3D printing tool for pulp molding process

Abstract

3D printing molds (710, 712) are used to produce three-dimensional pulp products (650, 740) from fiber pulp slurry. Transverse filaments (20, 320, 420) are incorporated into an infill structure with an openwork pattern. The transverse filaments form channels (30, 330, 430) that pass through the internal matrix of the mold. When vacuum pressure is applied, the openwork infill pattern and channels allow vacuum-suctioned material to move through the internal matrix of the 3D printing mold. The product surface of the mold includes an array of beads (10, 310, 410), formed by over-extrusion of molten material at the ends of the transverse filaments. The bead array narrows the openings of the channels created by the transverse filaments, preventing fibers from entering the mold matrix and clogging the material flow. This causes the fibers to aggregate on the product surface of the mold, forming a three-dimensional pulp product.

Description

Technical Field

[0001] This invention relates to tools and molds for forming three-dimensional (3D) objects, and more particularly to tools for vacuum forming pulp products formed by additive manufacturing processes (i.e., 3D printing). Background Technology

[0002] It is generally known in the art to provide 3D printed molds for vacuum forming of objects.

[0003] U.S. Patent Application Publication US 2022 / 0403604 A1, filed June 22, 2022 and published December 22, 2022 by inventors Andersson et al., relates to a tool or tool part, system including such a tool or tool part, method of producing such a tool or tool part, and method of molding a product from a pulp slurry. The tool or tool part includes a self-supporting tool wall portion having a product face for contacting the product and a back face on the opposite side of the wall relative to the product face. The tool wall portion has holes provided by a plurality of channels extending through the tool wall portion from the product face to the back face. The channels are straight or curved and have no more than one inflection point.

[0004] U.S. Patent Application Publication US 2023 / 0107827 A1, filed September 7, 2022 and published April 6, 2023 by inventors Briden et al., relates to an apparatus that may include a plurality of structures formed from molten portions of the build material particles and a plurality of porous sections supported by the plurality of structures. The plurality of porous sections may be formed from partially molten build material particles, wherein the partially molten build material particles may include build material particles that can be partially fused together to give the plurality of porous sections at least a predetermined porosity level.

[0005] U.S. Patent 11,752,688 B2, filed April 30, 2020, and granted September 12, 2023, by inventors Sealey et al., relates to a papermaking belt comprising material regions continuously laid out using a 3D printing process. These regions include at least one pouch-like region configured to form a three-dimensional structure within the paper web by applying a vacuum to pull the paper web toward the pouch-like region. In at least one exemplary embodiment, the region further includes at least one vacuum-breaking region configured to limit the amount of paper fibers pulled through the pouch-like region by the applied vacuum.

[0006] US Patent 10,040,249 B2, filed August 26, 2015, and granted August 7, 2018, by inventors Kraibühler et al., relates to a method for producing a three-dimensional object by means of generative construction from at least one coded material in a direct construction sequence via generative construction. At least one material component is dispensed in a programmable manner in a direct construction sequence via a control device, and structurally distinct regions of the object are produced as a result of the dispensing, wherein the geometric relationships obtained during dispensing correspond to the object. By selecting configuration criteria for different regions of the object structure predefined for the control device, and by controlling the dispensing unit during the dispensing of at least one material component for different regions of the object structure using the selected configuration criteria, a method is provided that allows material dispensing to be tailored to the individual requirements of the object.

[0007] U.S. Patent Application Publication US 2023 / 0166446 A1, filed January 27, 2023 and published June 1, 2023 by inventors Brent et al., relates to a method for manufacturing a deflection member. The method may include the steps of incorporating a monomer, a photoinitiator system, a photoinhibitor, and / or a reinforcing member. A further step includes blending the monomer, photoinitiator, and / or photoinhibitor to form a blended photopolymer resin. A further step may be exposing the photopolymer resin to radiation from a first radiation source and / or a second radiation source.

[0008] US Patent 6,261,493 B1, filed March 20, 1998 and granted July 17, 2001 by inventors Gayle et al., relates to a method and system for molding paper or alternative paper products in a mold having an outer surface and an inner surface, wherein at least a portion of the inner surface is porous and its pores are in continuous communication with the outer surface, and wherein the mold can be manufactured using solid free-form manufacturing techniques.

[0009] European Patent EP0 852 760 B1, filed by inventor Batchelder on September 17, 1996, and granted on December 4, 2002, relates to a method of manufacturing a three-dimensional object by depositing material in a predetermined pattern on a receiving surface, positioning the deposited material to introduce pockets of air or other fluids into the part, and adjusting the rate at which the material is dispensed from a dispenser to introduce a predetermined porosity into the object being formed. The optimal porosity in the object to be constructed depends on the shape at the time of material dispensing, but is typically in the range of 1% to 26%.

[0010] Patent application WO2022 / 072555 A1, filed by inventors Goldberg et al. on September 29, 2021, and published on April 7, 2022, concerning porous molds for manufacturing molded fiber parts and a method for additive manufacturing of the same, relates to a system and method for forming porous molds using additive manufacturing processes such as three-dimensional (3D) printing. In summary, it has been found that producing molds that are generally porous, or molds with porous regions or areas, can improve the performance of the mold and the quality of the parts produced therefrom. It has been further determined that porous molds can be produced using additive manufacturing techniques by manipulating mold manufacturing parameters, such as, but not limited to, layer thickness, number of peripheral layers, infill pattern, and infill density. By changing these manufacturing parameters, the porosity of the mold produced by an additive manufacturing apparatus (e.g., a 3D printer) can be customized for use with molded fibers.

[0011] Patent application WO 2023 / 064797 A1, filed on October 12, 2022, and published on April 20, 2023, by inventors Goldberg et al., relates to a method for manufacturing 3D-printed porous molds or filters, wherein the outer surface of the mold / filter is formed by a single layer of printed material. A support layer is then laid on the surface layer to form a porous body with a substantially uniform porosity across the entire surface of the mold / filter. The use of this porous body as a screen on a mold for manufacturing molded fiber parts and its general use as a filter with a 3D outer surface is described. Summary of the Invention

[0012] This invention relates to porous 3D printing molds for vacuum forming three-dimensional objects from aqueous pulp slurry.

[0013] One object of the present invention is to provide a porous tool for forming three-dimensional objects. This tool is specifically designed to prevent fibers from entering 3D printed mold components during negative pressure.

[0014] In one embodiment, the invention includes a mold formed using additive manufacturing technology, the mold comprising a product surface and an internal matrix, at least one transverse polymer layer, and at least one filler polymer layer, wherein the at least one transverse polymer layer comprises a plurality of adjacent columns of stacked filaments and a plurality of channels, each channel extending between two adjacent columns of stacked filaments, wherein there is an over-extrusion point at the end of each stacked filament facing the product surface, wherein the product surface of the mold includes a plurality of holes formed between the points of adjacent columns of stacked filaments, wherein the width of the holes is smaller than the width of the channels remote from the product surface, wherein the holes are configured to prevent fibers from entering the internal matrix of the mold, and wherein the filler polymer layer is deposited on the at least one transverse polymer layer. In other words, the distance between the over-extrusion point at the end of a first column of a first plurality of adjacent columns of stacked filaments facing the product surface and the over-extrusion point at the end of an adjacent second column of a first plurality of adjacent columns of stacked filaments facing the product surface is smaller than the distance remote from the product surface between the first column and the adjacent second column of stacked filaments. This forms narrow holes on the product surface and relatively wide channels inside the mold remote from the product surface. When used in the production of fibrous products, fibers are deposited on the product surface, and narrow pores prevent fibers from entering the internal matrix of the mold. If fibers pass through the narrow pores formed by beads on the product surface, the invasive fibers then enter a wider channel formed by transverse filaments. The increased width of the channel compared to the pores formed by the beads on the product surface allows the invasive fibers to pass through the channels of the mold without clogging them.

[0015] In another embodiment, the invention includes an additive manufacturing method for producing a vacuum forming die, the method comprising: depositing an initial transverse filament, wherein an extrusion point is passed over the end of the initial transverse filament; depositing at least one additional transverse filament on top of the initial transverse filament, wherein an additional extrusion point is passed over the end of the additional transverse filament; depositing at least one adjacent transverse filament row comprising a stacked transverse filament layer adjacent to the initial transverse filament and at least one additional transverse filament; wherein a stacking point is extruded at the end of each stacked transverse filament in at least one adjacent transverse filament row; and depositing a filler polymer layer on top of at least one additional transverse filament and at least one adjacent transverse filament row, wherein at least one filler polymer layer stabilizes the initial transverse filament, at least one additional transverse filament, and at least one adjacent transverse filament row.

[0016] In a third embodiment, the invention includes a system for molding pulp fiber products. The system includes a mold, a vacuum system, and pulp slurry. The mold includes a product surface and a back surface. The mold is produced using an additive manufacturing process. The vacuum system is coupled to the mold. The pulp slurry comprises natural fibers. A filler polymer layer is deposited on top of a first transverse polymer layer, which includes a first plurality of adjacent columns of stacked filaments. At least one additional transverse polymer layer is deposited on top of the filler polymer layer, which includes additional plurality of adjacent columns of stacked filaments. An over-extrusion point is formed at the end of each stacked filament facing the product surface. The product surface of the mold includes a plurality of holes formed between points of adjacent columns of stacked filaments. The holes are configured to prevent fibers from entering the internal matrix of the mold. The product surface of the mold contacts the pulp slurry. A negative pressure is applied to the mold by the vacuum system coupled to the mold. The natural fibers of the pulp slurry aggregate on the product surface of the mold to form a molded pulp product.

