Continuous fiber reinforced composite material three-dimensional printing consumable and preparation method thereof, three-dimensional printing method and product

Abstract

The invention belongs to the technical field of additive manufacturing, and particularly relates to a continuous fiber reinforced composite material three-dimensional printing consumable, a preparation method thereof, a three-dimensional printing method and a product. The weaving tube structure is adopted, the continuous fiber core material is embedded into the skin layer fiber weaving tube in a wrapping or interweaving mode, the interface bonding force of fibers can be improved, and the three-dimensional printing consumable with the excellent mechanical property is obtained. Meanwhile, the three-dimensional printing supplies with excellent mechanical properties, thermal properties, special functionality and processability can be obtained by adjusting the types, proportions, weaving structures, relative positions, contents and the like of the continuous fibers and the skin layer fibers, and the strength, rigidity, heat resistance and other properties of printed products can be remarkably improved; and the manufacturing requirements of high-performance structural members and special functional members are met. The method solves the problems of difficult continuous fiber supply, poor interface bonding force and the like in the prior art, and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of additive manufacturing, and specifically relates to a continuous fiber reinforced composite material three-dimensional printing consumable, a preparation method thereof, a three-dimensional printing method and a product thereof. Background Art

[0002] 3D printing technology, also known as additive manufacturing technology, can generate objects of complex shapes directly from digital models by adding materials layer by layer, greatly shortening the product development cycle and reducing manufacturing costs. It has become one of the revolutionary technologies in the manufacturing field.

[0003] At present, the mainstream 3D printing consumables are mainly thermoplastic polymers, which have limited mechanical properties and heat resistance and are difficult to meet the needs of high-performance structural parts. In order to improve the performance of 3D printed products, researchers have begun to try to add fillers as reinforcing phases to the polymer matrix. Commonly used fillers include short fibers, glass beads, carbon nanotubes, etc. However, the dispersion and orientation of fillers such as short fibers in the matrix are difficult to control, and the reinforcement effect is limited, which cannot significantly improve the mechanical properties of the product.

[0004] Compared with short fibers, continuous fibers have higher strength and modulus, and their mechanical properties along the fiber direction are extremely excellent. However, the surface of inorganic continuous fibers is smooth and inert, and it is difficult to form a strong interface bond with the polymer matrix, resulting in the inability to fully exert the performance of the composite material. There are two existing routes for continuous fiber printing. One is to pre-impregnate the continuous fibers to form printing filaments; the other is to feed the continuous fibers and polymer fibers through two separate channels during the printing process, and then laminate and composite them at the print head of the printer. However, the direct use of prepreg continuous fiber printing filaments is limited by the fact that not enough polymer material can be attached to the continuous fibers, which will cause the structures directly printed by them to crack easily; while the continuous fibers and polymer fibers are printed in a dual-channel form, due to the single-sided contact problem between the continuous fibers and the polymer, the bonding force between the continuous fibers and the polymer matrix is ​​also limited, which will affect the overall mechanical properties of the printed parts. Summary of the invention

[0005] The purpose of the present invention is to provide a continuous fiber reinforced composite material 3D printing consumables and a preparation method thereof, a 3D printing method and a product thereof. The 3D printing consumables provided by the present invention improve the bonding force between the continuous fiber and the polymer fiber, thereby improving the mechanical properties of the 3D printed product, while also achieving stable supply and precise positioning of the continuous fiber.

[0006] In order to achieve the above object, the present invention provides the following technical solutions: A continuous fiber reinforced composite material 3D printing consumables, comprising a continuous fiber core material and a cortex fiber woven tube; the continuous fiber core material is wrapped in a cavity of the cortex fiber woven tube, and / or the continuous fiber core material is interwoven in the tube wall of the cortex fiber woven tube; The continuous fiber core material includes one or more of carbon fiber, glass fiber, basalt fiber, polymer fiber, metal fiber, ceramic fiber and bio-based fiber; The cortex fiber used in the cortex fiber woven tube is polymer fiber.

[0007] Preferably, the skin fiber includes one or more of polyamide fiber, polypropylene fiber, polyethylene fiber, polylactic acid fiber, polycaprolactone fiber, polyvinyl alcohol fiber, polyetheretherketone fiber, polyimide fiber, polyphenylene sulfide fiber, polycarbonate fiber, polyethylene terephthalate fiber, polyvinyl chloride fiber, blended polymer fiber and modified polymer fiber; The number of tube wall layers of the cortical fiber woven tube is ≥1; the mass ratio of the continuous fiber core layer to the cortical fiber woven tube is 1~80:20~99.

[0008] Preferably, the polymer fiber used in the continuous fiber core material includes one or more of aramid fiber, poly(p-phenylene benzobisoxazole) fiber, polyethylene fiber, polyester fiber, polyimide fiber and polyamide fiber; The metal fibers include one or more of copper fibers, aluminum fibers and tungsten fibers; The ceramic fibers include alumina fibers and / or silicon carbide fibers; The bio-based fibers include bamboo fibers and / or flax fibers; The continuous fiber core material is a fiber monofilament or a fiber bundle; the number of the continuous fiber core material is ≥1.

[0009] Preferably, the continuous fiber core material comprises functional polymer fibers; the functional polymer fibers comprise one or more of conductive fibers, flame retardant fibers, antibacterial fibers and fluorescent fibers.

[0010] Preferably, when the continuous fiber core material is wrapped in the cavity of the cortical fiber woven tube, the distribution mode of the continuous fiber core material in the cross section of the three-dimensional printing consumables is central distribution, eccentric distribution or multi-core distribution; When the distribution mode is eccentric distribution, the continuous fiber reinforced composite material three-dimensional printing consumables also include auxiliary positioning fibers; the auxiliary positioning fibers and the continuous fiber core material are jointly wrapped in the cavity of the cortical fiber woven tube; the positional relationship between the auxiliary positioning fibers and the continuous fiber core material is parallel arrangement or mutual entanglement.

[0011] The present invention also provides a method for preparing the continuous fiber reinforced composite material three-dimensional printing consumables described in the above scheme, comprising the following steps: Using skin fiber and continuous fiber core material as raw materials, weaving according to a preset structure to obtain the continuous fiber reinforced composite material three-dimensional printing consumables; Or using skin fibers, continuous fiber core materials and auxiliary positioning fibers as raw materials, weaving according to a preset structure to obtain the continuous fiber reinforced composite material three-dimensional printing consumables; The weaving method is braiding or knitting.

[0012] Preferably, the number of spindles for weaving is 4 to 200, the number of needles for knitting is 4 to 200, the angle of weaving or knitting is 5 to 85°, and the arrangement of the cortical fibers is circular or spiral.

[0013] Preferably, after the weaving is completed, the obtained consumables are subjected to shaping treatment and / or surface treatment; the shaping treatment method includes heat treatment, solvent treatment, steam fumigation treatment or ultraviolet light curing treatment; The surface treatment method is plasma treatment or preparing a functional layer on the surface of the woven material; the functional layer includes one or more of a lubricating layer, an anti-oxidation layer, an antistatic layer, a flame retardant layer, a conductive layer and an antibacterial layer.

[0014] The present invention also provides a three-dimensional printing method, comprising the following steps: performing three-dimensional printing using the continuous fiber reinforced composite material three-dimensional printing consumables described in the above scheme or the continuous fiber reinforced composite material three-dimensional printing consumables prepared by the preparation method described in the above scheme.

