Automated manufacturing of 3D objects from composite materials

Abstract

A method of fabricating a three-dimensional object from a composite material is described. The method includes using an extrusion nozzle configured to extrude a composite material including a multi-strand filament with a thixotropic matrix material surrounding the multi-strand filament. Extruding an airborne three-dimensional object surface segment over at least a portion of the discontinuous work surface and simultaneously actuating a curing energy source to fixate and increase strength of the airborne three-dimensional object surface segment. The extruded surface segment of the airborne three-dimensional object is sufficiently rigid to maintain its shape without the use of a mandrel.

Description

Technical Field

[0001] The present method and apparatus relate to the manufacture of objects from composite materials, particularly the automated manufacture of three-dimensional objects.

Background Art

[0002] A composite material is a material that includes at least two distinct components. Typically, composite materials include a fiber reinforcement such as glass fiber, Kevlar®, carbon fiber, etc. and a resin. The resin can be epoxy, polyester resin, or vinyl ester. When the two components are mixed and processed, the two components are mechanically and chemically bonded to form a laminated part. The composite physical strength and properties of the composite material exceed those of either of the individual material components. The resin includes pigments or dyes and can provide the desired color to the composite material, reducing the need for a painting process. Composite materials reinforced with the most frequently used carbon and glass fibers are often generically referred to as "composites". Composites are a major manufacturing material (construction material) for three-dimensional objects, particularly large three-dimensional objects.

[0003] The labor-intensive wet lay-up process of stacking layers of a laminate and combining them with a liquid resin to cure is still the main manufacturing process for large three-dimensional objects. Typically, large and bulky three-dimensional composites are manufactured using the corresponding number of molds as two or more parts. The parts forming the three-dimensional object are joined together, a vacuum is applied, and a resin for bonding the mat is injected. Once the resin has cured, the two or more parts are joined together to form a three-dimensional object. The injection technique simplifies the resin introduction and curing process, but the lay-up is still a laborious process.

[0004] Almost all three-dimensional objects, particularly large three-dimensional objects, undergo further manufacturing steps. The outer surface of the three-dimensional object can be polished, painted, or coated with varnish. All processes are still manual and time-consuming and costly.

[0005] Composite materials are popular for several reasons. They are lightweight and high-strength. They have excellent resistance to almost all environments. Any composite material manufacturer can produce almost any composite if they have or can manufacture a suitable mold or mandrel. The manufacturing steps for three-dimensional objects made from the above-mentioned composite materials slow down the manufacturing process, increase the cost of the manufactured three-dimensional objects, and waste composite materials.

[0006] Despite the advantages of composite materials—lightweight, environmentally stable, and strong—the high cost of labor-intensive and time-consuming manufacturing methods hinders their development and use.

[0007] definition Lamination of composite material sheets is a process of taking one composite material sheet and laminating it onto another composite material sheet in order to give the material greater strength.

[0008] The term "aramid fiber" is a combination of the words "aromatic" and "polyamide." Aramid fibers are a general term for fibers in which at least 85% are amide bonds (-CO-NH-) directly bonded to two aromatic rings.

[0009] A complex three-dimensional object refers to a three-dimensional physical object that includes curved surfaces, planes, and surfaces that may protrude from the body of the object, which may be convex or concave, or, in the case of a hollow object, surfaces that may protrude into the hollow space or cavity inside the three-dimensional object. Surfaces can be inclined, oriented at various angles, and have various thicknesses or sizes.

[0010] A prepreg is a "pre-impregnated" composite fiber or strand that already contains a thermosetting polymer matrix material, such as epoxy or thermoplastic resin. The thermosetting matrix is ​​partially cured to allow for safe handling. This B-stage material requires specific storage conditions to prevent complete curing.

[0011] End face preparation is the process by which the ends of a manufactured composite segment are prepared for connection with the next composite segment. End face preparation includes reducing or increasing the end diameter, flanging, and chamfering.

[0012] A filament is the smallest unit of fibrous material. Filaments are formed during drawing and spinning and are the basic units that are assembled into fiber strands for composite materials.

[0013] Filament winding is a process for manufacturing composite structures of continuous reinforcing materials (filaments, wires, threads, tapes, etc.). After pre-impregnation with a matrix material or impregnation during winding, the filaments are arranged in a predetermined manner on a rotating and removable mold or mandrel to satisfy specific stress conditions.

[0014] An end effector is typically a tool attached to the end of a robotic arm that performs a desired function. This function could include material deposition, spray painting, or polishing a finished three-dimensional object.

