Layered gradient multifunctional sheath and additive manufacturing method thereof

Abstract

According to the layered gradient multifunctional sheath and the additive manufacturing method thereof, a gradient material structure is prepared by adopting an FDM technology, and the layered gradient multifunctional sheath sequentially comprises a weather-proof protective outer layer (ASA), a gradient transition middle layer (ASA-CF) and a structural function inner layer (PPA-CF) from outside to inside. According to the invention, excellent weather resistance and UV resistance of ASA and excellent mechanical strength and heat resistance of PPA-CF are organically combined by using an FDM technology, the integrated performance of external weather and internal strength is realized, gradient change of sheath materials is realized, and the total thickness of the sheath and the thickness ratio of each layer can be flexibly adjusted according to the specific installation position and borne environmental stress, so that the sheath can be widely applied to the field of high-voltage power cables. The high-weather-resistance and high-reliability high-weather-resistance and high-temperature-difference-resistance high-weather-resistance high-weather-resistance high-weather-resistance high-reliability high-weather-resistance high-weather-resistance high-weather-resistance high-weather-resistance high-reliability high-weather-resistance high-weather-resistance high-reliability high-weather-resistance high-weather-resistance high-reliability high-weather-resistance high-weather-resistance high-reliability high-weather-resistance high-reliability high-weather-resistance high-reliability high-weather-resistance high-reliability

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of additive manufacturing, in particular to a layered gradient multifunctional sheath and an additive manufacturing method thereof. BACKGROUND

[0002] Power towers are the core infrastructure of power transmission networks, and the long-term reliability of their attached components (such as insulating sheaths, hardware protection sheaths, etc.) is directly related to the safe and stable operation of the power grid. In areas such as the Qinghai-Tibet Plateau, power tower components are long-term served in extremely harsh environments, facing the following severe challenges: (1) strong ultraviolet radiation, leading to rapid aging, pulverization, and embrittlement of high molecular materials; (2) huge diurnal temperature difference (-35°C to +70°C), producing repeated thermal stress, which easily leads to material fatigue cracking and seal failure; (3) complex weather conditions such as hail, strong winds, and sandstorms, requiring components to have excellent mechanical strength and impact resistance; (4) electrochemical corrosion, requiring materials to have excellent insulation and corrosion resistance.

[0003] Currently, the sheaths formed by traditional injection molding or compression molding are mostly single homogeneous materials (such as HDPE, PVC, or ordinary engineering plastics), which are difficult to meet the requirements of multifunctional integration such as weather resistance, temperature resistance, toughness, and insulation. The use of single high-performance engineering plastics (such as PEEK) is costly, and their anti-UV performance is often poor.

[0004] Fused deposition modeling (FDM) technology provides an efficient and low-cost solution for manufacturing complex structural components. However, existing FDM technology is mostly used for manufacturing single-material components or simple double-material components, and fails to fully utilize the potential of functional gradient design to cope with the extreme environment of the plateau.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The existing technology has the problem that the sheaths formed by traditional injection molding or compression molding are mostly single homogeneous materials (such as HDPE, PVC, or ordinary engineering plastics), which are difficult to meet the requirements of multifunctional integration such as weather resistance, temperature resistance, toughness, and insulation. To solve the above problem, the present application provides a layered gradient multifunctional sheath and an additive manufacturing method thereof. The outer layer focuses on weather resistance, the middle layer focuses on stiffness and transition, and the inner layer focuses on strength and functional structure. The thickness of each layer can be flexibly adjusted according to the differences in different tower positions and service conditions, and the performance can be precisely customized, thereby comprehensively improving the service life and reliability of the sheath in the extreme environment of the plateau.

[0007] The present application is realized by the following technical solutions: In a first aspect, the present application provides a layered gradient multifunctional sheath, comprising a layered gradient structure formed by fused deposition modeling (FDM) technology, the layered gradient structure comprising an inner layer, a transition intermediate layer and an outer layer from inside to outside along the thickness direction; the outer layer material is acrylonitrile-styrene-acrylate copolymer (ASA), the transition intermediate layer material is carbon fiber reinforced acrylonitrile-styrene-acrylate composite material (ASA-CF), and the inner layer material is carbon fiber reinforced polyphthalic amide composite material (PPA-CF).