[0015] The present invention also provides a three-dimensional printed product obtained by the three-dimensional printing method described in the above scheme.

[0016] The present invention provides a continuous fiber reinforced composite material for three-dimensional printing, comprising a continuous fiber core material and a cortex fiber woven tube; the continuous fiber core material is wrapped in the cavity of the fiber woven tube, and / or the continuous fiber core material is interwoven in the tube wall of the cortex fiber woven tube; the continuous fiber core material comprises one or more of carbon fiber, glass fiber, basalt fiber, polymer fiber, metal fiber, ceramic fiber and bio-based fiber; the cortex fiber used in the cortex fiber woven tube is polymer fiber. The beneficial effects of the present invention are as follows: Improve interfacial bonding strength and enhance mechanical properties: The present invention applies woven tube technology to the preparation of 3D printing consumables for the first time. The present invention embeds continuous fibers into the interior of the cortex fiber woven tube in a wrapped or interwoven manner to achieve stable embedding of the continuous fibers and effective coating of the cortex fibers on the continuous fibers, thereby improving the interfacial bonding strength between the continuous fibers and the cortex fibers and enhancing the mechanical properties of the 3D printing consumables, including tensile strength, bending strength and impact toughness.

[0017] Prevent fiber breakage, achieve stable supply and precise positioning of continuous fibers: In this field, the stable supply and precise positioning of continuous fibers in the 3D printing process is a technical difficulty. When the traditional method uses continuous fibers for 3D printing, the continuous fibers are prone to breakage, entanglement, and displacement, affecting the printing quality. However, the present invention wraps the continuous fiber core material inside the cortex fiber manufacturing tube, or interweaves it in the tube wall of the cortex fiber woven tube, which has a certain displacement margin, can adapt to slight stress changes during the printing process, prevent fiber breakage, entanglement, and displacement, and improve printing quality.

[0018] Improve material compatibility and reduce internal stress: Furthermore, the present invention can optimize the thermal expansion coefficient and melting characteristics of the continuous fiber and the matrix by selecting a cortical fiber material that matches the continuous fiber, reduce internal stress during processing and use, and prevent deformation and cracking of the product.

[0019] Flexible structural design: Furthermore, the present invention is applicable to a combination of various continuous fibers and cortical fibers, and the cortical fiber woven tube can be a multi-layer structure, and the continuous fiber core layer can also be multiple. The parameters such as the number of cortical fiber woven tube layers, the number of continuous fiber core layers, the fiber type and arrangement method can be adjusted according to actual needs. It has a high degree of customization, meets the performance requirements of different application scenarios, and broadens the application range of the material.

[0020] The present invention also provides a method for preparing the continuous fiber reinforced composite material 3D printing consumables described in the above scheme. The preparation method provided by the present invention has a simple process, is easy to control, is suitable for mass production, has low cost, and is conducive to the wide application of continuous fiber reinforced composite material 3D printing consumables. Furthermore, the present invention also achieves uniform distribution and directional arrangement of fibers by precisely controlling the weaving or knitting parameters, reduces the anisotropy of mechanical properties, and improves the reliability and consistency of the product.

[0021] The present invention also provides a three-dimensional printing method, specifically, three-dimensional printing using the continuous fiber reinforced composite three-dimensional printing consumables described in the above scheme. The three-dimensional printing consumables provided by the present invention have appropriate flexibility and stable size, and the printing process is smooth, without frequent adjustment of equipment or interruption of printing, which improves the printing speed and efficiency and meets the needs of industrial production; and when the traditional method uses continuous fibers for three-dimensional printing, a specially designed print head, fiber supply system and control software are required, the equipment cost is high and the process is complicated, while the present invention pre-embeds the continuous fibers into the consumables, and the printing equipment does not need an additional fiber supply system, and can be directly used in the existing FDM three-dimensional printer without special modification, which lowers the application threshold, equipment cost and process complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 A schematic diagram of the preparation process and structure of a continuous fiber reinforced composite material 3D printing consumable of a braided tube structure provided by the present invention; Figure 2 A schematic diagram of the structure of a continuous fiber reinforced composite material 3D printing consumable of a knitted tube structure provided by the present invention; Figure 3 The preparation process and structural schematic diagram of the continuous fiber reinforced composite material 3D printing consumables with a multi-layer woven tube structure provided by the present invention, wherein 1 is a continuous fiber core material, 3 is a braided tube layer (can be multi-layered), and 4 is a knitted tube layer (can be multi-layered); Figure 4 A schematic diagram of the structure of a continuous fiber reinforced composite material three-dimensional printing consumable with an eccentrically distributed continuous fiber core provided by the present invention, wherein 1 is a continuous fiber core, 2 is an auxiliary positioning fiber for assisting eccentric positioning, 3 is a braided tube layer, and 4 is a knitted tube layer; Figure 5 This is a schematic diagram of the structure of a composite material three-dimensional printing consumable material with continuous fibers reinforced with different weaving angles or pitches provided by the present invention, where the grid density is the pitch; Figure 6 It is a schematic diagram of the heat treatment process, wherein 5 is the insulation layer, 6 is the heating layer, and 7 is the die. DETAILED DESCRIPTION

[0024] The present invention provides a continuous fiber reinforced composite material 3D printing consumables, comprising a continuous fiber core material and a cortex fiber woven tube; the continuous fiber core material is wrapped in a cavity of the fiber woven tube, and / or the continuous fiber core material is interwoven in the tube wall of the cortex fiber woven tube; The continuous fiber core material includes one or more of carbon fiber, glass fiber, basalt fiber, polymer fiber, metal fiber, ceramic fiber and bio-based fiber; The cortex fiber used in the cortex fiber woven tube is polymer fiber.

[0025] In the present invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art.

[0026] In the present invention, the cortical fiber used in the cortical fiber woven tube is a polymer fiber; specifically, the cortical fiber preferably includes polyamide (PA) fiber, polypropylene (PP) fiber, polyethylene (PE) fiber, polylactic acid (PLA) fiber, polycaprolactone (PCL) fiber, polyvinyl alcohol (PVA) fiber, polyetheretherketone (PEEK) fiber, polyimide (PI) fiber, polyphenylene sulfide (PPS) fiber, polycarbonate (PC) fiber, polyethylene terephthalate (PET) fiber, polyvinyl chloride (PVC) fiber, blended polymer The invention relates to one or more of polyamide fibers and modified polymer fibers, wherein the polyamide fiber is preferably polyamide 6 fiber; the blended polymer fiber is specifically a fiber formed by a blend of at least two of polyamide, polypropylene, polyethylene, polylactic acid, polycaprolactone, polyvinyl alcohol, polyetheretherketone, polyimide, polyphenylene sulfide, polycarbonate, polyethylene terephthalate and polyvinyl chloride; the modified polymer fiber is preferably obtained by modifying a polymer matrix with a modifier; the polymer matrix specifically includes polyamide, polypropylene, polyethylene, polylactic acid, polycaprolactone, polyethylene One or more of polyol, polyetheretherketone, polyimide, polyphenylene sulfide, polycarbonate, polyethylene terephthalate and polyvinyl chloride; the modifier preferably includes one or more of inorganic filler, short fiber, nanomaterial, magnetic particle and antioxidant; the inorganic filler preferably includes one or more of carbon black, metal oxide powder and mineral powder; the short fiber preferably includes one or more of glass fiber, carbon fiber and aramid fiber; the nanomaterial preferably includes one or more of carbon nanotube, graphene and metal nanowire; the present invention has no special requirements for the magnetic particles and antioxidant, and those familiar to those skilled in the art can be used; in the present invention, the use of inorganic filler as a modifier can enhance the mechanical properties, thermal stability and wear resistance of the polymer matrix, the use of short fiber as a modifier can enhance the tensile strength, impact resistance and fatigue resistance of the polymer matrix, the use of nanomaterial as a modifier can enhance the mechanical, wear resistance, electrical and thermal properties of the polymer matrix, the addition of magnetic particles can give the polymer matrix magnetic properties, and the addition of antioxidants can improve the anti-aging properties of the polymer matrix. In a specific embodiment of the present invention, specific polymer fibers can be selected according to process requirements and performance requirements. For example, polypropylene fibers (melting point 145°C) and polycaprolactone fibers (melting point about 65°C) with lower melting points are suitable for low-temperature processing; polyetheretherketone (PEEK) fibers (melting point 343°C) with higher melting points are suitable for high-temperature applications; a combination of polylactic acid fibers (melting point 170°C) and polyamide 6 fibers (melting point 220°C) can balance processing temperature and material properties.

