Light, thin and low-back-concave hard bulletproof plugboard and preparation method thereof

Abstract

The invention provides a light, thin and low-back-concave hard bulletproof plugboard and a preparation method thereof in order to solve the problem existing in reduction of BFS of a bulletproof vest hard plugboard in the prior art. According to the method, the composite material is obtained through the technologies of paving, hot pressing and the like on the ultra-high molecular weight polyethylene UD cloth, and the composite application of a high-strength and high-modulus film is adopted, so that the impact stress is transmitted in the in-plane orthogonal direction, the transmission range of stress waves is expanded, the in-plane deformation energy consumption of the body armor is increased, and the impact resistance of the body armor is improved. And the deformation of the body armor in the bullet movement direction is reduced, and the back depression is reduced.

Description

Technical Field

[0001] The present invention relates to the field of bulletproof vests, specifically rigid bulletproof inserts. Background Art

[0002] With the increase in the hardness and kinetic energy of bullets, rigid bulletproof inserts have gradually become the main solution for personal protection. Currently, rigid bulletproof inserts mainly consist of two layers. In the order from the bullet-facing surface to the back bullet-facing surface, the first layer is mainly a high-strength metal or ceramic plate. The main function of this layer is to rapidly reduce the bullet speed and deform the bullet to reduce the penetration ability of the bullet. The second layer is mainly a laminate made of high-strength organic fibers and adhesives, and commonly used is mainly ultra-high molecular weight polyethylene fiber (UHMWPE). The function of this layer is to absorb the remaining kinetic energy of the bullet.

[0003] During the entire penetration process, although the ceramic has high strength, it will quickly break after being impacted. The bullet still has great destructive power after passing through the ceramic. The ultra-high molecular weight polyethylene fibers in the fiber laminate of the second layer will be stretched by the impact of the bullet, creating a depression (BFS) on the laminate. If the depression is too large, it will cause blunt trauma to the soldier, resulting in fractures and organ ruptures, and in severe cases, it will even endanger life. According to the relevant standards in China, in addition to the requirement for bullet penetration (V50), there are also clear requirements for BFS for bulletproof vests. Under different protection levels, BFS must be ≤ 25 mm, and this indicator is higher than the 35 mm of foreign standards, which is sufficient to show that reducing the BFS of bulletproof vests is extremely important for protecting the wearer.

[0004] In order to reduce the BFS of the hard insert plate, many improvements have been made to the two parts of the hard insert plate. For the first-layer ceramic, aiming at the problem of crack propagation caused by the high brittleness of the ceramic, a polygon pattern splicing method has been proposed. To a certain extent, it can reduce crack propagation and improve the number of bulletproofs. However, the strength of the joint of this structure is low, which is prone to bullet perforation. For the ultra-high molecular weight polyethylene fiber laminate, due to the low transverse deflection of the fiber and the slow transverse transmission speed of stress waves inside the laminate, the BFS is relatively high. Therefore, researchers have proposed methods such as fiber surface modification, fiber blending, improvement of weaving methods, and addition of shear thickening fluid (STF) to improve the strength and modulus of the laminate. Among them, fiber surface modification can increase the friction between the fiber and the matrix and increase the frictional energy dissipation during fiber pull-out. However, fiber surface modification will reduce the fiber strength and affect the bulletproof performance. Using shear thickening fluid can increase the friction between yarns and thus improve the energy absorption efficiency. However, too much shear thickening fluid will lead to excessive friction, causing the failure mode of the yarn to change from mainly tensile to mainly shear, resulting in a decrease in energy absorption efficiency. Moreover, the shear thickening fluid will also make the bulletproof vest bulky, and there is a risk of leakage, reducing the stability of the bulletproof insert plate. Fiber blending and cross-layer mixing are also methods to reduce the BFS of the laminate. However, this method requires a multi-angle layering structure to interfere with the propagation of transverse waves, which not only has a complex manufacturing process but also does not significantly reduce the weight of the bulletproof vest. Summary of the Invention

[0005] The object of the present invention is to provide a preparation method of a low-back concave, thin and hard bulletproof insert plate, which is characterized in that:

