Underwater explosion-proof impact-resistant flexible composite material and preparation method thereof

Abstract

The invention relates to the field of anti-explosion and anti-impact materials, and discloses an underwater anti-explosion and anti-impact flexible composite material which is characterized in that the structure of the composite material is sequentially composed of a high-strength flexible outer layer, a high-energy absorption middle layer and a high-strength flexible inner layer. The high-strength flexible outer layer is made of a single-layer or multi-layer high-performance fiber material with the wave impedance within the range of 1.4 * 10 < 4 >-3 * 10 < 4 > MPa.s / m, the high-energy absorption middle layer is made of a foam material with the wave impedance within the range of 0.1-1.5 MPa.s / m, and the high-strength flexible inner layer is made of a single-layer or multi-layer high-performance fiber material with the wave impedance within the range of 1.4 * 10 < 4 >-3 * 10 < 4 > MPa.s / m. Based on the wave impedance mismatch theory, the high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer are combined together through the design of the multi-layer composite structure, so that the composite material can provide excellent impact resistance and can effectively absorb and dissipate impact energy.

Description

Technical Field

[0001] The present invention relates to the field of explosion-proof and impact-resistant materials, and in particular to an underwater explosion-proof and impact-resistant flexible composite material and a preparation method thereof. Background Art

[0002] In the field of modern safety protection, with the increasing complexity of the working environment and the increase in potential dangers, the demand for explosion-proof and impact-resistant materials has shown a rapid growth trend, especially in personal protective equipment, building materials and the military field. Protecting personal safety and equipment integrity has become a key issue that needs to be urgently addressed. However, the protective materials currently widely used on the market have technical bottlenecks in terms of versatility, adaptability and reliability, and it is difficult to meet the use requirements in complex environments. Traditional rigid materials are widely used for their high strength and high impact resistance, but due to their high stiffness, under strong impact, such materials are difficult to absorb and disperse impact energy, and are prone to local damage or even fracture. At the same time, they lack the ability to recover from deformation, resulting in irreversible permanent deformation after impact, thereby shortening the service life of the material and making it difficult to meet the needs of repeated use.

[0003] Flexible materials, due to their excellent ductility and cushioning properties, can, to a certain extent, reduce the damage caused by impact to the human body or equipment. However, the protective effect of such materials under high-intensity impact conditions is limited. Their impact resistance is significantly insufficient and cannot provide effective protection, especially when dealing with severe explosions and punctures from sharp objects. In addition, the dynamic impact performance of flexible materials further deteriorates in extreme environments (such as high humidity, high salt spray, or underwater), manifesting as a rapid attenuation of material strength, elastic modulus, and durability.

[0004] Whether it is rigid or flexible materials, the protective performance in underwater environments is difficult to meet actual needs. The high pressure and complex fluid dynamics conditions in underwater environments place higher demands on materials, such as resistance to compression deformation, water erosion resistance, and stable energy absorption capacity. However, existing protective materials generally lack effective design and processing technologies, and cannot simultaneously take into account durability and impact protection capabilities in underwater environments, resulting in poor performance in special operating environments. In addition, some protective materials are too heavy or lack flexibility, which also limits their application in the field of personal protective equipment with strict ergonomic requirements. Summary of the Invention

[0005] The main purpose of the present invention is to solve the technical problem that some protective materials in the prior art are too heavy or lack flexibility. An underwater explosion-proof and impact-resistant flexible composite material comprises the following steps:

[0006] An underwater explosion-proof and impact-resistant flexible composite material, characterized in that the structure of the composite material consists of a high-strength flexible outer layer, a high-energy absorption middle layer and a high-strength flexible inner layer in sequence.

[0007] The wave impedance of the high-strength flexible outer layer is 1.4×10 4 ~3×10 4 MPa·s / m range, with a thickness of 0.5-1.5 mm. The high energy absorption middle layer is made of a foam material with a wave impedance of 0.1-1.5 MPa·s / m and a thickness of 3-8 mm. The high strength flexible inner layer is made of a foam material with a wave impedance of 1.4×10 4 ~3×10 4 It is made of single or multi-layer high-performance fiber material with a temperature within the range of MPa·s / m and a thickness of 0.5 to 1.5 mm.

