CN112701492A - Wave-absorbing pyramid made of multilayer hard wave-absorbing material and preparation method thereof - Google Patents
Wave-absorbing pyramid made of multilayer hard wave-absorbing material and preparation method thereof Download PDFInfo
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- CN112701492A CN112701492A CN202011488939.9A CN202011488939A CN112701492A CN 112701492 A CN112701492 A CN 112701492A CN 202011488939 A CN202011488939 A CN 202011488939A CN 112701492 A CN112701492 A CN 112701492A
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- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 claims abstract description 16
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Abstract
The invention discloses a wave-absorbing pyramid made of multiple layers of hard materials, which is provided with a pyramid-shaped composite layer structure, wherein the composite layer structure comprises three wave-absorbing plate layers, the wave-absorbing plate layers are fixedly connected with one another in an adhesion mode, and a plurality of wave-absorbing pyramids are arranged in parallel in the horizontal direction. The hard conductive xps wave-absorbing material is formed by taking polystyrene resin as a raw material, adding an absorbent, a dispersing agent and a flame retardant, heating and mixing, adding into an extruder, and carrying out processes such as primary extrusion, foaming agent injection, secondary extrusion, compression molding and the like. The multi-layer hard material wave-absorbing pyramid and the preparation method thereof disclosed by the invention not only have excellent wave-absorbing performance, but also overcome the defects of water absorption, head hanging, aging and the like in the prior art.
Description
Technical Field
The invention relates to a wave-absorbing pyramid and a preparation method thereof, in particular to a wave-absorbing pyramid made of a multi-layer hard wave-absorbing material and a preparation method thereof.
Background
The microwave darkroom is an important guarantee facility for scientific research and production of a modern weapon equipment system, and provides electromagnetic environment conditions meeting requirements for scientific research and production of weapon equipment. The wave-absorbing material is a functional composite material, is the core of a microwave anechoic chamber and can effectively absorb electromagnetic wave energy irradiated on the wave-absorbing material, so that the reflected or scattered energy of the electric wave is obviously attenuated. With the development of modern weaponry and civil communication industries, microwave darkrooms are widely applied, and the large-scale development of wave-absorbing materials is driven. At present, common microwave darkroom angle cone type wave-absorbing materials comprise polyurethane foam angle cones, non-woven fabric angle cones, EPS angle cones, EPP angle cones and the like according to different base materials. Among them, polyurethane foam pyramid is the most widely used wave-absorbing pyramid in domestic use due to its advantages of low cost, high performance, etc., but it has the disadvantages of easy water absorption, drooping, aging, etc. There is no technical means for solving the problems in the prior art, and the problems need to be solved urgently.
Disclosure of Invention
The invention aims to provide a wave-absorbing pyramid made of a multi-layer hard wave-absorbing material, which solves the defects in the prior art.
The invention is realized by adopting the following technical scheme:
the utility model provides a multi-layer hard material inhale ripples pyramid which characterized in that, inhale the ripples pyramid and have the composite bed structure of pyramid form, composite bed structure includes three and inhales ripples panel layer, through the mode fixed connection that bonds between the ripples panel layer, a plurality of ripples pyramids of inhaling are arranged in parallel in the horizontal direction.
Further, the thickness of the wave-absorbing plate material layer is 50mm or 100 mm.
Further, the height of the wave-absorbing pyramid is 150mm or 300 mm.
Furthermore, the wave-absorbing plate layers are bonded through 801 glue.
Further, the wave-absorbing sheet material layer is xps extruded sheet.
A preparation method of a wave-absorbing pyramid is characterized by comprising the following steps:
step 1) taking polystyrene resin as a raw material, adding an absorbent, a dispersing agent and a flame retardant, heating and mixing, adding into an extruder, and molding into the hard conductive xps wave-absorbing material through processes of primary extrusion, foaming agent injection, secondary extrusion and compression molding. The wave-absorbing material is added with the absorbent in the processing process, is a body absorbing material, has excellent wave-absorbing capacity, has the characteristics of light weight, moisture resistance, environmental protection and the like of xps materials, and is a novel hard wave-absorbing material.
Wherein:
2-20 wt% of an absorbent;
1-3 wt% of a dispersant;
5-20 wt% of a flame retardant;
the other components are polystyrene resin;
step 2) is limited by a processing technology, the thickness of xps plates is generally not more than 100mm, therefore, the second step of the invention is to use an adhesive to bond hard conductive xps wave-absorbing materials to form a multilayer conductive xps plate, in order to further improve the absorption capacity of the wave-absorbing material, the invention bonds conductive xps plates with different resistances, the resistance of the bonded material is gradually increased from a bottom layer to a surface layer to form an impedance gradual change material, the reflection of electromagnetic waves on the surface of the material can be reduced, and the wave-absorbing performance of the material is improved.
