Multi-component additive manufacturing device

Abstract

An additive manufacturing apparatus that mixes a plurality of co-reactive components and extrudes a printable thermoset composition. The additive manufacturing apparatus includes: at least three pumping assemblies, each of the at least three pumping assemblies configured to dispense a respective printable component; a mixing assembly fluidly coupled to each of the at least three pumping assemblies, the mixing assembly comprising: a mixing volume; and a mechanical mixer, the mechanical mixer being positioned within the mixing volume; and a printing nozzle, fluidly coupled to the mixing assembly, configured to extrude the printable component during an additive manufacturing process.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 63 / 485,140, ​​filed on February 15, 2023, entitled “MULTI-COMPONENT ADDITIVE MANUFACTURING DEVICE,” which is incorporated by reference in its entirety.

[0003] Government licensing rights

[0004] This invention was made with government support under Contract No. W911NF-17-2-0227 (U.S. Army Research Laboratory). The government may have certain rights in this invention. Technical Field

[0005] The present disclosure relates to an additive manufacturing apparatus that mixes multiple co-reactive components and extrude a printable composition. Background Art

[0006] 3D printing is a process for creating objects from curable compositions, such as plastics. Curable compositions can be made from thermosetting compositions. During the printing of an object using a thermosetting composition, at least two co-reactive components are mixed together to produce a co-reactive composition. Thermosetting compositions can be used in ambient reactive extrusion (ARE) printing, in which the co-reactive composition is deposited onto a print platform using an additive manufacturing device and cured under ambient conditions.

[0007] Different co-reacting components produce different thermosetting compositions with different physical properties. Loading different co-reacting components into an additive manufacturing device to create a 3D object made of multiple thermosetting compositions can be very time consuming. Summary of the Invention

[0008] The present disclosure provides an additive manufacturing device, which includes at least three pumping assemblies, each of the at least three pumping assemblies being configured to dispense a corresponding printable component; a mixing assembly, which is fluidly connected to each of the at least three pumping assemblies, and the mixing assembly includes: a mixing volume; at least three fluid channels, wherein each of the at least three fluid channels is fluidly connected to one of the at least three pumping assemblies, and the corresponding printable component dispensed by each of the at least three pumping assemblies flows into the mixing volume through the fluid channel fluidly connected to the pumping assembly; and a mixer, which is positioned within the mixing volume and is configured to mix the printable components dispensed from the at least three pumping assemblies; a printing nozzle, which is fluidly connected to the mixing assembly and configured to extrude the printable component during an additive manufacturing process.

[0009] The present disclosure also provides a mixing assembly for use in an additive manufacturing process, the mixing assembly comprising: a mixing volume; at least three passages, the at least three passages being fluidly coupled to the mixing volume, wherein each of the at least three passages delivers a printable composition into the mixing volume; and a mixing device, wherein at least two of the printable compositions delivered by the at least three passages contain co-reactive components that react and cure under ambient conditions, and during the additive manufacturing process, the at least two co-reactive components are delivered to the mixing assembly substantially simultaneously and mixed by the mixing assembly before being discharged from the mixing assembly.

[0010] The present disclosure also provides a method of additive manufacturing, comprising: combining a first co-reacting component and a second co-reacting component in a mixing assembly, the first co-reacting component and the second co-reacting component reacting to form a first printable composition; extruding the first printable composition from the mixing assembly through a printing nozzle; flushing the printing nozzle with a non-co-reacting component; combining a third co-reacting component and a fourth co-reacting component in the mixing assembly, the third co-reacting component and the fourth co-reacting component reacting to form a second printable composition; and extruding the second printable composition through the printing nozzle.

[0011] The present disclosure also provides a method of additive manufacturing, comprising: combining a first co-reactive component and a second co-reactive component in a mixing assembly, the first co-reactive component and the second co-reactive component reacting to form a first printable composition; extruding the first printable composition from the mixing assembly through a printing nozzle; combining the first co-reactive component and a third co-reactive component in the mixing assembly, the first co-reactive component and the third co-reactive component reacting to form a second printable composition, the second printable composition sharing co-reactive chemical properties with the first printable composition; and extruding the second printable composition through the printing nozzle. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view of the additive manufacturing device;

[0013] Figure 2 yes Figure 1 Bottom view of the additive manufacturing device;

[0014] Figure 3 yes Figure 1 A front perspective view of an additive manufacturing device;

[0015] Figure 4 It is along Figure 3 A cross-sectional view of an additive manufacturing device along axis A;

[0016] Figure 5 It is along Figure 3 A cross-sectional view of an additive manufacturing device along axis A;

[0017] Figure 6 yes Figure 1 5. A front perspective view of a hybrid assembly within a diamond mount of an additive manufacturing apparatus;

[0018] Figure 7 yes Figure 6 A top perspective view of a diamond mount;

[0019] Figure 8 yes Figure 1 A perspective view of an impeller of an additive manufacturing device;

[0020] Figure 9 Is for display use Figure 1 A flowchart of a method for printing a 3D object using an additive manufacturing device; and

[0021] Figure 10 Is for display use Figure 1 Flowchart of a method for printing a 3D object using an additive manufacturing device. DETAILED DESCRIPTION

[0022] The present disclosure provides an additive manufacturing apparatus and a method for manufacturing a 3D-printed object using the apparatus.

