As mentioned before, the flow of the thermosetting resins can be adjusted by changing the molecular weight of the thermosetting resin, changing the degree of branching of the polymeric chains making up the thermosetting resin, or adding viscosifiers or viscosity reducers to the thermosetting resin. The following non-limiting examples describe such components. Examples of additives that may be used to formulate the resins to increase the viscosity under curing conditions include fumed silica, alkylammonium montmorillonite, wollastonite, calcium carbonate, magnesium oxide, hydroxyethyl cellulose, cellulose acetate butyrate and poly(ethylene oxide).

Examples of some additives that may be used to formulate the resins to reduce the viscosity include dioctylphthalate, dioctyladipate, triphenylphosphate, Bisphenol-A, low molecular weight polyvinyl acetates and low molecular weight polyvinyl butyrates.

Utilizing known viscosifiers and viscosity reducers and adjusting the above-mentioned parameters is well within the skill of those in this field. By way of example, in an embodiment utilizing one or more acrylic monomers, additives that may be found in the acrylic monomer include (1) a free radical stabilizer (e.g. monomethyl hydroquinone ether), (2) rheology modifier (e.g. fumed silica), (3) impact modifier (e.g. butyl rubber) and (4) oxidation-reduction initiator (e.g. cumene hydroperoxide - dimethylaniline).

In embodiments, the present subject matter is directed to a structure comprising, a cured multicomponent thermoset resin having an engineered three-dimensional shape. The structure will comprise one or more layers of a cured multicomponent thermoset resin. Accordingly, in embodiments, the structure can contain from 2 to an unlimited number of engineered layers; from 2 to about 10,000 layers; from 2 to about 5,000 layers; from 2 to about 1,000 layers; from 2 to about 500 layers; from 2 to about 250 layers; from 2 to about 100 layers; from 10 to about 500 layers; from 50 to about 500 layers; from 100 to about 500 layers; or from 250 to about 500 layers. Each layer may be of the same or different type of resin. Each layer may be the same or different dimensions. There is almost no limit to the shapes that can be prepared by additive manufacturing. The shapes will be designed and engineered to a specification. The methods described herein can prepare the structures according to the specification. In embodiments, the structure is an engineered three-dimensional shape designed using computer-aided design. Almost unlimited substantially identical copies of the structures can be prepared by the methods. In aspects of this embodiment, the present subject matter is directed to a plurality of monodisperse three-dimensional structures comprising, two or more discrete structures, each comprising or consisting essentially of a cured multicomponent thermoset resin having an engineered three-dimensional shape, wherein each structure of the plurality is substantially identical. In this embodiment, the material distinction is that the structure is fabricated using essentially only the thermoset resin.

As detailed above, both the support material and the structural material may be formed of multicomponent thermoset resin. A more easily removable formulation may be used for the support material, and a stronger formulation may be used for the structural material. Moreover, multiple formulations of structural multicomponent thermosetting resin may be used. For example, a stronger formulation may be utilized to form a skeleton of the three dimensional structure, and a more cost effective formulation may be used for the remainder of the structure. In some embodiments, three or more different multicomponent thermoset resins (e.g., a support resin and a plurality of structural resins) may be produced from the two or more component resin.

The device may operate generally according to a method comprising the following steps: (i) providing a first thermosetting resin component from a first container to a nozzle assembly, wherein the nozzle assembly includes a mixing assembly; (ii) providing a second thermosetting resin component from a second container to the nozzle assembly; (iii) combining the first thermoset resin and the second thermoset resin with the mixing assembly to create a structural multicomponent thermoset resin; (iv) extruding a first layer of the structural multicomponent thermoset resin from the nozzle assembly onto a build platform; (v) combining the first thermoset resin and the second thermoset resin with the mixing assembly to create a support multicomponent thermoset resin; (vi) extruding a first layer of the support multicomponent thermoset resin from the nozzle assembly onto a build platform; (vii) combining the first thermosetting resin component and the second thermosetting resin component with the mixing assembly to create a structural multicomponent thermoset resin; (viii) extruding a second layer of the structural multicomponent thermoset resin from the nozzle assembly onto the build platform; (ix) combining the first thermoset resin and the second thermoset resin with the mixing assembly to create a support multicomponent thermoset resin; (x) extruding a second layer of the support multicomponent thermoset resin from the nozzle assembly onto the build platform; and (viii) repeating step (iii)-(x) until the three-dimensional structure is built. Further, some embodiments of the method of additive manufacturing may include removing any support material from the completed three-dimensional structure. Structural and support resins need not be deposited at every layer and may depend on the design of the three-dimensional structure.