[0015] As used in this disclosure, the term “robot arm” includes robot arms, gantry, rails / guides with carriages, and other equivalents capable of lifting and carrying loads. [Overview of the project] [Means for solving the problem]

[0016] A method for manufacturing a three-dimensional object from a composite material is described. In one embodiment, the method involves using an extrusion nozzle configured to extrude a composite material containing multi-strand filaments together with a thixotropic matrix material surrounding the multi-strand filaments. A surface segment of the three-dimensional object is extruded into the air beyond at least a portion of a discontinuous work surface, and a curing energy source is activated simultaneously to fix the surface segment of the three-dimensional object in the air and increase its strength. The extruded surface segment of the three-dimensional object in the air is sufficiently rigid to maintain its shape without the use of a mandrel.

[0017] A discontinuous work surface, formed by individually adjustable supports terminating at a receptive surface configured to accept a desired orientation in space, supports the manufactured three-dimensional object. One or more robotic arms move and manipulate a suitable pickup end-effector tool to perform multiple tasks in the manufacturing of the three-dimensional object.

[0018] In one embodiment, the three-dimensional object is manufactured in layers, and each layer of the three-dimensional object is extruded from a different material. In some embodiments, one or more ribs supporting the surface segments of the three-dimensional object suspended in the air can be extruded simultaneously with the extrusion of the surface segments.

[0019] In some embodiments, a metal or polymer grid dispersed across an adjustable support platform serves as a substrate for the deposition of composite materials of a three-dimensional object.

[0020] Methods for fabricating three-dimensional objects from composite materials include the fabrication of reinforced multi-strand filaments with a thixotropic matrix material surrounding the multi-strand filaments. The multi-strand filaments can be formed into flat strips. Multiple different coatings can be deposited on the surface of these flat strips.

[0021] An apparatus for manufacturing a three-dimensional object from a composite material is also disclosed. The apparatus includes an adjustable support platform formed by a plurality of individually adjustable struts and at least one robotic arm configured to manipulate a plurality of end effector tools. The end effector tools can be, for example, a material extrusion nozzle, a grid diffusion device, a paint brush, a polishing tool, etc., which may be required in the manufacturing process.

Brief Description of the Drawings

[0022] To understand the apparatus and method and how they can be actually implemented, the embodiments will be described by way of only non-limiting examples with reference to the accompanying drawings. In the figures, the same reference numerals denote the same or similar parts.

[0023] [Figure 1] FIG. 1 is a side view of an embodiment of the present apparatus for manufacturing a three-dimensional object from a composite material.

[0024] [Figure 2] FIG. 1 is a cross-section C-C.

[0025] [Figure 3] FIG. 1 shows an embodiment of the heat curing device of the apparatus of FIG. 1.

[0026] [Figure 4A] FIG. 1 shows an embodiment of the on-site manufacturing of a composite multi-strand filament.

[0027] [Figure 4B] FIG. 1 shows another embodiment of the on-site manufacturing of a composite flat multi-strand filament.

[0028] [Figure 4C] FIG. 1 shows a further embodiment of the on-site manufacturing of a composite flat multi-strand filament.

[0029] <![CDATA[ [Figure 4D] ]]This is a further example of on-site manufacturing of composite flat multistrand filaments.

[0030] [Figure 4E] This is an example of on-site manufacturing of a flat strip of composite flat multi-strand in which the same side of the strip is coated with layers of different thicknesses.

[0031] [Figure 5] This block diagram shows the control and operation of the additional units of this device.

[0032] [Figure 6] This is an example of a method for manufacturing a three-dimensional object containing convex and concave segments from a composite material.

[0033] [Figure 7A] This is another embodiment of a method for manufacturing a three-dimensional object containing convex and concave segments from a composite material.

[0034] [Figure 7B] This is a further embodiment of a method for manufacturing a three-dimensional object including convex and concave segments from a composite material.

[0035] [Figure 8A] This document describes a method for manufacturing a three-dimensional object using a support grid.

[0036] [Figure 8B] This is an additional diagram showing a method for manufacturing a three-dimensional object using a support grid.

[0037] [Figure 9] Figure 6 shows a 3D object rotated to print the second face of the 3D object.

[0038] [Figure 10] This is an example demonstrating filament winding on the surface of a partially created three-dimensional object. [Modes for carrying out the invention]

[0039] Despite the advantages of composite materials in terms of weight, environmental stability, and strength, high-cost tools and labor-intensive, time-consuming manufacturing methods are hindering their development and use. The industry would progress rapidly if low-cost manufacturing processes became available that significantly reduce labor-intensive work, lessen the need for mandrels or molds, and maintain the quality of the manufactured objects.

[0040] This specification discloses automated methods and apparatus for manufacturing virtually any three-dimensional object from composite materials. The automated manufacturing methods are applicable to the manufacture of sculptures, exhibits, wind turbine rotor blades, wings, and boats. The proposed methods reduce manufacturing costs and provide greater accuracy in three-dimensional object profiles.