[0008] The high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer are composited by hot pressing with a high-performance adhesive film, and the high-performance adhesive film is a two-component polyurethane adhesive film or a hot melt adhesive web film.

[0009] The surface of the composite material is coated with a waterproofing agent, and the thickness of the waterproof layer is 5 to 20 μm.

[0010] The waterproofing agent is one or more of a fluorine-containing waterproofing agent, an organosilicon waterproofing agent, a graphene-modified waterproof coating, a composite waterproofing agent with nano-hydrophobic particles, or other functional waterproofing agents with hydrophobic / moisture-proof properties.

[0011] The high-strength flexible outer layer and the high-strength flexible inner layer are one or more of meta-aramid fiber, para-aramid fiber, carbon fiber, and ultra-high molecular weight polyethylene fiber.

[0012] The foam material of the high energy absorption middle layer has a density of 0.5 to 1 g / cm 3 Closed-cell, open-cell or semi-open-cell foam structure.

[0013] The present invention also relates to a method for preparing an explosion-proof and impact-resistant flexible composite material, comprising the following preparation steps:

[0014] The high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer materials are stacked according to a predetermined thickness;

[0015] The various layers of materials are tightly combined by hot pressing or vacuum forming to obtain an explosion-proof and impact-resistant flexible composite material.

[0016] During the hot pressing process, the high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer are hot-pressed and composited by a high-performance adhesive film, which is a two-component polyurethane adhesive film or a hot-melt adhesive web film.

[0017] The edges of the high-strength flexible outer layer and the high-strength flexible inner layer are individually sealed by using a hot pressing process, and a high-performance waterproof coating is applied to the surfaces of the high-strength flexible outer layer and the high-strength flexible inner layer.

[0018] The present invention has the following beneficial effects:

[0019] Based on the wave impedance mismatch theory, the present invention combines a high-strength flexible outer layer, a high-energy absorption middle layer and a high-strength flexible inner layer through the design of a multi-layer composite structure, so that the composite material can not only provide excellent impact resistance, but also effectively absorb and dissipate impact energy.

[0020] This invention utilizes a precisely controlled hot-pressing lamination process to achieve tight bonding between material layers, avoiding the debonding issues associated with traditional processes. Furthermore, by applying a high-performance waterproof coating (such as a fluorine-containing water repellent or a graphene-modified coating) to the material surface, the composite material's waterproofness is effectively enhanced, enabling it to maintain excellent performance in long-term underwater environments and preventing performance degradation due to water penetration. Its overall performance surpasses that of existing materials, making it particularly suitable for the complex field of underwater explosion protection.

[0021] The composite material of the present invention not only possesses excellent explosion-proof and impact-resistant properties but also exhibits high flexibility. This makes it particularly suitable for use in protective clothing and equipment, allowing for customized structures tailored to the protection needs of different parts of the human body. The composite material's flexible design allows it to closely conform to the contours of the human body, fully taking into account the body's functional requirements. For example, the composite material's thickness, layers, and structural layout can be adjusted as needed to accommodate the protection needs of different areas of the body, such as the limbs, chest, and waist, without compromising the wearer's mobility. This design effectively improves the comfort of human protective equipment while maintaining excellent explosion-proof and impact-resistant properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the present invention.

[0023] Figure 2 This is a diagram of the preparation process of the underwater explosion-proof and impact-resistant flexible composite material of the present invention.

[0024] Reference numerals:

[0025] An upper fiber layer 1, a lower fiber layer 2, an upper composite rubber layer 3, a lower composite rubber layer 4 and a foam layer 5. DETAILED DESCRIPTION

[0026] The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Accordingly, where appropriate, the technical features referred to by the above terms can be interchangeable so that the embodiments of the present invention can be implemented in an order different from that shown or described. In addition, the terms "including" or "having" and any variations thereof are intended to indicate non-exclusive inclusion. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatus.

[0027] The design idea of ​​the present invention:

[0028] Composite materials are used in human protection against underwater explosions. The process of underwater explosion shock waves propagating from the environment through materials to the human body forms a multi-layer structural path for shock wave propagation.