[0017] In another embodiment, the invention includes a method for producing a molded fiber product, the method comprising forming a mold via an additive manufacturing process, the steps of: depositing adjacent transverse filaments, wherein an extrusion point is formed at the end of each adjacent transverse filament facing the product surface; depositing at least one additional transverse filament on top of an initial transverse filament, wherein an additional extrusion point is formed at the end of the at least one additional transverse filament facing the product surface; forming a series of adjacent rows of stacked transverse filaments; depositing a filler polymer layer on top of the at least one additional transverse filament, wherein at least one filler polymer layer stabilizes the initial transverse filament and the at least one additional transverse filament; forming a product surface of the mold, wherein the product surface of the mold includes a plurality of holes formed between the extrusion points at the ends of the adjacent filaments and forms a back surface of the mold; and immersing the mold in a pulp slurry, wherein the mold is coupled to a vacuum system, wherein the vacuum system applies negative pressure to the product surface through the internal matrix of the mold.

[0018] These and other aspects of the invention will become apparent to those skilled in the art upon reading the following description of preferred embodiments in conjunction with the accompanying drawings, as they support the claimed invention. Attached Figure Description

[0019] The actual embodiments and features of the present invention are described below with reference to the accompanying drawings. It should be noted that the upper and lower ends of each figure, as well as the resulting vertical orientation, correspond to the upper and lower ends of the reference numerals in the corresponding figures and the vertical orientation.

[0020] Figure 1 An orthogonal top view of a series of transverse filaments according to an embodiment of the present invention is shown.

[0021] Figure 2 An orthogonal top view of a series of transverse filaments according to an embodiment of the present invention is shown.

[0022] Figure 3 An orthogonal top view of a series of transverse filaments according to an embodiment of the present invention is shown.

[0023] Figure 4 A side perspective view of a series of layered transverse filaments according to an embodiment of the present invention is shown.

[0024] Figure 5 An orthogonal view of a filling pattern according to an embodiment of the present invention is shown.

[0025] Figure 6 An orthogonal view of a filling pattern according to an embodiment of the present invention is shown.

[0026] Figure 7 A perspective view of a layered filling structure according to an embodiment of the present invention is shown.

[0027] Figure 8 A perspective view of a 3D printed design according to an embodiment of the present invention is shown.

[0028] Figure 9 A top perspective view of a 3D printed design according to an embodiment of the present invention is shown.

[0029] Figure 10 A perspective view of a 3D printed design according to an embodiment of the present invention is shown.

[0030] Figure 11 A perspective view of a 3D printed design according to an embodiment of the present invention is shown.

[0031] Figure 12 A mold according to an embodiment of the present invention is shown.

[0032] Figure 13 A perspective view of a composite mold according to an embodiment of the present invention is shown.

[0033] Figure 14 A perspective view of a multi-part mold according to an embodiment of the present invention is shown.

[0034] Figure 15 This is a schematic diagram of the system of the present invention. Detailed Implementation

[0035] This invention generally relates to a porous 3D printing mold for vacuum forming three-dimensional objects from aqueous pulp slurry. The tool is designed with an open-cell filling structure and a bead-like shell layer. The bead-like shell layer is formed by multiple intentionally placed Z-shaped scar points to prevent fibers from entering the 3D printing mold component during negative pressure.

[0036] In one embodiment, the invention includes a mold formed using additive manufacturing technology, the mold including a product surface and an internal matrix, at least one transverse polymer layer and at least one filler polymer layer, wherein the at least one transverse polymer layer includes a plurality of adjacent columns of stacked filaments, wherein there is an over-extrusion point at the end of each stacked filament facing the product surface, wherein the product surface of the mold includes a plurality of holes formed between the points of adjacent columns of stacked filaments, wherein the holes are configured to prevent fibers from entering the internal matrix of the mold, and wherein the filler polymer layer is deposited on the at least one transverse polymer layer.

[0037] In another embodiment, the invention includes an additive manufacturing method for producing a vacuum forming die, the method comprising: depositing an initial transverse filament, wherein an extrusion point is passed over the end of the initial transverse filament; depositing at least one additional transverse filament on top of the initial transverse filament, wherein an additional extrusion point is passed over the end of the additional transverse filament; depositing at least one adjacent transverse filament row comprising a stacked transverse filament layer adjacent to the initial transverse filament and at least one additional transverse filament; wherein a stacking point is extruded at the end of each stacked transverse filament in at least one adjacent transverse filament row; and depositing a filler polymer layer on top of at least one additional transverse filament and at least one adjacent transverse filament row, wherein at least one filler polymer layer stabilizes the initial transverse filament, at least one additional transverse filament, and at least one adjacent transverse filament row.

[0038] In a third embodiment, the invention includes a system for molding pulp fiber products. The system includes a mold, a vacuum system, and pulp slurry. The mold includes a product surface and a back surface. The mold is produced using an additive manufacturing process. The vacuum system is coupled to the mold. The pulp slurry comprises natural fibers. A filler polymer layer is deposited on top of a first transverse polymer layer, which includes a first plurality of adjacent columns of stacked filaments. At least one additional transverse polymer layer is deposited on top of the filler polymer layer, which includes additional plurality of adjacent columns of stacked filaments. An over-extrusion point is formed at the end of each stacked filament facing the product surface. The product surface of the mold includes a plurality of holes formed between points of adjacent columns of stacked filaments. The holes are configured to prevent fibers from entering the internal matrix of the mold. The product surface of the mold contacts the pulp slurry. A negative pressure is applied to the mold by the vacuum system coupled to the mold. The natural fibers of the pulp slurry aggregate on the product surface of the mold to form a molded pulp product.

[0039] In another embodiment, the invention includes a method for producing a molded fiber product, the method comprising forming a mold via an additive manufacturing process, the steps of: depositing adjacent transverse filaments, wherein an extrusion point is formed at the end of each adjacent transverse filament facing the product surface; depositing at least one additional transverse filament on top of an initial transverse filament, wherein an additional extrusion point is formed at the end of the at least one additional transverse filament facing the product surface; forming a series of adjacent rows of stacked transverse filaments; depositing a filler polymer layer on top of the at least one additional transverse filament, wherein at least one filler polymer layer stabilizes the initial transverse filament and the at least one additional transverse filament; forming a product surface of the mold, wherein the product surface of the mold includes a plurality of holes formed between the extrusion points at the ends of the adjacent filaments and forms a back surface of the mold; and immersing the mold in a pulp slurry, wherein the mold is coupled to a vacuum system, wherein the vacuum system applies negative pressure to the product surface through the internal matrix of the mold.

[0040] None of the prior art discloses the use of intentionally placed arrays of clumps on the surface of a 3D printed part, where each clump is intentionally placed and connected to a transverse filament. The product surface of the mold is the surface of the mold that contacts the deposited pulp layer that forms the product. Furthermore, none of the prior art discloses transverse filaments derived from clumps that are parallel and woven into a filler structure to form a 3D printed mold, with pores on the product surface that are significantly smaller than the openings formed by the filler components. This opening structure may narrow again at opposite ends of the filaments due to the use of filaments with beads placed at both ends. In one embodiment, the transverse components are substantially parallel and not tapered. The pores formed between the beads are very narrow. However, the pores on the product surface are achieved by depositing 3D printed beads on the product surface of the mold rather than by tapering the distance between the two transverse filaments. Therefore, compared to the channels formed by tapered transverse filaments in the prior art, the present invention enables narrower pores on the product surface for entry into the mold matrix.

[0041] 3D printing, or three-dimensional printing, has existed for over forty years. The concept of additive deposition, now known as 3D printing, encompasses many technologies. One such technology is fused deposition modeling (FDM), also called fused filament fabrication (FFF). This technology utilizes heated nozzles to melt and place thermoplastic filaments. As the molten filaments are deposited onto the build surface (i.e., the platform used to support the 3D printed structure during the printing process or a previously placed filament to which a new filament is being fused), the molten filaments fuse together. Another technology, stereolithography (SLA), uses a laser to direct UV light onto a liquid resin. Photopolymerization initiated by the directed UV laser solidifies the resin into a hardened structure. Other 3D printing technologies include selective laser sintering (SLS), digital light processing (DLP), multi-jet melting (MJF), PolyJet, direct metal laser sintering (DMLS), and electron beam melting (EBM). While this invention pertains to FDM additive manufacturing, those skilled in the art will understand that analogues to the molds of this invention can be produced using various additive manufacturing technologies.

[0042] 3D printing's rapid prototyping capabilities make it an attractive alternative to traditional tooling techniques. Traditional methods require expensive metal materials and time-consuming production processes to create molds. 3D printing reduces material costs and creates lightweight models at a much higher rate than traditional mold-making processes such as CNC machining, aluminum tooling, and welding. Therefore, 3D printing is significantly more efficient than alternative methods for mold production.