[0041] This specification also discloses the manufacture of a multistrand filament having a thixotropic matrix material surrounding a multistrand core. Coating the extruded multistrand core with the thixotropic material supports the near-instantaneous curing of the bonded multistrand material and simplifies the curing process.

[0042] This specification further discloses a method and apparatus for manufacturing large three-dimensional objects applicable to the manufacturing of three-dimensional objects at the object installation site.

[0043] Device Figure 1 is a side view of an embodiment of an apparatus for manufacturing a three-dimensional object from a composite material. The apparatus 100 includes an adjustable support platform 104 configured to support a manufactured three-dimensional object, for example, a three-dimensional object 108 placed on the support platform. The three-dimensional object is a complex object and includes planar segments and curved segments. The curved segments may consist of convex or concave surfaces. If a long three-dimensional object, for example, a wind turbine rotor blade or the body of a canoe, needs to be manufactured, its dimensions may exceed the reasonable dimensions of the adjustable support platform 104. A plurality of individually adjustable supports 116 form the adjustable support platform 104. Section 112 of the apparatus 100 also includes several independent adjustable three-dimensional object supports 116, arranged to support overhangs of an extended or protruding three-dimensional object 108 over the segments of the adjustable support platform 104. The adjustable support 116 is configured to move along the Z-axis and includes a receptive surface 120 that accepts overhangs of a long object 108 over a segment of the adjustable support platform 104. A rotating sphere 124 is positioned on the receptive surface 120 of the adjustable support 116 to facilitate repositioning of the object 108. The receptive surface 120 can be rotated within a range of approximately 340 degrees (Figure 2) in any direction with respect to the axis of symmetry 204 (Z-axis), so that any receptive surface 120 of the adjustable support 116 can support any curved three-dimensional object at any location on the adjustable support platform. In some embodiments, the adjustable support 116 with the receptive surface 120 can be repositioned to meet the manufacturing requirements of a particular three-dimensional object.

[0044] The frequency of the arrangement of the adjustable support columns 116 may vary depending on the device 100. The distance between the receiving surfaces 120 into which the rotating sphere 124 of the adjustable support columns 116 is inserted is selected to support minimal sag in the surface of the three-dimensional object 108 (Figure 1). In some embodiments, a rotating cylinder replaces the rotating sphere 124. A motor is connected to the rotating cylinder and can be used to manipulate the cylinder and assist in repositioning, such as rotation, of the manufactured three-dimensional object.

[0045] The apparatus 100 may include a guide 140. At least one robotic arm 144 may be attached to the guide 140 or move with the guide 140. Typically, the guide supports the movement of the robotic arm along the longest dimension of a three-dimensional object. One or more robotic arms 144 may be configured to perform different tasks. For example, they may have a composite material extrusion nozzle 148, a paint spray head, a three-dimensional object polishing device, or other necessary components. The robotic arms 144 move the composite material extrusion nozzle 148 and other end effectors (tools) connected to the robotic arms 144 in three directions or three axes (X, Y, and Z). The robotic arms 144 support the rotation of the end effectors around each of the three axes.

[0046] In some embodiments, the apparatus 100 may include a plurality of robotic arms, each having at least one robotic arm operating from below the adjustable support platforms 104 and 112. By repositioning the adjustable support column 116 to a specific location, the operation of the robotic arms accessing the adjustable support platforms 104 and 112 from below can be facilitated.

[0047] During the material extrusion process, the adjustable support platform 104 supports the manufactured three-dimensional object. The width of the adjustable support platform 104 sets at least one dimension of the three-dimensional object. In this case, the width of the adjustable support platform 104 can be from 1 meter to 4 meters. The number of adjustable supports can be used to adjust the length of the manufactured three-dimensional object.

[0048] One or more curing radiation sources 162 can accelerate the curing of the extruded filament 166. Several embodiments of the apparatus 100 (Figure 1) may include multiple means for curing the extruded material. One embodiment of the curing source may be multiple ultraviolet radiation sources 162 positioned near the extrusion nozzle. In further embodiments, the curing radiation sources may be positioned to direct radiation onto the freshly extruded elements of a three-dimensional object.

[0049] A laser beam or other optical alignment device 170 based on the use of a laser beam can be used for the alignment and calibration of the receiving surface 120 of the adjustable support column 116. This feature facilitates general alignment and calibration of off-site (field) three-dimensional object manufacturing equipment.

[0050] The heat can harden a portion of the extruded material. The apparatus 100 may include several IR (infrared) sources 304 (Figure 3) or even simple heaters positioned to heat the freshly extruded elements of the three-dimensional object. The IR sources 304 may be placed in a bridge-type holder 308 that is moved along the three-dimensional object being manufactured by a robotic arm. Alternatively, the IR sources 304 may be placed in a gantry that carries the IR sources along with the three-dimensional object being manufactured.

