Abstract: Scan strategies and post processing techniques are described for powder bed fusion additive manufacturing workflows using ultra-high molecular weight polyethylene (UHMWPE) powders. In one example, a method for fabricating a part includes generating a three-dimensional model for printing the part, loading the model into a controller of a powder bed fusion tool, generating a scan strategy for individual layers of the part based on the model, where the scan strategy includes a hatch spacing between scan lines in the individual layers, and forming an intermediate part from UHMWPE powder using the tool based on the scan strategy. The method can also include one or more post processing steps, such as heating the intermediate part in an oven at a temperature above the melt temperature of the UHMWPE powder for a period of time in an inert atmosphere, to finish the part.

Abstract: Binders and methods of binder jetting are provided based on the use of branched polymer binders. The applicants have found that, even more so than the molecular weight, the ability to achieve higher maximum printable concentrations leads to higher densities and improved structural properties of the manufactured articles. The methods can be used for a variety of articles from metal parts to structural ceramics, to tablets and other oral dosage forms. The branched chain polymers can include a short-chain branched polymer; a long-chained branched polymer; a hyper-branched polymer, a cyclic polymer; a comb-type polymer; a 3-arm star type polymer, a 4-arm star type polymer, a dendritic polymer, and a combination thereof. The branched-chain polymer can include various polymers such as polyvinylpyrrolidone, poly(vinyl alcohol), or poly(acrylic acid).

Abstract: In various aspects, top-down stereolithography apparatus and methods of use thereof are provided herein that allow for additive manufacturing of an article from a high-viscosity resin. The apparatus and methods can print resins having viscosities higher than conventional systems, e.g. viscosities up to about 100 Pa·s at the elevated temperature. The resin may have a room temperature viscosity of about 100 Pa·s, about 250 Pa·s, about 1000 Pa·s, or more. In some aspects, the resin is a solid at room temperature. The apparatus and methods do not rely upon solvents or other viscosity modifiers being added to the resin, and are capable of top-down additive manufacturing approaches which provide reduced stress on the printed article.

Abstract: Photocurable colloid binders are provided that overcome deficiencies associated with 3D printing of high molecular weight polymers via VAT photopolymerization. Methods of additive manufacturing are also provided using the binders. The approaches described herein effectively decouple the viscosity-molecular weight relationship by synthesizing and processing photo-reactive aqueous colloids that are sequestered within a photocrosslinkable scaffold. Sequestering polymers within discrete internal phases prevents inter-particle entanglement of the polymer chains, thus ensuring low viscosity. VP of polymer colloids results in a solid green body embedded with high molecular weight polymer particles. A post-processing heated drying step allows the polymers to coalesce and further entangle, forming a semi-interpenetrating network with mechanical performance of the high molecular weight material. The resins can further include inorganic particles such as silica and other ceramics, metal particles, and the like.

Abstract: Embodiments are described for forming regions of varying porosity within an additive manufacturing (AM) object through selective deposition of a binding agent during fabrication. Upon sintering, the selectively applied binding agent forms stochastic regions of porosity within the object that are not externally visible. In some implementations, embedded porous regions are selectively generated to form an identifier region that can be used as a unique part identification tag identifiable through non-destructive evaluation. The identifier tag may be useful in anti-counterfeiting security for parts fabricated through binding agent jetting (BT) and other additive manufacturing techniques.

Abstract: In various aspects, a polymer resin is provided for vat photopolymerization. The resin can include a polyamic acid salt formed from the addition of a photocrosslinkable amine to a polyamic acid. The resin can include a photoinitiator suitable for initiating crosslinking of the photocrosslinkable amine when exposed to a light source of a suitable wavelength and intensity. The polyamic acid can be formed, for instance, by the addition of a diamine to a suitable dianhydride. Methods of additive manufacturing using the resins are also provided.