[0023] I. definition

[0024] For the purpose of the following detailed description, it should be understood that the present disclosure may take various alternative changes and step sequences, unless expressly indicated to the contrary. In addition, except in any operating examples, or where otherwise indicated, all numerals used in the specification and claims to represent, for example, the amount of an ingredient should be understood to be modified by the term "about" in all cases. For example, the numerical range provided for the weight percentage of a component or the amount of an added component should be interpreted as being modified by the term "about". Therefore, unless indicated to the contrary, the numerical parameters set forth in the following specification and the appended claims are approximate values ​​that may vary according to the desired properties to be obtained by the present disclosure. At least, and not attempting to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be interpreted in light of the number of reported significant figures and by applying usual rounding techniques.

[0025] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the disclosure are approximations, the numerical values ​​set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0026] Furthermore, it should be understood that any numerical range recited herein is intended to include all subranges subsumed therein. For example, a range of "1 to 10" is intended to include all subranges from the recited minimum value of 1 to the recited maximum value of 10 (and including both the minimum and maximum values), i.e., having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0027] The use of the singular encompasses the plural, and the plural encompasses the singular, unless expressly stated otherwise. Furthermore, the use of "or" means "and / or" unless specifically stated otherwise, even though "and / or" may be explicitly used in some instances.

[0028] "Polymer" and "polymeric" refer to oligomers, homopolymers (eg, prepared from a single monomeric species), copolymers (eg, prepared from at least two monomeric species), terpolymers (eg, prepared from at least three monomeric species), and grafted polymers.

[0029] "Printing" refers to any process in which one material is deposited onto and / or reacts with another material and / or itself, such as three-dimensional printing.

[0030] "Co-reactive composition" refers to a composition comprising at least two different compounds that are capable of chemically reacting with each other to form a covalent bond.

[0031] "Co-reactive component" refers to a compound comprising at least one reactive functional group that reacts when combined with a chemically compatible functional group to form a co-reactive composition.

[0032] "Reactive functional group" refers to a chemical group that is capable of chemically reacting with another reactive functional group to form a covalent bond.

[0033] "Reactive compound" refers to a compound that includes at least one reactive functional group.

[0034] "Extrusion" refers to a process for creating objects in which material is pushed through a die. The extrusion die has a shape and size suitable for building the object. The extrusion die can have a fixed shape or a shape that can change during extrusion.

[0035] "Filler" refers to any compound added to a reactive compound or a co-reactive composition that is unreactive with at least a portion of the compound and / or composition. Fillers, as used herein, encompass particulates, fibers, slurries, mixtures, and any other compounds, and combinations thereof, that can be added to a reactive compound and / or a co-reactive composition.

[0036] "ARE" or ambient reactive extrusion refers to any additive manufacturing of a co-reactive composition that includes a co-reactive component.

[0037] "Environmental conditions" refers to the typical conditions of an indoor temperature-controlled environment. In this article, environmental conditions can describe an environment experiencing typical ambient temperature, atmospheric pressure and / or relative humidity values ​​of the interior space of a building, such as a temperature value as low as 20°C, 21°C or 22°C, as high as 28°C, 29°C or 30°C, or between any of the two aforementioned values ​​used as endpoints, such as 20°C to 30°C or 22°C to 27°C; an atmospheric pressure value as low as 0.85atm, 0.90atm, as high as 1.0atm or 1.05atm, or between any of the two aforementioned values ​​used as endpoints, such as 0.85atm to 1.05atm and 0.95atm to 1.0atm; and / or a relative humidity value as low as 25%, 35%, 45% or 50%, as high as 55%, 80% or 95%, or between any of the aforementioned values ​​used as endpoints, such as 25% to 95%, 40% to 80%, or 50% to 75%.

[0038] II. Co-reaction chemical properties

[0039] Additive manufacturing using co-reactive compositions, also known as ambient reactive extrusion or ARE-type 3D printing, typically utilizes at least two components that react (e.g., co-react) with each other. A first co-reactive component (sometimes referred to herein as a first reactant group, a first reactive functional group, Part A, and / or a first printable reactive component) and at least one second co-reactive component (sometimes referred to herein as a second reactant group, a second reactive functional group, Part B, and / or a second co-reactive component) chemically react with each other when extruded in combination and / or in a continuous manner to form a co-reactive composition (sometimes referred to herein as a printable composition). The co-reactive composition can then be cured under ambient conditions, or, depending on the chemical nature of the reaction, with the assistance of, for example, heat, actinic radiation (e.g., ultraviolet radiation), a catalyst, or post-extrusion curing agent addition, to form an object or portion of an object comprising a thermosetting polymer (sometimes referred to as a thermoset), a thermoplastic polymer, or a combination thereof. Those skilled in the art select at least the first co-reactive component and the second co-reactive component to obtain the desired final product (e.g., a thermoset, a thermoplastic, etc.).

[0040] A three-dimensional object formed from a co-reactive composition is additively manufactured by extruding the co-reactive composition in an at least partially reacted state onto a surface, such as a build platform. The co-reactive composition can be in an at least partially reacted state upon extrusion, and then fully react and solidify to form a layer of the co-reactive composition. Successive layers of the same or different co-reactive compositions can be deposited to form additional layers of material. The co-reactive composition can at least partially react when the co-reactive components are not immediately brought together (such as in a mixing volume) prior to extrusion. Alternatively, the two co-reactive components can be pre-mixed prior to extrusion and treated in a manner that prevents reaction (e.g., prevents solidification of the co-reactive composition), such as by freezing the composition during mixing.

[0041] It may be desirable to select the chemical properties of each layer of the deposited co-reactive composition to form covalent bonds between successive layers of material. Furthermore, different portions of an article may be printed from different co-reactive compositions (e.g., a first co-reactive composition is printed to form a first portion of an object, such as a base portion, an internal structure, etc., and a second co-reactive composition is printed to form a second portion of the object), and depending on the chemical reactivity between the different co-reactive compositions, covalent bonds may also form between different materials.

