PFA fluororesin material for selective laser sintering and preparation method thereof

Abstract

The invention provides a PFA fluororesin material for selective laser sintering and a preparation method of the PFA fluororesin material. The PFA fluororesin material is prepared from the following components in parts by weight: 100 parts of PFA fluororesin, 0.05 to 0.5 part of antioxidant, 0.3 to 1 part of flow promoter and 0.8 to 1.5 parts of body promoter. The flow promoter is one or more of gas-phase nano silicon dioxide, nano titanium dioxide, graphene nanobelts and a fluorosilane coupling agent; the antioxidant is one or more of a composite phenol antioxidant, magnesium hydroxide and a benzophenone light stabilizer; the body auxiliary agent is one or more of a carbon nano tube and nano silicon nitride. And the high-temperature thermoelectric conversion agent is bismuth telluride and a hydroxylated carbon nanotube. The PFA material has good heat resistance and corrosion resistance, the powder laying uniformity and interlayer bonding strength in the SLS forming process are improved through the optimized coating technology, the corrosion resistance of the PFA is not affected by the composite powder, and the material is endowed with the thermoelectric conversion capacity at the high temperature.

Description

Technical Field

[0001] The invention belongs to the technical field of selective laser sintering, and in particular relates to a PFA fluororesin material for selective laser sintering and a preparation method thereof. Background Art

[0002] Selective laser sintering (SLS) is a type of additive manufacturing process. The specific process is as follows: First, a layer of polymer powder is evenly laid within a build cylinder. The powder layer is then sintered using energy generated by thermal radiation and laser radiation. During this process, the polymer powder absorbs energy and transforms into a viscous flow state. Layer by layer, the powder is sintered to form a bond between the powder and the finished part. Once a layer is sintered, a new layer of powder is laid and the above steps are repeated until the entire part is formed. After sintering, the part and unsintered powder are cooled, and the excess powder is removed to complete the polymer part.

[0003] There are many types of materials suitable for selective laser sintering technology. The characteristics of these materials have achieved relatively good results in various fields. However, in the chemical industry, certain strong acid environments have relatively high requirements for the corrosion resistance and heat resistance of materials. Existing materials cannot meet the industry's application. Therefore, a new type of material is needed to be formed through selective laser sintering technology to fill the application needs of this type of industry and expand the application field of selective laser sintering technology. Summary of the Invention

[0004] In view of this, the present invention aims to provide a PFA fluororesin material for selective laser sintering and a preparation method thereof. The PFA material has excellent heat resistance and corrosion resistance, and can solve the gaps in the existing technology in the chemical industry.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows: A PFA fluororesin material for selective laser sintering, comprising the following components in parts by weight: 100 parts of PFA fluororesin (fusible polytetrafluoroethylene), 0.05-0.5 parts of antioxidant, 0.3-1 parts of flow aid, 0.8-1.5 parts of body aid.

[0006] Preferably, the PFA fluororesin material further comprises the following components in parts by weight: 0.2-3 parts of a high-temperature thermoelectric converter. Further preferably, the PFA fluororesin material further comprises the following components in parts by weight: 0.5-3 parts of a microcapsule additive.

[0007] Further preferably, the PFA fluororesin material includes the following components in parts by weight: 100 parts of PFA fluororesin, 0.08-0.3 parts of antioxidant, 0.5-0.8 parts of flow aid, 1-1.2 parts of body aid, 0.5-2.5 parts of high-temperature thermoelectric converter, and 0.8-2.5 parts of microcapsule aid.

[0008] Preferably, the flow aid is one or more of fumed nano-silica, nano-titanium dioxide, graphene nanoribbons and fluorosilane coupling agents; The antioxidant is one or more of a composite phenol antioxidant, magnesium hydroxide, and a benzophenone light stabilizer; The bodyizing agent is one or more of carbon nanotubes and nano silicon nitride.

[0009] Preferably, the high-temperature thermoelectric conversion agent is bismuth telluride and hydroxylated carbon nanotubes, and the mass ratio of bismuth telluride to hydroxylated carbon nanotubes is 1:(0.1-0.4).

[0010] Preferably, the microcapsule additive is composed of a core material and a wall material, wherein the core material is a fluorosilicone prepolymer and the wall material is a polyimide, and the mass ratio of the core material to the wall material is (1-2.5):1.

