CN112026303A - A kind of absorbing wood pile structure based on 3D printing technology and its making method - Google Patents

Abstract

The invention discloses a wave-absorbing wood pile structure based on a 3D printing technology, which comprises a bottom layer part, a middle layer part and a top layer part, wherein each layer is respectively formed by a plurality of cuboid strip layer units arranged at intervals in parallel, and the cuboid strip layer units are made of conductive ABS wires; the cuboid strip layer units of the middle layer part and the cuboid strip layer units of the bottom layer part are crossly stacked at an angle of 90 degrees; the cuboid strip layer units of the top layer part and the cuboid strip layer units of the middle layer part are stacked in a 90-degree crossed mode, and the cuboid strip layer units of the top layer part and the cuboid strip layer units of the bottom layer part are arranged in a staggered parallel mode. The invention also provides a manufacturing method of the wave-absorbing wood pile structure. The invention has the beneficial effects that: the wave-absorbing wood pile structure has a more complex space structure, the number of internal interfaces is greatly increased, incident electromagnetic waves are reflected and refracted for many times at the interfaces, the incidence times and the transmission distance of the electromagnetic waves are increased, and therefore the electromagnetic wave-absorbing performance of the material is effectively improved.

Description

A kind of absorbing wood pile structure based on 3D printing technology and its making method

technical field

The invention relates to the technical field of electromagnetic wave absorption, in particular to a wave-absorbing wood stack structure based on 3D printing technology and a manufacturing method thereof.

Background technique

With the continuous development of science and technology, people rely more and more on the great convenience brought by electronic products and equipment. However, the electromagnetic radiation generated by electronic equipment not only interferes with normal communication, but also deteriorates the living environment of human beings and endangers human health. In addition, with the continuous development of radar detection technology, missiles, aircraft, ships and other weapons and equipment are more and more easily detected by radar, and their survivability is facing huge challenges. For radar detection technology, the development of radar-absorbing stealth materials with strong electromagnetic wave absorption capability is an effective means to improve the battlefield survivability of military weapons and equipment, and it is also the most common and effective defense measure used in contemporary wars. Therefore, the development of materials with high electromagnetic wave absorption properties has become more and more urgent, whether in civilian or military fields.

Structural absorbing materials have become a research hotspot in the field of electromagnetic wave absorption. By adjusting the macroscopic and microscopic structures of the structural wave absorber, its impedance matching can be effectively adjusted, thereby realizing the adjustment of the wave absorbing performance. At present, the structural wave absorber adopts many honeycomb forms. Basically, the material with the honeycomb structure is dipped or coated, and the absorber is attached to the surface of the honeycomb structure material, so as to realize the preparation of the structural wave absorber, and its molding process is complicated. , the space structure is single, the electromagnetic wave cannot be reflected multiple times, and the electromagnetic wave absorption efficiency is low.

3D printing technology is based on three-dimensional model data, and uses the method of accumulating materials layer by layer to manufacture solid parts, which is completely different from the traditional removal processing (cutting) method. It can quickly manufacture complex parts with any shape and structure in a short cycle. Realize personalized manufacturing. Fused deposition modeling (FDM) is one of the most widely used technologies. It heats and extrudes the filament through a nozzle, builds up layer by layer according to the CAD model, and finally forms a solid part. Therefore, how to use 3D printing technology to design a wave absorber with a complex structure to improve the electromagnetic wave absorption efficiency is a key issue of current research.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a 3D printing-based wave-absorbing wood stack structure with high electromagnetic wave-absorbing efficiency and a manufacturing method thereof, aiming at the deficiencies of the prior art.

The technical scheme adopted in the present invention is as follows: a wave-absorbing wood stack structure based on 3D printing technology, including a bottom layer, a middle layer and a top layer, each of which is composed of a number of rectangular parallelepiped layer units arranged side by side, and the rectangular parallelepiped layer units It is made of conductive ABS wire; the cuboid strip unit in the middle layer and the cuboid strip unit in the bottom part are stacked at 90°; the cuboid strip unit in the top layer and the cuboid strip unit in the middle part are stacked at 90°, and The rectangular parallelepiped strip-layer units of the top layer part and the rectangular parallelepiped strip-layer units of the bottom layer part are arranged in parallel with dislocation.

According to the above scheme, the distance D between two adjacent rectangular parallelepiped layer units in each part is 3-8 mm.

According to the above scheme, the length L of the rectangular parallelepiped layer unit is 180 mm, the width W is 1-10 mm, and the height H is 1-3 mm.