Principle of the impedance grading layer: the wave-absorbing material with excellent performance needs to meet two conditions: firstly, the material needs to have lower resistivity, and can generate larger electromagnetic loss, so that electromagnetic waves can be fully absorbed by the material; and secondly, the material has higher resistivity, so that impedance matching with a free space is realized, electromagnetic waves can be conveniently incident into the material, and the electromagnetic waves cannot be reflected at an interface between the material and air. In general, a single material cannot satisfy the two conditions at the same time, so that the requirement on the resistivity of the material can be reduced through structural optimization, a multilayer structure is used, materials with different resistivities are combined, the resistivity of the material is gradually reduced from a surface layer to a bottom layer, and the structure can greatly reduce the reflection of the surface of the material and improve the absorption performance.
Although the advantage of the impedance gradual change structure is great, the structure is never used in the polyurethane wave-absorbing pyramid because the polyurethane wave-absorbing pyramid is mostly integrally processed and integrally impregnated, so that the overall resistance distribution of the material is relatively uniform, and the impedance gradual change structure cannot be formed. The multi-layer conductive xps board pasting forming mode is applicable to a structure with gradually changed impedance, and the impedance matching performance with air can be improved, the reflection at the interface can be reduced, and the wave-absorbing performance can be improved as long as the wave-absorbing flat boards with different resistances are selected for pasting so that the resistance of the material is increased from the lower layer to the surface layer.
For the multilayer impedance matching wave-absorbing material, the performance and the process are considered, the number of layers has a proper value under the constraint condition of different thicknesses, on one hand, under the constraint condition of a certain thickness, the more the number of layers is, the better the wave-absorbing performance is; on the other hand, an excessive number of layers brings certain difficulties in design and material preparation. Tests prove that the performance is improved most obviously from a single layer to two layers, and the wave-absorbing performance is improved in a limited manner by increasing the number of layers by more than 3 layers. Therefore, the wave-absorbing material is divided into three layers according to the difference of the resistivity, the height of each layer of material is one third of the total height of the pyramid, and the height of each layer of material is changed along with the change of the total height of the pyramid. As shown in detail.
In view of the above, the invention is suitable for the wave-absorbing pyramid material with the total height of less than 300 mm.
And 3) processing the wave-absorbing material with the impedance gradual change structure into a quadrangular pyramid as required to form a novel hard wave-absorbing pyramid, wherein the pyramid can be applied to a microwave darkroom, and overcomes the defects that the existing polyurethane pyramid is easy to absorb water, droop, age and the like.
Further, in step 1), the absorbent is 50% compressed carbon black, the dispersing agent is NNO (sodium naphthalenesulfonate formaldehyde condensate), and the flame retardant is aluminum hydroxide;
in the step 3), the wave-absorbing material with the impedance gradual change structure is processed into a quadrangular pyramid according to requirements.
Further, in the step 1), the polystyrene resin accounts for 70 wt%, the carbon black accounts for 15 wt%, the dispersant accounts for 2 wt%, and the flame retardant accounts for 13 wt%.
Further, in step 1), the polystyrene resin accounts for 82 wt%, the carbon black accounts for 8 wt%, the dispersant accounts for 1.5 wt%, and the flame retardant accounts for 8.5 wt%.
Further, in the step 1), the polystyrene resin accounts for 90 wt%, the carbon black accounts for 4 wt%, the dispersant accounts for 1 wt%, and the flame retardant accounts for 5 wt%.
The invention has the advantages that:
1) the novel hard wave-absorbing material is prepared by adding the carbon black absorbent into xps, has no sagging head, no water absorption and good aging resistance, and solves the defects of the existing polyurethane wave-absorbing material;
2) the wave-absorbing pyramid is introduced with a multilayer structure for the first time, the impedance matching performance of the material is improved through the gradual change of the resistivity of each layer, the reflection is reduced, and the wave-absorbing performance is improved;
3) make full use of xps's obturator, stereoplasm advantage prepares into the electrically conductive xps panel that has physical absorption ability, then through sticky connected mode again, bonds the electrically conductive xps board of multilayer, cuts the multilayer material that will bond at last into the angular cone shape, forms a neotype multilayer stereoplasm and inhale ripples pyramid, not only inhale the wave performance fine, overcome defects such as absorbing water, plumb joint, ageing that exist among the prior art moreover.
Drawings
Fig. 1 is a schematic view of a composite layer structure of the wave-absorbing plate material layers after bonding.
Figure 2 is a schematic view of the incorporation of the absorbing pyramids.