[0011] The method for preparing the PFA fluororesin material for selective laser sintering comprises the following steps: (1) PFA fluororesin pellets are subjected to a cryogenic crushing process to obtain PFA fluororesin powder; (2) Place the deep-cooled PFA fluororesin powder in a vacuum drying oven for drying to remove moisture from micromolecules and materials; (3) PFA fluororesin powder is added to a mixing barrel, and an antioxidant, a flow aid, a body aid, a high-temperature thermoelectric converter and a microcapsule aid are added at the same time, and the mixture is stirred to obtain a PFA fluororesin material.

[0012] Preferably, the melt index of the PFA fluororesin pellets in step (1) is 5-10 g / 10 min; the cryogenic process in step (1) is: adding the PFA fluororesin material into a cryogenic pulverizer, introducing liquid nitrogen, starting the cryogenic pulverizer, the pulverization temperature is -200°C to -150°C, the stirring rate is 3000-5000 rpm / min, the stirring time is 5-50 min, and the average particle size of the PFA fluororesin powder is 30-120 μm. The drying temperature in step (2) is 200-240°C, and the drying time is 7-10 hours; preferably, the drying temperature in step (2) is 220°C, and the drying time is 8 hours; Preferably, during stirring in step (3), the temperature of the stirring barrel is maintained at 30-40°C, the stirring rate is 50-1500 rpm / min, and the stirring time is 0.5-10 min; The obtained PFA fluororesin (fusible polytetrafluoroethylene) polymer material is screened to remove impurities generated during high-speed stirring, further improve the particle size distribution of the PFA fluororesin polymer material, and screened with an 80-mesh screen to remove impurities on the screen.

[0013] The PFA fluororesin material for selective laser sintering or the PFA fluororesin material for selective laser sintering prepared by the method is used in a method for manufacturing a three-dimensional object. The method for manufacturing a three-dimensional object comprises the following steps: S1: a powder spreader spreads the PFA fluororesin material described in step S1 on the base plate or the selectively fused layer to form a material layer; The S2 laser emits laser light, which is guided to selectively irradiate the fusion area on the material layer. The fusion area is the cross-sectional area corresponding to the three-dimensional object to be manufactured in the layer, thus completing the manufacture of the three-dimensional object.

[0014] Preferably, the powder spreading speed of the powder spreader in S1 is less than or equal to 250 mm / s. The beneficial effects of the present invention are as follows: 1. The present invention utilizes cryogenic pulverization technology, using liquid nitrogen as the grinding medium to achieve ultra-low-temperature pulverization. The optimal pulverization temperature is selected based on the material's brittle point. This method not only reduces energy consumption but also offers simple and controllable operation, successfully producing polymer powders that are difficult to prepare using other methods. During the preparation of PFA fluororesin powder, residual trace moisture and small molecular impurities within the material can severely impact its particle size uniformity and sintering performance. The present invention utilizes a vacuum drying oven to refine the PFA fluororesin powder. By precisely controlling the vacuum level and temperature parameters, the method achieves efficient removal of moisture and micromolecular impurities under negative pressure. Compared to traditional drying processes, this method utilizes the reduced boiling point of the material in a vacuum environment to avoid high-temperature damage to the PFA molecular chains. It also promotes a more uniform stress distribution between powder particles, ultimately reducing the coefficient of variation of the particle size distribution by over 30%. This technology not only effectively eliminates sintering defects such as bubbles and delamination caused by residual moisture, but also significantly improves powder flowability and molding accuracy by enhancing particle size uniformity, laying a solid foundation for the application of high-performance PFA materials in 3D printing.

[0015] 2. In selective laser sintering (SLS) technology, material fluidity directly determines molding quality. PFA fluororesin, due to its low surface energy and high inter-particle friction, is prone to agglomeration during the powder laying process. This can lead to problems such as insufficient powder bed flatness, interlayer bonding defects, and secondary sintering, ultimately causing overburning of the part surface and reduced dimensional accuracy.

[0016] This innovative coating process utilizes one or more of fumed nano-silica, nano-titania, graphene nanoribbons, and a fluorosilane coupling agent as flow aids. A high-speed stirring process is used to uniformly coat PFA particles with nano-silica. The unique nano-spherical structure and high surface area of ​​fumed silica effectively fill the gaps between PFA particles, reducing internal friction. Simultaneously, the silanol groups on the silica surface form a weak interaction with the PFA surface, forming a stable core-shell structure and significantly improving the material's fluidity. The optimized coating process can increase the bulk density of PFA powder by 20%-30% and the Hall effect flow rate by over 40%, effectively preventing problems such as agglomeration and powder defects during the powder spreading process. It significantly improves powder spreading uniformity and interlayer bonding strength during SLS molding, significantly reducing overburning of finished parts, and ultimately achieving high-precision, low-defect PFA part formation.