[0043] However, molds produced by additive deposition methods according to existing technologies lack horizontal and vertical screens to prevent fibers from entering the mold. Conventional FDM printing molds include a horizontal mold screen (i.e., a mold screen in a single plane formed when material is added to the top of the 3D printing mold). However, the vertical surface of such molds printed by conventional methods is detrimental to pulp product formation because there is no method for creating openings on the sides of the 3D printing mold. More precisely, the deposition of material on the horizontal surface of the mold results in the formation of a shape suitable for thermoforming. For vacuum forming, openings in the horizontal surface can be used for vacuum suction, but the vertical walls of existing 3D printing molds are solid, thus preventing the application of vacuum pressure through the walls. This invention provides a single mold with both horizontal and vertical product surfaces.

[0044] It is worth noting that additive manufacturing, especially FDM, is not a perfect process. The use of molten materials (e.g., thermoplastics) in 3D printing often results in over-extrusion of this material deposited onto the build surface. This over-extrusion of the filament is referred to as “clumps,” “bumps,” or “Z-scars,” and is common in 3D printing. Clumps occur in many 3D printing technologies, but are particularly prevalent in FDM printing. In fused deposition modeling, the extruder is used to repeatedly stop and start the deposition of the filament. The abrupt stop of filament deposition causes molten material to accumulate in the nozzle. This accumulation is applied at the beginning of the filament when the next filament is started. Clumps can also occur at the ends of the filament, where additional molten material is deposited when the nozzle hovers over the end of the filament before moving to the next start. High nozzle retraction rates (i.e., repeatedly stopping and starting new filaments) result in the formation of clumps in the 3D printed object. In this way, prior art 3D printed molds include irregular, accidental clumps located throughout the structure. See Shaqour, B., Abuabiah, M., Abdel-Fattah, S. et al., Gaining a better understanding of the extrusion process in fused filament fabrication 3D printing: a review. Int J Adv Manuf Technol 114, 1279–1291 (2021), doi:10.1007 / s00170-021-06918-6, which is incorporated herein by reference in its entirety.

[0045] This invention advantageously utilizes this over-extrusion phenomenon to form 3D printing molds for vacuum forming of 3D products. One or more features of the mold of this invention, particularly the product surface of the mold, are not formed by minimizing agglomeration as taught in the prior art, but rather by the intentional placement of over-extruded agglomerates (referred to herein as “beads”). The mold of this invention comprises bead-like transverse filaments and a filler structure. Layers and rows of transverse parallel filaments are printed across and along the filler structure. The purpose of the filler structure is to provide support for the 3D printing mold, while the transverse filaments, including bead-like ends or sections, are used to induce fiber accumulation on the mold surface. Beads are placed at one or both ends of each transverse filament, significantly reducing the size of the channel openings (i.e., orifices). Thus, the product surface (i.e., the mold surface in contact with the pulp, on which fiber pulp accumulates as disclosed herein) is formed using an array of beads intentionally placed at one or both ends of the transverse filaments to reduce the size of the orifices on the mold surface. As used herein, the term "transverse filament" refers to filaments deposited along the outer surface of a die in a line through the internal matrix of the die's infill structure or along the patterned infill structure. Furthermore, these filaments should not be limited to filaments placed in a straight or substantially straight line, but also include those deposited as lines having one or more curves (e.g., lines with repeating peaks and troughs) or spline curves (e.g., piecewise polynomial curves).

[0046] Furthermore, the mold of the present invention utilizes discontinuous transverse filaments, thereby limiting the length of the 3D printing line and reducing the number of clumps formed within the transverse filaments, as clump formation increases due to prolonged extrusion time. Using repeating transverse filaments, instead of a single continuous filament, reduces spontaneous clump formation and allows for the intentional placement of beads at desired ends of the transverse filaments. In 3D printing molds using continuous filaments and filaments with clumps throughout the channel, spontaneously formed clumps exist within the channel, causing fiber blockage during the vacuuming process of the pulp slurry. The pulp fibers are trapped in narrow portions of the mold matrix (i.e., the interior of the mold) and cannot pass through, clogging the mold and preventing further vacuum formation. This essentially renders the 3D printing mold useless for 3D object formation.

[0047] Therefore, the manipulation of bead placement is particularly advantageous in the specific field of using molds for vacuum forming three-dimensional products from aqueous fiber pulp. The pulp is applied to the product surface of the mold, and negative pressure (i.e., vacuum) is applied to the pulp through a porous mold. The size of the pores formed by the beads prevents fibers from entering the filling structure of the mold matrix while allowing fluid to pass through the pores. When the pulp is dewatered, the pulp fibers adhere to the product surface of the mold but cannot enter through the pores, thus accumulating on the product surface of the mold.

[0048] Referring now generally to the accompanying drawings, which are for the purpose of illustrating one or more preferred embodiments of the invention and are not intended to limit the invention thereto.

[0049] Figures 1 to 7 A 3D printed structural design element of a mold according to an embodiment of the present invention is shown. Figures 1 to 3 A top view of a series of transverse filaments according to an embodiment of the present invention is shown. Beads 10 are formed at one or both ends of the transverse filaments 20. Channels 30 formed between adjacent transverse filaments 20 include product surface holes 40 formed at one end of the channel 30, where pulp fibers forming the product are deposited. Those skilled in the art will understand that the transverse filaments of the present invention can be bent, such that a single printed filament forms two adjacent transverse filaments, as... Figure 1 As depicted herein. Furthermore, those skilled in the art will understand that, in one embodiment, the curved portions of the 3D printed mold require the use of angled transverse filaments. Figure 3 An angled transverse filament 20 is shown, with beads 10 formed at both ends of the filament 20. A channel 30 formed between adjacent filaments 20 includes a product surface hole 40 at one end of the channel 30 and a back surface hole 42 at the opposite end of the channel. As used herein, the term "back surface" refers to the die surface that does not come into contact with the pulp during product formation. Figure 4 A perspective view of a series of transverse filaments according to an embodiment of the present invention is shown. The angled transverse filaments 20 are layered and joined together by beads 10 formed at both ends of the filaments 20. In one embodiment, the transverse filaments are also joined together along the length of the filament. Channels 30 formed between adjacent filaments 20 include a product surface hole 40 at one end of the channel 30 and a back surface hole 42 at the opposite end of the channel.

[0050] In one embodiment, the lateral filaments of the present invention are discontinuous. More precisely, these filaments are repeating, lateral, parallel, and discontinuous. For the avoidance of doubt, the term "continuous" as used herein with respect to lateral filaments should be understood as an extended filament length placed in a forward-backward or "S" pattern without bringing the nozzle to a standstill or stopping filament deposition. Continuous filament deposition of lateral filaments involves placing three or more lateral filaments to form a mold without channels leading to both the product surface and the back of the mold. In contrast, discontinuous lateral filaments are placed in a unidirectional manner, including a starting point on the product surface and an ending point on the back, or in a segmented bidirectional manner, including a starting point on the product surface and an adjacent ending point, forming multiple "U"-shaped filaments. The starting point (i.e., bead) of each lateral filament has an increasing thickness because the 3D printing nozzle is static at these points before lateral acceleration to produce finer lateral filaments. Using short-pulse extrusion to form lateral filaments prevents the formation of clumps during long extrusion periods. Thus, the present invention overcomes the clogging problem commonly found in existing 3D printing molds, a problem caused by clumps deposited during the continuous extrusion of the transverse filament. In one embodiment, the endpoint of the transverse filament further includes beads formed by a stationary 3D printing nozzle. Therefore, the transverse filament of the present invention is configured to include beads at one or both ends of the transverse filament.

[0051] In one embodiment, transverse filaments are stacked on top of each other to form a stack of transverse filaments. In one embodiment, layered filaments are bonded by beads at one or both ends of the filament, without the filaments being bonded along the length of the printed filament. In one embodiment, layered filaments are bonded along the length of the filament. In one embodiment, layered filaments are bonded by beads at one or both ends of the filament and along the length of the filament. This layered transverse filament structure allows for the formation of walled channels, which can be used to allow vacuum-sealed material to pass through the internal matrix of the 3D printing mold without clogging the mold. This is further made possible by using beaded filaments. The beads are used to prevent the entry of fibers during vacuum forming, thereby preventing fiber clogging of the mold.

[0052] In one embodiment, channels are formed between layers of discontinuous transverse filaments. In another embodiment, the channels formed between the discontinuous transverse filaments comprise product surface holes opening on the product surface of the die, with the channel length having a consistent width. Thus, in one embodiment, the openings on the back side of the die (i.e., the surface that does not contact the pulp during product formation) are at the same or significantly similar distances to the parallel transverse filaments, such as... Figure 1As shown. In one embodiment, the opening on the back of the mold is the same as or significantly similar to the hole of the unit of the filling structure disclosed herein. In one embodiment, the channel of the present invention has a constant width. In other words, the channel of the present invention is not tapered, wherein the angled filaments form a narrow opening facing the product and a wider opening facing the back. More precisely, the narrow opening is formed by intentional beads placed at one or both ends of the transverse filaments, and the size of the channel itself is determined by the angle and distance between the transverse filaments. As a result, the size of the back hole is not always the same as the product surface hole. In one embodiment, the opening on the back of the mold is smaller than the distance between the parallel transverse filaments (e.g., 0.05 mm smaller, at least 0.1 mm smaller). In one embodiment, beads are formed at both the beginning and end of the transverse filaments. In one embodiment, the description of the transverse filaments of the present invention describes both single-bead filaments and double-bead filaments. In one embodiment, a second surface hole as described herein forms the product surface. For example, when the shape of the product requires protrusions to enter the mold, both ends of the double-bead channel are capable of forming a product surface for 3D printing mold protrusions.

