Preparation method of orthopedic protector based on bamboo fiber filled PLA (polylactic acid) material

Abstract

The invention provides a preparation method of an orthopedic protective tool based on a bamboo fiber filled PLA material, and relates to the technical field of additive manufacturing, the method comprises the following steps: obtaining bamboo fiber powder, carrying out silane oligomer modification treatment on the bamboo fiber powder to obtain modified bamboo fibers, and carrying out extrusion molding on the modified bamboo fibers to obtain the orthopedic protective tool. A bamboo fiber filled PLA particle material is prepared on the basis of modified bamboo fibers, PLA particles, PBAT particles, a nucleating agent and epoxidized soybean oil, melt extrusion 3D printing is conducted on the bamboo fiber filled PLA particle material on the basis of a particle extrusion type 3D printer, and the orthopedic protective tool is manufactured. The prepared bamboo fiber filled PLA meets the 3D printing requirement of the orthopedic protective tool, collapse caused by excessive softening at a high printing speed is avoided, and the printed bamboo fiber filled PLA orthopedic protective tool has good mechanical performance.

Description

Technical Field

[0001] The invention relates to the technical field of additive manufacturing, and in particular to a method for preparing an orthopedic protective gear based on bamboo fiber-filled PLA material. Background Art

[0002] Lightweight orthopedic protective gear is of great significance to the healthy growth of young people and the smooth recovery of the injured. It has the characteristics of high added value, large demand and short service life. However, current orthopedic protective gear is often produced with petroleum-based plastics such as polypropylene and polyvinyl chloride, which are difficult to degrade and have the risk of causing environmental pollution. Developing renewable and degradable new materials to replace petroleum-based plastics to produce orthopedic protective gear can effectively avoid the above problems.

[0003] Polylactic acid (PLA) is completely biodegradable and its synthetic raw materials are widely available. It also has good biocompatibility, excellent mechanical properties and good processability, making it an ideal alternative to petroleum-based plastics. However, PLA has problems with poor impact toughness and heat resistance. By blending flexible biodegradable plastics [such as polybutylene succinate (PBS), polybutylene adipate / terephthalate (PBAT), polycaprolactone (PCL), etc.] with PLA, its impact toughness can be greatly improved, but its heat resistance is further weakened. Therefore, it is often necessary to use inorganic fillers, glass fibers or carbon fibers to highly fill PLA blends to balance impact toughness and heat resistance. This in turn makes it difficult to recycle high-content glass fibers or carbon fibers after PLA degradation, causing environmental pollution problems. Natural plant fibers are widely available and completely degradable. If they are used as fillers to fill PLA, the aforementioned environmental pollution problems can be avoided. Among many plants, bamboo is a fast-growing and degradable biomass material. Bamboo fiber is a good choice for filling modified PLA, and bamboo fiber-filled PLA is an ideal material for producing lightweight orthopedic protective gear.

[0004] Traditional processes such as injection molding and hot pressing can only produce standardized orthopedic braces, which makes it difficult to achieve personalized production and cannot provide individuals with a comfortable wearing experience. 3D printing is the optimal process for molding personalized, lightweight orthopedic braces, but it requires that the printing raw materials have excellent printing performance. Excessive heat accumulation during the 3D printing process of orthopedic braces often causes the plastic to soften and cause the printed parts to collapse. At present, even highly filled PLA with inorganic fillers cannot meet the requirements of 3D printing of orthopedic braces. Therefore, it is urgent to develop a degradable material that meets the requirements of 3D printing of orthopedic braces and its corresponding 3D printing process. Summary of the invention

[0005] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a method for preparing an orthopedic protector based on bamboo fiber filled PLA material.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] The present invention provides a method for preparing an orthopedic protective gear based on bamboo fiber-filled PLA material, comprising:

[0008] Preparation of bamboo fiber filled PLA material;

[0009] Bamboo fiber-filled PLA material is printed into orthopedic protective gear based on a particle extrusion 3D printer.