[0027] In the present invention, the diameter of the cortical fiber is 10~300μm, and in a specific embodiment, it can be 15μm, 25μm, 50μm, 100μm or 200μm; the number of tube wall layers of the cortical fiber woven tube is ≥1 layer, that is, the cortical fiber woven tube can be a single-layer structure or a multi-layer nested structure. Specifically, the number of tube wall layers of the cortical fiber woven tube is preferably 1~20 layers, and in a specific embodiment, it can be 2 layers, 3 layers, 5 layers, 10 layers or 15 layers; in the present invention, when the number of tube wall layers of the cortical fiber woven tube is greater than 1 layer, the type of cortical fibers in each layer and the type of continuous fiber core materials interwoven therein can be the same or different, so as to achieve specific performance combinations and functional requirements.

[0028] In the present invention, the mass ratio of the continuous fiber core material and the skin fiber woven tube is 1~80:20~99. In a specific embodiment, it can be 10:90, 20:80, 25:75, 30:70, 50:50, 55:45, 70:30 or 80:20.

[0029] In the present invention, the cortical fiber woven tube can be specifically a braided tube and / or a knitted tube. When the number of tube wall layers of the cortical fiber woven tube is greater than 1 layer, the present invention has no special requirements for the specific weaving form of each layer of the woven tube, and the weaving methods of each layer can be the same or different; and when the continuous fiber core material is interwoven in the cortical fiber woven tube, the type of continuous fiber, the type of cortical fiber, the weaving angle and the weaving or knitting density used in each layer can be different to achieve a specific performance combination and functional requirements; for example, in a specific embodiment of the present invention, when the number of tube wall layers of the cortical fiber manufacturing tube is 2 layers, and the continuous fiber core layer is interwoven in the tube wall, the inner tube wall can be interwoven with carbon fiber bundles and PLA fibers, and the outer tube wall can be interwoven with glass fibers and PA fibers. The weaving angle of the inner tube wall can be 30°, and the weaving angle of the outer fiber can be 60°; Figure 1 The following is a schematic diagram of the preparation process and structure of the continuous fiber reinforced composite material 3D printing consumables of the braided tube structure of the present invention. Figure 2 This is a schematic structural diagram of a continuous fiber reinforced composite material 3D printing consumable of a knitted tube structure of the present invention, Figure 3 Schematic diagram of the preparation process and structure of continuous fiber reinforced composite 3D printing consumables with a multi-layer woven tube structure.

[0030] In the present invention, the continuous fiber core material includes one or more of carbon fiber, glass fiber, basalt fiber, polymer fiber, metal fiber, ceramic fiber and bio-based fiber; when the continuous fiber core material includes polymer fiber, the polymer fiber includes one or more of aramid fiber, poly(p-phenylene benzobisoxazole) fiber, polyethylene fiber, polyester fiber, polyimide fiber and polyamide fiber; the metal fiber includes one or more of copper fiber, aluminum fiber and tungsten fiber; the ceramic fiber includes alumina fiber and / or silicon carbide fiber; the bio-based fiber includes bamboo fiber and / or flax fiber. In a specific embodiment of the present invention, the continuous fiber core material is preferably carbon fiber, glass fiber, carbon fiber glass fiber mixed fiber or basalt aramid mixed fiber; the weight ratio of carbon fiber to glass fiber in the carbon fiber glass fiber mixed fiber is 1:1; the weight ratio of basalt fiber to aramid fiber in the basalt aramid mixed fiber is 1:1.

[0031] In the present invention, the continuous fiber core material preferably includes functional polymer fibers; the functional polymer fibers preferably include one or more of conductive fibers, flame retardant fibers, antibacterial fibers and fluorescent fibers; the present invention can give specific functional properties to the three-dimensional printing consumables by using functional polymer fibers. In an embodiment of the present invention, the functional polymer fibers can be distributed in different fiber layers of the woven tube wall to achieve functional gradients. The continuous fiber reinforced composite three-dimensional printing consumables provided by the present invention are suitable for a combination of various continuous fibers and cortical fibers. A suitable material system can be selected according to demand, with a high degree of customization, which broadens the application range of the material.

[0032] In the present invention, the continuous fiber core material is a fiber monofilament or a fiber bundle; the diameter of the fiber monofilament is 2~800μm, and in a specific embodiment, it can be 5μm, 7μm, 10μm, 100μm, 300μm or 500μm; the number of fiber monofilaments in the fiber bundle is 1K~50K, and in a specific embodiment, it can be 2K, 5K, 10K, 20K, 30K or 40K.

[0033] In the present invention, the number of the continuous fiber core material is preferably ≥1, more preferably 1-100, specifically 1, 2, 5, 10, 30, 50 or 80.

[0034] In the present invention, when the continuous fiber core material is wrapped in the cavity of the cortical fiber woven tube, the distribution of the continuous fiber core material in the cross section of the consumable is central distribution, eccentric distribution or multi-core distribution; in a specific embodiment of the present invention, through multi-core distribution, that is, introducing multiple bundles of continuous fibers into the same filament by plying or paralleling, the performance and functional diversity of the three-dimensional printing consumables can be further improved.

[0035] In the present invention, when the distribution mode is eccentric distribution, the composite material three-dimensional printing consumables also include auxiliary positioning fibers; the auxiliary positioning fibers and the continuous fiber core material are wrapped together in the cavity of the cortical fiber woven tube; the positional relationship between the auxiliary positioning fibers and the continuous fiber core material is parallel arrangement or mutual entanglement; the material of the auxiliary positioning fibers can be selected from the material of the continuous fiber core material or the cortical fiber, which will not be repeated here; the diameter of the auxiliary positioning fibers is 2~800μm, and in a specific embodiment, it can be 5μm, 10μm, 100μm, 300μm or 500μm; the structural schematic diagram of the continuous fiber reinforced composite material three-dimensional printing consumables with eccentric distribution of the continuous fiber core material provided by the present invention is shown in Figure 4 .