The present invention also provides a method for making the above-mentioned absorbing wood pile structure, which comprises the following steps:

Step 1, establish the model of the absorbing wood pile structure;

Step 2. Import the model STL into 3D printer after slicing;

Step 3, preparing the printing material: melt-blending the multi-walled carbon nanotubes with the ABS resin to obtain MWCNTs/ABS composite particles;

Step 4, wire drawing: drying the MWCNTs/ABS composite material particles and feeding them into a single-screw extruder to obtain a wire for printing, that is, a conductive ABS wire;

Step 5: Send the conductive ABS filament to the nozzle of the 3D printer, set the molding process parameters, and print layer by layer to obtain the absorbing wood pile structure.

According to the above scheme, in step 3, the amount of the multi-walled carbon nanotubes is 2-6% of the resin mass.

According to the above scheme, the diameter of the conductive ABS wire is 1.6-3.0 mm.

According to the above scheme, the electrical conductivity of the conductive ABS wire is 10 ^-10 to 10 ^-3 S/cm.

According to the above scheme, the molding process parameters are: the nozzle temperature is 220-280°C, the layer-by-layer printing layer height is 0.1-0.2mm, the filling degree is 100%, the printing speed is 20-60mm/s, and the temperature of the printing platform is 80 ~110°C.

The beneficial effects of the present invention are:

1. The absorbing wood stack structure of the present invention is a three-layer structure, the internal space is complex, and the cross-displacement stacking of each layer greatly increases the number of internal interfaces of the absorbing body, and the incident electromagnetic wave occurs multiple reflections and refractions at the interface. , which increases the incidence of electromagnetic waves and the transmission distance, thereby significantly improving the probability of electromagnetic wave loss.

2. The present invention adopts the 3D printing technology to make the structure of the absorbing wood pile, which is convenient to operate, has high safety, and can realize the preparation of the complex structure of the three-layer wood pile with zero error.

Description of drawings

FIG. 1 is a top view of the overall structure of Embodiment 1 of the present invention.

FIG. 2 is a side view of the overall structure of Embodiment 1. FIG.

FIG. 3 is a schematic diagram of a partial structure of Embodiment 1. FIG.

FIG. 4 is a schematic diagram of a fused deposition modeling printer.

FIG. 5 is a schematic structural diagram of Embodiment 2. FIG.

FIG. 6 is an effect diagram of electromagnetic wave absorbing performance evaluation of Example 1. FIG.

FIG. 7 is an effect diagram of electromagnetic wave absorbing performance evaluation of Example 2. FIG.

FIG. 8 is an effect diagram of electromagnetic wave absorbing performance evaluation of Example 3. FIG.

FIG. 9 is a partial schematic view of Example 3. FIG.

Among them: 1-printing filament, 2-transfer wheel, 3-nozzle, 4-printing entity, 5-adhesive sheet, 6-printing platform, 7-top part, 8-middle part, 9-bottom part, 10 - Cuboid strip layer unit.

Detailed ways

In order to better understand the present invention, the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

As shown in Figs. 1 to 3, an absorbing wood stack structure based on 3D printing technology includes a bottom layer part 9, a middle layer part 8 and a top layer part 7, and each part is composed of a number of cuboid strip layer units 10 arranged at intervals. The rectangular parallelepiped layer unit 10 is made of conductive ABS wire; the rectangular parallelepiped layer unit 10 of the middle layer part 8 and the rectangular parallelepiped layer unit 10 of the bottom layer part 9 are stacked at 90°; the rectangular parallelepiped layer unit 10 of the top layer part 7 and the middle layer part 8 are stacked. The rectangular parallelepiped strip layer units 10 are stacked at 90° in a cross-stack, and the rectangular parallelepiped strip layer units 10 of the top part 7 and the bottom layer part 9 are arranged in parallel with dislocations.

Preferably, the distance D between two adjacent rectangular parallelepiped layer units 10 in each part is 3-8 mm.

Preferably, the length L of the cuboid strip layer unit 10 is 180 mm, the width W is 1-10 mm, and the height H is 1-3 mm.

3 is a partial schematic view of Embodiment 1, the bottom layer 9 is arranged side by side by a plurality of rectangular parallelepiped layer units 10 with a spacing of 3 to 8 mm; the middle layer portion 8 is arranged side by side by a plurality of rectangular parallelepiped layer units 10 with a spacing of 3 to 8 mm; The top layer part 7 is arranged side by side by a plurality of cuboid strip layer units 10 at a pitch of 3-8 mm. The top layer part 7 and the middle layer part 8 are cross-stacked at 90°, and the top layer part 7 and the bottom layer part 9 are staggered and parallel, that is, the top layer part 7 is translated from the bottom layer part 9 to the width direction by 1 to 10 mm, and then translated to the height direction by 2 to 6 mm. s position.

A kind of manufacture method of the above-mentioned absorbing wood pile structure, the method comprises the steps:

Step 1. Modeling: CAD software is used to establish the model of the structure of the absorbing wood pile as described above.