[0051] Extrusion molding Figure 4A shows an embodiment of an extrusion nozzle 404 configured to extrude a reinforced multistrand filament manufactured in a mode similar to that disclosed in U.S. Patent Publication No. 2014 / 0328964, International Patent Publication No. 2019 / 245363, and European Patent No. 3231592. In one embodiment, the reinforced multistrand filament 406 is manufactured on-site along with the manufacture of the three-dimensional object. Alternatively, a pre-manufactured multistrand filament (prepreg) purchased from a third party may be used. In one embodiment, the reinforced filament 406 includes a multistrand core 408, a matrix material 412 surrounding the multistrand core, and an additional coating 416 to support rapid solidification of the reinforced filament 406. The additional coating 416 also smooths the surface of the multistrand reinforced filament 406. The core 408 of the reinforced filament may be one of the materials consisting of glass fiber, carbon fiber, aramid fiber, or Kevlar strands. The filament matrix 412 may be a polymer, such as one of the materials consisting of a two-component epoxy, a fast-curing epoxy, a polyester resin, or a vinyl ester. The epoxy component is mixed in a mixing chamber 424 before extrusion and extruded together with the multi-strand core or filament.

[0052] In further embodiments, the reinforcing filament 406, which may be a prepreg material, includes an additional coating layer 416 surrounding the matrix material. For example, the additional coating material may be a cationic curing epoxy or thixotropic material that supports the rapid solidification of the reinforcing filament 406.

[0053] In this disclosure, the reinforced multistrand filament 406 further passes through another coating system 428. The coating system 428 coats the original multistrand filament 402 with a layer of thixotropic material 416. The thixotropic material supports the near-instantaneous curing of the reinforced and coated filament 406. The thixotropic material may be Dimengel®, a proprietary photopolymer material available from the assignee of this application. Arrow 430 indicates the direction of travel of the multistrand filament.

[0054] In a further embodiment, the multistrand filament is manufactured as a flat strip 434 (Figure 4B). The strip 434 could be manufactured in advance as a prepreg and fed through two rollers 436 and 438. The advantage of the flat strip is that each face 442-444 of the strip can be easily coated with different coatings / materials, and each coated layer can be of a different thickness, forming a flat strip 434-1. For example, face 442 can be coated with a fast-curing or two-component epoxy, and face 444 can be coated with a thixotropic material. The strip 434-1 can be manufactured in a three-dimensional object manufacturing site by providing a multistrand core and a coating system 440.

[0055] The fast-curing epoxy may be a cationic epoxy that supports the rapid solidification of reinforcing filaments in the form of cylindrical or flat strips. The thixotropic material may be a material commercially available from the assignee of this application.

[0056] As already explained, the core of the reinforced filament 434 may be one of the materials consisting of glass fibers, carbon fibers, aramid fibers, or Kevlar strands.

[0057] Figure 4C shows a brush coating system in which each brush 446-448 can coat both sides of a flat strip 434 with the same or different material. Figure 4D shows a spray coating system in which a material spray nozzle 450 sprays different materials 452 or 454 onto both sides of a flat strip. Figure 4E-1 shows an example of a flat strip coated in a different way, forming layers 460 and 462 of different thicknesses. Figure 4E-2 shows an example in which one or more inkjet nozzles deposit different materials 472-1, 472-2, and 472-3 on the same side of a flat strip 434. The deposited materials may be of the same or different thicknesses.

[0058] The extrusion nozzle 404 (Figure 4A) extrudes multi-strand filaments 406, 434-1, etc., reinforced and coated with thixotropic material, to form planar and curved segments of a three-dimensional object 108 (Figure 1). U.S. Patent No. 10,639,846, by the same assignee and inventor, discloses a multi-nozzle extruder in which each extrusion nozzle operates independently of the other extrusion nozzles. This apparatus supports simultaneous printing of different segments of a three-dimensional object 108. Other sizes and shapes of nozzle cross-sections, e.g., hexagonal, square, elliptical, and rectangular, can be used depending on the requirements of the particular three-dimensional object. The diameter of the extrusion nozzle 404 (Figure 4A) is typically 2.0–2.5 mm. Rectangular or elliptical nozzles may be 1.0–2.5 mm wide and 5.0–10.0 mm long, but other larger or smaller sizes are also possible. The nozzles are interchangeable, allowing the apparatus 100 (Figure 1) to manufacture parts with various structural surfaces.

[0059] The feed rate at which the multi-strand filament 406 and other reinforcing filaments are extruded or coated can also be used to adjust the coating thickness. In one embodiment, the use of multiple extruder heads is envisioned. Multiple feeders can operate to extrude multiple strands and supply them to multiple extruder heads. The apparatus 100 can alternately switch between the multiple feeders to apply different multi-strand filaments to different segments of a three-dimensional object.