[0029] When a stress wave propagates from one medium to another medium with different wave impedance, the wave will be reflected and transmitted at the interface. Under normal incidence, the transmission stress σ at the interface is T and the incident stress σ I There are the following relationships:

[0030]

[0031] Where T is the transmission coefficient of the shock wave, ρ is the material density, g / cm 3 ; C is the wave velocity, m / s; ρ0C0 represents the material wave impedance, MPa·s / m.

[0032] Extended to the propagation of waves in an n-layer structure, that is, after 1, 2, ..., n layers are arranged in sequence, the final transmission coefficient is:

[0033]

[0034] It can be seen from the formula that in a layered structure, the ratio of wave impedances directly affects the stress amplitude of the transmitted wave, and different arrangement structures will lead to different transmission stresses.

[0035] First, the composite material of the present invention can be regarded as a whole, with the wave impedance set as ρ1c1 and the wave impedance of water set as ρ w c w , the ratio of the wave impedance of water and material is:

[0036]

[0037] When a one-dimensional elastic wave in water passes through a material and then transmits into the water near human skin, the intensity of the transmitted wave can be expressed as:

[0038]

[0039] To minimize the intensity of the transmitted wave, the value of n+1 / n needs to be as large as possible. In other words, the greater the difference between the material's wave impedance and that of water, the greater the shock wave attenuation. Therefore, the overall wave impedance of the material should be kept as mismatched as possible with that of water.

[0040] Secondly, composite materials contain layers of material with varying wave impedances. To minimize the magnitude of the shock wave transmission stress, the layers should be arranged in a reasonable order. The optimal stacking pattern can be determined by calculating the transmission coefficient of the multilayer composite material. The stacking pattern with the smallest transmission coefficient is considered to be the most effective combination for effectively blocking shock waves.

[0041] Based on the principle of impedance mismatch, the outer layer of underwater explosion-proof and impact-resistant flexible composite materials needs to have high impedance to better reflect shock waves. This invention adopts a "hard-soft-hard" structural design approach, designing high-strength, flexible fiber materials with relatively high impedance for the outer and inner layers. The middle layer should have a lower impedance, creating an impedance mismatch with the inner and outer layers to achieve excellent shock wave attenuation.

[0042] Preferably, the underwater explosion-proof and impact-resistant flexible composite material structure is composed of multiple single functional layers, specifically including: a high-strength flexible outer layer, a high-energy absorption middle layer and a high-strength flexible inner layer.

[0043] The high-strength flexible outer layer is composed of a single layer or multiple layers of functional layer materials, and the wave impedance of the functional layer materials is 1.4×10 4 ~3×10 4 MPa·s / m range, with a thickness of 0.5-1.5mm, for providing impact resistance to initial impact. The high energy absorption middle layer is made of foam material with a wave impedance of 0.1-1.5MPa·s / m, with a thickness of 3-8mm, for efficiently absorbing and dissipating impact energy. The high strength flexible inner layer is made of foam material with a wave impedance of 1.4×10 4 ~3×10 4 It is made of single or multi-layer high-performance fiber material in the MPa·s / m range with a thickness of 0.5 to 1.5 mm, used to provide secondary protection and maintain the structural integrity of the material.

[0044] The high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer are hot-pressed and composited at a temperature of 120 to 150° C. and a pressure of 1 to 2 MPa using a high-performance adhesive film with a thickness of 10 to 50 μm, thereby ensuring close bonding between the layers of material and enhancing the overall strength and toughness of the composite material.

[0045] The surface of the composite material is coated with a waterproofing agent, and the thickness of the waterproof layer is 5 to 20 μm. The waterproof coating can effectively improve the water resistance and adaptability of the material in an underwater environment.

[0046] Preferably, the high-performance fiber material is meta-aramid fiber, para-aramid fiber, carbon fiber, ultra-high molecular weight polyethylene fiber or a mixed fiber thereof to ensure a balance between the flexibility and strength of the material and achieve an ideal protective effect.

[0047] Preferably, the foam material of the high energy absorption middle layer has a density of 0.5 to 1 g / cm 3 The foam material has a closed-cell, open-cell or semi-open-cell foam structure. The foam material has a micro-pore structure that can effectively improve the overall impact energy absorption and cushioning performance of the composite material.