[0053] As disclosed herein, 3D printing allows for the formation of complex shapes and occasionally requires the use of angled lateral filaments to create curves and other convex or concave shapes. As used herein, the term "angled lateral filament" describes a series of adjacent filaments that are not parallel due to their filament trajectories. However, in one embodiment, these angled filaments are approximately parallel or nearly parallel, wherein the angle between adjacent filaments is between about 0.01 degrees and about 5 degrees. In one embodiment, the lateral filaments of the present invention are angled. Figure 3 and Figure 4 Exemplary embodiments of angled transverse filaments according to certain embodiments of the present invention are shown. However, those skilled in the art will understand that the product surface holes (and back holes, for angled double-bead filaments) are still formed using beads to minimize the distance between the end of one filament and the end of an adjacent filament. Therefore, in one embodiment, the angle of the angled transverse filaments is not a determining factor for the hole size of the product-facing surface of the mold of the present invention.

[0054] In one embodiment, the beads of the present invention are located on one or both distal ends of the transverse filament. At the beginning of each filament, the nozzle remains temporarily stationary while calculating the next automatic movement (i.e., the lateral movement of the body forming the transverse filament). As a result, the nozzle over-extrudes molten material at the beginning of the transverse filament. Similarly, the nozzle is also prone to over-extruding molten filament at the end of the movement because the filament is extruded over the duration of the print line, and the static pause of the nozzle before moving to the next print area results in the extrusion of additional molten material. Therefore, those skilled in the art will understand that in one embodiment, the beads of the present invention are significantly different from 3D printing designs in which the thickness of the filament has been intentionally increased. In one embodiment, the design of the mold of the present invention uploaded to the 3D printer does not include an area of ​​filament deposition added at the beginning of each transverse filament. The beads are over-extruded filaments whose positions have been intentionally calculated, although the molten material used to form the beads is not intentionally extruded. Furthermore, those skilled in the art will understand that the beads of the present invention are not placed on the entire transverse filament, nor are they clumps formed along the length of the transverse filament due to over-extrusion.

[0055] In one embodiment, beads are located at one end of a transverse filament, forming a bead-like product surface with a non-bead back side. In another embodiment, beads are located at both ends of a transverse filament (i.e., a double-bead filament). The beads formed at both ends of the double-bead filament form the product surface of the mold, which can be used to mold products having concave or convex surfaces along the molded product surface. Those skilled in the art will understand that in the case of a molded product having a concave surface, the mold used to produce the product has a corresponding convex surface. Similarly, convex surfaces in the molded product surface are formed by the corresponding concave area of ​​the mold. For product shapes with concave and / or convex surfaces, the present invention can utilize double-bead filaments that traverse the corresponding convex or concave surface of the mold and have beads at both ends. In this way, the system of the present invention can produce complex mold shapes for forming surface features of molded products. In the vacuum forming process of 3D molded pulp products, an aqueous pulp slurry is applied to the mold (e.g., by immersing the mold in a bucket of slurry or injecting the slurry into the mold). When negative pressure is applied to the pulp through the channels of the mold, the pulp fibers are vacuum-drawn onto the product surface of the mold. The pores formed between the beads on the product surface (i.e., the surface in contact with the pulp) prevent fibers from entering the channels of the mold. In one embodiment, the size of the pores formed between the beads is such that fibers are prevented from entering the channels of the mold. In another embodiment, the size of the pores formed between the beads is such that the amount of fiber entering the mold channels is significantly reduced compared to conventional molds. In one embodiment, the pores on the product surface are between about 0.25 mm and about 1 mm. Those skilled in the art will understand that the dimensions of the channels and pores of the present invention can be increased or decreased to suit the type of fiber used to manufacture the pulp. For example, fine fibers with a reduced average length and width require narrower pore sizes to prevent fiber entry compared to a fiber blend with large fibers having a larger average width and thickness than fine fibers. The dimensions of the additive printing nozzle determine the width of the filament deposited from the nozzle and the beads formed by the nozzle. In one embodiment, a nozzle with a diameter of 0.15 mm deposits filaments with a width of about 0.15 mm and beads with a width of about 0.4 to 0.5 mm.

[0056] As used herein, the term "back hole" refers to a hole formed by beads on the rearward-facing surface of a die. In one embodiment, the back hole is formed by beads of angled double-bead filaments, wherein the filament angle results in a hole formed by a pair of adjacent filaments being wider than the hole at the other end of the same pair of adjacent filaments. The term back hole refers to a hole present on the back side of a die that does not come into contact with the pulp during the production of the pulp product. In one embodiment, the width of the back hole is about 0.25 mm to about 1 mm smaller than the width of the hole on the product surface. In one embodiment, the width of the back hole is between about 0.25 mm and about 1 mm. In one embodiment, the diameter of the bead is about 0.5 mm. In one embodiment, the diameter of the bead is between about 0.45 mm and 0.85 mm. In another embodiment, the diameter of the bead is between about 0.4 and 0.5 mm.

[0057] In one embodiment of the invention, the transversely layered filaments form channels in the mold of the invention. The channels have an increased width compared to the product surface holes formed by beads. This is partly due to the difference in thickness between the beads and the transverse filaments. In one embodiment, the transverse filaments have a reduced thickness compared to beads formed at one or both ends of the transverse filaments. In one embodiment, the transverse filaments have a width (i.e., thickness) of about 0.15 mm. In one embodiment, the width of the transverse filaments is between about 0.10 mm and 0.20 mm. In one embodiment, the width of the transverse filaments is between about 0.05 mm and 0.25 mm. In one embodiment, the width of the transverse filaments is at least about 0.10 mm. In one embodiment, the width of the transverse filaments is at least about 0.15 mm. In one embodiment, the transverse filaments have a thickness between about 0.1 mm and 0.5 mm.

[0058] In one embodiment, the distance between the transverse filaments is from about 0.5 mm to about 1.5 mm. In one embodiment, the distance between the transverse filaments is between about 0.30 mm and about 0.40 mm. In one embodiment, the distance between the transverse filaments is between about 0.20 mm and about 0.60 mm. In one embodiment, the distance between the transverse filaments is between about 0.10 mm and about 0.70 mm. Those skilled in the art will understand that the angle of the angled transverse filaments affects the aperture size of the channel as disclosed herein. In one embodiment, the aperture formed on the product surface and the back of the die is smaller than (e.g., less than 0.05 mm, less than at least 0.1 mm) the distance between the parallel transverse filaments just before the extrusion of the beads. In one embodiment, the product surface aperture is about 0.30 mm to about 0.40 mm wide. In one embodiment, the product surface aperture is about 0.20 mm to about 0.40 mm wide. In one embodiment, the product surface aperture is about 0.10 mm to about 0.70 mm wide. In one embodiment, the product surface aperture is about 0.30 mm to about 0.40 mm wide. In one embodiment, the back hole is about 0.20 mm to about 0.40 mm wide. In another embodiment, the back hole is about 0.10 mm to about 0.70 mm wide. Since the back is not designed to contact the pulp and draw water into the hole, the back hole can be completely blocked during the printing process or at a later stage, for example, by additional solid elements of the die.

[0059] In one embodiment, if fibers penetrate the product surface formed by beads, the invasive fibers enter channels formed by transverse filaments. The increased width of the channels compared to the pores formed by beads allows the invasive fibers to pass through the die channels without clogging them. In one embodiment, the invasive fibers pass through the non-beaded back side of the die and are then vacuumed out there along with the pulp fluid. Furthermore, in one embodiment, the channels formed by transverse filaments are deposited on the surface as disclosed herein and... Figure 8The layers of the filling structure are depicted herein. The internal matrix of the mold, formed by the combination of transverse filaments and the filling structure, guides the invasive fibers and vacuum fluid through the mold matrix and out through the non-enclosed (e.g., non-beaded) back side of the mold. Thus, in one embodiment, the channel formed by the transverse filaments has sufficient width to allow the invasive fibers to pass through unimpeded. Furthermore, in one embodiment, the units of the filling structure of the inner matrix have sufficient pore size to allow the invasive fibers to pass through unimpeded. In one embodiment, the transverse filaments are double-beaded filaments as disclosed herein, forming channels with pores at both ends. The pulp fluid, as well as any invasive fibers, is evacuated through the product surface pores and transferred through the mold matrix, exiting the mold matrix through the units of the filling structure. That is, the pulp fluid, as well as any invasive fibers, is evacuated through the product surface pores and deflected through the mold matrix to exit the mold matrix in a plane not parallel to the channel.