[0060] Additional unit for the device Figure 5 is a block diagram of additional units of the apparatus 100, their control, and operation. The apparatus 100 includes a control computer 152 that controls the operation of the apparatus 100 (Figure 1). The control computer 152 receives the profile and length of a three-dimensional object to be manufactured from a CAD system, for example, a three-dimensional object 108. The computer 152 adjusts the angle and height of the receiving surface 120 of a support column 116 (Figure 1) that is adjustable to fit the profile and length of the three-dimensional object 108. The control computer 152 controls the movement of one or more robot arms 144, the extrusion speed of a material trough nozzle 148, the curing energy level, and other three-dimensional object manufacturing parameters.

[0061] The control computer 152 controls robotic arms such as the 3D object polishing device 504, the paint spraying device 508, and the varnish deposition device 512 as needed. The robotic arm 144 or similar moves the extrusion nozzle 148 and other end effectors (tools) attached to the robotic arm in three directions or three axes (X, Y, and Z) and supports the rotation of the end effectors.

[0062] The control computer 152 can be configured to control the simultaneous painting of several robot arms 144, for example, several robot arms configured to control the movement and extrusion of different materials through different nozzles, a three-dimensional object, and other different surface segments.

[0063] Robot arm A robotic arm is a series of links moved by motor-driven joints. Typically, end effectors are attached to the ends of the series of links. An end effector is a tool that performs a desired function. The robotic arm moves the end effector from one location to another. This specification discloses the use of several end effector tools suitable for depositing extruded material, spraying paint, and polishing finished three-dimensional objects. The robotic arm is configured to operate multiple interchangeable end effector tools. Some robotic arms can operate several end effector tools simultaneously.

[0064] U.S. Patents 8,974,213, 9,162,391, and 9,527,243 of the same assignee disclose a method for reinforcing a three-dimensional object by inserting a net or grid of metal or polymer between extruded layers. In another embodiment, a robotic arm 144 or similar equipped with a suitable pickup end effector tool can be positioned to pick up a metal or polymer grid (net) 804 (Figure 8) and spread over a receiving surface 120 of an adjustable support 116. Such a grid with a appropriately selected mesh provides a convenient substrate for depositing extruded material.

[0065] The robotic arm may have built-in pressure sensors, vision sensors, etc., which provide desired feedback to the computer 152 and adjust the movement of the robotic arm.

[0066] In this disclosure, one or more robotic arms are mounted on a rail 140 to support the movement of the robotic arms along the rail. At least one collision detection sensor operates to provide a computer that controls the movement of the robotic arms in relation to any possible collisions.

[0067] The robotic arm 144 is configured to reach all points on the surface of the adjustable support platform and the adjustable support section 112, and to keep the nozzle 148 perpendicular to the surface segment of the extruded three-dimensional object at all times. The nozzle 148 mounted on the robotic arm 144 can rotate at least 180 degrees around the X, Y, and Z axes, respectively. The use of the robotic arm holding the nozzle 148 supports the extrusion of the entire arc / rib (Figure 7A) in a single setup.

[0068] During the manufacturing process of a three-dimensional object made of composite material, the robotic arm 144 moves the extrusion nozzle 148 along the longitudinal guide 140 to various points along the longitudinal guide 140, depositing reinforcing filaments (Figures 6 and 7) at different angles to the adjustable platforms 104 and 112 (Figure 6) and adjustable support surfaces of the three-dimensional object. The reinforcing filaments are applied to the three-dimensional object in a helical pattern. The angle of the helix can be adjusted to deposit the number of helices required to create a continuous layer.

[0069] A continuous surface can be formed by attaching at least one layer of a reinforced filament using a fast-curing epoxy matrix to a three-dimensional object in a helical pattern. A multi-strand filament with a two-component epoxy matrix can form subsequent layers of the three-dimensional object. Such a three-dimensional object structure provides additional strength to the object. Other modifications and substitutions of materials between layers to obtain the best-resulting strength are within the scope of disclosure.

[0070] Examples Figure 6 shows an embodiment of a method for extruding a three-dimensional object 600 made from a composite material. The three-dimensional object 600 includes a convex segment 604 and a concave segment 608. All surface segments of the three-dimensional object 600 terminate at the same level, forming a planar or flat surface 602 of the three-dimensional object 600 on an adjustable support platform 104 / 112. A CAD system provides information about the three-dimensional object 600 to a control computer 152. The control computer 152 operates to level all receiving surfaces 120 of the support column 116 and form a plane on the adjustable support platform.

[0071] Apparatus 100 (Figure 1) extrudes a composite material to form arcs of convex segment 604 and concave segment 608. The arcs of convex segment 604 and concave segment 608 are connected to adjustable support platforms 104 / 112. In another embodiment, a strip of composite material forming a plane 602 can form a tightly closed contour. The extruded material, for example, a thixotropic material, hardens immediately after exiting nozzle 404, and the strips of material forming plane 602, convex 604, and concave 608 become hard enough not to deform under their own weight. The surface segments 604 and 608 of a three-dimensional object suspended in the air, formed by the extruded composite material, are hard enough to remain suspended in the air. No mandrel was used in the manufacture of the surface segments 604 and 608 of the three-dimensional object.