[0048] Preferably, the high-performance adhesive film is a two-component polyurethane adhesive film or a hot melt adhesive web film, and its curing time does not exceed 5 minutes to ensure that the composite material can be hot-pressed in a short time to ensure production efficiency.

[0049] Preferably, the waterproofing agent includes a fluorine-containing waterproofing agent, a silicone waterproofing agent, a graphene-modified waterproof coating or a composite waterproof coating with nano-hydrophobic particles. The thickness of the waterproof layer is 5 to 30 μm, which can effectively enhance the water resistance and impact resistance of the composite material in underwater and humid environments.

[0050] Preferably, the method for preparing the composite material structure comprises the following steps:

[0051] 1) preparing the required polymer-based materials and reinforcing fibers, wherein the fibers may include aramid, carbon fibers, or other high-performance fibers; stacking a high-strength flexible outer layer, a high-energy absorption middle layer, and a high-strength flexible inner layer according to a predetermined thickness, wherein the outer layer material may have a thickness of 0.5 to 1.5 mm, the middle layer may have a thickness of 1 to 10 cm, and the inner layer may have a thickness of 0.5 to 1.5 mm;

[0052] 2) The layers of materials are tightly bonded together by hot pressing or vacuum forming, with the temperature controlled at 120-150°C and the pressure at 1-2 MPa to ensure close bonding between the layers of materials and form a dense composite structure;

[0053] 3) Perform post-waterproofing treatment to enhance the composite material's performance and durability underwater and in extreme environments. This treatment can utilize fluorine-containing water repellents, silicone water repellents, graphene-modified water repellent coatings, composite water repellent coatings with nano-hydrophobic particles, or other types of water repellents to enhance the composite material's underwater adaptability and ensure excellent impact resistance in underwater environments.

[0054] Preferably, during the hot pressing process, the temperature and pressure can be adjusted according to different material performance requirements to optimize the bonding strength and flexibility of the composite material.

[0055] Preferably, the waterproofing agent is applied by spraying with a spraying pressure of 0.3 to 0.8 MPa, ensuring that the waterproof coating evenly covers the surface of the composite material and reaches a predetermined thickness.

[0056] For ease of understanding, the specific process of the embodiment of the present invention is described below. Figure 1 The first embodiment of the underwater explosion-proof and impact-resistant flexible composite material method in the embodiment of the present invention includes:

[0057] Example 1: Figure 1 The figure shows an explosion-proof and impact-resistant flexible composite material. The composite material comprises an upper fiber layer 1, a lower fiber layer 2, an upper composite adhesive layer 3, a lower composite adhesive layer 4, and a foam layer 5, which are sequentially stacked and bonded together. The upper fiber layer 1 is made of a single layer of Kevlar fabric woven in a plain weave structure, the lower fiber layer 2 is made of a single layer of Kevlar fabric woven in a plain weave structure, the upper composite adhesive layer 3 is a hot-melt adhesive film, the lower composite adhesive layer 4 is a hot-melt adhesive film, and the foam layer 5 is made of semi-open polyurethane foam.

[0058] The upper fiber layer 1 and lower fiber layer 2 are located in the outermost layers. The upper fiber layer 1 contacts the upper composite adhesive layer 3, and the contact interface is formed by the melting of the hot melt adhesive film. The lower fiber layer 2 contacts the lower composite adhesive layer 4, and the contact interface is formed by the melting of the hot melt adhesive film. The foam layer 5 is located in the innermost layer. The upper fiber layer 3 is located above and in contact with the foam layer 5, and the contact interface is formed by the melting of the hot melt adhesive film. The lower fiber layer 4 is located below and in contact with the foam layer 5, and the contact interface is formed by the melting of the hot melt adhesive film.

[0059] The method for preparing the above-mentioned explosion-proof and impact-resistant flexible composite material comprises the following preparation steps:

[0060] The upper fiber layer 1, the lower fiber layer 2, the upper composite adhesive layer 3, the lower composite adhesive layer 4 and the foam layer 5 are cut according to the desired sizes to ensure that the edges are neat and meet the final requirements of the composite material.