[0042] Specifically, articles can be printed to have a rigid portion and a flexible portion, a rigid portion and a foam-like portion, a tactile portion and a rigid and / or flexible portion, two portions comprising different densities, one or more conductive portions, one or more thermally / electrically conductive portions, two or more different colors, two or more different rheological profiles, two or more different materials comprising different affinities for water and / or solvents, etc. Articles can also be printed such that the co-reactant composition is deposited onto an existing article (e.g., other thermosets and / or thermoplastics, metals, wood, composites, ceramics, etc.), thereby producing an article comprising both the co-reactant composition and a non-co-reactant composition.

[0043] Due to the covalent bonding between printed layers, additive manufacturing as described herein can result in objects with greater strength, particularly along the Z (e.g., vertical) axis, compared to other extruded or printed parts. Strong intra- and inter-layer covalent bonding not only produces stronger parts, but also more uniform part geometry; that is, fewer printed lines and / or parts have different variations. The ability to form objects with multiple substrates and / or parts containing different co-reactive or non-co-reactive compositions in one process is another advantage.

[0044] Suitable co-reactive compositions and the co-reactive components that can form them are described in Table 1. These co-reactive compositions can be printed by any of the methods described herein (alone or in combination) to form three-dimensional objects.

[0045]

[0046]

[0047]

[0048] Another advantage of additive manufacturing using co-reactive compositions may be that the co-reactive compositions can be three-dimensionally printed at relatively low viscosities. Thus, relatively large amounts (e.g., high relative weight percentages) of additives and / or fillers can be included in the co-reactive components while maintaining a printable viscosity. Both the type and / or amount of additives can be selected or "tuned" to obtain the desired chemical and / or physical properties of the printed article. The co-reactive compositions can be tuned by adding additives and / or fillers to obtain desired mechanical properties (e.g., strength, elasticity, stiffness, sag resistance, etc.), surface properties (e.g., hardness, texture, smoothness, etc.), chemical resistance (e.g., solvent resistance, etc.), thermal resistance (including flame retardancy, etc.) or thermal conductivity, and / or electrical insulation or electrical conductivity. The co-reactive compositions can also be tuned by adding one or more catalyst / activator / promoter additives to any printable co-reactive component to obtain desired reaction kinetics, such as reaction rate.

[0049] Table 2 describes additives that may be included in any co-reaction composition, such as those described in Table 1. Depending on the desired chemical and / or physical properties of the resulting object, additives may be included in either or both of the first co-reaction component and the second co-reaction component (e.g., either or both of Part A / Part B). In this case, Table 2 describes specific additives and fillers that may be suitable for ambient reactive extrusion-based three-dimensional printing, but Table 2 is non-limiting. Thus, other additives may be included in the co-reaction composition, such as those known to those skilled in the coating, extrusion, and thermoplastic arts.

[0050]

[0051]

[0052]

[0053] Any suitable combination of co-reaction composition and optional additives / fillers can be printed using a three-dimensional printing system suitable for mixing and extruding raw materials. Two or more positive displacement pumps (e.g., positive displacement pumps, progressive cavity pumps, etc.) can each discharge two co-reaction components associated with the co-reaction composition in a combined or continuous manner (e.g., a first reaction component discharged by a first metering pump and a second co-reaction component discharged by a second metering pump) pumped into a mixing volume. In some cases, the mixing volume can include mechanical (e.g., driven) mixing characteristics. Upon entering the mixing volume, the first and second co-reaction components begin to mix and react, and are then extruded through the extrusion printing nozzle in an at least partially reacted state. Once extruded, the two co-reaction components further react and cure. As described above, the reaction can be carried out under ambient conditions, or UV light can be used to accelerate ambient curing to form a thermosetting material, a thermoplastic material, or a combination thereof. The printable thermosetting co-reaction composition can be exposed to UV light to accelerate curing during printing, before printing, after printing, before any cleaning steps, during the cleaning steps, and / or after the cleaning steps.

[0054] III. Multi-component additive manufacturing device

[0055] Conventional two-printhead devices can only print one co-reactive composition at a time. With some devices, users may need to replace or switch printheads in order to print 3D objects made from multiple co-reactive compositions. Alternatively, users may even need multiple two-printhead devices to print 3D objects made from multiple printable compositions. The disclosed additive manufacturing device can print multiple co-reactive compositions, such as the co-reactive compositions described above, simultaneously and / or sequentially to achieve objects with multiple physical properties (such as texture, elasticity, hardness, etc.). The versatility of the disclosed additive manufacturing device has the following benefits: increased speed of multi-composition printing due to the lack of need to switch printheads; reduced costs due to the need for only one device to print multiple compositions; and the fact that multiple printable compositions are printed in rapid succession allows different printing compositions to combine while in liquid form so that they react with each other and solidify at the boundaries between the compositions.

[0056] The additive manufacturing apparatus 10 of the present application is designed to hold a plurality of pumping assemblies 20 of co-reactive components used in additive manufacturing, such as Figures 1 to 3 Different co-reactive components share co-reactive chemical properties with each other. These co-reactive components can be combined to form a printable composition. Each printable composition is made from a combination of at least two of the printable co-reactive components. The additive manufacturing device 10 is configured to print any of the printable compositions described in Section II using any of the printable co-reactive components discussed above.