[0060] In one embodiment, the units of one or more filler layers of the inner matrix have sufficient pore size to allow invasive fibers to pass through unimpeded, while the outer filler layer (e.g., a filler layer on a horizontal product surface) has very narrow pore size to prevent fiber entry. The outer filler layer forms a substantially horizontal product surface, while the pores formed by the beads of the present invention form a product surface with a vertical component. In one embodiment, the mold of the present invention comprises multiple outer filler layers (e.g., 3 to 5 layers). This advantageously increases the strength of the outer product surface, which is configured to allow fibers to aggregate in horizontal areas of the product surface. As used herein, the terms “horizontal” and “vertical” do not refer to the orientation of the 3D printing mold in use, but rather to the orientation of the printing equipment during production. 3D printers typically include a linear actuator that moves the print head. The movement of the print head along the X and Y axes defines one layer of the printed product. After completing this layer, the print head typically moves along the Y axis to form the next layer. The X and Y axes define a horizontal plane. The Z axis defines a vertical direction. Transverse filaments with beads at the ends, as described herein, typically extend in the horizontal plane. Multiple stacked transverse filaments form a stack. Beads at the ends of two adjacent stacked filaments form holes through which liquid from the pulp permeates. The holes formed by the beads extend vertically or in a direction with a vertical component. It is impossible to form horizontal holes with stacked beads. Therefore, the outer filler layer printed on a horizontal plane defined by the X and Y axes of the printer has sufficiently small apertures to form a screen or mesh on the horizontal surface, preventing fibers from entering through the mesh openings and defining the horizontal product surface. The product surface with a vertical component is defined by the beads at the ends of the transverse filaments. The die shape is divided into multiple parallel stacks extending vertically and forming holes at the ends. The inner filler structure extends through the holes between the transverse filaments. The outer filler structure forms holes without a vertical component on the product surface (i.e., the horizontal product surface).

[0061] Those skilled in the art will understand that the sufficient width and pore size of the cells of the inner matrix filling structure (so as not to impede invasive fibers) depend on several factors, including the orientation of the transverse filaments and the filling structure, the size of the fibers used to form the product, the volume of fibers and fluid entering the matrix, and the negative pressure applied to the fibers by a vacuum. Furthermore, the channel widths disclosed herein are narrow enough to allow the filament beads to form sufficiently narrow pores to prevent fibers from entering the inner matrix of the mold, while allowing the channels to be wide enough to allow invasive fibers to pass unimpeded. However, the pore size of the cells is not a factor determining the size of the pores on the product surface of the vertical product surface. Therefore, in embodiments of the invention, the pores of the inner matrix filling structure can be significantly wider than the width of the channels. In one embodiment, the pores of the cells of the inner matrix filling structure are significantly wider than the width of the channels, while the horizontal product surface is formed by a filling layer having cell pores with dimensions similar to those of the product surface pores (e.g., within about 0.1 mm, within about 0.2 mm, within about 0.05 mm).

[0062] Figures 5 to 6 An orthogonal view of a fill pattern according to an embodiment of the present invention is shown, while Figure 7 A perspective view of a repeating layered filling structure according to an embodiment of the present invention is shown. The filling structure includes filling walls 50 and units 60 formed by openings in the filling structure. Figure 7 No lateral filaments deposited between one or more layers of the filled structure are depicted.

[0063] In one embodiment, the infill structure is a honeycomb structure. In another embodiment, the infill structure is a grid structure. Those skilled in the art will understand that the infill pattern can be formed from any 3D printable pattern that includes both open structures and provides sufficient support for the 3D printing mold during the formation of the three-dimensional pulp product. Both honeycomb and grid patterns provide increased strength and mechanical resistance, enabling the mold to support itself during high-pressure vacuuming. In one embodiment, the mold is capable of withstanding a vacuum pressure between about -1 and about -0.6 atm. In another embodiment, the mold is capable of withstanding a vacuum pressure of about -0.8 atm. The infill pattern of the mold is also configured to provide support for the mold during the drying of the molded fiber article within the mold. In one embodiment, the mold is capable of withstanding a pressure between about 2 atm and about 6 atm. Examples of alternative infill patterns include, but are not limited to, grid patterns, cubic patterns, octahedral patterns, triangular patterns, trihedral patterns, line patterns, spiral icosahedral patterns, zigzag patterns, cross-shaped patterns, and concentric patterns.

[0064] The layered infill structure supports the transverse filaments of the mold of the present invention, increasing the strength of the mold by adding layers and density to the 3D structure. In one embodiment, the infill structure has an infill density between about 20% and about 50%. In another embodiment, the infill structure has an infill density between about 20% and about 70%. In yet another embodiment, the infill structure has an infill density between about 35% and about 60%. In yet another embodiment, the infill structure has an infill density of about 50%. Those skilled in the art will understand that increased infill density provides greater strength to the 3D printed mold. The mold must have sufficient strength to minimize the effects of negative pressure applied to it. However, increasing the density of the infill structure reduces the size of the pores formed by the units of the infill structure, thereby minimizing the volume of fluid and intrusive material (i.e., fibers entering through the pores on the product surface formed by the beaded filaments) passing through the internal matrix of the mold. As a result, the reduced pore size increases the likelihood of clogging (i.e., clogging by fibers capable of passing through the pores or by the accumulation of fluid evacuated from the slurry). Therefore, infill density is an important consideration in some embodiments of the 3D printed mold of the present invention.

[0065] In one embodiment, the cells of the filler structure have pores between approximately 0.5 mm and 2 mm. Those skilled in the art will understand that, in one embodiment, in embodiments using both horizontal and vertical product surfaces, the pores of the filler structure cells affect the width of the channels as disclosed herein. In such embodiments, the pores formed on a horizontal product surface are determined by the width of the pores of the filler structure cells. Furthermore, in embodiments where the internal matrix at least partially comprises the filler structure, the pores of the filler structure cells must have sufficient width to prevent fiber blockage within the matrix (therefore, fiber type may need to be considered when determining the size of the filler structure cells and the fill density). Thus, in one embodiment, the pores of the filler structure cells are wider than the channels formed by transverse filaments.

[0066] Figure 8 A 3D printed design structure according to an embodiment of the present invention is illustrated. Beads 310 are formed at both ends of transverse filaments 320. Channels 330 include layered transverse filaments 320. The layered filaments 320 are bonded to a filler layer 350. The beads 310 formed on the product surface of the mold form product surface holes 340 and back surface holes 342 at the ends of the channels 330 formed by the layered transverse filaments 320. The stacked layered transverse filaments 320 form a material stack extending transversely through the printing mold. These stacks are stabilized by filler layers added at regular intervals as disclosed herein.

[0067] In one embodiment, the channel of the present invention is formed by two adjacent stacks of layered filaments. The layered filaments form the walls of the channel, preventing lateral movement of fluid and material evacuated into the matrix inside the mold. Regularly spaced filler layers provide lateral bonding between adjacent stacks, thereby stabilizing the 3D printed structure. In one embodiment, the stack of layered filaments between two filler layers comprises 2 to 10 layers (i.e., 2 to 10 lateral filaments). In one embodiment, the stack of layered filaments between two filler layers comprises 5 to 15 layers. In one embodiment, the stack of layered filaments between two filler layers comprises 10 to 12 layers. In one embodiment, the filler layers are placed between the lateral filament layers at 1 mm intervals (i.e., the vertical stack between two filler layers is approximately 1 mm high). Those skilled in the art will understand that the number of filament layers used to form each stack between two filler layers is structurally limited because the layered filaments lack lateral bonding without filler layers.

[0068] In one embodiment, a filler layer is printed between stacks of lamellar filaments. In another embodiment, regular increments of lamellar filaments are bonded together (i.e., forming stacks), with the filler layer printed between the bonded increments. In yet another embodiment, the filler layer is printed between stacks of lamellar filaments, creating gaps between the stacks with the same height as the thickness of the filler layer. In yet another embodiment, the filler layer creates porous bottom and top surfaces of channels formed by the stacks of lamellar filaments. As disclosed herein, increasing the filler density reduces the size of the pores formed by the units of the filler structure. This reduces the rate at which fluid and material can pass through the internal matrix of the mold, thereby increasing the likelihood of clogging (i.e., clogging by fibers capable of passing through the pores or by the accumulation of fluid evacuated from the slurry). Therefore, in one embodiment, the filler density of the present invention is from about 20% to about 40%.

[0069] In one embodiment, the filler structure has identical repeating layers. In one embodiment, adjacent (i.e., two or more adjacent layers) identical layers are bonded together. In one embodiment, regular increments of the filler layers (e.g., five layers) are bonded together with at least one transverse filament printed between each bonded increment separating the increments (e.g., a first increment of five bonded layers is separated from a second increment of five bonded layers). In one embodiment, each individual layer of the filler structure is separated by one or more transverse filaments printed between unbonded layers. In one embodiment, the transverse filaments printed between one or more layers of the filler structure include beads at one end of the filament. In one embodiment, the transverse filaments printed between one or more layers of the filler structure include beads at both ends of the filament. In one embodiment, the filler structure at the outer surface of the mold has identical repeating layers. These adjacent (i.e., two or more adjacent layers) identical layers of the filler structure can be bonded together and increase the strength of the outer surface of the mold, which can withstand mechanical strain and / or can form the product surface.