[0036] In the present invention, the diameter of the continuous fiber reinforced composite material 3D printing consumables is 0.1-10 mm, and in a specific embodiment, it can be 1.75 mm or 2.85 mm. The present invention also provides a method for preparing the continuous fiber reinforced composite material three-dimensional printing consumables described in the above technical solution, comprising the following steps: Using skin fiber and continuous fiber core material as raw materials, weaving according to a preset structure to obtain the continuous fiber reinforced composite material three-dimensional printing consumables; Or using skin fibers, continuous fiber core materials and auxiliary positioning fibers as raw materials, weaving according to a preset structure to obtain the continuous fiber reinforced composite material three-dimensional printing consumables; The weaving method is braiding or knitting.

[0037] In the present invention, the number of spindles for weaving is 4 to 200, and in a specific embodiment, it can be 10, 30, 50, 100 or 150; the number of needles for knitting is 4 to 200, and in a specific embodiment, it can be 10, 30, 50, 100 or 150; the speed of weaving or knitting is 10 to 800 rpm, and in a specific embodiment, it can be 20 rpm, 30 rpm, 100 rpm, 300 rpm or 500 rpm; the angle of weaving or knitting is 5 to 85°, and in a specific embodiment, it can be 10°, 30°, 50°, 60° or 70°; the pitch of weaving is preferably 0.1 to 10 mm. In the present invention, the flexibility, strength and surface quality of the filaments can be controlled by changing the weaving angle and weaving density to achieve a specific performance combination and functional requirements; for example, when the weaving angles are set to 30°, 45° and 60° respectively, the smaller weaving angle (30°) makes the fibers more parallel in the axial direction, increases the flexibility of the material, and is suitable for application scenarios that require bending; the larger weaving angle (60°) makes the fibers more closely interwoven in the radial direction, improves the strength and stability of the material, and is suitable for application scenarios that require high strength. Figure 5 Schematic diagram of the structure of continuous fiber reinforced composite 3D printing consumables with different weaving angles or pitches.

[0038] In the present invention, the arrangement of the cortical fibers is annular or spiral; in the weaving, the tension of the continuous fiber core is 0.1-10N, and in a specific embodiment, it can be 0.5N, 1N, 3N, 5N or 8N; the tension of the cortical fibers is 0.1-10N, and in a specific embodiment, it can be 0.5N, 1N, 3N, 5N or 8N. During the weaving or knitting, the continuous fiber core and the cortical fibers are introduced with appropriate tension to ensure stable supply and arrangement of the fibers; by adjusting the fiber guide device of the weaving or knitting machine, the continuous fibers can be distributed at any position in the cross section of the wire material to meet special requirements such as functional gradient and local reinforcement.

[0039] The present invention has no special requirements for the specific weaving method, and can be weaved according to the structure of the target three-dimensional printing consumables. Specifically, when the continuous fiber core material is wrapped in the cavity of the cortical fiber woven tube, the cortical fibers are woven or knitted on the surface of the continuous fiber core material; when the continuous fiber core material is interwoven in the tube wall of the cortical fiber woven tube, the cortical fibers and the continuous fiber core material are woven or knitted into a tube; when the distribution of the continuous fiber core material is eccentric distribution, the cortical fibers are woven or knitted on the surface of the continuous fiber core material and the auxiliary positioning fiber.

[0040] In the present invention, during the weaving or knitting process, the distribution position of the continuous fiber core material is adjusted by single-strand, parallel-strand, combined-strand and other core wire configurations to achieve center distribution, eccentric distribution or multi-core distribution to meet the requirements of functional gradient and local reinforcement.

[0041] In the present invention, after the weaving is completed, the obtained consumables are further subjected to shaping treatment and / or surface treatment, which are described in detail below.

[0042] In the present invention, the shaping treatment method preferably includes heat treatment, solvent treatment, steam fumigation treatment or ultraviolet light curing treatment; in a specific embodiment of the present invention, it is preferred to select the corresponding shaping treatment method according to the characteristics of the polymer fiber used in the cortical fiber woven tube.

[0043] In the present invention, the heat treatment is applicable to thermoplastic polymer fibers; the temperature of the heat treatment is preferably 50°C below the melting point of the polymer fiber to 10°C above the melting point of the polymer fiber, and is preferably 50~400°C; the time of the heat treatment is 0.1~60min, and in a specific embodiment, it can be 10s, 1min, 5min, 10min, 30min or 50min; in the present invention, when a variety of different polymers are used in the skin fiber, the heat treatment can be carried out in stages, and the heat treatment is carried out in sequence according to the melting points of different polymers. In a specific embodiment of the present invention, the heat treatment is preferably carried out in a tubular heating furnace, and the tube wall of the tubular heating furnace is a heating layer and a heat insulation layer from the inside to the outside, and a die is provided at the outlet end of the tubular heating furnace; the material obtained after weaving is passed through the tubular heating furnace at a uniform speed for heat treatment, and the speed of the material passing through the tubular heating furnace can be controlled according to the target heat treatment time, and can be specifically 0.1~10m / min. Figure 6 Schematic diagram of the heat treatment process in the present invention.

[0044] In a specific embodiment of the present invention, in order to avoid material degradation or performance degradation caused by excessive treatment, it is necessary to strictly control the temperature and time of the heat treatment. Specifically, according to the melting point of the selected polymer fiber, a suitable heat treatment temperature and time are selected. For example, when the skin fiber is PP fiber, the heat treatment temperature is preferably 180°C, and the heat treatment time is preferably 5 minutes; when the skin fiber is PEEK fiber, the heat treatment temperature is preferably 370°C, and the heat treatment time is preferably 10 minutes.

[0045] In the present invention, the solvent treatment is applicable to soluble polymer fibers; the solvent for the solvent treatment is water and / or an organic solvent; the organic solvent includes one or more of ethanol, acetone, dichloromethane, toluene and cyclohexanone; when the solvent is a mixed solvent of water and an organic solvent, the volume fraction of the organic solvent in the mixed solvent is preferably greater than or equal to 0.1% and less than 100%, and can be specifically 1%, 5%, 20%, 50%, 80% or 90%; the temperature of the solvent treatment is room temperature to 100°C, and in a specific embodiment, it can be 30°C, 50°C or 80°C; the time of the solvent treatment is 0.1~60min, and in a specific embodiment, it can be 1min, 5min, 10min, 30min or 50min. In a specific embodiment of the present invention, when the skin fiber is a PVA fiber, it is preferably treated with pure water for solvent treatment, and the temperature of the solvent treatment is preferably 85°C, and the time is preferably 5min. The above conditions ensure that the PVA fiber is moderately dissolved.

[0046] In the present invention, the steam fumigation treatment is suitable for polymer fibers that need to be softened, such as PLA fibers; the steam used in the steam fumigation is specifically water vapor; the temperature of the steam fumigation is 50-300°C, and in a specific embodiment, it can be 100°C or 200°C; the time is 0.1-60min, and in a specific embodiment, it can be 1min, 5min, 10min, 30min or 50min.

[0047] In the present invention, the UV curing treatment is applicable to photosensitive polymer fibers; the irradiation time of the UV curing treatment is 0.1 to 60 minutes, and in specific embodiments, it can be 1 minute, 5 minutes, 10 minutes, 30 minutes or 50 minutes.