Abstract: A method for fabricating an item using a high-viscosity photoresin is described that includes providing tooling that comprises an extruder and a light source: depositing. by the extruder of the tooling. a first non-patterned layer of the high-viscosity photoresin: selectively photocuring. by the light source of the tooling. the first non-patterned layer into a first predetermined layer shape: depositing. by the extruder of the tooling. a second nonpatterned layer of the high-viscosity photoresin: and selectively photocuring. by the light source of the tooling. the second non-patterned layer into a second predetermined layer shape.

Abstract: Polymer resins for the vat photopolymerization of thermoplastics are provided, in particular for the vat photopolymerization of thermoplastics with exception thermal stability and mechanical properties. In some aspects, the polymer resins are prepared by ring opening of an aromatic dianhydride with an alcohol containing an acrylate or methacrylate to produce a photocrosslinkable diacid monomer; conversion of the photocrosslinkable diacid monomer to a photocrosslinkable diacyl chloride; and polymerization of the photocrosslinkable diacyl chloride with an aromatic diamine to produce a photocrosslinkable precursor polymer. Upon crosslinking and drying, a thermal imidization can yield aromatic polyimide polymers with high yield and with micron-scale structural resolution.

Abstract: Disclosed are examples for optimizing topology and toolpath creation for multi-axis additive manufacturing. In some examples, layer-less multi-axis ME is achieved by propagating a support structure, propagating deposition paths aligned to arbitrary directions and following an orientation field for the given geometry, and explicitly ordering deposition paths to avoid collisions. In other examples, layer-less multi-axis ME is achieved by aligning extrudate in a three-dimensional space with the orientation field output by a topology optimization algorithm, planning a suitable support structure to enable multi-axis fabrication, and ordering the resulting deposition paths for collision-free fabrication. The created toolpaths can be transmitted to a multi-axis printer for printing.

Abstract: Polymer resins for the vat photopolymerization of thermoplastics are provided, in particular for the vat photopolymerization of thermoplastics with exception thermal stability and mechanical properties. In some aspects, the polymer resins are prepared by ring opening of an aromatic dianhydride with an alcohol containing an acrylate or methacrylate to produce a photocrosslinkable diacid monomer; conversion of the photocrosslinkable diacid monomer to a photocrosslinkable diacyl chloride; and polymerization of the photocrosslinkable diacyl chloride with an aromatic diamine to produce a photocrosslinkable precursor polymer. Upon crosslinking and drying, a thermal imidization can yield aromatic polyimide polymers with high yield and with micron-scale structural resolution.

Abstract: Photocurable colloid binders are provided that overcome deficiencies associated with 3D printing of high molecular weight polymers via VAT photopolymerization. Methods of additive manufacturing are also provided using the binders. The approaches described herein effectively decouple the viscosity-molecular weight relationship by synthesizing and processing photo-reactive aqueous colloids that are sequestered within a photocrosslinkable scaffold. Sequestering polymers within discrete internal phases prevents inter-particle entanglement of the polymer chains, thus ensuring low viscosity. VP of polymer colloids results in a solid green body embedded with high molecular weight polymer particles. A post-processing heated drying step allows the polymers to coalesce and further entangle, forming a semi-interpenetrating network with mechanical performance of the high molecular weight material. The resins can further include inorganic particles such as silica and other ceramics, metal particles, and the like.

Abstract: Photocurable colloid binders are provided that overcome deficiencies associated with 3D printing of high molecular weight polymers via VAT photopolymerization. Methods of additive manufacturing are also provided using the binders. The approaches described herein effectively decouple the viscosity-molecular weight relationship by synthesizing and processing photo-reactive aqueous colloids that are sequestered within a photocrosslinkable scaffold. Sequestering polymers within discrete internal phases prevents inter-particle entanglement of the polymer chains, thus ensuring low viscosity. VP of polymer colloids results in a solid green body embedded with high molecular weight polymer particles. A post-processing heated drying step allows the polymers to coalesce and further entangle, forming a semi-interpenetrating network with mechanical performance of the high molecular weight material. The resins can further include inorganic particles such as silica and other ceramics, metal particles, and the like.