Example System Architecture

Referring back to FIG. 1, and in accordance with some example embodiments, the control module 150 can include or be connected to various means, such as processor, memory, and/or input/output device 156. As referred to herein, "module" includes hardware, software and/or firmware configured to perform one or more particular functions. In this regard, the means of control module 150 as described herein may be embodied as, for example, circuitry, hardware elements (e.g., a suitably programmed processor, combinational logic circuit, and/or the like), a computer program product comprising computer-readable program instructions stored on a non-transitory computer- readable medium (e.g., memory) that is executable by a suitably configured processing device (e.g., processor), or some combination thereof.

The processor may, for example, be embodied as various means including one or more microprocessors with accompanying digital signal processor(s), one or more processor(s) without an accompanying digital signal processor, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuitry, one or more computers, various other processing elements including integrated circuits such as, for example, an ASIC (application specific integrated circuit) or FPGA (field

programmable gate array), or some combination thereof. Accordingly, although a single processor may be referenced, in some embodiments processor comprises a plurality of processors. The plurality of processors may be embodied on a single computing device or may be distributed across a plurality of computing devices collectively configured to function as the control module 150. The plurality of processors may be in operative communication with each other and may be collectively configured to perform one or more functionalities of control module 150 as described herein. In an example

embodiment, processor is configured to execute instructions stored in memory or otherwise accessible to processor. These instructions, when executed by processor, may cause control module 150 to perform one or more of the functionalities of control module 150 as described herein.

The memory may comprise, for example, volatile memory, non-volatile memory, or some combination thereof. Although illustrated in some embodiments as a single memory, memory may comprise a plurality of memory components. The plurality of memory components may be embodied on a single computing device or distributed across a plurality of computing devices. In various embodiments, memory may comprise, for example, a hard disk, random access memory, cache memory, flash memory, a compact disc read only memory (CD-ROM), digital versatile disc read only memory (DVD-ROM), an optical disc, circuitry configured to store information, or some combination thereof. Memory may be configured to store information, data (including item data and/or profile data), applications, instructions, or the like for enabling control module 150 to carry out various functions in accordance with example embodiments of the present invention. For example, in at least some embodiments, memory is configured to buffer input data for processing by processor. Additionally or alternatively, in at least some embodiments, memory is configured to store program instructions for execution by the processor. Memory may store information in the form of static and/or dynamic information. This stored information may be stored and/or used by control module 150 during the course of performing its functionalities.

Communications module 155 may be embodied as any device or means embodied in circuitry, hardware, a computer program product comprising computer readable program instructions stored on a computer readable medium (e.g., memory) and executed by a processing device (e.g., processor), or a combination thereof that is configured to receive and/or transmit data from/to another device and/or network, such as, for example, a control module and/or the like. In some embodiments, communications module 155 (like other components discussed herein) can be at least partially embodied as or otherwise controlled by processor. In this regard, communications module 155 may be in communication with processor, such as via a bus. Communications module 155 may include, for example, an antenna, a transmitter, a receiver, a transceiver, network interface card and/or supporting hardware and/or firmware/software for enabling communications with another computing device. Communications module 155 may be configured to receive and/or transmit any data that may be stored by memory using any protocol that may be used for communications between computing devices.