Step 2: Perform STL slicing settings on the model, import the model after slicing settings into the 3D printer, and level the printing platform 6 .

Step 3: Preparation of printing material: The multi-walled carbon nanotubes (MWCNTs) with a mass fraction of 2-6 wt% are melt-blended with ABS resin in a twin-screw extruder to obtain MWCNTs/ABS composite material particles. The dosage of the multi-walled carbon nanotubes is 2-6% of the resin mass.

In the present invention, the temperature of each zone of the twin-screw extruder is: 185-205°C for the first zone, 195-215°C for the second zone, 200-220°C for the third zone, 200-225°C for the fourth zone, and 195-215°C for the head; The screw extruder melt blending is the prior art, and details are not repeated here.

Step 4, wire drawing: drying the MWCNTs/ABS composite material particles in an oven for 2-4 hours, and then feeding them into a single-screw extruder to obtain a printing wire 1, that is, a conductive ABS wire.

In the present invention, the electrical conductivity of the conductive ABS wire is 10 ^-10 to 10 ^-3 S/cm. The diameter of the conductive ABS wire is 1.6 to 3.0 mm.

In the present invention, the temperature of each zone of the single-screw extruder is: 195-215°C in the first zone, 210-230°C in the second zone, 200-220°C in the third zone; cooling water temperature 50-60°C, main engine speed 600-900r/s, traction The rotating speed of the machine is 350-450 r/s; it is the prior art to use a single-screw extruder to obtain a conductive wire material, which will not be repeated here.

Step 5: Send the conductive ABS filament into the nozzle 3 of the 3D printer, set the molding process parameters, and print layer by layer to obtain the absorbing wood pile structure, that is, the printing entity 4 in Figure 4. The molding process parameters are: the temperature of the printer nozzle 3 is 220-280°C, the layer-by-layer printing layer height is 0.1-0.2mm, the filling degree is 100%, the printing speed is 20-60mm/s, and the temperature of the printing platform 6 is 80 ~110°C. The 3D printer is a fused deposition modeling printer (FDM printer); an adhesive sheet 5 is used on the printing platform 6 (the adhesive sheet 5 is pasted on the printing platform 6, and the printing entity 4 is printed layer by layer on the adhesive sheet, that is, the glue The adhesive sheet 5 connects the printing platform 6 and the printing entity 4) to ensure that the printing structure is not warped.

Example 1

As shown in Figures 1 to 3, each layer of the absorbing wood stack structure is composed of rectangular parallelepiped layer units 10 side by side, the length L of the rectangular parallelepiped layer unit 10 is 180mm, the width W is 5mm, and the height H is 1.2mm; the same layer The spacing D of some adjacent cuboid strip layer units 10 is 5mm; the middle layer part 8 and the bottom layer part 9 are stacked at 90°; the top layer part 7 and the middle layer part 8 are stacked at 90°, and the top layer part 7 and the bottom layer part 9 are staggered Parallel, that is, the position of the top layer 7 is translated from the bottom part 9 to the width direction by 5mm, and then translated to the height direction by 2.4mm. The overall structural size is 180mm (length) × 180mm (width) × 3.6mm (height).

Made using the above method:

Steps 1 and 2 are the same as above. In step 3, multi-walled carbon nanotubes (MWCNTs) with a mass fraction of 6 wt.% and ABS resin are melt-blended in a twin-screw extruder. Each zone of the twin-screw extruder The temperature is: 205°C in the first zone, 215°C in the second zone, 220°C in the third zone, 225°C in the fourth zone, and 215°C in the machine head to obtain MWCNTs/ABS composite particles. In step 4, the prepared MWCNTs/ABS composite material pellets were dried in an oven for 4 hours, and then added to a single-screw extruder. The temperature of each zone of the single-screw extruder was: 215°C for the first zone, 230°C for the second zone, and 220°C for the third zone. ℃; the cooling water temperature is 60℃, the main engine speed is 870r/s, and the tractor speed is 410r/s to obtain a printable conductive ABS wire with a diameter of 2.85mm and a conductivity of 6.3×10 ^-3 S/cm. In step 5, the nozzle temperature 3 of the 3D printer is 260°C, the layer height of the layer-by-layer printing is 0.1mm, the filling degree is 100%, the printing speed is 30mm/s, and the temperature of the printing platform 6 is 100°C; layer-by-layer printing, Obtain an absorbent wood stack structure.