[0057] The additive manufacturing apparatus 10 of the present application may include at least three pumping assemblies 20, a mixing assembly 30, and a printing nozzle 60. The apparatus 10 may include a top mount 8 that supports each of the at least three pumping assemblies 20 and removably couples the additive manufacturing apparatus 10 to a 3D printer. Each of the at least three pumping assemblies 20 may be configured to dispense a co-reactive component into the mixing assembly 30. Additionally, one of the at least three pumping assemblies 20 may include a flushing medium to be dispensed between printing of different printable compositions by the additive manufacturing apparatus 10. The additive manufacturing apparatus 10 is configured to dispense multiple co-reactive components from the at least three pumping assemblies 20 into the mixing assembly 30. The printable co-reactive components may be mixed in the mixing assembly 30 to form a printable composition. The printable composition may be extruded from the mixing assembly 30 through the printing nozzle 60. The printing nozzle 60 may deposit the printable composition to form a 3D object. Each of the components comprising the additive manufacturing apparatus 10 and the method of printing are discussed in more detail below.

[0058] A. Pumping components

[0059] At least three pumping assemblies 20 can be removably coupled to the diamond mount 40 of the additive manufacturing apparatus 10 of the present disclosure. Each of the at least three pumping assemblies 20 is fluidically coupled to a source of a corresponding co-reactive component. The corresponding co-reactive component is discharged into the fluid channel 34 through the distal end of each of the at least three pumping assemblies 20. The fluid channel is discussed in more detail below. Figures 6 and 7 As shown, the diamond mount 40 includes at least three orifices 36 that correspond to and receive the distal ends of the at least three pumping assemblies 20. The diamond mount 40 can be configured to connect the distal ends of the at least three pumping assemblies 20 to the fluid channel 34 so that the discharged co-reactive components flow from the at least three pumping assemblies 20 into the fluid channel 34. Mounting holes 46 can be arranged on the diamond mount 40 so that the diamond mount 40 can be removably coupled to the mount to provide stability to the additive manufacturing device 10. The at least three pumping assemblies 20 can be angled relative to the axis A, such as Figure 3 Between the support of the top mount 8 and the support of the diamond mount 40 of the at least three pumping assemblies 20, the at least three pumping assemblies are angled so that the distal end of each of the at least three pumping assemblies points towards the axis A.

[0060] refer to Figures 1 to 5 Each of the at least three pumping assemblies 20 includes a positive displacement pump, such as a screw pump 22. To prevent backflow, the screw pump 22 can be configured similar to a screw. Due to the design of the screw pump 22, as the printable co-reactive component is expelled, the flow can only move in the discharge direction. Additionally, the screw pump 22 can meter the flow to a given volume dose. Alternatively, any cartridge-type, pen-type, or other co-reactive composition extruder can be used in the pumping assembly 20.

[0061] like Figures 1 to 3 As can be seen in FIG, the additive manufacturing apparatus 10 may include a first screw pump 22a, a second screw pump 22b, a third screw pump 22c, a fourth screw pump 22d, and a fifth screw pump 22e, each containing a different co-reactive component. Figures 1 to 3 A configuration of five progressive cavity pumps 22 is illustrated, but it should be understood that the additive manufacturing apparatus 10 may be adapted to include only four progressive cavity pumps, or alternatively, only three progressive cavity pumps.

[0062] The first screw pump 22a can coordinate with the second screw pump 22b, which also discharges the second co-reacting component, to discharge the first co-reacting component. Similarly, the third screw pump 22c can coordinate with the fourth screw pump 22d, which also discharges the fourth co-reacting component, to discharge the third co-reacting component. The fifth screw pump 22e can coordinate with at least one of the first, second, third, or fourth screw pumps 22a-22d to discharge the fifth co-reacting component. Alternatively, any of the screw pumps 22 can include a flushing medium. To clean the additive manufacturing apparatus, the flushing medium can be discharged from the screw pump 22 between printing different printable compositions.

[0063] B. Hybrid components

[0064] refer to Figures 4 to 6 A mixing assembly for an additive manufacturing apparatus 10 is provided. Located downstream of the pumping assembly 20 within a diamond mount 40, the mixing assembly 30 may include a mixing volume 32, at least three fluid channels 34, and a mixer 38. The at least three fluid channels 34 fluidly connect each of the progressive cavity pumps 22 to the mixing volume 32. The configuration of the at least three fluid channels 34 may be adapted for any assembly such that the discharged co-reactant composition flows through the at least three fluid channels 34 into the mixing volume 32. The mixing volume 32 may be cylindrical in shape or any other geometric shape adapted to capture the discharged co-reactant composition. The geometry of the mixing volume 32 may depend on the nature or volume of the discharged co-reactant composition, or the available space within the diamond mount 40.

[0065] The timing of the arrival of the printable co-reactive components into mixing volume 32 can affect the reaction between the co-reactive components. Residence time refers to the time that elapses between the entry of one co-reactive component into mixing volume 32 and the entry of another co-reactive component into mixing volume 32 for mixing into a printable composition. The residence time between one co-reactive composition and another co-reactive composition can be less than 5 seconds. The progressive cavity pump 22, containing the printable co-reactive components included in a given printable composition, dispenses the printable co-reactive components such that the printable co-reactive components are present in mixing volume 32 simultaneously or enter mixing volume 32 from passage 34 within 5 seconds of each other. Once within mixing volume 32, the co-reactive components mix together to form a printable composition.

[0066] Within the mixing volume 32 is a mixer 38, Figure 4 and Figure 8 4. The impeller 42 is best seen in the drawing, such as an impeller 42. The impeller 42 may be a helical element having threads 44 that dynamically or statically mix the co-reactant compositions as the compositions enter the mixing volume 32. For dynamic mixing, the impeller 42 may be connected to a motor 6 such that the impeller 42 rotates within the mixing volume 32.