[0008] In a specific embodiment, the thickness of the outer layer accounts for 20-40% of the thickness of the layered gradient structure, the thickness of the transition intermediate layer accounts for 10-30% of the thickness of the layered gradient structure, and the thickness of the inner layer accounts for 30-60% of the thickness of the layered gradient structure.

[0009] In a specific embodiment, the thickness of the layered gradient structure is 4-8 mm.

[0010] In a second aspect, the present application provides an additive manufacturing method of a layered gradient multifunctional sheath, comprising the following steps: S1, pretreating ASA, ASA-CF and PPA-CF, which are three materials to be printed; S2, gradient layering design and three-dimensional modeling of the sheath; S3, slicing the sheath to be printed and adding a support structure; S4, FDM printing of the target sheath to obtain a multi-layer gradient part; S5, removing the support structure of the layered gradient sheath and cleaning the surface; S6, annealing the layered gradient sheath to obtain a layered gradient multifunctional sheath.

[0011] In a specific embodiment, the pretreatment of ASA, ASA-CF and PPA-CF, which are three materials to be printed, in step S1 specifically comprises: placing ASA and ASA-CF in a blast oven and drying at 90℃ for 6-8 h; placing PPA-CF in a blast oven and drying at 120℃ for 8-12 h.

[0012] The present application removes moisture existing in the materials during storage through pretreatment, which can avoid the vaporization of moisture during printing, resulting in the presence of micro-bubbles in the extruded material, which seriously weakens the interlayer bonding force and makes the surface quality rough.

[0013] In a specific embodiment, the step S2 of gradient layering and three-dimensional modeling of the sheath specifically comprises: constructing a three-dimensional model of the sheath by using Solidworks three-dimensional modeling software, the model is divided into three layers in the thickness direction, and the total thickness (D) is 3mm to 10mm; the thickness (d1) of the outer layer accounts for 20% to 40% of the total thickness, that is, d1=(20% to 40%) x D; the thickness (d2) of the transition intermediate layer accounts for 10% to 30% of the total thickness, that is, d2=(10% to 30%) x D; the thickness (d3) of the inner layer accounts for 30% to 60% of the total thickness, that is, d3=(30% to 60%) x D, and it satisfies: d1+d2+d3=D.

[0014] The outer layer printing material is acrylonitrile-styrene-acrylate copolymer (ASA), which has low strength, and pure ASA can provide the best UV resistance and weather resistance to protect the internal material from sunlight degradation; the transition intermediate layer printing material is carbon fiber reinforced acrylonitrile-styrene-acrylate composite material (ASA-CF), and the addition of carbon fiber (CF) can greatly improve the rigidity and dimensional stability of the layer, which acts as a supporting framework for the outer layer to prevent large sheath parts from warping and deforming under the action of temperature difference; the inner layer material is carbon fiber reinforced polyphthalic amide composite material (PPA-CF), which has high strength and can provide the required ultimate mechanical properties of the sheath to ensure the structural integrity under extreme weather conditions such as strong wind and hail.

[0015] The present application accurately sets the thickness of each layer in advance through modeling software, reducing the difficulty of slicing in the printing software; at the same time, the present application can flexibly adjust the thickness of each layer and the different proportion of the total thickness according to the differences of different tower positions and service conditions to realize the precise customization of different performances of the sheath, and finally realize the flexible design of the sheath performance.

[0016] In a specific embodiment, the step S3 of slicing the sheath to be printed and adding related supports specifically comprises: adding a support structure to the model in the Bambu Studio software, the support structure type is tree-shaped support, the threshold angle is 30 to 45°, and the support spacing is 2mm, which can avoid deformation, falling and other problems of the part caused by complex structure design during printing; the boundaries of the three regions are accurately divided in the slicing software, and the "modifier" or "region type" function of the software is used to assign the above different materials to the outer layer, the transition layer and the inner layer respectively.