Abstract: Photocurable colloid binders are provided that overcome deficiencies associated with 3D printing of high molecular weight polymers via VAT photopolymerization. Methods of additive manufacturing are also provided using the binders. The approaches described herein effectively decouple the viscosity-molecular weight relationship by synthesizing and processing photo-reactive aqueous colloids that are sequestered within a photocrosslinkable scaffold. Sequestering polymers within discrete internal phases prevents inter-particle entanglement of the polymer chains, thus ensuring low viscosity. VP of polymer colloids results in a solid green body embedded with high molecular weight polymer particles. A post-processing heated drying step allows the polymers to coalesce and further entangle, forming a semi-interpenetrating network with mechanical performance of the high molecular weight material. The resins can further include inorganic particles such as silica and other ceramics, metal particles, and the like.

Abstract: Binders and methods of binder jetting are provided based on the use of branched polymer binders. The applicants have found that, even more so than the molecular weight, the ability to achieve higher maximum printable concentrations leads to higher densities and improved structural properties of the manufactured articles. The methods can be used for a variety of articles from metal parts to structural ceramics, to tablets and other oral dosage forms. The branched chain polymers can include a short-chain branched polymer; a long-chained branched polymer; a hyper-branched polymer, a cyclic polymer; a comb-type polymer; a 3-arm star type polymer, a 4-arm star type polymer, a dendritic polymer, and a combination thereof. The branched-chain polymer can include various polymers such as polyvinylpyrrolidone, poly(vinyl alcohol), or poly(acrylic acid).

Abstract: In various aspects, top-down stereolithography apparatus and methods of use thereof are provided herein that allow for additive manufacturing of an article from a high-viscosity resin. The apparatus and methods can print resins having viscosities higher than conventional systems, e.g. viscosities up to about 100 Pa·s at the elevated temperature. The resin may have a room temperature viscosity of about 100 Pa·s, about 250 Pa·s, about 1000 Pa·s, or more. In some aspects, the resin is a solid at room temperature. The apparatus and methods do not rely upon solvents or other viscosity modifiers being added to the resin, and are capable of top-down additive manufacturing approaches which provide reduced stress on the printed article.

Abstract: In various aspects, a polymer resin is provided for vat photopolymerization. The resin can include a polyamic acid salt formed from the addition of a photocrosslinkable amine to a polyamic acid. The resin can include a photoinitiator suitable for initiating crosslinking of the photocrosslinkable amine when exposed to a light source of a suitable wavelength and intensity. The polyamic acid can be formed, for instance, by the addition of a diamine to a suitable dianhydride. Methods of additive manufacturing using the resins are also provided.

Abstract: A water soluble container comprises a water soluble shell enclosing a volume. The water soluble shell comprises a set of voxels.

Abstract: Polymer resins for the vat photopolymerization of thermoplastics are provided, in particular for the vat photopolymerization of thermoplastics with exception thermal stability and mechanical properties. In some aspects, the polymer resins are prepared by ring opening of an aromatic dianhydride with an alcohol containing an acrylate or methacrylate to produce a photocrosslinkable diacid monomer; conversion of the photocrosslinkable diacid monomer to a photocrosslinkable diacyl chloride; and polymerization of the photocrosslinkable diacyl chloride with an aromatic diamine to produce a photocrosslinkable precursor polymer. Upon crosslinking and drying, a thermal imidization can yield aromatic polyimide polymers with high yield and with micron-scale structural resolution.

Abstract: A water soluble container comprises a water soluble shell enclosing a volume. The water soluble shell comprises a set of voxels.

Abstract: A vending machine for creating a three-dimensional object having an enclosure having an exterior and interior. The interior receives and houses at least one three-dimensional printer. An interface for accepting an instruction associated with an object to be printed and transmitting the instruction to the printer. A storage section for storing a printed object that provides access to the printed part but limits or prohibits access to the interior.