[0067] Dynamic mixing of the co-reactant composition by driving the impeller 42 can have certain advantages over static mixing. Generally speaking, mechanical mixing can result in more thoroughly mixed co-reactant compositions than static mixing (e.g., due to the driving properties of the impeller 42). In this case, the size of the mixing volume 32 can be relatively smaller than the mixing volume required for static mixing, thereby reducing the overall size of the additive manufacturing device 10 (e.g., reducing the size of the mixing volume 32). This relatively small size of the additive manufacturing device 10 can result in more stable printing because the amount of retained material within the additive manufacturing device 10 (e.g., the amount of material between the pumping assembly 20 and the print nozzle 60) is reduced, thereby increasing the granularity of the pumping rate control.

[0068] Additionally, the reaction rate between the printable co-reactive components can be more easily controlled by driving the impeller 42. Specifically, the drive speed of the impeller 42 (e.g., the resulting revolutions per minute (RPM) at which the impeller 42 spins) can be adjusted to achieve a target overall mixing rate. The RPM also affects the amount of material extruded from the print nozzle 60. Thus, the RPM can be tuned to simultaneously affect the degree of mixing and the extrusion rate, both of which affect the degree and rate of reaction of the printable co-reactive components.

[0069] Furthermore, the drive impeller 42 and the pumping assembly 20 can be controlled independently of one another. Thus, both the RPM and the pumping rate can be independently tuned, and the combination of the two can achieve any of the following: a desired degree of reaction of the printable co-reactive component, a target reaction rate of the printable co-reactive component, a resonance time of the material in the mixing volume 32, and / or an extrusion rate of the co-reactive composition from the mixing volume 32.

[0070] The additive manufacturing apparatus 10 can maintain the printable composition within the mixing volume for a period of time. The period of time can be 0 seconds, 1 second, 2 seconds, 3 seconds to 5 seconds, 6 seconds, 7 seconds, or any range using any two of the foregoing as endpoints, such as 0 seconds to 7 seconds, 1 second to 6 seconds, 2 seconds to 5 seconds, or 3 seconds to 4 seconds. Maintaining the printable composition within the mixing volume ensures that the printable co-reactive components are fully mixed and form a homogenous printable composition.

[0071] C. Print nozzle

[0072] The printable composition in the mixing volume 32 is extruded out of a print nozzle 60. The print nozzle 60 is removably coupled to a plug 62 that seals the distal end of the mixing volume 32. The plug 62 ensures that the printable composition does not leak from the mixing volume 32. The print nozzle 60 can be a variety of shapes to facilitate extrusion of the printable composition.

[0073] D. Flushing medium

[0074] Once the printable composition is extruded from the nozzle 60 to form a 3D object, the user may want to change the type of printable composition extruded from the additive manufacturing device 60. To ensure that the mixing assembly 30 is free of previously printed printable composition, a flushing medium may be pumped through one of the at least three pumping assemblies 20. The flushing medium may be a commercially available non-reactive medium configured to clear the printable composition from the mixing assembly 30. The flushing medium may be a flowable non-reactive composition such as, but not limited to, a hydrogel.

[0075] IV. Printing with an additive manufacturing device

[0076] The present disclosure provides a method for printing using an additive manufacturing apparatus 10 .

[0077] refer to Figure 9 , illustrates an additive manufacturing method for printing a 3D object using an additive manufacturing apparatus 10. Method 100 includes a combining step 102, an extrusion step 104, a rinsing step 106, a combining step 108, and an extrusion step 110. In combining step 102, a first co-reacting component and a second co-reacting component are combined in a mixing assembly. The printable co-reacting component can be any of the co-reacting components mentioned in Section II above. Prior to combining, the first and second co-reacting components can be held in corresponding pumping assemblies of the additive manufacturing apparatus. To combine the first and second co-reacting components, the components can be added to the mixing assembly and mixed using an impeller. Once combined, the first and second co-reacting components can react to form a first printable composition. Mixing parameters such as mixing time, mixing speed, mixing apparatus, temperature, and / or pressure can vary depending on operating parameters or desired product parameters, such as the amount and type of co-reacting components used, the volumes of the components in the mixture, the desired properties of the printable composition, the desired properties of the printed object, and any combination of the foregoing. The first printable composition can be any of the printable compositions mentioned above in Section II.

[0078] Extrusion step 104 involves extruding the first printable composition from the mixing assembly through a print nozzle onto a printing surface to form the 3D object. The printing surface can be a print bed or any other material. The speed at which the first printable composition is extruded from the mixing assembly can vary depending on the properties of the printable composition.

[0079] Continuing with printing the second printable composition, a flushing step 106 includes flushing the mixing assembly with a non-co-reactive component. The non-co-reactive component can be any commercially available flushing medium. The flushing medium can be maintained in a pumping assembly, similar to the first and second co-reactive components. Flushing step 106 removes residual printable composition or previous co-reactive components from the mixing assembly, thereby preventing contamination of the additional printable composition by the previous co-reactive component or printable composition.

[0080] To accelerate curing, the printable co-reactive composition can optionally be exposed to UV light during printing, before printing, after printing, before the washing step, during the washing step, and / or after the washing step.

[0081] During the combining step 108, the third and fourth co-reacting components are combined in a mixing assembly. The printable co-reacting component can be any of the printable co-reacting components mentioned in Section II above. Prior to combining, the third and fourth co-reacting components can be held in corresponding pumping assemblies of the additive manufacturing device. To combine the third and fourth co-reacting components, the components can be added to the mixing assembly and mixed using an impeller. Once combined, the third and fourth co-reacting components can react to form a second printable composition. Similar to the first printable composition, the mixing parameters can vary depending on the properties of the printable co-reacting component and the second printable composition. The second printable composition can also be any of the printable compositions mentioned in Section II above.