Detailed Description
The invention will be better understood by the following description of embodiments thereof, but the specific embodiments given by the applicant should not be taken as limiting the technical solution of the invention, and any changes in the definition of the components or technical features and/or in the form of a whole structure without substantial changes should be taken as the protection scope defined by the technical solution of the invention.
xps an extruded sheet is a rigid foam sheet produced by mixing a polystyrene resin as a raw material with other raw and auxiliary materials and a polymer, heating and mixing the mixture while injecting a catalyst, and then extruding and molding the mixture. xps has perfect closed-cell honeycomb structure, is an excellent thermal insulation material, and is commonly used for thermal insulation of building roofs and walls.
xps board can be used as wave absorbing material by coating thin wave absorbing coating on xps board, air drying, and splicing to form quadrangular pyramid. The wave-absorbing pyramid has the advantages that the hard and closed pore structure of xps is utilized, and the problems of polyurethane pyramid such as droop, water absorption and the like are avoided; the disadvantage is that the surface absorption is only carried out, the body absorption is not carried out, the absorption performance is poor, and the method can only be used for EMC dark rooms with lower requirements on the absorption performance.
The wave-absorbing pyramid made of the multiple layers of hard materials shown in the figures 1 and 2 is provided with a composite layer structure in a pyramid shape, the composite layer structure comprises three wave-absorbing plate layers, namely a wave-absorbing plate layer 1, a wave-absorbing plate layer 2 and a wave-absorbing plate layer 3, the thickness of the wave-absorbing plate layer 1 is H1, the thickness of the wave-absorbing plate layer 2 is H2, the thickness of the wave-absorbing plate layer 3 is H3, the wave-absorbing plate layers are fixedly connected in an adhesion mode, and the wave-absorbing pyramids are arranged in parallel in the horizontal direction. In this embodiment, there are three wave-absorbing sheet layers of the composite layer structure, but in actual production, the number of the wave-absorbing sheet layers of the composite layer structure is not limited to three, and those skilled in the art can set any number according to the needs of actual situations. In the following two embodiments, the thicknesses H1-H3 of the wave-absorbing sheet layers 1-3 are 50mm or 100mm, the overall height of the wave-absorbing pyramid composed of the wave-absorbing sheet layers is 150mm or 300mm, the wave-absorbing sheet layers are bonded by 801 glue, and the wave-absorbing sheet layers are xps extruded sheets.
The following two examples have the following composition of matter:
2-20 wt% of an absorbent;
1-3 wt% of a dispersant;
5-20% of a flame retardant;
the other components are polystyrene resin;
wherein the absorbent is 50% of compressed carbon black, the dispersant is NNO (sodium naphthalene sulfonate formaldehyde condensate), and the flame retardant is aluminum hydroxide;
example 1
The formula ingredients shown in the table 1 are used, the materials are added into an extruder, three conductive xps wave absorbing plates with different sheet resistances are prepared through processes of primary extrusion, foaming agent injection, secondary extrusion, compression molding and the like, the thickness of each wave absorbing plate is 100mm, the three conductive xps wave absorbing plates are bonded by 801 glue, all layers are arranged as shown in the figure 1, after the structure is stable, a cutting machine is used for processing the materials into an angular cone, as shown in the figure 2, the total height of the angular cone is 300mm, the wave absorbing performance of the wave absorbing plate is 3-5dB higher than that of a polyurethane wave absorbing angular cone with the same height due to the adoption of an impedance gradual change structure, and the wave absorbing plate is made of a hard material and cannot have the defects of sagging, water absorption, aging and the like after.
TABLE 1 formulation for electrical conduction xps
| Numbering | Polystyrene resin (wt%) | Carbon Black (wt%) | Dispersant (wt%) | Flame retardant (wt%) |
| 1 | 70 | 15 | 2 | 13 |
| 2 | 82 | 8 | 1.5 | 8.5 |
| 3 | 90 | 4 | 1 | 5 |
The absorption properties of the pyramids are shown in table 2.
TABLE 2 wave-absorbing pyramid vertical incidence reflectivity with total height of 300mm
Example 2
The formula ingredients shown in the table 1 are used, the ingredients are added into an extruder, three conductive xps wave-absorbing plates with different sheet resistances are prepared through processes of primary extrusion, foaming agent injection, secondary extrusion, compression molding and the like, the thickness of each plate is 50mm, the three conductive xps wave-absorbing plates are bonded by 801 glue, all layers are arranged as shown in the figure 1, after the structure is stable, a cutting machine is used for processing the materials into an angular cone, as shown in the figure 2, the total height of the angular cone is 150mm, the wave-absorbing performance of the wave-absorbing plate is 2-4dB higher than that of a polyurethane wave-absorbing angular cone with the same height due to the adoption of an impedance gradual change structure, and the wave-absorbing plate is made of a hard material and cannot have the defects of sagging, water absorption.