[0010] Preferably, the bamboo fiber-filled PLA material is prepared by:

[0011] Obtaining bamboo fiber powder, and subjecting it to silane oligomer modification treatment to obtain modified bamboo fiber;

[0012] Bamboo fiber filled PLA particle material was prepared based on modified bamboo fiber, PLA particles, PBAT particles, nucleating agent and epoxidized soybean oil.

[0013] Preferably, bamboo fiber powder is obtained and subjected to silane oligomer modification treatment to obtain modified bamboo fiber, specifically, as follows:

[0014] Add bamboo fiber powder into water and stir to disperse it. The stirring time is 5 to 120 minutes.

[0015] Add silane oligomer into bamboo fiber / water dispersion, and continue stirring for 30-180 minutes at a temperature of 30-80°C.

[0016] After stopping stirring, the mixture is allowed to stand, the precipitate is taken out, and the precipitate is washed, filtered, and dried to obtain modified bamboo fiber.

[0017] Preferably, the silane oligomer is at least one of a bisaminosilane oligomer, an aminosilane oligomer and an epoxysilane oligomer, and the ratio of the silane oligomer to the bamboo fiber powder is 0.05-5 wt %.

[0018] Preferably, the bamboo fiber-filled PLA particle material is prepared based on modified bamboo fiber, PLA particles, PBAT particles, a nucleating agent and epoxidized soybean oil, specifically:

[0019] PLA particles, PBAT particles, modified bamboo fiber, nucleating agent and epoxidized soybean oil were premixed in proportion for 10 minutes;

[0020] The premixed materials are put into a twin-screw extruder for extrusion and mixing, the mixing temperature is 190~230℃, and the screw speed is 60~400 rpm;

[0021] The extruded material strips are immersed in a water tank for cooling and then pulled into a pelletizer for pelletization to obtain bamboo fiber-filled PLA granular materials.

[0022] Preferably, the basic components of the bamboo fiber-filled PLA particle material are: 40-80 wt% of PLA, 3-30 wt% of PBAT, 5-20 wt% of modified bamboo fiber, 0.3-5 wt% of nucleating agent, and 0.5-5 wt% of epoxidized soybean oil.

[0023] Preferably, the nucleating agent is at least one of sebacic acid diphenyl dihydrazide, adipic acid diphenyl dihydrazide and zinc phenylphosphonate.

[0024] Preferably, the bamboo fiber-filled PLA material is printed into orthopedic protective gear based on a particle extrusion 3D printer, specifically:

[0025] Based on a particle extrusion 3D printer, bamboo fiber-filled PLA particle material is melt-extruded and 3D printed to make orthopedic protective gear. The nozzle temperature of the particle extrusion 3D printer is 190~250 ℃, the layer height is 0.2~2 mm, the line speed is 10~100 mm / s, and the chamber temperature is 10~60 ℃.

[0026] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0027] The present invention provides a method for preparing an orthopedic protective gear based on bamboo fiber-filled PLA material, the method comprising obtaining bamboo fiber powder, subjecting it to silane oligomer modification treatment, obtaining modified bamboo fiber, preparing bamboo fiber-filled PLA granular material based on modified bamboo fiber, PLA particles, PBAT particles, nucleating agent and epoxy soybean oil, and melt-extruding 3D printing the bamboo fiber-filled PLA granular material based on a particle extrusion 3D printer to make an orthopedic protective gear. The bamboo fiber-filled PLA granular material provided by the present invention can meet the 3D printing process requirements of orthopedic protective gear, and can complete the printing and molding of various types of orthopedic protective gear with high quality within the expected time without collapse. On the one hand, this is due to the fact that there are more silane oligomer functional groups on the surface of the modified bamboo fiber, which can form dense secondary bonds with the PLA molecular chain to improve its melt modulus. On the other hand, the nucleating agent can induce PLA crystallization and further improve the melt modulus. The bamboo fiber-filled PLA granular material, preparation method and orthopedic protective gear 3D printing process provided by the present invention have good industrialization prospects, care for the rehabilitation of the injured and the healthy growth of young people, and help build a healthy China. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 It is a schematic diagram comparing the appearance photos and SEM fiber photos of the unmodified bamboo fiber and the modified bamboo fiber in the present invention;