[0082] Extrusion step 110 includes extruding the second printable composition from the mixing assembly through a print nozzle and onto the printing surface. The speed at which the second printable composition is extruded from the mixing assembly can vary depending on the properties of the printable composition. The second printable composition can be extruded onto the already deposited first printable composition, such that the first printable composition and the second printable composition become a 3D printed object. The second printable composition can be deposited onto the first printable composition faster than the first printable composition can fully cure. If the first printable composition is not fully cured, the first and second printable compositions can react at the boundary between the first and second printable compositions to form a single 3D printed object. In addition, to accelerate curing, the second printable composition can be exposed to UV light during printing, before printing, after printing, before the rinsing step, during the rinsing step, and / or after the rinsing step.

[0083] Continuing to print the printable composition, method 100 may optionally include a second rinsing step 112. Rinsing step 112 may include rinsing the mixing assembly with a rinsing medium, similar to rinsing step 106. Furthermore, method 100 may optionally be repeated to fully complete the desired 3D printed object. A 3D object printed using method 100 may include multiple printable compositions printed in rapid succession from the same additive manufacturing device. By rinsing the mixing assembly between printing different printable compositions, method 100 can print different printable compositions free from contaminants from each printable composition.

[0084] The 3D printed object created using method 100 can be made from multiple printable compositions. Due to the speed with which multiple printable compositions can be printed using method 100, the final 3D printed object can be made from printable compositions that react with each other and form a multi-printable composition 3D object.

[0085] The present disclosure provides a second method of printing using the additive manufacturing apparatus 10 .

[0086] refer to Figure 10 , illustrates an additive manufacturing method for printing a 3D object using an additive manufacturing apparatus 10. Method 200 includes a combining step 202, an extruding step 204, a combining step 206, and an extruding step 208. In combining step 202, a first co-reacting component and a second co-reacting component are combined in a mixing assembly. The printable co-reacting component can be any of the printable co-reacting components mentioned in Section II above. Prior to combining, the first and second co-reacting components can be held in corresponding pumping assemblies of the additive manufacturing apparatus. To combine the first and second co-reacting components, the components can be added to the mixing assembly and mixed using an impeller. Once combined, the first and second co-reacting components can react to form a first printable composition. Mixing parameters such as mixing time, mixing speed, mixing apparatus, temperature, and / or pressure can vary depending on operating parameters or desired product parameters, such as the amount and type of co-reacting components used, the volumes of the components in the mixture, the desired properties of the printable composition, the desired properties of the printed object, and any combination of the foregoing. The first printable composition can be any of the printable compositions mentioned above in Section II.

[0087] Extrusion step 204 involves extruding the first printable composition from the mixing assembly through a print nozzle onto a printing surface to form the 3D object. The printing surface can be a print bed or any other material. The speed at which the first printable composition is extruded from the mixing assembly can vary depending on the properties of the printable composition.

[0088] In a combining step 206, the third co-reacting component is combined with the first co-reacting component in a mixing assembly. The printable co-reacting component can be any of the printable co-reacting components mentioned in Section II above. Prior to combining, the third co-reacting component can be retained in a pumping assembly of the additive manufacturing device. Each pumping assembly of the additive manufacturing device can contain a co-reacting component. The first co-reacting component can react with each of the other co-reacting components to form a different printable composition. That is, each co-reacting component reacts with the first co-reacting component to form a corresponding printable composition. The first, second, third, fourth, and fifth co-reacting components can be retained in corresponding pumping assemblies.

[0089] Referring back to step 206, to combine the first and third co-reactive components, the components can be added to a mixing assembly and mixed using an impeller. Once combined, the first and third co-reactive components can react to form a second printable composition. Similar to the first printable composition, the mixing parameters can vary depending on the properties of the printable co-reactive components and the second printable composition. The second printable composition can also be any of the printable compositions mentioned in Section II above.

[0090] Extrusion step 208 involves extruding the second printable composition from the mixing assembly through a print nozzle onto a printing surface to form the 3D object. The printing surface can be a print bed or any other material. The speed at which the first printable composition is extruded from the mixing assembly can vary depending on the properties of the printable composition.

[0091] The second printable composition can be extruded onto the deposited first printable composition, such that the first printable composition and the second printable composition become a single 3D printed object. The second printable composition can be deposited onto the first printable composition faster than the first printable composition can fully cure. If the first printable composition is not fully cured, the first printable composition and the second printable composition can react at the boundary between the first printable composition and the second printable composition to form a single 3D printed object.

[0092] Method 200 may optionally include a rinsing step 210, which comprises rinsing the mixing assembly with a non-co-reactive component. The non-co-reactive component may be the rinsing medium described previously. Flushing step 210 can remove any residual printable composition or previously used co-reactive component from the mixing assembly, thereby preventing contamination of additional printable compositions by previously used co-reactive components or printable compositions. Step 210 is not required but may be included as desired. Additionally, method 200 may be optionally repeated to form multiple printable composition 3D objects.

[0093] Examples

[0094] Aspects of the present disclosure are further illustrated by reference to the following examples. It will be apparent to those skilled in the art that many modifications, both to materials and methods, can be made without departing from the scope of the present disclosure.