[0072] In another embodiment, the apparatus 100 extrudes a strip of material to form the contour of the plane 602. The apparatus 100 (Figure 1) continues to extrude arcs of convex segment 604 and concave segment 608 connected to the contour of the plane 602.

[0073] The strips of material forming the segments of plane 602 are a kind of intermediate support that reinforces the contour of the three-dimensional object 600, and are not necessarily printed in every pass.

[0074] The robot arm 144 moves the extrusion nozzle 404 in three directions or along three axes (X, Y, and Z) and supports the rotation of the extrusion nozzle 404 around each of the three axes. During the movement, the nozzle 404 extrudes the reinforced and coated filament 406, forming segments of at least a three-dimensional object 600. Nozzle 148 is configured to move in a similar manner to nozzle 404.

[0075] When one extrusion nozzle is operated, segments of the three-dimensional object 600 are sequentially extruded. U.S. Patent No. 10,639,846, by the same assignee and inventor, discloses a multi-nozzle extruder in which each extrusion nozzle operates independently of the other extrusion nozzles. Such an apparatus supports the simultaneous printing of different segments of the three-dimensional object 600. According to this manufacturing method, the production of the three-dimensional object 600 does not require a mandrel or mold.

[0076] The apparatus 100 can support the manufacture of a three-dimensional object 600 as an assembly of layers. The layers may be made of different materials. For example, one layer may be manufactured using a fast-curing epoxy, and another layer may be manufactured using a two-component epoxy. The apparatus 100 with a single extrusion head can sequentially extrude the different layers. The apparatus with multiple extrusion heads can simultaneously extrude layers made of different materials.

[0077] U.S. Patent No. 10,328,635, issued by the same assignee, discloses a method and apparatus for manufacturing three-dimensional objects. In the case of multiple identical three-dimensional objects, the apparatus 600 can be configured to manufacture a mold using a suitable material. The mold can be used to manufacture (form) identical three-dimensional objects. The disclosed method saves manufacturing time and reduces the manufacturing cost of identical three-dimensional objects.

[0078] Figure 7A shows another embodiment of a method for manufacturing a three-dimensional object including convex and concave segments made of composite material. The strength of surface segments of a long three-dimensional object that is taller than 50 mm and spans discontinuous or individually adjustable platform surfaces 104 / 112 can be reinforced by adding internal support walls or ribs 704. The internal support ribs 704 can be printed simultaneously with the convex segments 604 and concave segments 608 of the three-dimensional object 600. The internal support walls or ribs (Figure 7) precisely conform to the contour of the three-dimensional object. In some embodiments, the ribs or walls 704 can be manufactured to show the cross-section of the entire three-dimensional object, i.e., to extend 360 degrees around. Ribs extending 360 degrees around can support repositioning of the three-dimensional object, e.g., rotation of the three-dimensional object.

[0079] The internal support wall (Figure 7B) may be a pair of columns 710 or of other form. Openings to support the introduction of cables or tubes can be created in the support wall or placed between the columns 710. The position and frequency of the internal support wall and columns can be selected to maintain the integrity of the manufactured three-dimensional object.

[0080] In another embodiment, if the three-dimensional object does not have a flat surface, the apparatus 100 can begin manufacturing the three-dimensional object by spreading a metal or polymer grid (net) 804 over the relevant receiving surface 120 of an adjustable support column 116 using a robotic arm 812 or another robotic arm. A control computer 152 (Figure 1) receives data of the three-dimensional object from a CAD system and operates to position all the receiving surfaces 120 of the support member 116 to conform to the curvature and length of the three-dimensional object to be manufactured. The use of the net or grid 804 supports the extrusion of any three-dimensional object shape. Figure 8B shows the spreading of the grid substrate 804 by the robotic arm 812.

[0081] The robotic arm moves the extrusion nozzle 404 in three directions or along three axes (X, Y, and Z) and supports the rotation of the extrusion nozzle 404 around each of the three axes. During the movement, the nozzle 404 extrudes the reinforced and coated filament 406, forming at least a portion of a three-dimensional object. The manufactured three-dimensional object may include convex or concave segments.

[0082] In both embodiments shown in Figures 6 and 7, the manufactured three-dimensional object may include several internal structures that enhance the strength and functional elements of the three-dimensional object. Composite materials with controlled porous structures, such as honeycomb, are known to increase the strength of three-dimensional objects. For example, an extruded controlled porous structure may have variable pitch and height of cell walls. For instance, in the case of a wind turbine rotor blade, the spar portion may have a honeycomb structure with a pitch that varies along the length of the blade.