[0017] Antioxidants are used to specifically address the problem of PFA materials being susceptible to oxidative degradation and mechanical property degradation during high-temperature processing and long-term use. Compound phenolic antioxidants effectively inhibit the thermal oxidative aging reaction of PFA materials at processing temperatures above 260°C by capturing free radicals, extending the material's oxidation induction time by over 40%. While exerting its flame retardant effect, magnesium hydroxide can neutralize acidic substances produced by trace hydrolysis during PFA processing, preventing molecular chain breakage and increasing the tensile strength retention of the product to 95%. Benzophenone-based light stabilizers can absorb ultraviolet rays in the 290-400nm band, significantly reducing the yellowing index and embrittlement risk of PFA materials in outdoor applications. Through multi-component optimization, the antioxidant system forms a synergistic network with the PFA matrix, which not only enhances the material's weather resistance and heat stability, but also improves its extrusion molding fluidity, extending the service life of PFA products by over 1.5 times in harsh environments such as semiconductors and chemical corrosion protection.

[0018] This innovative discovery utilizes one or more of carbon nanotubes and nano-silicon nitride as bulking additives, uniformly embedding them into the interstices of PFA molecular chains through molecular-level dispersion technology. This significantly improves the overall performance of PFA materials. Carbon nanotubes, with their excellent mechanical reinforcement properties and ultra-high aspect ratio, can construct a three-dimensional network structure within the PFA matrix, significantly enhancing the material's tensile strength, creep resistance, and wear resistance, enabling it to maintain a stable physical form even under high-temperature and high-pressure conditions. Nano-silicon nitride, through its unique interfacial effect, effectively improves the surface hardness and chemical stability of PFA, imparting enhanced scratch and corrosion resistance, making it particularly suitable for demanding applications such as semiconductor etching and chemical fluid transportation. When used synergistically, these two additives form a "hard and flexible" reinforcement system. While maintaining PFA's inherently excellent weather resistance and non-stick properties, they significantly expand its application in mechanical seals, high-temperature insulation, aerospace, and other fields, opening up new avenues for the innovative development of high-performance engineering plastics.

[0019] This invention innovatively utilizes bismuth telluride nanosheets and hydroxylated carbon nanotubes as high-temperature thermoelectric converters. Bismuth telluride is a thermoelectric material, but the carbon nanotubes form a continuous thermoelectric pathway within PFA through a "bridging" effect. This prevents bismuth telluride from oxidative failure at high temperatures (200-260°C) (conventional bismuth telluride readily oxidizes above 200°C in air). The antioxidant properties of PFA provide a protective shell. Hydroxylated carbon nanotubes form weak hydrogen bonds with the fluorine atoms of PFA, modulating the thermal vibration frequency of the PFA molecular chain and raising the thermoelectric figure of merit (ZT) to 0.8 at 250°C (pure bismuth telluride has a ZT of only 0.4 at this temperature). The composite powder does not affect PFA's corrosion resistance (weight change in 98% sulfuric acid remains ≤0.05% over 24 hours), while imparting high-temperature thermoelectric conversion capability (output voltage ≥1.2V at a temperature gradient of 50°C). The present invention innovatively adopts microcapsules composed of fluorosilicone prepolymer as the core material and polyimide as the wall material. The core function of the microcapsule is to give PFA fluororesin the ability to repair dynamic damage. When the material produces tiny cracks due to mechanical stress, hot and cold shock or penetration of corrosive media, the stress at the crack tip will pierce the polyimide wall material and release the fluorosilicone prepolymer. The fluorosilicone prepolymer automatically undergoes a cross-linking reaction and forms a chemical bond with the PFA fluororesin molecular chain, filling the cracks and restoring the integrity of the material, thereby extending the service life of PFA fluororesin parts. DETAILED DESCRIPTION

[0020] Unless otherwise defined, technical terms used in the following examples and comparative examples have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The experimental reagents used in the following examples and comparative examples, unless otherwise specified, are conventional biochemical reagents; and the experimental methods described, unless otherwise specified, are conventional methods.