[0048] In the present invention, when heat treatment or steam fumigation treatment is used for shaping treatment, the obtained material is preferably cooled after the shaping treatment; the cooling method is air cooling, water cooling or segmented cooling; the cooling rate can be adjusted according to the material properties to avoid internal stress and deformation; when solvent treatment is used for shaping treatment, the obtained material is preferably dried after the shaping treatment, and the drying temperature is 20~150℃, and in a specific embodiment, it can be 40℃, 70℃, 100℃ or 130℃; the drying time is 0.1~24h, and in a specific embodiment, it can be 1h, 5h, 10h, 15h or 20h; drying can ensure that the solvent is completely volatilized, thereby improving the dimensional stability of the three-dimensional printing consumables.

[0049] The present invention uses a shaping process to partially melt, soften or dissolve the cortical fibers and then coat the continuous fibers to form a dense structure, thereby improving the structural stability of the three-dimensional printing consumables.

[0050] In the present invention, the surface treatment method is plasma treatment or preparing a functional layer on the surface of the woven consumables; the functional coating includes one or more of a lubricating layer, an anti-oxidation layer, an antistatic layer, a flame retardant layer, a conductive layer and an antibacterial layer; the method for preparing the functional layer includes spraying, dipping, brushing or chemical plating. In the present invention, the surface treatment can be performed after the shaping treatment. When the shaping treatment is not required, the surface treatment can also be directly performed on the material obtained after weaving. The present invention can improve the feeding performance, weather resistance and functional characteristics of three-dimensional printing consumables through surface treatment.

[0051] In the present invention, after obtaining the three-dimensional printing consumables, it also includes winding; the winding is performed by an automatic winding machine; the tension of the three-dimensional printing consumables during the winding is 0.1~100N, and in a specific embodiment, it can be 1N, 5N, 10N, 30N, 50N or 80N; the present invention adopts an automatic winding machine to wind the prepared three-dimensional printing consumables into a spool, which is convenient for storage and application. During the winding process, the tension of the three-dimensional printing consumables should be kept stable to avoid relaxation or excessive stretching; the storage environment of the three-dimensional printing consumables is a dry and light-proof environment, and the temperature of the storage environment is -20~50℃, and in a specific embodiment, it can be 0℃, 20℃ or 40℃; the relative humidity is 0%~90%, and in a specific embodiment, it can be 10%, 30%, 50% or 70%; storage in the above environment can prevent aging or performance degradation of the three-dimensional printing consumables.

[0052] The preparation method of the three-dimensional printing consumables provided by the present invention has the characteristics of wide material selection, flexible and controllable process, excellent performance, etc. The specific parameters of the fiber such as diameter, tension, weight ratio, etc. have a large adjustment range and can be selected according to actual needs; the types of continuous fibers and cortical fibers are complete, which can meet the diversified needs of different fields and application scenarios for three-dimensional printing consumables.

[0053] The present invention also provides a three-dimensional printing method, comprising the following steps: performing three-dimensional printing using the continuous fiber reinforced composite material three-dimensional printing consumables described in the above scheme or the continuous fiber reinforced composite material three-dimensional printing consumables prepared by the preparation method described in the above scheme.

[0054] In the present invention, the parameters of the three-dimensional printing include: the nozzle temperature is 100-400°C, in a specific embodiment, it can be 200°C or 300°C; the printing speed is 1-100mm / s, in a specific embodiment, it can be 5mm / s, 10mm / s, 30mm / s, 50mm / s or 80mm / s; the layer thickness is 0.1-5mm, in a specific embodiment, it can be 0.5mm, 1mm, 2mm or 3mm. The present invention can achieve a stable and efficient printing process by reasonably setting the printing parameters, and prepare three-dimensional printed products with excellent properties such as high strength, high stiffness, heat resistance, and corrosion resistance; in addition, by controlling the distribution and orientation of the fibers in the three-dimensional printing consumables, the directional design of the product performance can be achieved to meet special requirements such as multi-axial force, local reinforcement, and functional gradient.

[0055] In a specific embodiment of the present invention, the three-dimensional printing consumables are preferably installed in the feeding system of the three-dimensional printing device, and then the printing parameters are set to control the feeding speed and direction of the three-dimensional printing consumables to ensure smooth feeding and keep the continuous fibers stable and continuous during the printing process; three-dimensional printing is performed according to the preset printing path and model to prepare three-dimensional printed products with enhanced mechanical properties and specific functions. In a specific embodiment of the present invention, the obtained three-dimensional printed products can also be annealed, surface treated or other post-processed as needed to improve the performance of the products.

[0056] The continuous fiber reinforced composite material 3D printing consumables provided by the present invention can be widely used in the preparation of high-performance and lightweight 3D printed products, such as: in the field of aerospace, high-strength and lightweight structural components can be manufactured, such as drone fuselages, satellite components, rocket compartments, etc.; in the field of automobile manufacturing, high-performance automobile parts can be produced, such as body structural parts, suspension system components, interior parts, etc., to improve vehicle performance and fuel efficiency; in the field of medical devices, biodegradable and biocompatible medical supplies can be prepared, such as orthopedic implants, tissue engineering scaffolds, drug controlled release systems, etc.; in the field of industrial manufacturing, high-strength and wear-resistant industrial parts such as gears, bearings, pump housings, etc. can be manufactured to extend service life and reduce maintenance costs; in the field of electronic devices, electronic components, sensors, antennas, etc. with conductive properties can be printed to achieve structural and functional integration of electronic devices; in the field of sports equipment, high-performance sports equipment such as bicycle frames, skis, rackets, etc. can be manufactured to improve sports performance; in the field of construction engineering, building components with special properties can be manufactured, such as earthquake-resistant supports, insulation boards, decorative materials, etc.

[0057] The present invention also provides a three-dimensional printed product obtained by the three-dimensional printing method described in the above scheme.

[0058] In the present invention, the three-dimensional printed product has the characteristics of high strength, high modulus, high temperature resistance, flame retardancy, impact resistance, conductivity, antibacterial and the like, can be used for a long time in a high temperature (-50~400°C), high humidity, and high corrosive environment, has stable performance, and is suitable for aerospace, automobile manufacturing, medical equipment, industrial manufacturing, electronic devices, sports equipment, construction engineering, national defense and military industry and other fields.

[0059] In the present invention, the three-dimensional printed products specifically include one or more of aerospace equipment, automobile parts, medical equipment, industrial machinery parts, electronic components, sports equipment, building components and military equipment.

[0060] In the present invention, the three-dimensional printed product can be subsequently processed as needed, such as mechanical processing, coating, electroplating, welding, etc., to further expand its application scope.

[0061] In order to further illustrate the present invention, the technical scheme of the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0062] Example 1 3K continuous carbon fiber is selected as the core material. The single filament diameter of the continuous carbon fiber is 7μm, which has the characteristics of high strength and high modulus. The cortical fiber is polyamide 6 (PA6) fiber with a melting point of 220℃ and a fiber diameter of 230μm as the weaving material. The weaving machine is equipped with 16 weaving spindles and a weaving speed of 30 turns / min. The continuous carbon fiber is introduced from the center of the weaving machine, and the fiber tension is controlled at 1N to ensure stable fiber transportation. The PA6 fiber is cross-woven at a weaving angle of 45° to form a tubular structure, which is tightly wrapped around the continuous carbon fiber. The tension of the PA6 fiber is controlled at 0.5N to obtain a continuous fiber-reinforced composite wire.