Communications module 155 may additionally or alternatively be in communication with the memory, input/output module and/or any other component of control module 150, such as via a bus.

Input/output module 156 may be in communication with processor to receive an indication of a user input and/or to provide an audible, visual, mechanical, or other output to a user. As such, input/output module 156 may include support, for example, for a keyboard, a mouse, a joystick, a display, a touch screen display, a microphone, a speaker, a scanner, a RFID reader, barcode reader, biometric scanner, and/or other input/output mechanisms. In embodiments wherein control module 150 is embodied as a server or database, aspects of input/output module 156 may be reduced as compared to

embodiments where control module 150 is implemented as an end-user machine or other type of device designed for complex user interactions. In some embodiments (like other components discussed herein), input/output module 156 may even be eliminated from control module 150. Input/output module may be in communication with the memory, communications module 155, and/or any other component(s), such as via a bus. One or more than one input/output module and/or other component can be included in control module 150.

Examples

The following non-limiting examples are provided of several multicomponent thermosetting resins in accordance with various embodiments of the present invention: Example 1 : MATERIAL EXTRUSION OF THIXOTROPIC, TWO-

COMPONENT FORMULATION:

FIG. 3 shows the components of the apparatus and their relative positions as detailed above. FIG. 4 shows the internal structure of the manifold 220 that is shown in FIG. 3. Two thixotropic mixtures were made to make a formulation that did not thermoset, which demonstrates that a thixotropic liquid with the right rheology can be printed on the test apparatus. The first mixture, PART A, consisted of 212.5g of water, 75 g of HDK® T30 supplied by Wacker® and 10 drops of McCormick® yellow food coloring. This mixture was placed on a blender and stirred on medium speed for 4 minutes. This mixture was then placed in a closed plastic container for 16 hours. The formulation gelled during this time. The second mixture, PART B, was made in a manner similar to the first except in place of yellow food coloring McCormick® red food coloring was used. This two-component formulation was printed on a Hyrel® 30M printer. An EMO 25 extrusion head 225 was placed in a first slot of the assembly and another EMO 25 extrusion head 225 was placed in a third slot of the assembly. Each of the two extrusion barrels were connected to a manifold 220 with tubing 235 made of polyfluoroethylene and the manifold 220 was placed in a second slot of the assembly. Attached to the manifold 220 was a mixing chamber 120 having a static mix tip, MXR® SP 20 AC, that was 5.9 inches long supplied by NordsonEFD Inc. The set up of the apparatus from Example 1 is shown in FIGS. 3-4.

With this set up of the Hyrel® 30M, the two-component formulation was printed in the shape of an ASTM D638 tensile specimen. The yellow PART A was placed in the barrel in slot # 1 and the red PART B was placed in the barrel in slot # 3. The settings for the EMO 25 extrusion head in slot # 1 are given in Table 1.

In the embodiment of Table 1, a pulse of the extrusion head is the smallest displacement that can be made with the pumps (e.g., extruder heads 225). In Example 1 , 1.6 pulses would displace 1 nl, and it is understood that the extrusion head may only pump in pulses that are integers. "Prime steps" may represent the number of pulses that the extrusion head performs before beginning a printing step (e.g., analogous to priming a pump). Depending upon the compressibility of the liquid, additional prime steps may be required (e.g., the more compressible a liquid is the more prime steps are needed).

Similarly, "unprime steps" may represent the number of pulses that the extrusion head may perform in the reverse direction at the end of printing steps. Unpriming may prevent liquid from leaving the extruder when it is not desired.

The settings for the EMO 25 extrusion head 225 in the third slot were the same except that Clone Head was 1 1. "Clone head" in the depicted embodiment indicates that the extruder head that is designated the "clone" may copy the commands given to the master head. In Example 1, the extruder head in the third slot slot is copying all the commands given to the extruder head in the first slot (e.g., position 1) on axis 1, where axis 1 is the only axis on the example apparatus. The tensile specimen was printed to the dimensions specified by ASTM D638 and the two components were thoroughly mixed to a uniform orange color.