[0030] Figure 2 Schematic diagram for comparing 3D printed foot orthotics in Example 3 and Comparative Example 3;

[0031] Figure 3 A schematic flow chart of a method for preparing an orthopedic protective gear based on bamboo fiber-filled PLA material provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The purpose of the present invention is to provide a carbon fiber reinforced PA6 composite material for 3D printing. The prepared bamboo fiber-filled PLA meets the requirements of 3D printing of orthopedic protective gear and does not collapse due to excessive softening at a faster printing speed; the printed bamboo fiber-filled PLA orthopedic protective gear has good mechanical properties.

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Figure 3 A flow chart of a method provided by an embodiment of the present invention, such as Figure 3 As shown, the present invention provides a method for preparing an orthopedic protective gear based on bamboo fiber filled PLA material, comprising:

[0036] Step 100: preparing bamboo fiber-filled PLA material;

[0037] Step 200: Print the bamboo fiber-filled PLA material into an orthopedic brace based on a particle extrusion 3D printer.

[0038] In step 100, bamboo fiber-filled PLA material is prepared, specifically:

[0039] Step 101: obtaining bamboo fiber powder, and performing silane oligomer modification treatment on the powder to obtain modified bamboo fiber;

[0040] Step 102: preparing bamboo fiber-filled PLA particle material based on modified bamboo fiber, PLA particles, PBAT particles, a nucleating agent and epoxidized soybean oil.

[0041] In step 101, bamboo fiber powder is obtained and subjected to silane oligomer modification treatment to obtain modified bamboo fiber, specifically:

[0042] 1. Add bamboo fiber powder into water and stir to disperse. The stirring time is 5 to 120 minutes, preferably 15 to 30 minutes;

[0043] 2. Add the silane oligomer into the bamboo fiber / water dispersion, and continue stirring for 30 to 180 minutes, preferably 60 minutes, at a stirring temperature of 30 to 80°C, preferably 50°C;

[0044] 3. After stopping stirring, let it stand, take out the precipitate, and wash, filter and dry it to obtain modified bamboo fiber.

[0045] The silane oligomer is at least one of bisaminosilane oligomer, aminosilane oligomer and epoxysilane oligomer, and the ratio of the silane oligomer to the bamboo fiber powder is 0.05-5 wt %, preferably 0.3 wt %.

[0046] In step 102, bamboo fiber-filled PLA particle material is prepared based on modified bamboo fiber, PLA particles, PBAT particles, a nucleating agent and epoxidized soybean oil, specifically:

[0047] 1. Premix PLA particles, PBAT particles, modified bamboo fiber, nucleating agent and epoxidized soybean oil in proportion for 10 minutes;

[0048] 2. The premixed materials are put into a twin-screw extruder for extrusion and mixing. The mixing temperature is 190-230°C, preferably 210°C, and the screw speed is 60-400 rpm, preferably 280-320 rpm;

[0049] 3. Immerse the extruded material strips in a water tank to cool them, and then pull them into a pelletizer for pelletization to obtain bamboo fiber-filled PLA granular materials.

[0050] The basic components of the bamboo fiber filled PLA particle material are: PLA accounts for 40-80 wt%, PBAT accounts for 3-30 wt%, modified bamboo fiber accounts for 5-20 wt%, nucleating agent accounts for 0.3-5 wt%, and epoxidized soybean oil accounts for 0.5-5 wt%.

[0051] The nucleating agent is at least one of sebacic acid diphenyl dihydrazide, adipic acid diphenyl dihydrazide and phenylphosphonic acid zinc, and can induce crystallization of PLA melt during cooling.