[0017] In a specific embodiment, the step S4 of FDM printing of the target sheath to obtain a multi-layer gradient part specifically comprises: using the "modifier" or "region type" function of the software to assign independent printing parameters to the outer layer, the transition intermediate layer and the inner layer respectively; the printing process of each layer is as follows: (a) Outer layer (ASA): print layer thickness 0.2 mm, nozzle temperature 250-260℃, hot bed temperature 90-95℃, print speed 40-60 mm / s, cooling fan speed 20-50%, retraction setting length 0.8 mm; (b) Transition intermediate layer (ASA-CF): print layer thickness 0.2 mm, nozzle temperature 265-280℃, hot bed temperature 95-105℃, print speed 30-50 mm / s, cooling fan speed 0-20%, retraction setting length 0.8 mm; (c) Inner layer (PPA-CF): print layer thickness 0.18 mm, nozzle temperature 295-305℃, hot bed temperature 110-115℃, print speed 30-45 mm / s, cooling fan speed 0%, retraction setting length 0.7 mm; First, the smaller layer height can increase the Z-axis interlayer bonding area and improve the strength, and the inner layer of the present application uses 0.18 mm to further improve the density and clearness of functional structure; the outer layer is easy to degrade at high temperature.

[0018] Secondly, if the temperature of the inner layer PPA-CF is insufficient, it will cause poor fluidity and weak interlayer bonding, so the high-temperature bed is crucial for printing engineering plastics, and the present application gradually increases the temperature from the outside to the inside to match the material shrinkage rate; the high-temperature chamber can greatly reduce the printing internal stress and warping, and provide the best printing environment for ASA and PPA-CF, which is a decisive factor for realizing high-strength interlayer bonding.

[0019] In addition, the slower print speed selected by the present application allows the material to have enough time to fully melt with the previous layer, and the transition layer and the inner layer which most need strength should use slower speed.

[0020] Finally, the ASA of the outer layer can accept a small amount of cooling to improve and adjust the detail performance, while the PPA-CF of the inner layer must turn off the fan to force slow cooling, promote interlayer molecular diffusion and fusion, and prevent interlayer separation caused by rapid cooling.

[0021] In a specific embodiment, in step S5, the surface cleaning of the layered gradient sheath after the support structure is removed includes: after the printing is completed and the part is cooled to room temperature, the part is taken out from the printer, the tree-shaped support used for supporting the structure during the printing process is removed using tweezers, and then the part is wiped with an alcohol solution with a volume percentage of 50%, and naturally air dried, to obtain a layered gradient sheath with good surface quality.

[0022] In a specific embodiment, the step S6 of annealing the layered gradient sheath to obtain the layered gradient multifunctional sheath specifically comprises: placing the printed layered gradient sheath into a blast drying oven and annealing at 80-100 DEG C for 8-12 hours; eliminating the printing internal stress, improving the material crystallinity, and significantly improving the interlayer bonding strength (Z-axis strength) and the overall thermal stability of the part, so that it can better withstand the severe temperature difference of the plateau.

[0023] Compared with the prior art, the present application has the following advantages and beneficial effects: 1. The layered gradient multifunctional sheath and the additive manufacturing method thereof provided by the embodiment of the present application realize the integration of the excellent weather resistance, UV resistance of ASA and the excellent mechanical strength and heat resistance of PPA-CF through functional gradient design, achieve the integrated performance of "weather resistance outside and strength inside", have excellent ultraviolet radiation resistance, temperature difference resistance, high strength and high reliability, can perfectly cope with the complex environment of the plateau, and significantly improve the service life of the highland power facility part. 2. The layered gradient multifunctional sheath and the additive manufacturing method thereof provided by the embodiment of the present application utilize the FDM technology, realize the material gradient change, and propose a adjustable layer thickness ratio design criterion, so that the thickness of each layer can be flexibly adjusted according to the specific installation position and the main failure mode (such as aging or mechanical damage) of the sheath, the performance is accurately customized, the material is optimally utilized, and the longest service life of the part is realized. 3. The layered gradient multifunctional sheath and the additive manufacturing method thereof provided by the embodiment of the present application can utilize the FDM technology to print the complex drainage and dust prevention functional structures in the inner layer at one time, reduce the assembly steps, and improve the overall reliability. 4. The layered gradient multifunctional sheath and the additive manufacturing method thereof provided by the embodiment of the present application can effectively guarantee the interlayer bonding strength of the gradient material and the overall quality of the printed part through the control of the material processing, printing parameters and post-processing technology in the additive process, especially the control of the key parameters such as chamber temperature and cooling fan, and overcome the technical difficulties of easy warping and easy layering of engineering materials. 5. The layered gradient multifunctional sheath and the additive manufacturing method thereof provided by the embodiment of the present application ingeniously utilize the material flexibility of the FDM technology, integrate the "weather resistance" of ASA, the "stability" of ASA-CF and the "strong toughness" of PPA-CF into one, realize the effect of 1+1+1>3, and is not a simple material replacement, but an innovative design from the perspective of material-structure-function integration, which provides a new and highly reliable solution for the manufacturing of power facility parts in the harsh environment of the plateau. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required to be used in the examples will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0025] Figure 1 The present application provides Figure 1 A model schematic diagram of a multi-layer composite kit; Figure 2 A tensile mechanical property diagram of a sheath prepared in Examples 1-3 of the present application and a single-material sheath; Figure 3 A diagram of the change in bending strength of the sheath prepared in Examples 1-3 of the present application after 144h of ultraviolet irradiation; Figure 4 A diagram of the bending performance of the sheath prepared in Examples 1-3 of the present application after 144h of salt spray testing. DETAILED DESCRIPTION