[0021] Example 1 Step 1: PFA pellets were added to a cryogenic mill, liquid nitrogen was introduced, the pulverization temperature was controlled at -180°C, the stirring speed was 4000 rpm, and the pulverization time was 20 min, thereby obtaining a powder with an average particle size of 50 μm.

[0022] Step 2: Dry the PFA powder obtained in step 1 in a vacuum drying oven at 220°C for 8 hours with a vacuum degree of ≤10Pa to remove moisture and small molecular impurities, thereby improving the material purity and sintering performance.

[0023] Step 3: Add 100 parts of PFA powder, 0.3 parts of antioxidant benzophenone, 0.5 parts of flow aid fumed nano-silica, 1.2 parts of bodyizing aid carbon nanotubes, 2.2 parts of high-temperature thermoelectric converter (2 parts of bismuth telluride and 0.2 parts of hydroxylated carbon nanotubes), and 3 parts of microcapsules (2 parts of fluorosilicone prepolymer and 1 part of polyimide) into a stirring barrel, maintain the temperature in the barrel at 45°C, and stir at 2000 rpm for 8 minutes to evenly disperse the fumed nano-silica on the surface of the PFA powder and allow the carbon nanotubes to fully contact the PFA particles to form a uniform mixture.

[0024] Step 4: Pass through an 80-mesh sieve (made of stainless steel, pore size 0.18mm) to remove agglomerated particles and impurities. The screening process controls the vibration frequency to 30Hz and the amplitude to 2mm to ensure screening efficiency and quality.

[0025] Step 5: Place the PFA powder obtained in the above steps on the SLS selective laser sintering equipment for sintering.

[0026] Step 6: After sintering, anneal at 220℃ for 2h to form stable hydrogen bonds between CNT and PFA interface. Then test. Comparative Example 1 Based on Example 1, the antioxidant was removed, and the rest was the same as Example 1. Comparative Example 2 Based on Example 1, the flow aid was removed, and the rest was the same as Example 1. Comparative Example 3 Based on Example 1, the bodyizing agent was removed, and the rest was the same as Example 1. Comparative Example 4 Based on Example 1, the high-temperature thermoelectric conversion agent was removed, and the rest was the same as Example 1.

[0027] Comparative Example 5 Based on Example 1, the hydroxylated carbon nanotubes in the high-temperature thermoelectric conversion agent were removed, and the rest were the same as in Example 1.

[0028] Comparative Example 6 Based on Example 1, bismuth telluride in the high-temperature thermoelectric conversion agent was removed, and the rest was the same as Example 1.

[0029] Comparative Example 7 Meltable polytetrafluoroethylene powder was placed on a selective laser sintering (SLS) machine for sintering. After sintering, it was annealed at 220°C for 2 hours to form stable hydrogen bonds at the CNT / PFA interface. Testing was then performed. Comparative Example 8 Based on Example 1, the microcapsules were removed, and the rest were the same as in Example 1.

[0030] Table 1

[0031] It can be seen from Table 1 that no antioxidant is added in Comparative Example 1. The function of the antioxidant is to effectively inhibit the thermal oxidative aging reaction of the material in a high temperature environment by capturing free radicals and prolong the oxidation induction time. Without the antioxidant, the heat resistance of the material drops sharply, and it is easy to degrade and lose performance after long-term use.

[0032] In Comparative Example 2, no flow aid is added. The function of the flow aid is to fill the gaps between material particles, reduce the friction between materials, and improve the fluidity of the powder. Without it, the flow performance is significantly reduced, resulting in insufficient flatness of the powder bed and defects in interlayer bonding.

[0033] In Comparative Example 3, no bulking agent was added. The bulking agent's function is to enhance the mechanical properties of the material through a three-dimensional grid structure and improve tensile strength. Without it, the mechanical properties are greatly reduced, and the product is prone to cracking.

[0034] Comparative Examples 4, 5, and 6 do not add a high-temperature thermoelectric converter, or do not add one of the two. The bismuth telluride in the high-temperature thermoelectric converter provides thermoelectric performance, while the hydroxylated carbon nanotubes form a continuous thermoelectric pathway through a "bridging effect." The PFA matrix protects them from oxidation and corrosion, and the weak hydrogen bonding between the hydroxylated carbon nanotubes and PFA improves the thermoelectric figure of merit. Without either of these, the thermoelectric performance fails. Furthermore, when either bismuth telluride (Comparative Example 6) or hydroxylated carbon nanotubes (Comparative Example 5) is missing, the thermoelectric performance fails to meet the specified standards.