[0052] In step 200, the bamboo fiber-filled PLA material is printed into an orthopedic protective gear based on a particle extrusion 3D printer, specifically:

[0053] Based on a particle extrusion 3D printer, bamboo fiber-filled PLA particle material is melt-extruded and 3D-printed to make an orthopedic protective gear, wherein the nozzle temperature of the particle extrusion 3D printer is 190-250°C, preferably 220°C, the layer height is 0.2-2 mm, preferably 0.6 mm, the line speed is 10-100 mm / s, preferably 30-60 mm / s, and the chamber temperature is 10-60°C, preferably 15-30°C;

[0054] The 3D printing process of the orthopedic brace is to directly melt-extrude the PLA granules filled with extruded granules of bamboo fiber for 3D printing, which has the significant advantages of low cost and short molding cycle compared with the wire 3D printing process;

[0055] The particle extrusion 3D printing is performed using a commercial particle extrusion 3D printer (CI Uni-Print 4-axis).

[0056] The present invention provides several embodiments and comparative examples to verify the method provided by the present invention:

[0057] The above method can be summarized into three steps: (1) modifying commercially available bamboo fiber powder with silane oligomers; (2) premixing and melt-extruding PLA particles, PBAT particles, modified bamboo fiber, nucleating agent and epoxidized soybean oil to prepare bamboo fiber-filled PLA; and (3) using a particle extrusion 3D printer to print the bamboo fiber-filled PLA into lightweight, high-strength orthopedic protective gear.

[0058] Embodiment 1:

[0059] 1. Put 1000 g of bamboo fiber powder into water and stir to disperse it. Then slowly add 3 g of epoxy silane oligomer while stirring and raise the temperature to 50 °C and continue stirring for 2 h. Stop stirring, let it stand, take out the precipitate, wash it, filter it, and dry it to obtain modified bamboo fiber.

[0060] 2. Prepare bamboo fiber-filled PLA pellets by melt mixing in a twin-screw extruder. PLA accounts for 50 wt%, PBAT accounts for 25 wt%, modified bamboo fiber accounts for 15 wt%, nucleating agent accounts for 1 wt%, and epoxidized soybean oil accounts for 9 wt%; the extrusion temperature is 210 °C and the screw speed is 280 r / min.

[0061] 3. Use a particle extrusion 3D printer to print bamboo fiber-filled PLA into standard mechanical splines along the z-axis direction. In addition, a foot orthosis model with greater printing difficulty was selected for 3D printing testing. The printer nozzle size is 0.8 mm, the nozzle temperature is 220 ℃, the layer height is 0.6 mm, and the line speed is 40 mm / s.

[0062] Embodiment 2:

[0063] 1. Put 1000 g of bamboo fiber powder into water and stir to disperse it. Then slowly add 3 g of epoxy silane oligomer while stirring and raise the temperature to 50 °C and continue stirring for 2 h. Stop stirring, let it stand, take out the precipitate, wash it, filter it, and dry it to obtain modified bamboo fiber.

[0064] 2. Prepare bamboo fiber-filled PLA pellets by melt mixing in a twin-screw extruder. PLA accounts for 69 wt%, PBAT accounts for 10 wt%, modified bamboo fiber accounts for 15 wt%, nucleating agent accounts for 1 wt%, and epoxidized soybean oil accounts for 5 wt%; the extrusion temperature is 210 ℃ and the screw speed is 280 r / min.

[0065] 3. Use a particle extrusion 3D printer to print bamboo fiber-filled PLA into standard mechanical splines along the z-axis direction. In addition, a foot orthosis model with greater printing difficulty was selected for 3D printing testing. The printer nozzle size is 0.8 mm, the nozzle temperature is 230 ℃, the layer height is 0.6 mm, and the line speed is 40 mm / s.

[0066] Embodiment 3:

[0067] 1. Put 1000 g of bamboo fiber powder into water and stir to disperse it. Then slowly add 3 g of epoxy silane oligomer while stirring and raise the temperature to 50 °C and continue stirring for 2 h. Stop stirring, let it stand, take out the precipitate, wash it, filter it, and dry it to obtain modified bamboo fiber.

[0068] 2. Prepare bamboo fiber-filled PLA pellets by melt mixing in a twin-screw extruder. PLA accounts for 60 wt%, PBAT accounts for 20 wt%, modified bamboo fiber accounts for 10 wt%, nucleating agent accounts for 5 wt%, and epoxidized soybean oil accounts for 5 wt%; the extrusion temperature is 210 ℃ and the screw speed is 280 r / min.