[0070] Figures 9 to 11 A top view of a 3D printed design structure according to an embodiment of the present invention is shown. Beads 410 are formed at both ends of transverse filaments 420. Channels 430 include layered transverse filaments 420. Layered filaments 420 are bonded to a filler layer 450. The beads 410 formed on the product surface of the mold form product surface holes 440, 445 at the ends of the channels 430 formed by the layered transverse filaments 420. Figure 10 An outer filler layer 455 is further depicted, having a fill density greater than that of the inner matrix filler layer 450. In one embodiment, the fill density of one or more outer filler layers is greater than that of the inner filler layer. Figure 11 A mold with a layer density combination is depicted, one part comprising layers of multiple transverse filaments between filler structural layers, and another part comprising filler layers and transverse filaments in a 1:1 ratio. It is worth noting that... Figures 9 to 11 The orientation of the structures depicts the horizontal product surface of the mold formed by the filler layer and the vertical product surface of the mold formed by the beads. In additive manufacturing, the vertical product surface is oriented vertically, while the horizontal product surface is oriented on a horizontal or near-horizontal plane.

[0071] In one embodiment, bead-like filaments are incorporated into the outer layer of the filler structure to form at least a portion of the product surface, such as... Figure 10As shown. Beads formed at one or both ends of the filament create product surface apertures on the product surface of the mold as disclosed herein. Thus, the system of the present invention can be used to customize 3D printing molds to include additional product surfaces, since the beaded filaments applied to the outer surface of the infill structure can be placed onto the product surface with high specificity. One or more beaded ends of the filament create product surface apertures to prevent fiber ingress. The apertures (i.e., product surface apertures or back apertures) are narrower than the width of the channels formed by the transverse filaments. Therefore, the narrow openings formed by the beaded filaments comprise a portion of the product surface. In one embodiment, the product surface is formed by the beaded ends of the transverse filaments at a vertically extending surface and the outer layer of the infill structure at a horizontal surface. In one embodiment, the units of the layered internal infill structure have the same apertures and do not determine the width of the channels of the present invention.

[0072] In one embodiment, beads are joined along the product surface of the mold. In one embodiment, beads are joined by molding each bead to an adjacent bead in a row of beads. In one embodiment, beads are joined by fusing each bead to an adjacent bead. In one embodiment, beads are joined by transverse filaments deposited along a row of beads, the transverse filaments being molded onto the rows of beads. In one embodiment, beads are joined by transverse filaments deposited along a row of beads, the transverse filaments being molded onto the beads in the row, while column-shaped beads are molded onto adjacent beads in the column. In one embodiment, beads are joined by transverse filaments deposited along a column of beads, the transverse filaments being molded onto the beads in the column, while transversely adjacent beads are molded onto adjacent beads in the column.

[0073] Figure 12 A mold according to an embodiment of the present invention is shown. When the remaining portion of the pulp is vacuum-evacuated through the matrix 520 of the mold, the bead-like product surface 510 filters fibers from the pulp. Those skilled in the art will understand that, as used herein, the matrix refers to the filling structure and transverse filaments encompassing the interior of the mold. The product surface 510 includes vertical and horizontal portions; the vertical portions are formed by a continuous layer of beads, wherein pores are defined by two adjacent beads, and the horizontal portions are formed by a grid-printed external filling structure.

[0074] In the vacuum forming process of 3D molded pulp products, an aqueous pulp slurry is applied to the product surface of the mold (e.g., by immersing the mold in a bucket of slurry or by injecting the slurry into the mold). A configuration of filler structures and open-cell units of discontinuous filaments allows negative pressure (i.e., vacuum suction) to be applied to the slurry through the mold. When suction is applied, the pulp fibers are vacuum-drawn onto the product surface of the mold. The product surface pores formed by the bead array and the pores (i.e., cells) of the external filler structure on the product surface prevent fibers from entering the mold's channels, while the layered filler structure and the internal stack formed by stacked transverse filaments support the integrity of the mold and guide the vacuum-evacuated material, along with the aggregated fibers, away from the product surface during this process. In one embodiment, the pulp slurry is injected into the mold. In another embodiment, the mold is partially (i.e., a portion of the mold) or completely (i.e., the entire mold) immersed in the pulp slurry. Those skilled in the art will understand that the invention can be used in various mechanisms for vacuum forming. In one embodiment, the mold is placed in a recess of a vacuum chamber, and vacuum pressure is applied to the back of the mold through the vacuum chamber. In one embodiment, the mold is fixed to a vacuum system, and vacuum pressure is applied to the mold through the vacuum system.

[0075] In one embodiment, the product surface of the mold is configured to be offset by 90 degrees, such that the horizontal and vertical product surfaces of the mold form a 90-degree angle at their intersection. In another embodiment, the horizontal and vertical product surfaces of the mold form an angle between 10 degrees and approximately 170 degrees at their intersection.

[0076] Figure 13A composite mold according to an embodiment of the present invention is illustrated. Partial mold components 610, 620, 630 are configured to connect when placed on a base 640, thereby forming a continuous mold surface (i.e., product surface). A molded fiber product 650 is vacuum-formed using the composite mold and pressed by an insert 660. As used herein, the term "composite mold" refers to a mold comprising multiple partial mold components. When the partial molds are connected to form a composite mold, each partial mold is capable of including complex shapes (i.e., shapes with irregular surfaces and / or angles). Using a composite mold formed from partial mold components, complex 3D products with protrusions, undercuts, corners, edges, ridges, and markings can be manufactured. By separating the partial molds, products with these features, particularly those with undercuts, can be released from the composite mold. Products formed using a single mold cannot include many of these complex features, at least in part because a single mold cannot be deconstructed to release the molded product. In one embodiment, the 3D printing mold design of the present invention is incorporated into one or more partial mold components. In one embodiment, the mold of the present invention is a composite mold comprising 3D printed partial mold components according to an embodiment of the present invention. In one embodiment, the 3D printed composite mold is the mold described in German Patent Publication No. 102019120854, the entire contents of which are incorporated herein by reference.

[0077] The partial mold components of the present invention are connected by at least one connecting element. In one embodiment, the connecting element connects multiple partial molds to a base. In one embodiment, the connecting element is used to connect at least one partial mold component to the base. In one embodiment, the connecting element secures multiple partial molds together. The connecting element stabilizes both the composite mold and the base by securing the partial mold components to the base, thereby preventing the mold components from shifting during vacuum forming of the 3D product. In one embodiment, the connecting element is a clamp that surrounds the composite mold when the partial mold components are assembled. The clamp is then closed to secure the partial mold components together. In one embodiment, the connecting element is a clamping collar fixed to the base, and the partial molds are assembled and pressed into the clamping collar. In one embodiment, the connecting element is a cup-shaped object in which the partial mold components are placed. In one embodiment, the bottom of the cup forms the base of the mold. In one embodiment, the connecting element is formed using a 3D printing process (e.g., the process of the present invention). In one embodiment, the connecting element comprises metal (e.g., aluminum) or plastic. In one embodiment, the connecting element is one or more protrusions configured to interlock with corresponding recesses (e.g., a protrusion of a partial mold component is configured to interlock with a recess of an adjacent partial mold component). In one embodiment, the connecting element is one or more buckles, clips, snaps, buttons, or temporary welds. In one embodiment, the connecting element is one or more pins attached to a partial mold component and extending into a pinhole of a second partial mold component. In one embodiment, the molding components are designed to interlock when negative pressure is applied to the composite mold.

[0078] Figure 14 A perspective view of a multi-part mold according to an embodiment of the present invention is shown. 3D-printed partial molds 710, 712 are fixed to vacuum blocks 730, 732 and secured by fastening rims 720, 722. Multiple 3D products 740 are formed using the multi-part mold.

[0079] To meet the increasing demand for 3D pulp products, the mold of the present invention can be fixed to a vacuum block for the simultaneous production of multiple 3D products. In one embodiment, the vacuum block comprises two halves of a 3D printed mold. The vacuum block includes two separable hydraulic halves, allowing the two fixed mold halves to engage and disengage as the vacuum block halves engage and disengage. To form multiple pulp products using this multi-part mold, the two halves are joined, and a complete mold is formed by the joined halves. Pulp slurry is applied to the interior of the mold, and vacuum pressure is applied to the slurry via the vacuum block through the 3D printed mold. When the forming step is complete, the two halves of the mold separate the formed 3D product, which can be removed. In one embodiment, the product is heated, pressed, and / or dried in the multi-part mold before separation from the vacuum block. This allows for faster formation of pulp products and the formation of pulp products with thin walls. Conventional vacuum forming methods cannot dry the product within the mold and require the shape to have a certain thickness to provide strength when removing the fragile wet product. However, drying the product within the mold eliminates the need for a minimum thickness to withstand processing, as the product is not processed until fully dried. Therefore, the mold of the present invention can be used in combination with such a system to allow the production of 3D pulp products.

[0080] In one embodiment, each vacuum block is configured with a separate vacuum system, such that the multi-part mold system includes at least two vacuum systems. In one embodiment, identical partial molds are attached to individual vacuum blocks, which apply negative pressure only to the partial molds attached to them. Each vacuum block is configured to apply the same negative pressure to the partial molds for the same duration to form a product with uniform integrity. In one embodiment, the partial molds attached to each vacuum block are not identical. The vacuum blocks are then configured to apply different negative pressures to the partial molds for the same duration, or to apply the same negative pressure for different times, to form a product with uniform integrity. In one embodiment, multiple vacuum blocks can employ the same vacuum system, such that when the blocks are sealed together, a single vacuum system is used to vacuum-form the product.