[0035] In Comparative Example 7, ordinary fusible polytetrafluoroethylene powder was used, but the effect was poor.

[0036] In Comparative Example 8, no microcapsules are added. The function of the microcapsules is that when the PFA fluororesin parts produce tiny cracks due to mechanical stress, hot and cold shock or penetration of corrosive media, the stress at the crack tip will pierce the polyimide wall material and release the fluorosilicone prepolymer. The fluorosilicone prepolymer automatically undergoes a cross-linking reaction, thereby extending the service life. After the microcapsules are missing, the gaps and holes in the material will become larger and larger under the environment of 98% sulfuric acid, 200°C, and 3000h, resulting in a decrease in tensile strength.

[0037] Based on the above implementation data results, a thermoelectric module can be integrated into the outer wall of a chemical reactor to generate electricity by utilizing the temperature difference between the 200°C high temperature inside the reactor and the ambient temperature to power the corrosion sensor (only PFA can withstand both the strong acid in the reactor and the high temperature of the power generation component).

[0038] Example 2 Based on Example 1, the antioxidant in step 3 was changed to magnesium hydroxide. Other steps were the same as in Example 1.

[0039] Example 3 Based on Example 1, the antioxidant in step 3 was changed to N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine (1098 antioxidant). Other steps were the same as in Example 1.

[0040] Example 4 Based on Example 1, the flow aid in step 3 was changed to nano-titanium dioxide. Other aspects were the same as in Example 1.

[0041] Example 5 Based on Example 1, the step of changing the tertiary additive to nano-silicon carbide is changed. Other aspects are the same as Example 1.

[0042] Example 6 Based on Example 1, the change in step 3 was to use 2.2 parts of the high-temperature thermoelectric conversion agent (1.5 parts of bismuth telluride and 0.7 parts of hydroxylated carbon nanotubes). Other steps were the same as in Example 1.

[0043] Example 7 Based on Example 1, the flow aid was changed to a fluorosilane coupling agent. Other steps were the same as in Example 1.

[0044] Comparative Example 9 Based on Example 1, the change to step 3 is 2.2 parts of high-temperature thermoelectric conversion agent (0.2 parts of bismuth telluride and 2 parts of hydroxylated carbon nanotubes). Other steps are the same as Example 1. Table 2

[0045] Table 2 shows that in Examples 2 and 3, the benzophenone antioxidant was replaced with magnesium hydroxide and 1098 antioxidant, both of which have the effect of enhancing the antioxidant properties of the material. The oxidation induction time of benzophenone is longer than that of magnesium hydroxide and 1098 antioxidant, and the thermal oxidation resistance is better.

[0046] In Example 4, the flow aid fumed nano-silica was replaced with nano-titanium dioxide, both of which have the function of enhancing the flow properties of the material. The flow properties of fumed nano-silica are better than those of nano-titanium dioxide, which is manifested in higher bulk density and shorter Hall flow number.

[0047] In Example 5, the solidifying agent carbon nanotubes are replaced with nano-silicon carbide, which has the function of enhancing the mechanical properties of the material and improving the tensile strength. The mechanical properties of carbon nanotubes are better than those of nano-silicon nitride, and the tensile strength is higher, and the material is more wear-resistant and scratch-resistant. In Example 7, using a fluorosilane coupling agent as the flow aid surprisingly resulted in a significant improvement in the thermoelectric figure of merit (ZT) at 250°C. The fluorinated groups lower the surface energy of PFA, creating a superhydrophobic surface that prevents the adhesion of liquid contaminants. Furthermore, the coupling effect allows for more uniform dispersion of the thermoelectric converter, reduces interfacial defects, and improves the stability of the ZT at 250°C.

[0048] In Comparative Example 10, the bismuth telluride content in the high-temperature thermoelectric converter is relatively low. Even if the content of hydroxylated carbon nanotubes is increased, the thermoelectric figure of merit drops to 0.45ZT, and the thermoelectric performance is basically ineffective. Comparative Example 10 Based on Example 1, the pulverization temperature in step 1 was changed to 20° C. Other conditions were the same as in Example 1. Powder production was unsuccessful.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A PFA fluororesin material for selective laser sintering, characterized by: The PFA fluororesin material includes the following components in parts by weight: 100 parts of PFA fluororesin, 0.05-0.5 parts of antioxidant, 0.3-1 parts of flow aid, 0.8-1.5 parts of body aid.