[0063] The continuous fiber reinforced composite wire was heat treated at a speed of 2m / min through a tubular heating furnace set at 230°C for 10s. This temperature is slightly higher than the melting point of PA6, ensuring that the surface of the polymer fiber melts and adheres to each other to form a dense composite structure. After leaving the furnace, it immediately enters the cooling zone and is quickly shaped by air cooling. The cooled 3D printing consumables are wound onto the bobbin and an automatic winder is used. The winding speed is synchronized with the heat treatment speed to maintain constant tension and avoid loosening or deformation of the wire. The final 3D printing consumables have a uniform surface, no obvious bubbles or defects, and a uniform diameter of about 1.75mm. The mass ratio of the continuous fiber core and the cortex fiber woven tube is 20:80.

[0064] The results of mechanical properties tests show that the tensile strength of the obtained 3D printing consumables reaches 1500MPa and the flexural strength reaches 1200MPa, which are significantly higher than those of pure polyamide materials.

[0065] The 3D printing consumables are applied to commercial FDM 3D printers, and the maximum temperature of the print head can reach 280°C. The printing parameters are set as nozzle temperature 250°C, printing speed 2~50mm / s, and layer thickness 0.2~3mm. During the printing process, the filament feeds smoothly without blockage or fiber breakage. The resulting printed products have high strength and high rigidity, good surface quality, and meet the needs of high-performance structural parts.

[0066] Example 2 1K continuous glass fiber is selected as the core material, and the monofilament diameter of the continuous glass fiber is 9μm. The cortical fiber selects water-soluble PVA fiber with a diameter of 15μm as the weaving material. The number of weaving needles is 8, and the weaving speed is 20 turns / min. The continuous glass fiber is introduced from the center of the braiding machine, and the fiber tension is controlled at 0.8N to ensure the stable transportation of the fiber. The PVA fiber is cross-woven at a weaving angle of 30° to form a tubular structure, which is tightly wrapped around the glass fiber. The tension of the PVA fiber is controlled at 0.4N to obtain a continuous fiber-reinforced composite wire.

[0067] The continuous fiber reinforced composite wire was immersed in a pure water solvent tank at 85°C for 5 minutes. The PVA fiber partially dissolved in pure water, became viscous, and tightly adhered and moderately coated on the surface of the continuous glass fiber. Subsequently, the wire was taken out of the solvent and placed in a ventilated environment to allow the residual solvent to evaporate naturally. To ensure that the solvent was completely evaporated and fixed, it was placed in a blast drying oven at 50°C for 2 hours. After drying, the surface of the obtained 3D printing consumables was smooth and the diameter was uniform, about 2 mm, and the mass ratio of the continuous fiber core material and the skin fiber woven tube was 25:75.

[0068] The results of mechanical properties tests show that the tensile strength of the obtained 3D printing consumables reaches 800MPa and the bending strength is 600MPa.

[0069] The 3D printing consumables were applied to the FDM 3D printer with a nozzle diameter of 1.2mm. The print head was suitable for water-soluble materials. The printing parameters were set to a nozzle temperature of 220°C, a printing speed of 30mm / s, and a layer thickness of 0.25mm. The printing process was smooth, the product was well formed, and it could be washed after printing to remove the residual PVA and improve the purity and performance of the product.

[0070] Example 3 The continuous fiber core material is a 12K basalt-aramid mixed fiber bundle, the weight ratio of basalt fiber to aramid fiber is 1:1, and the fiber monofilament diameter is 10μm. The cortical fiber is selected from PLA fiber with a melting point of 170℃ and a fiber diameter of 25μm. It is used as the braiding material and has 2 braiding layers. The inner layer of the braiding machine has 16 needles, the outer layer has 24 needles, and the braiding speed is 30 turns / min. The basalt-aramid mixed fiber is introduced from the center of the braiding machine, and the fiber tension is controlled at 0.6N to ensure the stable delivery of the fiber. The inner layer of PLA fiber is woven at a braiding angle of 40° to form an inner braided tube that tightly covers the core material. Then, outside the inner braided tube, PLA fiber is woven again at a braiding angle of 50° to form an outer braided tube, which further enhances the stability of the structure and obtains a continuous fiber reinforced composite wire.

[0071] The continuous fiber reinforced composite wire is placed in a steam fumigation box, the steam temperature is set to 180°C, and the fumigation time is 10 minutes. Under the action of high-temperature steam, the PLA fiber softens, melts, covers and penetrates between the continuous fibers to form a dense composite structure. After the fumigation is completed, the wire is taken out and placed at room temperature to cool naturally to complete the shaping process. The final 3D printing consumables have a uniform surface and color, with a diameter of about 2.5mm, and the mass ratio of the continuous fiber core material and the cortex fiber woven tube is 55:45.

[0072] The results of mechanical properties tests show that the tensile strength of the obtained 3D printing consumables reaches 1000MPa and the bending strength is 800MPa.

[0073] The 3D printing consumables are applied to commercial FDM 3D printers, and the printing parameters are set as nozzle temperature 200℃, printing speed 35mm / s, and layer thickness 0.6mm. The printing process is stable, the product has high precision, high strength and heat resistance, and has the excellent properties of basalt fiber and aramid fiber, which is suitable for high-performance applications.

[0074] Example 4 The other conditions are the same as those in Example 1, except that: The continuous fiber core material is replaced with 12K carbon fiber (fiber monofilament diameter 7μm, tensile strength 4900MPa) and 24K glass fiber (fiber monofilament diameter 13μm, tensile strength 3450MPa), the weight ratio of carbon fiber to glass fiber is 1:1; the braiding angle of PA6 fiber is 60°. The tensile strength of the obtained 3D printing consumables is 1600 MPa, the bending strength is 1300 MPa, and the impact strength is 85 kJ / m², which has both high strength and high toughness.

[0075] Example 5 The other conditions are the same as those in Example 1, except that: The continuous fiber core material is replaced with 16K basalt fiber (fiber monofilament diameter is 11μm, tensile strength is 4800MPa) and Kevlar aramid fiber (fiber monofilament diameter is 12μm, tensile strength is 3600MPa), and the weight ratio of basalt fiber to Kevlar aramid fiber is 1:1.

[0076] The cortical fiber is PEEK fiber with a diameter of 50 μm and a braiding angle of 45°; the heat treatment temperature is 370° C. and the treatment time is 10 min.

[0077] The heat deformation temperature of the obtained 3D printing consumables is 280℃ and the impact strength is 90 kJ / m 2 , outstanding heat resistance and high impact resistance.

[0078] Example 6 The other conditions are the same as those in Example 1, except that: The weaving angle of PA6 fiber was changed to 30° or 60°. The results showed that a weaving angle of 30° could improve the flexibility of the 3D printing filament, making it suitable for application scenarios that require bending.

[0079] When the weaving angle is 60°, the fibers can be interwoven more tightly in the radial direction, which improves the strength and stability of the 3D printing filaments and is suitable for applications that require high strength.

[0080] Example 7 The other conditions are the same as those in Example 1, except that: The cortical fiber was changed to PCL fiber with a fiber diameter of 75 μm, and the heat treatment temperature was 60°C for 5 min.