[0069] 3. Use a particle extrusion 3D printer to print bamboo fiber-filled PLA into standard mechanical splines along the z-axis direction. In addition, a foot orthosis model with greater printing difficulty was selected for 3D printing testing. The printer nozzle size is 0.8 mm, the nozzle temperature is 220 ℃, the layer height is 0.6 mm, and the line speed is 40 mm / s.

[0070] Embodiment 4:

[0071] 1. Put 1000 g of bamboo fiber powder into water and stir to disperse it. Then slowly add 3 g of epoxy silane oligomer while stirring and raise the temperature to 50 °C and continue stirring for 2 h. Stop stirring, let it stand, take out the precipitate, wash it, filter it, and dry it to obtain modified bamboo fiber.

[0072] 2. Prepare bamboo fiber-filled PLA pellets by melt mixing in a twin-screw extruder. PLA accounts for 63 wt%, PBAT accounts for 20 wt%, modified bamboo fiber accounts for 10 wt%, nucleating agent accounts for 2 wt%, and epoxidized soybean oil accounts for 5 wt%; the extrusion temperature is 210 ℃ and the screw speed is 280 r / min.

[0073] 3. Use a particle extrusion 3D printer to print bamboo fiber-filled PLA into standard mechanical splines along the z-axis direction. In addition, a foot orthosis model with greater printing difficulty was selected for 3D printing testing. The printer nozzle size is 0.8 mm, the nozzle temperature is 220 ℃, the layer height is 0.6 mm, and the line speed is 40 mm / s.

[0074] Comparative Example 1:

[0075] The only difference from Example 1 is that the amount of bamboo fiber-modified epoxy silane oligomer added is 50 g.

[0076] Comparative Example 2:

[0077] The only difference from Example 2 is that no nucleating agent is added.

[0078] Comparative Example 3:

[0079] The only difference from Example 3 is that unmodified bamboo fiber is used to fill PLA.

[0080] Comparative Example 4:

[0081] The only difference from Example 4 is that the 3D printing line speed is 80 mm / s.

[0082] The test results of mechanical properties and crystallization behavior are shown in Table 1:

[0083] Table 1 Tensile strength data of fused deposition modeling products prepared in Examples 1 to 4 and Comparative Examples 1 to 4

[0084] Case Z-direction tensile strength Notched impact strength Crystallinity Foot protection printing performance Example 1 16.1±1.3 MPa <![CDATA[8.5±0.8 kJ / m 2 ]]> 12.0% Slight collapse in the heel area Example 2 18.8±1.6 MPa <![CDATA[6.2±0.5 kJ / m 2 ]]> 11.3% Slight collapse in the heel area Example 3 21.6±2.7 MPa <![CDATA[5.3±0.6 kJ / m 2 ]]> 17.4% Smooth printing without collapse Example 4 19.5±2.3 MPa <![CDATA[5.9±0.9kJ / m 2 ]]> 13.7% Finished printing, surface convex and concave Comparative Example 1 13.3±2.1 MPa <![CDATA[6.8±0.8 kJ / m 2 ]]> 12.4% Slight collapse in the heel area Comparative Example 2 19.3±2.0 MPa <![CDATA[6.0±0.3kJ / m 2 ]]> 3.1% Partial collapse of the heel Comparative Example 3 18.6±1.3 MPa <![CDATA[5.5±0.5 kJ / m 2 ]]> 15.9 % Partial collapse of the heel Comparative Example 4 22.3±2.6 MPa <![CDATA[5.2±1.5kJ / m 2 ]]> 13.9% Partial collapse of the heel

[0085] As can be seen from Table 1, the bamboo fiber-filled PLA provided by the present invention can meet the 3D printing process requirements of orthopedic protective gear. This is due to the fact that the surface of the modified bamboo fiber has more silane oligomer functional groups, which can form dense secondary bonds with the PLA molecular chain to increase its melt modulus; on the other hand, the nucleating agent can induce PLA crystallization and further increase the melt modulus. Therefore, the printing and molding of the orthopedic protective gear can be completed with high quality within the expected time without collapse. In addition, the z-direction tensile strength and impact strength of the product are both high, ensuring the good mechanical properties of the orthopedic protective gear.