Example 2

The wave absorbing structure shown in FIG. 5 is a rectangular parallelepiped (flat plate, no internal structure) of 180 mm (length)×180 mm (width)×3.6 mm (height). Made by traditional methods, as follows:

Step 1: Ingredients

Multi-walled carbon nanotubes (MWCNTs) with a mass fraction of 6 wt.% and ABS resin were melt-blended in a twin-screw extruder. The temperature of each zone of the twin-screw extruder was: 205 °C in the first zone, 215 °C in the second zone, The temperature of the third zone is 220 °C, the fourth zone is 225 °C, and the machine head is 215 °C to obtain MWCNTs/ABS composite particles.

Step 2: Molding

Put the MWCNTs/ABS composite material particles prepared in step 1 with a theoretical molding mass of 110% into a molding die, the molding temperature is 210 °C, the molding pressure is 5 MPa, and the molding time is 15 minutes, then the mold is cooled to 60 °C, and demolded. , to obtain a flat absorbing material.

Example 3

The preferred honeycomb structure electromagnetic wave absorbing material prepared by the existing traditional impregnation method is shown in Figure 9.

Electromagnetic absorption performance evaluation:

For the wave-absorbing structures prepared in Example 1 and Example 2, the reflection loss at 2-18 GHz was tested by a vector network analyzer to evaluate the electromagnetic wave-absorbing performance, as shown in Figure 6 and Figure 7, it can be seen that The reflection loss peak value of the absorber structure in Example 2 is only -6.95dB, and the effective absorption bandwidth (less than -10dB, indicating that more than 90% of electromagnetic wave absorption) is 0, which cannot meet the requirements of broadband wave absorption; The peak reflection loss of the three-layer absorbing wood stack structure of 1 is -22.15dB, and the effective absorption bandwidth below -10dB can reach 5.43GHz, and it is concentrated in two absorbing frequency bands, namely C-band (4-8GHz) and In the Ku-band (12-18GHz), the electromagnetic wave absorption efficiency is greatly improved; the electromagnetic wave absorption performance of the better honeycomb structure electromagnetic wave absorber prepared by the existing traditional impregnation method is shown in Figure 8, although a lower reflection loss can be obtained. The peak value is -21.61dB and the wide effective absorption bandwidth is 3.9GHz, but its absorption frequency band is single and only concentrated in the X-band (8-12GHz), which makes its application limited.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims (8)

1. a kind of absorbing wood stack structure based on 3D printing technology, it is characterized in that, comprise bottom layer part, middle layer part and top layer part, each part is respectively formed by several cuboid strip layer units arranged side by side, and the cuboid strip layer unit adopts conductive ABS wire production; the cuboid strip layer unit in the middle part and the cuboid strip layer unit in the bottom part are stacked at 90°; the cuboid strip layer unit in the top part and the cuboid strip layer unit in the middle part are stacked at 90°, and the top part is stacked at 90° The rectangular parallelepiped strip layer units are arranged in parallel with the rectangular parallelepiped strip layer units of the bottom part. 2 . The absorbing wood stack structure based on 3D printing technology according to claim 1 , wherein the distance D between two adjacent rectangular parallelepiped layer units in each part is 3-8 mm. 3 . 3 . The absorbing wood stack structure based on 3D printing technology according to claim 1 , wherein the length L of the rectangular parallelepiped layer unit is 180 mm, the width W is 1-10 mm, and the height H is 1-3 mm. 4 . 4. A manufacturing method of the absorbing wood stack structure according to any one of claims 1 to 3, wherein the method comprises the steps of: Step 1, establish the model of the absorbing wood pile structure; Step 2. Import the model STL into 3D printer after slicing; Step 3, preparing the printing material: melt-blending the multi-walled carbon nanotubes MWCNTs with the ABS resin to obtain MWCNTs/ABS composite particles; Step 4, wire drawing: drying the MWCNTs/ABS composite material particles and feeding them into a single-screw extruder to obtain a wire for printing, that is, a conductive ABS wire; Step 5: Send the conductive ABS filament to the nozzle of the 3D printer, set the molding process parameters, and print layer by layer to obtain the absorbing wood pile structure. 5 . The manufacturing method of the absorbing wood stack structure according to claim 4 , wherein, in step 3, the amount of the multi-walled carbon nanotubes is 2-6% of the resin mass. 6 . 6 . The manufacturing method of the absorbing wood stack structure according to claim 4 , wherein the diameter of the conductive ABS wire is 1.6-3.0 mm. 7 . 7 . The method for preparing an absorbing wood stack structure according to claim 4 , wherein the electrical conductivity of the conductive ABS wire is 10 ⁻¹⁰ to 10 ⁻³ S/cm. 8 . 8 . The preparation method of the absorbing wood stack structure according to claim 4 , wherein the molding process parameters are: the nozzle temperature is 220-280° C., the layer-by-layer printing layer height is 0.1-0.2 mm, and the filling degree is 0.1-0.2 mm. 9 . 100%, the printing speed is 20～60mm/s, and the temperature of the printing platform is 80～110℃.

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