Fire-retardant type wide-frequency-band high-power compound wave-absorbing material and preparing method thereof

Abstract

The invention relates to a fire-retardant type wide-frequency-band high-power compound wave-absorbing material and a preparing method thereof. The material comprises an outer shell, an inner core and a base, wherein the outer shell is a polyhedron formed by a set of pyramids arranged side by side, the wedges of the pyramids are towards the same side, the inner core is located inside the outer shell, the base is located at the bottom of the outer shell, the outer shell is made of non-woven cloths, the inner core and the base are made of polyurethane foams, the inner surface and the outer surface of the outer shell are respectively provided with a first fire-retardant wave-absorbing agent layer in a coating mode, and the inner core and the base are immersed in second fire-retardant wave-absorbing agents. Both the first fire-retardant wave-absorbing agents and the second fire-retardant wave-absorbing agents comprise acetylene black, alpha-SiC, aluminum hydroxide, kaolin, pentaerythritol, and App-3. The corresponding preparing method comprises the steps of preparing the outer shell, preparing the inner core and the base, and inserting the inner core into the outer shell, and therefore the wave-absorbing material is obtained. The wave-absorbing material has good wave absorbing performance and fire retardance, and the preparing method is simple and easy to implement.

Description

technical field [0001] The invention relates to a flame-retardant wide-band high-power composite wave-absorbing material and a preparation method thereof, belonging to the cross field of material science and microwave technology. Background technique [0002] As far as the applicant knows, an anechoic chamber refers to the use of wave-absorbing materials (ie, microwave absorbing materials) to pave the inner wall to reduce electromagnetic wave reflection, thereby forming a close to "free space" (ie, an open space without electromagnetic wave reflection) or "semi-free space" (ie, open space with only ground reflections). The anechoic chamber can simulate the "open field" to carry out the measurement, debugging and comprehensive experiments of radar, radio and military and civilian electronic and electrical equipment. The performance of the anechoic chamber mainly depends on the performance of the absorbing material. Absorbing materials are a class of materials that can absor...

AI Technical Summary

Problems solved by technology

[0004] However, the polyurethane foam absorbing material itself also has insurmountable shortcomings: First, although the polyurethane foam absorbing material has undergone flame-retardant treatment, due to the characteristics of the polyurethane foam itself, it is difficult for the oxygen index to exceed 30, and the flame-retardant performance can only reach B2. level, prone to fire accidents in some extreme cases

Second, polyurethane foam has poor power resistance. When high-power electromagnetic waves radiate on the polyurethane foam absorbing material, most of the electromagnetic wave energy is converted into heat after being absorbed by the foam core due to the electrical loss of the absorbing agent. The excellent thermal insulation performance of the sponge material makes it difficult to dissipate heat, which makes the core temperature of the polyurethane absorbing material rise sharply, resulting in the failure of the absorbing agent in the absorbing material, and even fire accidents in some cases

Third, when the polyurethane foam absorbing material is at a high height, due to its own weight, after a period of use, the pointed end of the material pyramid will bend and other phenomena, which will make the darkroom aesthetics worse and the overall darkroom Decreased electrical performance

[0007] However, the above-mentioned non-woven wave-absorbing materials also have some insurmountable shortcomings: since the non-woven wave-absorbing material is made of non-woven wave-absorbing substrates by cutting, folding, and bonding, its wave-absorbing form is mainly electromagnetic waves. surface absorption, and there are gaps between the pyramid elements that cannot be completely avoided

[0008] In addition, the above-mentioned non-woven wave-absorbing material requires two-step coating in the production process, one step is to apply the wave-absorbing coating, and the other is to apply the flame-retardant coating, which will inevitably increase the process and is not conducive to improving production efficiency

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