[0061] The upper fiber layer 1, lower fiber layer 2, upper composite adhesive layer 3, lower composite adhesive layer 4, and foam layer 5 are stacked in sequence and placed in a hot press. The temperature is set to 110°C and the pressure is 2 MPa. The hot press is maintained for 3 minutes. This process ensures uniform bonding between the layers of material, forming a composite structure with high strength and toughness.

[0062] The edges of the upper fiber layer 1 and the lower fiber layer 2 are individually sealed using a hot pressing process to further enhance the sealing performance of the material, prevent moisture from penetrating between the layers, and thus improve the durability and waterproofness of the composite material.

[0063] A high-performance waterproof coating is applied to the surfaces of the upper fiber layer 1 and the lower fiber layer 2. Using a water-resistant agent (such as a fluorine-containing water repellent or a graphene-modified coating), the coating is applied uniformly through spraying or dipping to enhance the composite's waterproof properties. This step effectively prevents water penetration, maintains the material's excellent performance in underwater environments, and extends the composite's service life.

[0064] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some of the technical features thereof can be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An underwater explosion-proof and impact-resistant flexible composite material, characterized by: The structure of the composite material consists of a high-strength flexible outer layer, a high-energy absorption middle layer and a high-strength flexible inner layer in sequence.

2. The underwater explosion-proof and impact-resistant flexible composite material according to claim 1, characterized in that: The high-strength flexible outer layer has a wave impedance of 1.4×10 4 ~3×10 4 The high energy absorption middle layer is made of a foam material with a wave impedance of 0.1 to 1.5 MPa·s / m, and the high strength flexible inner layer is made of a foam material with a wave impedance of 1.4×10 4 ~3×10 4 It is made of single or multi-layer high-performance fiber materials in the MPa·s / m range.

3. The underwater explosion-proof and impact-resistant flexible composite material according to claim 1, characterized in that: The high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer are composited by hot pressing with a high-performance adhesive film, and the high-performance adhesive film is a two-component polyurethane adhesive film or a hot melt adhesive web film.

4. The underwater explosion-proof and impact-resistant flexible composite material according to claim 1, characterized in that: The surfaces of the high-strength flexible inner layer and the high-strength flexible outer layer are coated with a waterproofing agent, and the thickness of the waterproof layer is 5 to 20 μm.

5. The underwater explosion-proof and impact-resistant flexible composite material according to claim 1, characterized in that: The waterproofing agent is one or more of a fluorine-containing waterproofing agent, an organosilicon waterproofing agent, a graphene-modified waterproof coating, a composite waterproofing agent with nano-hydrophobic particles, or other functional waterproofing agents with hydrophobic / moisture-proof properties.

6. The underwater explosion-proof and impact-resistant flexible composite material according to claim 1, characterized in that: The high-strength flexible outer layer and the high-strength flexible inner layer are one or more of meta-aramid fiber, para-aramid fiber, carbon fiber, and ultra-high molecular weight polyethylene fiber.

7. The underwater explosion-proof and impact-resistant flexible composite material according to claim 1, characterized in that: The high energy absorption middle layer is a foam material with a density of 0.5 to 1 g / cm 3 Closed-cell, open-cell or semi-open-cell foam structure.

8. A method for preparing an explosion-proof and impact-resistant flexible composite material, characterized in that: The method comprises the following preparation steps: The high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer materials are stacked according to a predetermined thickness; The various layers of materials are tightly combined by hot pressing or vacuum forming to obtain an explosion-proof and impact-resistant flexible composite material.

9. The method for preparing an explosion-proof and impact-resistant flexible composite material according to claim 8, characterized in that: During the hot pressing process, the high-strength flexible outer layer, the high-energy absorption middle layer and the high-strength flexible inner layer are hot-pressed and composited by a high-performance adhesive film, which is a two-component polyurethane adhesive film or a hot-melt adhesive web film.

10. The method for preparing an explosion-proof and impact-resistant flexible composite material according to claim 8, characterized in that: The edges of the high-strength flexible outer layer and the high-strength flexible inner layer are individually sealed by using a hot pressing process, and a high-performance waterproof coating is applied to the surfaces of the high-strength flexible outer layer and the high-strength flexible inner layer.

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