[0026] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the examples. The illustrative embodiments of the present application and the description thereof are only used to explain the present application and should not be regarded as a limitation on the present application.

[0027] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one of ordinary skill in the art that the present application can be practiced without these specific details. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present application.

[0028] In the entire specification, the mention of "one embodiment", "an embodiment", "one example" or "an example" means that the specific features, structures or characteristics described in connection with the embodiment or example are included in at least one embodiment of the present application. Therefore, the phrases "one embodiment", "an embodiment", "one example" or "an example" appearing at various places in the entire specification do not necessarily refer to the same embodiment or example. In addition, specific features, structures or characteristics can be combined in one or more embodiments or examples in any appropriate combination and / or sub-combination. The term "and / or" used herein includes any and all combinations of one or more of the relevant listed items.

[0029] "RANGES" disclosed herein are defined, for each range by endpoints, to include the endpoint values. Ranges formed by combinations of any of the individual minimum and maximum values disclosed are within the scope of the application. For example, if a range of 60-120 and a range of 80-110 are disclosed, a range of 80-120 is also contemplated. Additionally, if a minimum range value of 1 and a maximum range value of 3 are disclosed, a range of 1-3 is contemplated. Unless otherwise stated, the numerical ranges "a-b" are intended to indicate any and all sub-combinations of the values between a and b, inclusive of the endpoints. For example, the numerical range "0-5" is intended to indicate that all real numbers between 0 and 5 inclusive of the endpoints are contemplated herein. For example, the numerical range "0-5" is intended to indicate that all real numbers between 0 and 5 inclusive of the endpoints are contemplated herein. "0-5" is merely a shorthand for listing all real numbers between 0 and 5 inclusive of the endpoints. Additionally, when a parameter is stated to be an integer > 2, it is equivalent to stating that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc. Unless otherwise specified, all steps of the application can be performed in any order, preferably in the order specified. For example, the method comprises steps (a) and (b) means that the method can comprise steps (a) and (b) in the order specified, or the method can comprise steps (b) and (a) in the order specified. For example, the method can further comprise step (c) means that step (c) can be added to the method in any order. For example, the method can comprise steps (a), (b) and (c), or the method can comprise steps (a), (c) and (b), or the method can comprise steps (c), (a) and (b), etc.

[0030] Example 1 The embodiment of the application provides an additive manufacturing method of a layered gradient multifunctional sheath, which is used for a comprehensive sheath of a general part of a tower and a pole, and comprises the following steps. Step 1, pretreating ASA, ASA-CF and PPA-CF three materials to be printed; The ASA and the ASA-CF are placed into a blast oven and dried at 90 DEG C for 8 h; the PPA-CF is placed into a blast oven and dried at 120 DEG C for 12 h.

[0031] Step 2, gradient layer design and three-dimensional modeling of the sheath; A three-dimensional model of the sheath is constructed through a Solidworks three-dimensional modeling software. The model is divided into three layers in the thickness direction, and the total thickness D is 5 mm, the outer layer thickness d1 is 1.5 mm, the transition intermediate layer thickness d2 is 1.25 mm, and the inner layer thickness d3 is 2.25 mm.