[0095] Example 1 - In-line composition variation using ARE 3D printing

[0096] Each of the five printhead pumps was loaded with a different formulation to allow two unique thermosetting compositions to be printed into a single 3D printed part, as shown in Table 3. To print the first composition, Pump 1 was loaded with the first amine formulation (Formulation A), and Pump 2 was loaded with the first isocyanate formulation (Formulation C). The first section of the part was printed by metering the formulations from Pumps 1 and 2 in a fixed volume ratio through a mixer to produce the first thermosetting composition. The first composition was deposited on the print bed according to a predefined tool path until the part section was completed. The print head then moved to a defined purge position. The purge compound loaded from Pump 3 was then metered through the mixer to remove all of the first composition from the print head. Once the purge was complete, the print head returned to the area on the print bed where the second section of the part could be printed. The second section was printed by metering a second amine formulation (Formulation B) from Pump 4 and a second isocyanate formulation (Formulation D) from Pump 5 through a mixer at a fixed volume ratio to produce a second thermoset composition. The second composition was deposited onto the print bed following a predefined tool path to complete the final part in conjunction with the first section. Each individual printing step was performed under ambient conditions, while the final multi-composition part was cured at 71°C for 48 hours.

[0097] Table 3: Multi-pump loading according to Example 1

[0098]

[0099] Table 4 lists various combinations of different printable compositions (eg, Formulations 2-45) that can be loaded into five printhead pumps and then printed according to the protocol described for Example 1.

[0100] Table 4: Example of multi-pump loading according to Example 1

[0101]

[0102]

[0103]

[0104]

[0105] Example 2 - On-demand material property adjustment using ARE 3D printing

[0106] The five printhead pumps were loaded with distinct formulations to achieve on-demand adjustment of the material properties of the 3D-printed part, as shown in Table 5. Pump 1 was loaded with isocyanate formulation E, and pumps 2-5 were each loaded with amine formulations AD. At the start of printing, the first section was printed by metering formulations AD relative to formulation E through a mixer at a defined volume ratio to produce a first thermoset composition with known material properties. At the end of the first section, the second section was printed by varying the ratio of formulations AD relative to formulation E; thereby, a second thermoset composition with different material properties from the first thermoset composition was formed. This process was repeated two more times to create third and fourth thermoset compositions for the third and fourth sections of the printed part. This resulted in a 3D-printed part with four sections, each with different material properties. Each individual printing step was performed under ambient conditions, with the final multi-composition part cured at 71°C for 48 hours.

[0107] Table 5: Multi-pump loading according to Example 2

[0108]

[0109] Table 6 shows various combinations of different printable compositions (eg, Formulations 47-65) that can be loaded into five printhead pumps and then printed according to the protocol described with respect to Example 2.

[0110] Table 6: Example of multi-pump loading according to Example 2

[0111]

[0112]

[0113]

[0114] Example 3 - ARE 3D printing using a multi-component additive manufacturing device

[0115] In this example, five printhead pumps were loaded with different formulations to achieve on-demand adjustment of the material properties of 3D-printed components, as shown in Table 7. Printable co-reactive components were combined in different configurations to produce printable compositions comprising a single printable co-reactive chemical property. However, the physical properties of the printable composition varied depending on the formulation of the printable co-reactive components in each pump used. For example, during a first print, isocyanate formulation A and amine formulation C were mixed to produce a first polyurea thermoset composition having a first set of properties. However, during a second print, isocyanate formulation B and amine formulation D were mixed to produce a second polyurea thermoset composition having a second set of properties. Furthermore, during a third print, isocyanate formulation A and amine formulation E were mixed to produce a third polyurea thermoset composition having a third set of properties. The first, second, and third sets of properties can differ in terms of the tensile strength, elasticity, flexibility, and other desired physical properties of the printable composition based on the formulation of each printable co-reactive component. Each individual printing step was performed under ambient conditions, while the final multi-composition part was cured at 71°C for 48 hours.

[0116] Table 7: Example of multi-pump loading according to Example 3

[0117]

[0118] Table 8 shows various combinations of different printable compositions (eg, Formulations 67-83) that can be loaded into five printhead pumps and then printed according to the protocol described with respect to Example 3.

[0119] Table 8: Example of multi-pump loading according to Example 3

[0120]

[0121]

[0122]

[0123] Example 4 - UV curing 3D printing using a multi-component additive manufacturing device

[0124] Each of the five printhead pumps was loaded with a distinct formulation to allow two unique printable thermoset compositions to be printed into a single 3D-printed part, as shown in Table 9. To print the first printable thermoset composition, Pump 1 was loaded with the first vinyl (or allyl) ether formulation (Formulation A), and Pump 2 was loaded with the first thiol formulation (Formulation B). The first section of the part was printed by metering the formulations from Pumps 1 and 2 at a fixed volume ratio through a mixer to produce the first thermoset composition. The first composition was deposited onto the print bed following a predefined tool path until the part section was complete. Shortly after extrusion of the mixed two-component material, the material was exposed to a UV wavelength (395 nm), which cured the extruded polymer matrix within seconds. The print head then moved to a defined purge position. The purge compound loaded from Pump 3 was then metered through the mixer to remove all of the first composition from the print head. Once the purge was complete, the print head returned to the area of ​​the print bed where the second section of the part would be printed. The second section is printed by metering a second vinyl (or allyl) formulation (Formulation C) in pump 4 and a second thiol formulation (Formulation D) in pump 5 through a mixer in a fixed volume ratio to produce a second printable thermoset composition. The second composition is deposited on the print bed according to a predefined tool path to complete the final part in conjunction with the first section. Shortly after extrusion of the mixed 2-component material, the material is exposed to a UV wavelength that cures the extruded polymer matrix within seconds. The final multi-composition part is then subjected to additional UV radiation (5 minutes to 30 minutes) to ensure complete curing of the polymer matrix throughout the part. Each individual printing step is performed under ambient conditions, while the final multi-composition part is cured at 71°C for up to 48 hours.