The absorption properties of the pyramids are shown in table 3 below.
TABLE 3 Total height 150mm wave-absorbing pyramid vertical incidence reflectivity
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore intended that all such changes and modifications as fall within the true spirit and scope of the invention be considered as within the following claims.
Claims (10)
1. The utility model provides a multi-layer hard material's inhale ripples pyramid which characterized in that, inhale the ripples pyramid and have the composite bed structure of pyramid form, composite bed structure includes three and inhales ripples sheet material layer, through the mode fixed connection that bonds between the ripples sheet material layer, a plurality of ripples pyramids of inhaling are parallel arrangement on the horizontal direction.
2. The multi-layer hard material absorbing pyramid as claimed in claim 1, wherein the absorbing sheet material layer has a thickness of 50mm or 100 mm.
3. The absorbing pyramid of multilayer hard material according to claim 1, characterized in that its height is 150mm or 300 mm.
4. The wave-absorbing pyramid made of multiple layers of hard materials according to claim 1, wherein the wave-absorbing sheet material layers are bonded by 801 glue.
5. The multi-layer hard material absorbing pyramid as claimed in any one of claims 1 to 5, wherein the absorbing sheet material layer is xps extruded sheet.
6. A preparation method of a wave-absorbing pyramid is characterized by comprising the following steps:
step 1) taking polystyrene resin as a raw material, adding an absorbent, a dispersing agent and a flame retardant, heating and mixing, adding into an extruder, and forming into a hard conductive xps wave-absorbing material through processes of primary extrusion, foaming agent injection, secondary extrusion and compression molding;
wherein:
2-20 wt% of an absorbent;
1-3 wt% of a dispersant;
5-20 wt% of a flame retardant;
the other components are polystyrene resin;
step 2) bonding the hard conductive xps wave-absorbing material by using an adhesive to form a plurality of conductive xps plates, bonding conductive xps plates with different resistances, and gradually increasing the resistance of the bonded material from the bottom layer to the surface layer to form an impedance gradual change material;
and 3) processing the wave-absorbing material with the impedance gradual change structure into a pyramid as required to form a novel hard wave-absorbing pyramid.
7. The method for preparing the wave-absorbing pyramid according to claim 6, wherein in the step 1), the absorbent is 50% compressed carbon black, the dispersant is NNO, and the flame retardant is aluminum hydroxide;
in the step 3), the wave-absorbing material with the impedance gradual change structure is processed into a quadrangular pyramid according to requirements.
8. The method for preparing the wave-absorbing pyramid according to claim 6 or 7, wherein in the step 1), the polystyrene resin accounts for 70 wt%, the carbon black accounts for 15 wt%, the dispersing agent accounts for 2 wt%, and the flame retardant accounts for 13 wt%.
9. The method for preparing the wave-absorbing pyramid according to claim 6 or 7, wherein in the step 1), the polystyrene resin accounts for 82 wt%, the carbon black accounts for 8 wt%, the dispersing agent accounts for 1.5 wt%, and the flame retardant accounts for 8.5 wt%.
10. The method for preparing the wave-absorbing pyramid according to claim 6 or 7, wherein in the step 1), the polystyrene resin accounts for 90 wt%, the carbon black accounts for 4%, the dispersing agent accounts for 1 wt%, and the flame retardant accounts for 5 wt%.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6784419B1 (en) * | 1999-10-28 | 2004-08-31 | Kabushiki Kaisha Riken | Electromagnetic wave absorber |
| CN101769058A (en) * | 2010-02-12 | 2010-07-07 | 泰州拓谷超细粉体材料有限公司 | Multilayer microwave unreflected chamber absorbing material filled by loose foam blocks |
| CN103408788A (en) * | 2013-08-06 | 2013-11-27 | 南京洛普电子工程研究所 | Flame-retardance wave-absorbing polystyrene foam material and preparation method thereof |
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2020
- 2020-12-16 CN CN202011488939.9A patent/CN112701492A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6784419B1 (en) * | 1999-10-28 | 2004-08-31 | Kabushiki Kaisha Riken | Electromagnetic wave absorber |
| CN101769058A (en) * | 2010-02-12 | 2010-07-07 | 泰州拓谷超细粉体材料有限公司 | Multilayer microwave unreflected chamber absorbing material filled by loose foam blocks |
| CN103408788A (en) * | 2013-08-06 | 2013-11-27 | 南京洛普电子工程研究所 | Flame-retardance wave-absorbing polystyrene foam material and preparation method thereof |
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Application publication date: 20210423 |