[0006] (1) Lay a nylon adhesive film on the ultra-high molecular weight polyethylene UD cloth, and the obtained composite material is denoted as UD1 composite material; preferably, the ultra-high molecular weight polyethylene UD cloth used in the present invention is a unidirectional tape prepared from polyethylene spun fibers with a molecular weight of 1.5 million to 9 million. Preferably, the ultra-high molecular weight polyethylene UD cloth is a unidirectional tape made by orthogonally stacking 18 - 50 layers at 0 / 90°; the single-filament breaking strength of the ultra-high molecular weight polyethylene fiber UD cloth is 35 - 45 cn / dtex. The thickness of the ultra-high molecular weight polyethylene fiber UD cloth is 0.11 mm - 0.50 mm;

[0007] (2) Lay an aromatic polyamide film on the nylon adhesive film of the UD1 composite material, and the obtained composite material is denoted as UD2 composite material;

[0008] (3) Lay a nylon adhesive film on the aromatic polyamide film of the UD2, and the obtained composite material is denoted as UD3 composite material;

[0009] (4) Lay the ultra-high molecular weight polyethylene UD cloth on the nylon adhesive film of the UD3 composite material, and the obtained composite material is denoted as UD4 composite material;

[0010] (5) Heat the UD4 composite material, and the obtained composite sheet is denoted as composite sheet AFUD;

[0011] (6) Stack a number of cut composite sheets AFUD;

[0012] (7) Put the stacked composite sheets AFUD into a vulcanizer for hot pressing to obtain a composite laminate;

[0013] (8) Stack the ceramics, polyurethane adhesive film, and composite laminate in order from bottom to top, and then put them into a hot press can for hot pressing and laminating.

[0014] Further, in step (2), the aromatic polyamide film is selected from poly(p-phenylene terephthalamide) film, p-phenylene terephthalamide benzimidazole polymer film, and m-phenylene isophthalamide polymer film. Preferably, the tensile fracture strength of the film is ≥275 MPa, the thickness is 8 - 24 μm, and its molecular formula is as follows:

[0015] Poly(p-phenylene terephthalamide)

[0016] P-phenylene terephthalamide benzimidazole polymer

[0017] M-phenylene isophthalamide polymer

[0018] Further, in step (3), the nylon adhesive film is one of nylon 6, nylon 66, and nylon 1010. Preferably, the thickness of the adhesive film is 4 - 8 μm.

[0019] Further, in step (5), the composite is carried out by a hot pressing process, with a pressure of 20 - 50 MPa, a temperature of 120 - 125 °C, and maintained for 10 - 15 minutes.

[0020] Further, in step (6), the surface density range after stacking is 8 kg / m 2 ~ 12 kg / m 2 .

[0021] Further, in step (7), the hot pressing pressure of the vulcanizer is 2 - 5 MPa, the hot pressing temperature is 120 °C ± 5 °C, and the pressure holding time is 10 - 20 minutes. The surface density of the PE laminate of the present invention is 7 - 15 kg / m 2 .

[0022] Further, in step (8), the ceramic is one of silicon carbide ceramics and boron carbide ceramics. Preferably, the areal density of the ceramic is 10-18 kg / m2.

[0023] Further, in step (8), the autoclave pressure is 1-2 MPa. Preferably, the thickness of the polyurethane adhesive film used in this step is 0.5-1.5 mm, and the areal density is 10-50 g / m2.

[0024] The present invention also claims to protect a low-back concave, thin and hard bulletproof insert plate prepared based on the above method.

[0025] The technical effect of the present invention is beyond doubt. For the material obtained by the present invention, due to the composite application of high-strength and high-modulus films, the impact stress is not only transmitted along the in-plane orthogonal directions, expanding the transmission range of stress waves, increasing the in-plane deformation energy consumption of the bulletproof vest, but also reducing the deformation amount of the bulletproof vest in the bullet movement direction and minimizing the back depression. Through live ammunition comparison experiments, the back depression is reduced by 25%. Description of the Drawings

[0026] Figure 1 It is a process flow chart of the present invention. Detailed Embodiments

[0027] The present invention will be further described below in conjunction with embodiments, but it should not be understood that the above-mentioned subject matter scope of the present invention is limited to the following embodiments. Without departing from the above technical idea of the present invention, various substitutions and modifications made according to ordinary technical knowledge and customary means in the art should be included within the protection scope of the present invention.