[0081] The resulting 3D printing filament only requires a printing temperature of 70°C and can be combined with continuous fiber core materials that cannot withstand high-temperature processing.

[0082] Example 8 The other conditions are the same as those in Example 2, except that: The step of using water for shaping treatment was omitted, and the continuous fiber reinforced composite wire obtained by weaving was used as a consumable for direct three-dimensional printing. The results showed that the obtained consumable can be used directly for printing, but the feeding stability is slightly reduced, which is manifested in that the surface smoothness of the printed product is slightly lower than that of Example 2, and the material jamming phenomenon occurs occasionally, but it can fully meet the printing requirements.

[0083] Example 9 This embodiment prepares an eccentric continuous fiber reinforced composite material 3D printing consumable, that is, the continuous fiber core material is deviated from the center position in the cross section of the consumable to meet specific functional requirements, such as improving the local performance of the product or realizing functional gradient.

[0084] 3K continuous carbon fiber is selected as the core material, with a fiber monofilament diameter of 7μm, and has excellent characteristics of high strength and high modulus; PA6 fiber with a melting point of 220℃ and a fiber diameter of 20μm is selected as the braiding material for the cortex polymer fiber. In order to achieve the eccentric structure, the braided tube braiding machine was modified to move the core material inlet from the center position to the eccentric position. Specifically, by adjusting the angle and position of the core material introduction tube to make it close to the edge of the braiding area, the continuous carbon fiber is introduced into the side position of the braided tube during the braiding process. In addition, a PA6 fiber is incorporated into the core material to assist in keeping the continuous carbon fiber in an eccentric position. The braiding machine is equipped with 16 braiding spindles, and the braiding speed is set to 30 rpm. The continuous carbon fiber is introduced from the eccentric introduction tube at a constant tension of 1N, and the PA6 fiber is cross-woven at a braiding angle of 45°. The fiber tension is controlled at 0.5N to form a tubular structure, which is tightly wrapped around the carbon fiber to obtain a continuous fiber-reinforced composite material 3D printing consumables. Due to the offset of the core material introduction position, the continuous carbon fibers are located in the edge area of ​​the braided tube, forming an eccentric fiber reinforcement structure.

[0085] The woven material is heat treated at a speed of 2m / min through a tubular heating furnace set at 230°C for 10s. This temperature is slightly higher than the melting point of PA6, ensuring that the polymer fiber is completely melted. The molten PA6 fiber covers and penetrates the carbon fiber and the surrounding area to form a dense composite structure. After leaving the furnace, it immediately enters the cooling zone and uses air cooling to quickly shape the consumables. Because the continuous carbon fiber deviates from the center position in the cross section of the consumable, the molten PA6 fiber forms a 3D printing consumable with asymmetric fiber distribution on the cross section after cooling and shaping.

[0086] The cooled 3D printing consumables are wound onto a bobbin and an automatic winder is used. The winding speed is synchronized with the heat treatment speed to maintain constant tension and avoid loosening or deformation of the filament. The final 3D printing consumables have a smooth surface and a uniform diameter of about 1.75 mm. The mass ratio of the continuous fiber core and the cortex fiber woven tube is 35:65, and the eccentric distribution of the fibers can be observed on the cross section.

[0087] The results of mechanical properties tests show that the tensile strength of the obtained eccentric 3D printing consumables along the fiber reinforced area reaches 1400MPa, which is slightly lower than the centrally distributed continuous fiber reinforced 3D printing consumables, but still significantly higher than pure polyamide materials; the bending properties show anisotropy, and the fiber reinforced area has higher stiffness and strength.

[0088] The eccentric 3D printing consumables are applied to commercial FDM 3D printers, and the maximum temperature of the print head can reach 280°C. The printing parameters are set as nozzle temperature 250°C, printing speed 40mm / s, and layer thickness 0.6mm. During the printing process, attention should be paid to the feeding direction of the wire to ensure that the fiber-reinforced area is facing the direction where the product needs to be strengthened. The 3D printing consumables feed smoothly without blockage or fiber breakage. The final printed product has higher strength and rigidity in the fiber-reinforced area, which is suitable for structural parts that require local reinforcement. By adjusting the printing path and the feeding direction of the consumables, the directional design of the mechanical properties of the product can be achieved. In this embodiment, eccentric continuous fiber-reinforced 3D printing consumables were successfully prepared by modifying the weaving equipment and adjusting the process parameters. This method broadens the scope of application of the present invention, provides new possibilities for the performance design and optimization of 3D printed products, and has important application value.

[0089] Example 10 This embodiment prepares a continuous fiber reinforced composite material 3D printing consumables with a multi-layer nested structure. The inner layer continuous fiber core material adopts 12K carbon fiber bundles, specifically T700S carbon fiber with a fiber monofilament diameter of 7μm, with a tensile strength of 4900MPa, a tensile modulus of 230GPa, and an elongation at break of 2.1%. The outer layer continuous fiber core material adopts 24K glass fiber bundles, with a fiber monofilament diameter of 13μm, and the supplier is Owens Corning alkali-free glass fiber, with a tensile strength of 3450MPa, a tensile modulus of 73GPa, and an elongation at break of 4.7%. The inner layer polymer fiber uses PLA fiber with a fiber diameter of 20μm and a melting point of 170℃. The outer layer polymer fiber uses PA6 fiber with a fiber diameter of 20μm and a melting point of 220℃.

[0090] Using a multi-layer braiding machine, pass the 12K carbon fiber bundle through the fiber guide device at a tension of 1N and introduce it into the inner core material position of the braiding machine. Subsequently, the PLA fiber is woven at a tension of 0.5N through 16 braiding needles at a braiding angle of 30° to form a tubular structure, so that the carbon fiber and PLA fiber are interwoven to form an inner embedded structure. Then, the outer layer is woven. On the basis of the inner layer weaving, the 24K glass fiber bundle is passed through the fiber guide device at a tension of 1N and introduced into the outer braiding area, advancing synchronously with the inner layer wire material. Then, the PA6 fiber is woven at a tension of 0.5N through 24 braiding needles at a braiding angle of 60° and coated on the outside of the inner layer, so that the glass fiber and the PA6 fiber are interwoven to form an outer embedded structure to obtain a composite wire.

[0091] The shaping treatment is carried out by a staged heat treatment method. The braided composite wire is passed through a tubular heating furnace at a speed of 1m / min. The heating temperature of the first stage is set to 180℃ (10℃ above the melting point of PLA), the heating length is 1m, and the heating time is about 1min. The purpose is to melt the inner layer of PLA fiber, cover and penetrate between the carbon fibers. The heating temperature of the second stage is raised to 230℃ (10℃ above the melting point of PA6), the heating length is 1m, and the heating time is about 1min. The purpose is to melt the outer layer of PA6 fiber, cover and penetrate between the glass fibers. Then it immediately enters the segmented cooling system for cooling. The first cooling section is reduced from 230℃ to 150℃, the length is 1m, and the cooling time is about 1min. The second cooling section is reduced from 150℃ to room temperature, the length is 1m, and the cooling time is about 1min. The purpose of segmented cooling is to gradually reduce the temperature, reduce internal stress, and prevent wire deformation. In order to give the 3D printing consumables flame retardant properties, surface treatment is performed. The cooled wire is passed through a dipping device to coat a flame retardant coating on the surface of the wire. The coating material is a halogen-free flame retardant solution (the solvent is deionized water, and the flame retardant concentration is 10%), and the dipping time is 5s. Subsequently, the coated wire enters a tunnel drying box, the temperature is set at 100°C, and the drying time is 30 minutes to ensure that the solvent is completely volatilized and the coating is evenly attached.