[0083] Once the manufacturing of the three-dimensional object made of composite material is complete, the three-dimensional object 600 (Figure 9) can be repositioned, for example, by rotating it 180 degrees around one of the faces of the three-dimensional object. Rotation of the three-dimensional object can be achieved by appropriate adjustment of the support column 116 and the use of a robotic arm. Additional convex or concave segments 900 can be manufactured facing opposite sides of the arcs 604 and 608 of the object 600.

[0084] Once the manufacturing of the three-dimensional object is complete, the nearly finished assembly of the three-dimensional object needs to be polished. One or more robotic arms holding pads equipped with sandpaper can be operated to polish the outer surface of the wind turbine rotor blades 1000. In a similar manner, a robotic arm can be used to operate a paint spraying device to paint and varnish the surface of the wind turbine rotor blades.

[0085] Apparatus 100 (Figure 1) is suitable for manufacturing three-dimensional objects having the cross-section of a conventional airfoil profile. Airfoils are the profiles of airplane wings and wind turbine blades, and other three-dimensional objects include convex and concave surfaces. Airfoils and canoes are relatively long objects. This manufacturing method proposes manufacturing such long three-dimensional objects by cutting the object into several sections, manufacturing each section separately, and joining them into one long three-dimensional object. The strength of the connection area can be increased by using grids, filament winding, and extrusion of stronger material, following appropriate end face preparation.

[0086] U.S. Patents 8,974,213, 9,162,391, and 9,527,243, issued by the same assignee, disclose methods for reinforcing three-dimensional objects by inserting a net or grid of metal or polymer between extruded layers. Three-dimensional objects printed by the methods described in these patents spread a grid on a flat surface or a surface having uniform curvature. Object 600 has segments 604 having positive curvature 604 and negative curvature 608. In one embodiment, the grid can be segmented according to the three-dimensional object segments to be manufactured. In another embodiment, different filament windings can be applied to different three-dimensional object segments.

[0087] In one embodiment, a three-dimensional object can be manufactured as a single solid. In another embodiment, a large segment of the three-dimensional object, for example, half (Figure 6), is manufactured. To manufacture other surface segments, the three-dimensional object 600 can be repositioned, for example, by rotating it, to facilitate the manufacture of other surface segments 900 (Figure 9). Changing the angle of the receiving surface 120 (Figure 6) supports the rotation of the three-dimensional object 600, which is rotated to print a second surface of the three-dimensional object. Changing the position of the receiving surface 120, operating rollers, using a robotic hand, etc., can assist in the process of repositioning the three-dimensional object.

[0088] Figure 10 shows an example illustrating filament winding on the surface of a partially fabricated three-dimensional object. Filament winding reinforces the partially fabricated three-dimensional object 1000 and provides a convenient substrate on which additional layers of three-dimensional object material can be deposited. The three-dimensional object can be repositioned for filament winding by various means, including the operation of rollers, the use of a robotic arm, and similar processes.

[0089] Once the manufacturing of a three-dimensional object is complete, the nearly finished assembly of the three-dimensional object needs to be polished. One or more robotic arms holding pads equipped with sandpaper can be operated to polish the outer surface of the three-dimensional object, such as a wind turbine rotor blade. In a similar manner, a robotic arm can be used to operate a paint spraying device to paint and varnish the surface of the wind turbine rotor blade.

[0090] While this specification refers to the accompanying drawings and examples, it will be understood by those skilled in the art that various changes and modifications can be made without departing from the technical spirit and scope of this specification.

Claims

1. A method for manufacturing a three-dimensional object from composite materials, To provide a composite material comprising a multistrand filament together with a thixotropic matrix material surrounding the multistrand filament, To provide at least one extrusion nozzle configured to extrude the composite material, Extrusion molding of a three-dimensional object surface segment that extends into the air beyond at least a portion of a discontinuous work surface, By activating a hardening energy source, the three-dimensional object surface segments spread in the air are fixed in place, and their strength is increased. Includes, A method for extruding three-dimensional object surface segments that are suspended in the air and are sufficiently rigid to maintain their shape without the use of a mandrel.

2. The method according to claim 1, wherein the three-dimensional object surface segments extending into the air coincide with the surface contour of the manufactured three-dimensional object.

3. The method according to claim 1, wherein the three-dimensional object surface segment is extruded and at the same time a hardening energy source is activated to promote the complete hardening of the three-dimensional object surface segment that is spread in the air.

4. The method according to claim 1, wherein the discontinuous work surface is formed by individually adjustable supports terminated with pads configured to accept a desired orientation in space.

5. The method according to claim 1, wherein a robotic arm equipped with a pickup end effector tool suitable for performing multiple operations in the manufacturing of the three-dimensional object surface segment is used.