[0032] Step 3, slice the sheath to be printed and add relevant support; Add support to the model in Bambu Studio software, the support type is tree support, the threshold angle is 30°, the support spacing is 2 mm, the slicing form is automatic generation, and the gradual transition function is set.

[0033] Step 4, FDM printing of the target sheath to obtain a multi-layer gradient part; After presetting the process parameters in Bambu Studio software, automatic printing is performed, and the printing process of each layer is as follows: (a) outer layer (ASA): printing layer thickness is 0.2 mm, nozzle temperature is 255℃, hot bed temperature is 90℃, printing speed is 60 mm / s, cooling fan speed is 35%, and retraction setting length is 0.8 mm; (b) transition layer (ASA-CF): printing layer thickness is 0.2 mm, nozzle temperature is 275℃, hot bed temperature is 100℃, printing speed is 45 mm / s, cooling fan speed is 10%, and retraction setting length is 0.8 mm; (c) inner layer (PPA-CF): printing layer thickness is 0.18 mm, nozzle temperature is 300℃, hot bed temperature is 110℃, printing speed is 40 mm / s, cooling fan speed is 0%, and retraction setting length is 0.7 mm; Step 5, remove the support structure from the layered gradient sheath, and clean the surface; After printing, the part is cooled to room temperature, taken out of the printer, the tree-shaped support structure used for the printing process is removed from the part using tweezers, then it is wiped with an alcohol solution with a volume percentage of 50%, and naturally air dried, to obtain a layered gradient sheath with good surface quality.

[0034] Step 6, annealing treatment of the layered gradient sheath to obtain a layered gradient multifunctional sheath; The printed layered gradient sheath is placed in a blast drying oven at 90℃ for 10 h, and a layered gradient sheath with good performance is obtained.

[0035] Example 2 The embodiment of the present application provides an additive manufacturing method of a layered gradient multifunctional sheath, which is used for a high-strength sheath of a tuyere strong wind impact part, and comprises the following steps: Step 1, pretreatment of ASA, ASA-CF and PPA-CF three kinds of materials to be printed; The ASA and ASA-CF are placed in a blast drying oven at 90℃ for 8 h, and the PPA-CF is placed in a blast drying oven at 120℃ for 12 h.

[0036] Step 2, gradient layer design and three-dimensional modeling of the sheath, as shown in Figure 1 ; A three-dimensional model of the sheath was constructed using Solidworks three-dimensional modeling software. The model was divided into three layers in the thickness direction, with a total thickness D = 8 mm, an outer layer thickness d1 = 2 mm, a transition intermediate layer thickness d2 = 1.2 mm, and an inner layer thickness d3 = 4.8 mm.

[0037] Step 3, slicing and adding related support to the sheath to be printed; Support was added to the model in Bambu Studio software, with tree support as the support type, a threshold angle of 30°, a support spacing of 2 mm, automatic slicing, and a gradual transition function set.

[0038] Step 4, FDM printing of the target sheath to obtain a multi-layer gradient part; After setting the process parameters in Bambu Studio software, the printing was automatically completed, with the following printing process for each layer: (a) outer layer (ASA): printing layer thickness of 0.2 mm, nozzle temperature of 260°C, hot bed temperature of 95°C, printing speed of 55 mm / s, cooling fan speed of 30%, and retraction setting length of 0.8 mm; (b) transition layer (ASA-CF): printing layer thickness of 0.2 mm, nozzle temperature of 270°C, hot bed temperature of 95°C, printing speed of 50 mm / s, cooling fan speed of 20%, and retraction setting length of 0.8 mm; (c) inner layer (PPA-CF): printing layer thickness of 0.18 mm, nozzle temperature of 300°C, hot bed temperature of 115°C, printing speed of 30 mm / s, cooling fan speed of 0%, and retraction setting length of 0.7 mm; Step 5, removing the support structure from the layered gradient sheath and cleaning the surface; After printing, the part was cooled to room temperature and removed from the printer. The tree support structure used during the printing process was removed using tweezers, and then the part was wiped with a 50% alcohol solution and air dried, resulting in a layered gradient sheath with good surface quality.