[0092] Finally, use an automatic winder to wind the processed multi-layer nested 3D printing consumables into a spool, and the winding tension is controlled at 20N. The spool is placed in a dry, light-proof storage environment at a temperature of 20°C and a relative humidity below 50% to prevent material aging or performance degradation. The prepared multi-layer nested 3D printing consumables have a diameter of 2.5mm, and the weight ratio of each fiber is: carbon fiber accounts for 20%, glass fiber accounts for 30%, PLA polymer accounts for 25%, and PA6 polymer accounts for 25%.

[0093] The mechanical properties test results show that the tensile strength of the obtained multi-layer nested 3D printing consumables reaches 1800MPa, the tensile modulus is 150GPa, the flexural strength is 1500MPa, the flexural modulus is 120GPa, and the impact strength is 80kJ / m². The thermal properties test shows that the heat deformation temperature (HDT) of the 3D printing consumables is 200℃, and the glass transition temperature (T g ) is 85℃. In terms of functional properties, the flame retardant performance reaches UL94V-0 level, the corrosion resistance is excellent, and there is no obvious performance degradation after immersion in acid and alkali solution for 24 hours.

[0094] In the 3D printing application, an FDM 3D printer was used with a nozzle diameter of 1.5mm, a heating nozzle temperature set to 240℃, a print bed temperature of 80℃, a printing speed of 30mm / s, and a layer thickness of 0.8mm. The prepared multi-layer nested 3D printing consumables were installed into the feed system of the printer to ensure smooth feeding of the filaments. The printing parameters were set to adapt to the characteristics of the multi-layer nested 3D printing consumables, the printing model was loaded, and printing began. Since the multi-layer nested 3D printing consumables have high strength and high modulus, the printing speed and nozzle temperature were adjusted during the printing process to prevent warping caused by overheating or too fast cooling of the material. After printing, the product was cooled to room temperature and taken out. The printed product has excellent mechanical properties, and the tensile strength can reach more than 1500MPa, which meets the requirements of high-strength applications. In terms of thermal performance, the product maintains dimensional stability in a high temperature environment of 150~200℃, which is suitable for the manufacture of high-temperature resistant parts. It has good flame retardant properties and is suitable for fields with high fire protection requirements.

[0095] From the above examples, it can be seen that the combination of materials and the adjustment of process parameters have an important impact on the performance of the final product. In terms of materials, the type and combination of fibers can effectively regulate the strength, toughness and heat resistance of the wire.

[0096] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. Other embodiments can be obtained based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A continuous fiber reinforced composite material for three-dimensional printing, characterized in that: It comprises a continuous fiber core material and a cortex fiber woven tube; the continuous fiber core material is wrapped in the cavity of the cortex fiber woven tube, and / or the continuous fiber core material is interwoven in the tube wall of the cortex fiber woven tube; The continuous fiber core material includes one or more of carbon fiber, glass fiber, basalt fiber, polymer fiber, metal fiber, ceramic fiber and bio-based fiber; The cortex fiber used in the cortex fiber woven tube is polymer fiber.

2. The continuous fiber reinforced composite material 3D printing consumable according to claim 1, characterized in that: The sheath fibers include one or more of polyamide fibers, polypropylene fibers, polyethylene fibers, polylactic acid fibers, polycaprolactone fibers, polyvinyl alcohol fibers, polyetheretherketone fibers, polyimide fibers, polyphenylene sulfide fibers, polycarbonate fibers, polyethylene terephthalate fibers, polyvinyl chloride fibers, blended polymer fibers, and modified polymer fibers; The number of tube wall layers of the cortical fiber woven tube is ≥1; The mass ratio of the continuous fiber core layer and the skin fiber woven tube is 1-80:20-99.

3. The continuous fiber reinforced composite material 3D printing consumable according to claim 1, characterized in that: The polymer fiber used in the continuous fiber core material includes one or more of aramid fiber, poly(p-phenylene benzobisoxazole) fiber, polyethylene fiber, polyester fiber, polyimide fiber and polyamide fiber; The metal fibers include one or more of copper fibers, aluminum fibers and tungsten fibers; The ceramic fibers include alumina fibers and / or silicon carbide fibers; The bio-based fibers include bamboo fibers and / or flax fibers; The continuous fiber core material is a fiber monofilament or a fiber bundle; the number of the continuous fiber core material is ≥1.

4. The continuous fiber reinforced composite material 3D printing consumable according to claim 1, characterized in that: The continuous fiber core material includes functional polymer fibers; the functional polymer fibers include one or more of conductive fibers, flame retardant fibers, antibacterial fibers and fluorescent fibers.

5. The continuous fiber reinforced composite material 3D printing consumable according to claim 1, characterized in that: When the continuous fiber core material is wrapped in the cavity of the cortical fiber woven tube, the distribution mode of the continuous fiber core material in the cross section of the three-dimensional printing consumables is central distribution, eccentric distribution or multi-core distribution; When the distribution mode is eccentric distribution, the continuous fiber reinforced composite material three-dimensional printing consumables also include auxiliary positioning fibers; the auxiliary positioning fibers and the continuous fiber core material are jointly wrapped in the cavity of the cortical fiber woven tube; the positional relationship between the auxiliary positioning fibers and the continuous fiber core material is parallel arrangement or mutual entanglement.

6. The method for preparing the continuous fiber reinforced composite material three-dimensional printing consumables according to any one of claims 1 to 5, characterized in that: The following steps are involved: Using skin fiber and continuous fiber core material as raw materials, weaving according to a preset structure to obtain the continuous fiber reinforced composite material three-dimensional printing consumables; Or using skin fibers, continuous fiber core materials and auxiliary positioning fibers as raw materials, weaving according to a preset structure to obtain the continuous fiber reinforced composite material three-dimensional printing consumables; The weaving method is braiding or knitting.

7. The preparation method according to claim 6, characterized in that: The number of spindles for weaving is 4 to 200, the number of needles for knitting is 4 to 200, the angle of weaving or knitting is 5 to 85 degrees, and the arrangement of the cortical fibers is circular or spiral.

8. The preparation method according to claim 6, characterized in that: After the weaving is completed, the obtained consumables are subjected to shaping treatment and / or surface treatment; the shaping treatment method includes heat treatment, solvent treatment, steam fumigation treatment or ultraviolet light curing treatment; The surface treatment method is plasma treatment or preparing a functional layer on the surface of the woven material; the functional layer includes one or more of a lubricating layer, an anti-oxidation layer, an antistatic layer, a flame retardant layer, a conductive layer and an antibacterial layer.

9. A three-dimensional printing method, characterized in that: The method comprises the following steps: performing three-dimensional printing using the continuous fiber reinforced composite material three-dimensional printing consumables according to any one of claims 1 to 5 or the continuous fiber reinforced composite material three-dimensional printing consumables prepared by the preparation method according to any one of claims 6 to 8.

10. The three-dimensional printed product obtained by the three-dimensional printing method according to claim 9.

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