6. The method according to claim 5, wherein the preferred pickup end effector tool is one of a group of tools consisting of a nozzle, a paintbrush, a polishing tool, and a grid pickup tool.

7. The method according to claim 1, wherein the three-dimensional object is extruded in layers, and each layer is extruded from a different material.

8. The method according to claim 1, wherein ribs supporting the three-dimensional object surface segments extending in the air are extruded.

9. The method according to claim 1, wherein ribs supporting the surface segment of the three-dimensional object extend 360 degrees around it, and the ribs support the repositioning of the three-dimensional object.

10. The method according to claim 1, comprising manufacturing a multistrand filament having a thixotropic matrix material surrounding a multistrand core at a manufacturing site.

11. The method according to claim 1, wherein an extruded multi-strand core is coated with a thixotropic material.

12. A method for manufacturing a three-dimensional object from composite materials, To provide a multi-strand filament together with a thixotropic matrix material surrounding the multi-strand filament, To provide an extrusion nozzle configured to extrude composite materials, To provide a discontinuous work surface and to extrude at least one three-dimensional object surface segment that extends into the air beyond at least a portion of the discontinuous work surface, To activate the hardening energy source and promote the complete hardening of the three-dimensional work surface of the object that is spread out in the air, A method in which a three-dimensional object surface segment formed by an extruded composite material that spreads in the air is sufficiently rigid and remains suspended in the air.

13. The method according to claim 12, wherein the three-dimensional object surface segment extending in the air continuously changes its direction in space.

14. The method according to claim 12, wherein the manufacture of the three-dimensional object does not require the use of a mandrel.

15. The method according to claim 12, wherein the strength of the three-dimensional object is enhanced by inserting a grid of metal or polymer between the extruded layers.

16. The method according to claim 12, wherein a robotic arm is used to pick up a metal or polymer grid and spread it onto a receiving surface of an adjustable support.

17. The method according to claim 12, wherein a metal or polymer grid serves as a substrate for depositing a composite material of the three-dimensional object.

18. A device for manufacturing three-dimensional objects from composite materials, An adjustable support platform formed by multiple individually adjustable supports, A material extrusion nozzle configured to extrude a composite material of a three-dimensional object to be manufactured, A robotic arm configured to operate multiple end-effector tools and Includes, At least one robotic arm maintains at least one extrusion nozzle perpendicular to the surface of a surface segment of the extruded three-dimensional object, The apparatus is configured such that the material extrusion nozzle extrudes the composite material, which includes multi-strand filaments together with a thixotropic matrix material surrounding the multi-strand filaments.

19. An apparatus for manufacturing a three-dimensional object from a composite material, An adjustable support platform formed by multiple individually adjustable supports, A material extrusion nozzle configured to extrude a composite material of a three-dimensional object to be manufactured, A robotic arm configured to operate multiple end-effector tools and Includes, At least one robotic arm maintains at least one extrusion nozzle perpendicular to the surface of a surface segment of the extruded three-dimensional object, The apparatus wherein the extrusion nozzle covers the multistrand filament with an additional coating, and the additional coating increases the strength of the multistrand filament.

20. The apparatus according to claim 18 or 19, wherein the individually adjustable support columns terminate at an object receiving surface configured to accept a desired orientation in space.

21. The apparatus according to claim 20, wherein the object receiving surface terminates each of the adjustable supports, and the object receiving surface rotates 340 degrees in any direction with respect to the axis of symmetry (Z-axis) of the adjustable supports.

22. The apparatus according to claim 18 or 19, wherein the robot arm holding the material extrusion nozzle is configured to follow the contour of a three-dimensional object surface element that is suspended in the air.

23. The apparatus according to claim 18 or 19, wherein at least one robotic arm is configured to operate a plurality of interchangeable end-effector tools.

24. The apparatus according to claim 22, wherein a control computer receives the contours of the three-dimensional object surface segments spread in the air from a CAD system.

25. The apparatus according to claim 18 or 19, wherein at least one robotic arm moves the material extrusion nozzle and maintains the extrusion nozzle perpendicular to the surface segment of the extruded three-dimensional object.

26. The apparatus according to claim 18 or 19, wherein a control computer dynamically changes the angle of the extrusion nozzle so that the angle of the extrusion nozzle is perpendicular to the surface segment of the extruded three-dimensional object.

27. The apparatus according to claim 18 or 19, wherein the cross-section of the extrusion nozzle is one of the group of cross-sections consisting of a circular cross-section, a rectangular cross-section, and a hexagonal cross-section.

28. The apparatus according to claim 18 or 19, wherein at least one robotic arm is configured to reach all points of the three-dimensional object to be manufactured.

29. The apparatus according to claim 18 or 19, wherein the manufacture of a three-dimensional object does not require the use of a mandrel or mold.

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