Example 2: MATERIAL EXTRUSION OF THIXOTROPIC,

THERMOSETTING TWO-COMPONENT FORMULATION:

Two thixotropic mixtures were made to make a formulation that did thermoset. Preparation of PART A of the two-component, thermosetting formulation was performed by combining 261.3 grams of bisphenol A diglycidyl ether with 7.8 grams of HDK® H18 supplied by Wacker Chemie AG. This mixture was stirred with a stainless steel paddle at 292 rpm for 30 minutes and then stirred overnight at 90 rpm.

Preparation of PART B of the two-component, thermosetting formulation was performed by combining 249.3 grams of isophorone diamine with 39.9 grams of HDK® HI 8. This mixture was stirred with a stainless steel paddle at 300 rpm for one hour at which time the speed was increased to 410 rpm and the mixture was stirred an additional hour.

The same set up of the Hyrel® 30M as was used in Example 1 was used to print this thermosetting formulation. The two-component formulation was printed in the shape of an ASTM D638 tensile specimen. PART A was placed in the barrel in the first slot and PART B was placed in the barrel in the third slot. The settings for the EMO 25 extrusion head 225 in first slot are given in Table 2.

Feed rate (%) 0.69

Clone head off

The settings for the EMO 25 extrusion head 225 in the third slot are given in Table 3.

Table 3 : Settings for EMO 25 Extrusion Head in Slot # 1

Parameter Value

Layer Z (mm) 0.7

Build platform temperature (°C) 60

Pulses per nl 1.6

Prime steps 5000

Unprime steps 4000

Feed rate (%) 0.31

Clone head 11

The tensile specimen was printed to the dimensions specified by ASTM D638. The tensile specimen fully cured after 16 hours at ambient conditions.

Example 3 includes a thixotropic methyl methacrylate thermosetting resin in which component A is methyl methacrylate with cumene hydroperoxide and rheology modifiers and other additives and component B is methyl methacrylate with dimethylaniline and rheology modifiers and other additives. This system would be applied at room temperature.

Example 4 includes a thixotropic urethane resin in which component A is an isocyanate terminated urethane and rheology modifiers and component B is tri(hydroxyethyl)amine and rheology modifiers. This system would be applied at room temperature.

Example 5 includes a thixotropic epoxy resin in which component A is a bisphenol A epoxy and rheology modifiers and component B is an amine-terminated polyethylene oxide and rheology modifiers. This system would be applied to the build platform at a temperature between 40°C and 60°C. Example 6 includes a thixotropic phenolic-azetidinium resin in which component A is a phenol formaldehyde resin at a pH>10 with the addition of sodium hydroxide and rheology modifiers and component B is a polyamidoamine-epichlorohydrin adduct and rheology modifiers. This system would be applied to the build platform at a temperature between 40°C and 60°C.

Conclusion

It is to be noted that the term "a" or "an" entity refers to one or more of that entity; for example, "a nanoparticle" is understood to represent one or more

nanoparticles. As such, the terms "a" (or "an"), "one or more," and "at least one" can be used interchangeably herein.

Throughout this specification and the claims, the words "comprise," "comprises," and "comprising" are used in a non-exclusive sense, except where the context requires otherwise.

As used herein, the term "about," when referring to a value is meant to encompass variations of, in some embodiments ± 20%, in some embodiments ± 10%, in some embodiments ± 5%, in some embodiments ± 1%, in some embodiments ± 0.5%, and in some embodiments ± 0.1% from the specified amount, as such variations are appropriate to perform the disclosed methods or employ the disclosed compositions.

Further, when an amount, concentration, or other value or parameter is given as either a range, preferred range, or a list of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Where a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints thereof, and all integers and fractions within the range. It is not intended that the scope of the presently disclosed subject matter be limited to the specific values recited when defining a range.

All publications and patent applications mentioned in the specification are indicative of the level of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the foregoing list of embodiments and appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.