[0039] Step 6, annealing treatment of the layered gradient sheath to obtain a layered gradient multifunctional sheath; The printed layered gradient sheath was placed in a drum drying oven and annealed at 100°C for 12 h, resulting in a layered gradient sheath with good performance.

[0040] Example 3 The embodiment of the application provides an additive manufacturing method of a layered gradient multifunctional sheath, which is used for a high-weather-resistant sheath of a strong-sun surface, and comprises the following steps: Step 1, pretreating ASA, ASA-CF and PPA-CF which are three materials to be printed; The ASA and the ASA-CF are placed in a blast oven and dried at 90 DEG C for 8 hours, and the PPA-CF is placed in a blast oven and dried at 120 DEG C for 12 hours.

[0041] Step 2, gradient layer design and three-dimensional modeling of the sheath; A three-dimensional model of the sheath is constructed by using a Solidworks three-dimensional modeling software, the model is divided into three layers in the thickness direction, the total thickness D is 4 mm, the outer layer thickness d1 is 1.5 mm, the transition intermediate layer thickness d2 is 0.8 mm, and the inner layer thickness d3 is 1.7 mm.

[0042] Step 3, slicing the sheath to be printed and adding related supports; Supports are added to the model in the Bambu Studio software, the support type is tree-shaped support, the threshold angle is 30 DEG, the support spacing is 2 mm, the slicing form is automatic generation, and the gradient transition function is set.

[0043] Step 4, FDM printing of the target sheath, to obtain a multi-layer gradient part; After presetting the process parameters in the Bambu Studio software, automatic printing is performed, and the printing process of each layer is as follows: (a) outer layer (ASA): the printing layer thickness is 0.2 mm, the nozzle temperature is 260 DEG C, the hot bed temperature is 95 DEG C, the printing speed is 40 mm / s, the cooling fan speed is 50%, and the retraction setting length is 0.8 mm; (b) transition layer (ASA-CF): the printing layer thickness is 0.2 mm, the nozzle temperature is 280 DEG C, the hot bed temperature is 105 DEG C, the printing speed is 40 mm / s, the cooling fan speed is 10%, and the retraction setting length is 0.8 mm; (c) inner layer (PPA-CF): the printing layer thickness is 0.18 mm, the nozzle temperature is 295 DEG C, the hot bed temperature is 110 DEG C, the printing speed is 30 mm / s, the cooling fan speed is 0%, and the retraction setting length is 0.7 mm; Step 5, removing the support structure of the layered gradient sheath and cleaning the surface; After printing is completed, the part is cooled to room temperature, taken out of the printer, the tree-shaped support structure used for the printing process is removed from the part by using tweezers, then the part is wiped with an alcohol solution with a volume percentage of 50%, and naturally air-dried, so that the layered gradient sheath with good surface quality is obtained.

[0044] Step 6: Anneal the layered gradient sheath to obtain the layered gradient multifunctional sheath. The printed layered gradient sheath is placed in a forced-air drying oven and annealed at 80°C for 8 hours to obtain a high-performance layered gradient sheath.

[0045] Performance testing 1. The mechanical properties of the layered gradient sheaths prepared in Examples 1-3 and the sheaths prepared from a single material were tested under normal conditions, after 144 hours of ultraviolet irradiation, and after 144 hours of salt spray testing. The results are as follows: Figures 2-4 As shown.

[0046] from Figure 2 As can be seen from the data, ASA-CF has the lowest strength among the single-material kits, while PPA-CF has the highest strength. Examples 1, 2, and 3 can all achieve high bending strength (>185MPa), meeting the sheath performance requirements.

[0047] from Figure 3 As can be seen from the comparison before and after ultraviolet irradiation treatment, ASA, as the outermost material, can play a good role in resisting ultraviolet radiation. After ultraviolet irradiation treatment, Examples 1, 2 and 3 all maintained high bending strength (>170MPa), and the decrease was within 15MPa.

[0048] from Figure 4 As can be seen from the comparison before and after corrosion treatment, ASA, as the outermost material, can play a good role in corrosion resistance. After corrosion treatment, Examples 1, 2 and 3 all maintained high flexural strength (>170MPa), and the decrease was within 15MPa.