2. The PFA fluororesin material for selective laser sintering according to claim 1, wherein: The PFA fluororesin material further comprises the following components in parts by weight: 0.2-3 parts of a high-temperature thermoelectric conversion agent.

3. The PFA fluororesin material for selective laser sintering according to claim 2, characterized in that: The PFA fluororesin material further comprises the following components in parts by weight: 0.5-3 parts of microcapsule additive.

4. The PFA fluororesin material for selective laser sintering according to claim 3, wherein: The PFA fluororesin material includes the following components in parts by weight: 100 parts of PFA fluororesin, 0.08-0.3 parts of antioxidant, 0.5-0.8 parts of flow aid, 1-1.2 parts of body aid, 0.5-2.5 parts of high-temperature thermoelectric converter, and 0.8-2.5 parts of microcapsule aid.

5. The PFA fluororesin material for selective laser sintering according to any one of claims 3 to 4, characterized in that: The flow aid is one or more of fumed nano-silica, nano-titanium dioxide, graphene nano-ribbons and fluorosilane coupling agents; The antioxidant is one or more of a composite phenol antioxidant, magnesium hydroxide, and a benzophenone light stabilizer; The bodyizing agent is one or more of carbon nanotubes and nano silicon nitride; The high-temperature thermoelectric conversion agent is bismuth telluride and hydroxylated carbon nanotubes, and the mass ratio of bismuth telluride to hydroxylated carbon nanotubes is 1:(0.1-0.4); The microcapsule additive is composed of a core material and a wall material, wherein the core material is a fluorosilicone prepolymer, the wall material is a polyimide, and the mass ratio of the core material to the wall material is (1.5-2.5):

1.

6. The method for preparing a PFA fluororesin material for selective laser sintering according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: (1) PFA fluororesin pellets are subjected to a cryogenic crushing process to obtain PFA fluororesin powder; (2) Place the deep-cooled PFA fluororesin powder in a vacuum drying oven for drying to remove moisture from micromolecules and materials; (3) PFA fluororesin powder is added to a mixing barrel, and an antioxidant, a flow aid, a body aid, a high-temperature thermoelectric converter and a microcapsule aid are added at the same time, and the mixture is stirred to obtain a PFA fluororesin material.

7. The method for preparing a PFA fluororesin material for selective laser sintering according to claim 6, characterized in that: The PFA fluororesin pellets in step (1) have a melt index of 5-10 g / 10 min; the cryogenic process in step (1) comprises: adding the PFA fluororesin material into a cryogenic pulverizer, introducing liquid nitrogen, starting the cryogenic pulverizer, and grinding at a temperature of -200°C to -150°C, a stirring rate of 3000 to 5000 rpm / min, and a stirring time of 5 to 50 min to obtain a PFA fluororesin powder with an average particle size of 30 to 120 μm; The drying temperature in step (2) is 200-240° C., and the drying time is 7-10 h. Preferably, the drying temperature in step (2) is 220° C., and the drying time is 8 h.

8. The method for preparing a PFA fluororesin material for selective laser sintering according to claim 6, wherein: During stirring in step (3), the temperature of the stirring barrel is maintained at 30-40°C, the stirring rate is 50-1500 rpm / min, and the stirring time is 0.5-10 min; The obtained PFA fluororesin polymer material is sieved to remove impurities generated during high-speed stirring, further improve the particle size distribution of the PFA fluororesin polymer material, and sieve it through an 80-mesh sieve to remove impurities on the sieve.

9. A method for manufacturing a three-dimensional object using the PFA fluororesin material for selective laser sintering according to any one of claims 1 to 5 or the PFA fluororesin material for selective laser sintering prepared by the method according to any one of claims 6 to 9, characterized in that: The method for manufacturing a three-dimensional object comprises the following steps: S1: a powder spreader spreads the PFA fluororesin material described in step S1 on the base plate or the selectively fused layer to form a material layer; The S2 laser emits laser light, which is guided to selectively irradiate the fusion area on the material layer. The fusion area is the cross-sectional area corresponding to the three-dimensional object to be manufactured in the layer, thus completing the manufacture of the three-dimensional object.

10. The use according to claim 9, characterized in that S1 The powder spreading speed of the powder spreading device is less than or equal to 250 mm / s.

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