[0081] This invention provides a tool that allows drying within a mold. Drying molded fiber articles within a mold allows for the production of thin-walled articles because the wet, newly molded article does not need to be moved after formation but before drying occurs, as is the case in various prior art techniques. More precisely, articles are molded within the mold of this invention to produce molded fiber articles with a thickness between 0.01 mm and 1 mm. Furthermore, a fine profile of the molded fiber article is produced during drying with flowing air. The air presses the fibers against a screen on the product surface of the mold and finely reshapes them. Prior art systems are not configured to produce threaded sides without directional control during drying, which can only be achieved by using a mold capable of forming and drying articles, as is the case in this invention.

[0082] In one embodiment, the 3D printing method of the present invention utilizes molten material to form beads, filaments, infill structures, protrusions, recesses, and / or other connecting mechanisms. In one embodiment, the 3D printing method of the present invention utilizes molten material to form beads, filaments, and infill structures, while protrusions, recesses, and / or other connecting mechanisms are not 3D printed. In one embodiment, the molten material used to produce the printed part includes a biodegradable material, such as a biodegradable thermoplastic polymer or natural fiber polymer composite (NFPC). Examples of materials that can be used to form printed parts include, but are not limited to: biodegradable thermoplastics such as thermoplastic starch-based plastics (TPS), polyhydroxyalkanoates (PHA), polylactic acid (PLA), polybutylene succinate (PBS), or polycaprolactone (PCL); biodegradable thermoplastic resins such as bio-based polyethylene (PE), bio-based polyethylene terephthalate (PET), bio-based technical performance polymers (e.g., various polyamides (PA) or partially bio-based polyurethanes (PUR)); and natural fiber-based compositions (e.g., NFPC) derived from plants such as hemp, flax, jute, wood, lignocellulosic plant fibers, bamboo, or sweetgrass, or any combination thereof. In one embodiment, the molten material used to form the printed part is acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), polyethylene terephthalate (PETG), nylon, thermoplastic polyurethane (TPU), polyvinyl alcohol (PVA), high-impact polystyrene (HIPS), carbon fiber, Kevlar fiber, glass fiber, resin, aluminum, stainless steel, tool steel, titanium, nickel alloy, or any combination thereof.

[0083] Those skilled in the art will understand that the threshold temperature of the mold is determined in part by the material used to print the mold. In one embodiment, the vacuum is configured to withstand temperatures up to 200°C. In one embodiment, the vacuum is configured to withstand temperatures up to 300°C. In one embodiment, the vacuum is configured to withstand temperatures up to 500°C.

[0084] This invention includes an additive manufacturing process in which a 3D printer is used to print a mold as disclosed herein. In one embodiment, the 3D printing process includes a user device receiving one or more input designs to be 3D printed and transmitting one or more designs to the 3D printer (e.g., wirelessly). Figure 15 This is a schematic diagram of an embodiment of the present invention, illustrating a computer system, typically described as 800, for controlling the 3D printing process, having a network 810, multiple computing devices 820, 830, 840, a server 850, and a database 870.

[0085] Server 850 is constructed, configured, and coupled to enable communication with multiple computing devices 820, 830, and 840 via network 810. Server 850 includes a processing unit 851 having an operating system 852. The operating system 852 enables server 850 to communicate with remote distributed user devices via network 810. Database 870 can house the operating system 872, memory 874, and programs 876.

[0086] In one embodiment of the invention, system 800 includes a network 810 for distributed communication via wireless communication antenna 812 and processed by at least one mobile communication computing device 830. Alternatively, wireless and wired communication and connectivity between the devices and components described herein include wireless network communication such as Wi-Fi, Global Microwave Access Interoperability (WIMAX), radio frequency (RF) communication (including RF identification (RFID)), near field communication (NFC), Bluetooth (including Bluetooth Low Energy (BLE)), ZigBee, infrared (IR) communication, cellular communication, satellite communication, Universal Serial Bus (USB), Ethernet communication, communication via fiber optic cable, coaxial cable, twisted pair cable, and / or any other type of wireless or wired communication. In another embodiment of the invention, system 800 is a virtual computing system capable of executing any or all aspects of the software and / or application components presented herein on computing devices 820, 830, 840. In some aspects, computer system 800 can be implemented using hardware or a combination of software and hardware, either in a dedicated computing device, integrated into another entity, or distributed across multiple entities or computing devices.

[0087] By way of example and not limitation, computing devices 820, 830, and 840 are intended to represent various forms of electronic devices including at least a processor and memory, such as servers, blade servers, mainframes, mobile phones, personal digital assistants (PDAs), smartphones, desktop computers, netbooks, tablet computers, workstations, laptops, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely exemplary and are not intended to limit the embodiments of the invention described and / or claimed in this application.

[0088] In one embodiment, computing device 820 includes components such as processor 860, system memory 862 having random access memory (RAM) 864 and read-only memory (ROM) 866, and system bus 868 coupling memory 862 to processor 860. In another embodiment, computing device 830 may additionally include components such as storage device 890 for storing operating system 892 and one or more applications 894, network interface unit 896, and / or input / output controller 898. Each component may be coupled to each other via at least one bus 868. Input / output controller 898 may receive and process input from or provide output to multiple other devices 899, including but not limited to alphanumeric input devices, mice, styluses, display units, touchscreens, game controllers, joysticks, touchpads, signal generation devices (e.g., speakers), augmented reality / virtual reality (AR / VR) devices (e.g., AR / VR headsets), or printers.

[0089] By way of example and not limitation, processor 860 may operate as a general-purpose microprocessor (e.g., a central processing unit (CPU)), a graphics processing unit (GPU), a microcontroller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a programmable logic device (PLD), a controller, a state machine, gated or transistor logic, a discrete hardware component, or any other suitable entity or combination thereof capable of performing computations, processing instructions and / or information for execution.

[0090] In another embodiment, such as Figure 15 As shown in 840, multiple processors 860 and / or multiple buses 868 can be used with multiple types of memory 862 (e.g., a combination of DSP and microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core) when appropriate.

[0091] Furthermore, multiple computing devices can be connected, with each device providing a portion of the necessary operation (e.g., a server cluster, blade server cluster, or multiprocessor system). Alternatively, some steps or methods can be performed by circuits specific to a given function.

[0092] According to various embodiments, computer system 800 can operate in a networked environment using logical connections to local and / or remote computing devices 820, 830, 840 via network 810. Computing device 830 can be connected to network 810 via network interface unit 896 connected to bus 868. The computing device can transmit communication media via wired network, direct wired connection, or wirelessly (e.g., acoustic, RF, or infrared) through antenna 897 communicating with network antenna 812 and network interface unit 896, which may include digital signal processing circuitry if necessary. Network interface unit 896 can provide communication under various modes or protocols.

[0093] In one or more exemplary aspects, the instructions can be implemented in hardware, software, firmware, or any combination thereof. A computer-readable medium can provide volatile or non-volatile storage for one or more sets of instructions, such as an operating system, data structures, program modules, application programs, or other data embodying any one or more methods or functions described herein. A computer-readable medium can include memory 862, processor 860, and / or storage medium 890, and is operable as a single medium or multiple media (e.g., a centralized or distributed computer system) storing one or more sets of instructions 900. Non-transitory computer-readable media includes all computer-readable media, with the sole exception of transient propagation signals themselves. Instructions 900 can also be transmitted or received on network 810 via a network interface unit 896 serving as a communication medium, which can include modulated data signals such as carrier waves or other transmission mechanisms, and include any transmission medium. The term "modulated data signal" means a signal having one or more of its characteristics that are altered or set in a manner relating to the encoding of information in the signal.

[0094] Storage device 890 and memory 862 include, but are not limited to, volatile and non-volatile media such as cache, RAM, ROM, EPROM, EEPROM, flash memory or other solid-state memory technologies; disks (e.g., digital universal disk (DVD), HD-DVD, Blu-ray, optical disc (CD) or CD-ROM) or other optical storage devices; magnetic tape cassettes, magnetic tape, disk storage, floppy disk or other magnetic storage devices; or any other medium that can be used to store computer-readable instructions and can be accessed by computer system 800.

[0095] In one embodiment, computer system 800 is located within a cloud-based network. In one embodiment, server 850 is a designated physical server for distributed computing devices 820, 830, and 840. In one embodiment, server 850 is a cloud-based server platform. In one embodiment, the cloud-based server platform hosts serverless functionality for distributed computing devices 820, 830, and 840.

[0096] In another embodiment, computer system 800 is within an edge computing network. Server 850 is an edge server, and database 870 is an edge database. Edge server 850 and edge database 870 are part of an edge computing platform. In one embodiment, edge server 850 and edge database 870 are assigned to distributed computing devices 820, 830, and 840. In one embodiment, edge server 850 and edge database 870 are not assigned to distributed computing devices 820, 830, and 840. Distributed computing devices 820, 830, and 840 connect to edge servers in the edge computing network based on proximity, availability, latency, bandwidth, and / or other factors.

[0097] It can also be envisioned that computer system 800 could not include Figure 15 All components shown can include Figure 15 Other components not explicitly shown in the document, or those that can be utilized with Figure 15 The architectures shown are completely different. The various illustrative logic blocks, modules, elements, circuits, and algorithms described in conjunction with the embodiments disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. To clearly illustrate this interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application (e.g., in a different order or in a different manner); however, such implementation decisions should not be construed as departing from the scope of this invention.