[0125] Table 9: Prophetic Example of Multi-Pump Loading According to Example 4

[0126]

[0127] Table 10 shows various combinations of different printable compositions (eg, Formulations 85-96) that can be loaded into five printhead pumps and then printed according to the protocol described with respect to Example 4.

[0128] Table 10: Prophetic Example of Multi-Pump Loading According to Example 4

[0129]

Claims

1. An additive manufacturing device comprising: at least three pumping assemblies, each pumping assembly of the at least three pumping assemblies being configured to dispense a respective printable component; a mixing assembly fluidly coupled to each of the at least three pumping assemblies, the mixing assembly comprising: Mixing volume; at least three fluid channels, wherein each of the at least three fluid channels is fluidly coupled to one of the at least three pumping assemblies, and the respective printable component dispensed by each of the at least three pumping assemblies flows into the mixing volume through the fluid channel fluidly coupled to the pumping assembly; and a mechanical mixer positioned within the mixing volume, the mixer configured to mechanically mix the printable components dispensed from the at least three pumping assemblies; and A print nozzle is fluidly coupled to the mixing assembly, the print nozzle being configured to extrude the printable composition during an additive manufacturing process.

2. The additive manufacturing apparatus of claim 1 , wherein each of the three pumping assemblies comprises a progressive cavity pump, each of the progressive cavity pumps being fluidly coupled to a source of the corresponding printable component.

3. The additive manufacturing apparatus according to any one of claims 1 or 2, wherein at least two of the printable components dispensed by at least two of the at least three pumping assemblies comprise co-reactive components; wherein each of the co-reactive components reacts with each other under ambient conditions during the additive manufacturing process.

4. The additive manufacturing apparatus according to any one of claims 1 to 3, wherein each of the at least three pumping assemblies dispenses a different printable component. 5 . The additive manufacturing apparatus according to claim 1 , wherein the at least three pumping assemblies include five pumping assemblies.

6. The additive manufacturing apparatus of claim 4 , wherein each of the different printable components comprises a first printable co-reactive component, a second printable co-reactive component, a third printable co-reactive component, and a fourth printable co-reactive component, and The first printable co-reactive component and the second printable co-reactive component react to form a first co-reactive composition, and the third printable co-reactive component and the fourth printable co-reactive component react to form a second co-reactive composition different from the first co-reactive composition.

7. The additive manufacturing apparatus of claim 6, wherein a first pumping assembly cooperates with a second pumping assembly that discharges the second printable co-reactive component to discharge the first printable co-reactive component; and The third pumping assembly cooperates with a fourth pumping assembly that discharges the fourth printable co-reactive component to discharge the third printable co-reactive component.

8. The additive manufacturing apparatus according to any one of claims 1 to 7, wherein one of the printable components discharged by the at least three pumping assemblies comprises a flushing medium.

9. The additive manufacturing apparatus of claim 8, wherein the flushing medium is discharged into the mixing assembly and discharges residual one or more printable components present in the mixing assembly.

10. A three-dimensional object additively manufactured by the additive manufacturing apparatus according to any one of claims 1 to 9.

11. A mixing assembly for use in an additive manufacturing process, the mixing assembly comprising: Mixing volume; at least three passages fluidly coupled to the mixing volume, wherein each of the at least three passages delivers a printable composition into the mixing volume; as well as Mechanical mixing device, and wherein at least two of the printable compositions delivered by the at least three passageways comprise printable co-reactive components that react and cure under ambient conditions, and during the additive manufacturing process, each of the printable co-reactive components is delivered to the mixing assembly substantially simultaneously and mixed by the mixing device before being discharged from the mixing assembly.

12. The mixing assembly of claim 11, wherein the at least three passages comprise five passages.

13. The mixing assembly of claim 12, wherein four of the five passages deliver four printable co-reactive components to the mixing volume.

14. A mixing assembly according to any one of claims 11 or 12, wherein one of the passages conveys a non-printable co-reactive component.

15. The mixing assembly of claim 11, wherein the five channels deliver five printable co-reactive components to the mixing volume, each of the five printable co-reactive components constituting the same co-reactive composition.

16. A three-dimensional object additively manufactured by the additive manufacturing apparatus according to any one of claims 11 to 15.

17. A method of additive manufacturing, comprising: combining a first printable co-reactive component and a second printable co-reactive component in a mixing assembly comprising a mechanical mixer, wherein the first printable co-reactive component and the second printable co-reactive component react to form a first printable composition; extruding the first printable composition from the mixing assembly through a print nozzle; flushing the print nozzle with a non-co-reactive component; mixing a third printable co-reactive component and a fourth printable co-reactive component in said mixing assembly comprising said mechanical mixer, said third printable co-reactive component and said fourth printable co-reactive component reacting to form a second printable composition; as well as The second printable composition is extruded through the printing nozzle.

18. A three-dimensional object additively manufactured by the additive manufacturing method according to claim 17.

19. A method of additive manufacturing, comprising: combining a first printable co-reactive component and a second printable co-reactive component in a mixing assembly comprising a mechanical mixer, wherein the first printable co-reactive component and the second printable co-reactive component react to form a first printable composition; extruding the first printable composition from the mixing assembly through a print nozzle; mixing the first printable co-reactive component and a third printable co-reactive component in the mixing assembly comprising the mechanical mixer, the first printable co-reactive component and the third printable co-reactive component reacting to form a second printable composition, the second printable composition sharing a co-reactive chemical property with the first printable composition; as well as The second printable composition is extruded through the printing nozzle.

20. A three-dimensional object additively manufactured by the additive manufacturing method according to claim 19.

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