[0049] In summary, the sheath prepared according to the embodiments of the present invention has excellent resistance to ultraviolet radiation, resistance to temperature differences, high strength and high reliability, and can perfectly cope with the complex environment of high altitude.

[0050] 2. The three materials used in this invention were soaked in water, and their mass changes were calculated. The results are shown in Table 1.

[0051] As can be seen from Table 1, ASA and ASA-CF have strong water resistance and are suitable as external materials for composite gradient structures, while PPA-CF has strong water absorption and is therefore used as an internal material for gradient structures.

[0052] Table 1 .

[0053] The above detailed description of the specific embodiments of the present application has been given to understand the purpose, technical solutions and beneficial effects of the present application. It should be understood that the above description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A layered gradient multi-functional jacket, characterized by, The layered gradient structure includes a layered gradient structure printed by using a fused deposition modeling (FDM) technology, the layered gradient structure sequentially includes an inner layer, a transition intermediate layer and an outer layer from inside to outside along a thickness direction; the outer layer material adopts acrylonitrile-styrene-acrylate copolymer (ASA), the transition intermediate layer material adopts carbon fiber reinforced acrylonitrile-styrene-acrylate composite material (ASA-CF), and the inner layer material adopts carbon fiber reinforced polyphthalamide composite material (PPA-CF).

2. A layered gradient multi-functional jacket according to claim 1, wherein, The thickness of the outer layer accounts for 20-40% of the thickness of the layered gradient structure, the thickness of the transition intermediate layer accounts for 10-30% of the thickness of the layered gradient structure, and the inner layer accounts for 30-60% of the thickness of the layered gradient structure.

3. A layered gradient multi-functional jacket according to claim 1, wherein, The thickness of the layered gradient structure is 4-8 mm.

4. The method of additive production of a layered gradient multifunctional jacket according to any of claims 1 to 3, characterized in that, The method comprises the following steps: S1, pretreating ASA, ASA-CF and PPA-CF which are three materials to be printed; S2, gradient layering design and three-dimensional modeling are performed on a sheath; S3, the sheath to be printed is sliced and a support structure is added; S4, the target sheath is printed by FDM to obtain a multi-layer gradient part; S5, the layered gradient sheath is removed from the support structure and the surface is cleaned; S6, the layered gradient sheath is annealed to obtain a layered gradient multifunctional sheath.

5. The method of additive production of a layered gradient multifunctional jacket according to claim 4, characterized in that, In step S1, the specific method of pretreatment is as follows: ASA, ASA-CF and PPA-CF are placed in an oven for drying to remove moisture from the materials.

6. The method of making a layered gradient multifunctional jacket of claim 4, wherein, In step S2, the specific method of layering design and three-dimensional modeling is as follows: a three-dimensional model of the sheath is constructed by using Solidworks three-dimensional modeling software, and the three-dimensional model is divided into three layers in the thickness direction according to the design thickness of each layer.

7. The method of additive production of a layered gradient multifunctional jacket according to claim 4, characterized in that, In step S3, a support structure is added to the model in Bambu Studio software, and the support structure type is tree-shaped support.

8. The method of additive production of layered gradient multifunctional jacket according to claim 4, characterized in that, In step S4, The outer layer printing parameters are: the printing layer thickness is 0.2 mm, the nozzle temperature is 250-260℃, and the hot bed temperature is 90-95℃; The transition intermediate layer printing parameters are: the printing layer thickness is 0.2 mm, the nozzle temperature is 265-280℃, and the hot bed temperature is 95-105℃; The inner layer printing parameters are: the printing layer thickness is 0.18 mm, the nozzle temperature is 295-305℃, and the hot bed temperature is 110-115℃.

9. The method of additive production of layered gradient multifunctional jacket according to claim 4, characterized in that, In step S5, after the printing is completed and cooled to room temperature, the tree-shaped support structure used for the printing process is removed, and the surface is wiped with an alcohol solution.

10. The method of additive production of layered gradient multifunctional jacket according to claim 4, characterized in that, In step S6, the layered gradient sheath after printing is annealed at 85-95℃ for 10-12 h to obtain a layered gradient sheath with good performance.

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