[0098] After reading the foregoing description, certain modifications and improvements will arise in the mind of those skilled in the art. The examples provided above are intended to illustrate various aspects of the invention, and it will be apparent to those skilled in the art that they are not intended to limit the scope of the invention. For the sake of brevity and readability, all modifications and improvements have been omitted herein, but such modifications and improvements are suitably within the scope of the invention.

[0099] The features of the invention disclosed in this specification, drawings, and claims can be used individually or in any combination to implement various embodiments of the invention. The invention is not limited to the described embodiments. It can be varied within the scope of the claims and, with due consideration of the knowledge of those skilled in the art.

Claims

1. A mold produced using additive manufacturing technology, comprising: -Product surface and internal matrix; - At least one transverse polymer layer comprising a plurality of adjacent columns of stacked filaments; -At least one filled polymer layer; as well as - Multiple channels, wherein each channel is defined between two adjacent columns of stacked filaments; -The point is over-extruded at the end of each stacked filament facing the product surface; - wherein the product surface of the mold includes a plurality of holes formed between points of adjacent columns of stacked filaments, wherein the width of the holes is smaller than the width of the channels distal to the product surface, and the holes are configured to prevent fibers from entering the internal matrix of the mold; and - wherein a filling polymer layer is deposited on the at least one transverse polymer layer.

2. The mold according to claim 1, wherein, The at least one transverse polymer layer and the at least one filled polymer layer comprise at least one component selected from the group consisting of biodegradable thermoplastic polymers, natural fiber polymer composites (NFPC), polylactic acid (PLA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PETG), and nylon.

3. The mold according to claim 1, wherein, The at least one filling polymer layer is a honeycomb pattern, grid pattern, cube pattern, octahedral pattern, triangle pattern, hexagonal pattern, line pattern, spiral icosahedral pattern, serrated pattern, cross pattern, or concentric pattern.

4. The mold according to claim 1, wherein, The at least one transverse polymer layer is approximately 1 mm thick.

5. The mold according to claim 1, wherein, At least one additional lateral polymer layer is deposited on top of the filler layer, wherein at least one additional filler layer is deposited on top of the at least one additional lateral polymer layer.

6. The mold according to claim 1, wherein, The internal matrix is ​​wider than the plurality of holes on the product surface of the mold.

7. The mold according to claim 1, wherein, The at least one transverse polymer layer is not tapered.

8. The mold according to claim 1, wherein, The at least one filler layer forms at least a portion of the surface of the product, wherein at least one additional point is extruded on the at least one filler layer.

9. The mold according to claim 1, wherein, Applying a vacuum to the mold allows negative pressure to pass through the internal matrix of the mold to the surface of the product.

10. An additive manufacturing method for producing a vacuum forming die, comprising: - Deposit initial transverse filaments, wherein the extrusion point is located at the end of the initial transverse filaments; - An initial transverse filament column is formed by sequentially depositing multiple additional transverse filaments on top of the initial transverse filament, wherein an over-extrusion attachment point is formed at the end of each additional transverse filament. - Deposit at least one adjacent transverse filament row, comprising a layer of stacked transverse filaments adjacent to the initial transverse filament row, wherein a stacking point is extruded at the end of each stacked transverse filament in the at least one adjacent transverse filament row, and wherein a channel is defined between the initial transverse filament row and the at least one adjacent transverse filament row, the channel having a narrow orifice between the over-extrusion points at the ends of each transverse filament; and - A filler polymer layer is deposited on top of the at least one additional transverse filament and the at least one adjacent transverse filament row, wherein the at least one filler polymer layer stabilizes the initial transverse filament row and the at least one adjacent transverse filament row.

11. The method according to claim 10, wherein, The initial transverse filament, the dot, the at least one additional transverse filament, the additional dot, and the filler polymer layer comprise at least one component selected from the group consisting of biodegradable thermoplastic polymers, natural fiber polymer composites (NFPC), polylactic acid (PLA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PETG), and nylon.

12. The method according to claim 10, wherein, The filling polymer layer can be a honeycomb pattern, grid pattern, cube pattern, octahedral pattern, triangle pattern, hexagonal pattern, line pattern, spiral icosahedral pattern, serrated pattern, cross pattern, or concentric pattern.

13. The method of claim 10, further comprising depositing at least one additional transverse filament layer on top of the filled polymer layer.

14. The method of claim 13, further comprising depositing at least one additional filler layer through the at least one additional lateral filament layer in increments of about 1 mm.

15. The method according to claim 10, wherein, The distance between the overlapping points is less than the distance between the initial transverse filament and the overlapping transverse filament.

16. The method of claim 10, further comprising applying a vacuum to the mold, wherein, Applying negative pressure to the mold allows the negative pressure to pass through the internal matrix of the mold to the product surface of the mold.

17. A system for molding pulp fiber products, comprising: - A mold comprising a product surface and a back surface, wherein the mold is produced using an additive manufacturing process; - A vacuum system connected to the mold; and pulp slurry comprising natural fibers; - wherein a filler polymer layer is deposited on top of a first transverse polymer layer, wherein the first transverse polymer layer comprises a first plurality of adjacent columns of stacked filaments; - wherein at least one additional transverse polymer layer is deposited on top of the filler polymer layer, wherein the at least one additional transverse polymer layer comprises additional multiple adjacent columns of stacked filaments; -The point is over-extruded at the end of each stacked filament facing the product surface; -In this context, multiple channels are defined between adjacent columns of stacked filaments; - wherein the product surface of the mold includes a plurality of holes formed between points of adjacent columns of stacked filaments, wherein the holes are narrower than the width of the channel, and wherein the holes are configured to prevent fibers from entering the internal matrix of the mold; - wherein the product surface of the mold contacts the pulp slurry, and wherein a negative pressure is applied to the mold by a vacuum system connected to the mold; and - wherein the natural fibers of the pulp are aggregated on the product surface of the mold to form a molded pulp product.

18. The system according to claim 17, wherein, The distance between the over-extrusion point at the end of the first column of the first plurality of adjacent columns of the stacked filaments facing the product surface and the over-extrusion point at the end of the second column of the first plurality of adjacent columns of the stacked filaments facing the product surface is less than the distance between the first column of the first plurality of adjacent columns of the stacked filaments and the second column of the first plurality of adjacent columns of the stacked filaments.

19. The system according to claim 17, wherein, The first plurality of adjacent columns are approximately 1 mm high.

20. The system according to claim 17, wherein, The internal matrix is ​​wider than the plurality of holes on the product surface of the mold.

21. The system according to claim 17, wherein, Each of the plurality of holes is between approximately 0.25 mm and approximately 1 mm.

22. The system according to claim 17, wherein, The filling polymer layer can be a honeycomb pattern, grid pattern, cube pattern, octahedral pattern, triangle pattern, hexagonal pattern, line pattern, spiral icosahedral pattern, serrated pattern, cross pattern, or concentric pattern.

23. The system according to claim 17, wherein, At least one additional filler polymer layer is deposited through the at least one additional lateral polymer layer in increments of approximately 1 mm.

24. A method for producing a molded fiber product, comprising: - The steps involved in forming a mold via an additive manufacturing process include: - Deposit adjacent transverse filaments, wherein there is an over-extrusion point at the end of each adjacent transverse filament facing the product surface; - At least one additional transverse filament is deposited on top of the initial transverse filament, wherein an over-extrusion attachment point is formed at the end of the at least one additional transverse filament facing the product surface to form a series of adjacent columns of stacked transverse filaments and channels between adjacent columns. - A filler polymer layer is deposited on top of the at least one additional transverse filament, wherein the at least one filler polymer layer stabilizes the initial transverse filament and the at least one additional transverse filament; - The product surface forming the mold, wherein the product surface of the mold includes a plurality of holes formed between extrusion points at the ends of adjacent filaments, wherein the orifice of each hole is narrower than the width of a channel remote from the product surface; and - Forming the back side of the mold; and - The mold is immersed in pulp slurry, wherein the mold is connected to a vacuum system, wherein the vacuum system applies negative pressure to the surface of the product through the internal matrix of the mold.

25. The method according to claim 24, wherein, Each of the series of adjacent columns is approximately 1 mm high.

26. The method according to claim 24, wherein, Each of the plurality of holes is between approximately 0.25 mm and approximately 1 mm.

27. The method according to claim 24, wherein, The back side of the mold is not porous.

28. The method according to claim 24, wherein, The mold is formed using additive manufacturing fused deposition modeling (FDM) technology.

29. The method according to claim 24, wherein, The adjacent transverse filaments, the point, the at least one additional transverse filament, the additional point, and the filler polymer layer comprise at least one component selected from the group consisting of biodegradable thermoplastic polymers, natural fiber polymer composites (NFPC), polylactic acid (PLA), polycarbonate (PC), acrylonitrile butadiene styrene (ABS), polyethylene terephthalate (PETG), and nylon.

30. The method according to claim 24, wherein, The filling polymer layer can be a honeycomb pattern, grid pattern, cube pattern, octahedral pattern, triangle pattern, hexagonal pattern, line pattern, spiral icosahedral pattern, serrated pattern, cross pattern, or concentric pattern.

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