[0086] Figure 1 The following are appearance photos and SEM fiber photos of the unmodified bamboo fiber and the modified bamboo fiber in the present invention. As can be seen from the figure, the color of the modified bamboo fiber changes to dark yellow, indicating that its surface structure has changed; the SEM results show that the surface of the modified bamboo fiber contains a large amount of silicon, indicating that the silane oligomer is successfully grafted to the surface of the bamboo fiber.

[0087] Figure 2 The 3D printed foot orthotics in Example 3 and Comparative Example 3 are shown. As can be seen from the figure, the surface of the foot protector in Example 3 is smooth, the contour is highly consistent with the model, and the printing quality is high; while the foot protector in Comparative Example 3 is significantly deformed, and the heel part is significantly collapsed.

[0088] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0089] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing an orthopedic protective gear based on bamboo fiber filled PLA material, characterized in that: include: Preparation of bamboo fiber filled PLA material; Bamboo fiber-filled PLA material is printed into orthopedic protective gear based on a particle extrusion 3D printer.

2. The method according to claim 1, characterized in that: Preparation of bamboo fiber filled PLA material, specifically: Obtain bamboo fiber powder, and perform silane oligomer modification treatment on the powder to obtain modified bamboo fiber; Bamboo fiber filled PLA particle material was prepared based on modified bamboo fiber, PLA particles, PBAT particles, nucleating agent and epoxidized soybean oil.

3. The method according to claim 2, characterized in that Obtain bamboo fiber powder, and perform silane oligomer modification treatment on it to obtain modified bamboo fiber, specifically: Add bamboo fiber powder into water and stir to disperse it. The stirring time is 5 to 120 minutes. Add silane oligomer into bamboo fiber / water dispersion, and continue stirring for 30-180 minutes at a temperature of 30-80°C. After stopping stirring, the mixture is allowed to stand, the precipitate is taken out, and the precipitate is washed, filtered, and dried to obtain modified bamboo fiber.

4. The method according to claim 3, characterized in that The silane oligomer is at least one of a bisaminosilane oligomer, an aminosilane oligomer and an epoxysilane oligomer, and the ratio of the silane oligomer to the bamboo fiber powder is 0.05-5 wt %.

5. The method according to claim 2, characterized in that: Bamboo fiber filled PLA particle material was prepared based on modified bamboo fiber, PLA particles, PBAT particles, nucleating agent and epoxidized soybean oil, specifically: PLA particles, PBAT particles, modified bamboo fiber, nucleating agent and epoxidized soybean oil were premixed in proportion for 10 minutes; The premixed materials are put into a twin-screw extruder for extrusion and mixing, the mixing temperature is 190-230°C, and the screw speed is 60-400 rpm; The extruded material strips are immersed in a water tank for cooling and then pulled into a pelletizer for pelletization to obtain bamboo fiber-filled PLA granular materials.

6. The method according to claim 5, characterized in that The basic components of the bamboo fiber filled PLA particle material are: PLA accounts for 40-80 wt%, PBAT accounts for 3-30 wt%, modified bamboo fiber accounts for 5-20 wt%, nucleating agent accounts for 0.3-5 wt%, and epoxidized soybean oil accounts for 0.5-5 wt%.

7. The method according to claim 5, characterized in that The nucleating agent is at least one of sebacic acid diphenyl dihydrazide, adipic acid diphenyl dihydrazide and zinc phenylphosphonate.

8. The method according to claim 2, characterized in that: Based on the particle extrusion 3D printer, bamboo fiber filled PLA material is printed into orthopedic protective gear, specifically: Based on a particle extrusion 3D printer, bamboo fiber-filled PLA particle material is melt-extruded and 3D printed to make orthopedic protective gear. The nozzle temperature of the particle extrusion 3D printer is 190~250 ℃, the layer height is 0.2~2 mm, the line speed is 10~100 mm / s, and the chamber temperature is 10~60 ℃.

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