[0028] Embodiment 1:

[0029] A method for preparing a thin and light low-back concave hard bulletproof insert plate, characterized by comprising the following steps:

[0030] (1) Spread a nylon adhesive film on a UD cloth of ultra-high molecular weight polyethylene fiber

[0031] The nylon adhesive film is a nylon 66 adhesive film with a thickness of 8 μm. The UD cloth of ultra-high molecular weight polyethylene fiber is a unidirectional tape prepared from polyethylene spun fibers with a molecular weight of 9 million. The single-filament breaking strength of the UD cloth of ultra-high molecular weight polyethylene fiber is 45 cN / dtex. The thickness of the UD cloth of ultra-high molecular weight polyethylene fiber is 0.110 mm to 0.150 mm.

[0032] (2) Continuously lay a biaxially oriented poly(p-phenylene terephthalamide) film on the nylon adhesive film in step (1)

[0033] The tensile fracture strength of the film is 472 MPa, and the thickness is 12 μm.

[0034] (3) Lay the nylon adhesive film described in step (1) on the biaxially stretched poly(p-phenyleneterephthalamide) in step (2).

[0035] (4) Lay a layer of the ultra-high molecular weight polyethylene fiber UD cloth described in step (1) on the nylon adhesive film in step (3).

[0036] (5) Thermally press and laminate the system of ultra-high molecular weight polyethylene UD cloth - nylon film - aromatic polyamide film - nylon adhesive film - ultra-high molecular weight polyethylene UD cloth obtained in step (4) to obtain a composite sheet AFUD. When thermally pressing, heat the temperature to 120 °C, the pressure is 20 MPa, and keep warm and press for 10 minutes.

[0037] (6) Cut the composite sheet AFUD according to the dimensions of the army multi-curved bulletproof vest, and stack it according to the areal density of 9.7 kg / m 2 .

[0038] (7) Put the stacked materials into a vulcanizer for hot pressing to obtain a composite laminate. When hot pressing, the temperature is 120 °C ± 5 °C, and the pressure is 2 MPa.

[0039] (8) Stack the boron carbide ceramic, polyurethane adhesive film, and composite laminate in order from bottom to top, and then put them into a hot press can for hot pressing and laminating. Hot pressing time: 4 h, pressure: 1 MPa, temperature: 95 °C.

[0040] The boron carbide ceramic has a strength of 380 MPa, an HV hardness greater than 2900, a thickness of 6 ± 5 mm, and an areal density of 15.9 kg / m2. The polyurethane adhesive film has a thickness of 5 μm and an areal density of 50 g / m 2 .

[0041] Comparative example of Example 1

[0042] The material of the pe laminate in the comparative example consists of 6 layers of ultra-high molecular weight polyethylene fiber UD cloth (the material and specifications are the same as those used in the lightweight and low-back concave hard bulletproof vest); stack them according to the areal density of 9.7 kg / m 2 (about 54 layers), and then hot press them into a pe laminate under the same working conditions, and use the same ceramic and adhesive film to laminate them into a hard insert.

[0043] Bulletproof performance test of Example 1

[0044] 1. Use an electronic balance to weigh the weight of the prepared hard bulletproof insert.

[0045] 2. Calculate the areal density: divide the weight of the chip by the area, and the obtained areal density is 25.6 kg / m 2 .

[0046] 3. Arrange the experimental device according to the Class III bulletproof standard in GJB 4300A-2012, and use a ballistic gun to fire a 56-type armor-piercing bullet at the exact center of the bulletproof insert plate to verify the protection performance of the bulletproof vest chip.

[0047] 4. It can be obtained from the analysis of the live ammunition shooting test data that, compared with the comparative example, the maximum reduction of the back depression of the bulletproof vest obtained in Example 1 is 25%.

[0048] Table 1 Live Ammunition Test Results

[0049] Group Back Flattening (BFS) Sample No. 1 of Example 1 20mm Sample No. 2 of Example 1 21mm Sample No. 3 of Example 1 20mm Sample No. 1 of the Comparative Example of Example 1 25mm Sample No. 2 of the Comparative Example of Example 1 24mm Sample No. 3 of the Comparative Example of Example 1 25mm

[0050] Example 2:

[0051] A preparation method of a thin and low-back depression rigid bulletproof insert plate, characterized by comprising the following steps:

[0052] (1) Spread a nylon adhesive film on the ultra-high molecular weight polyethylene fiber UD cloth

[0053] The nylon adhesive film is a nylon 66 adhesive film with a thickness of 8 um. The ultra-high molecular weight polyethylene fiber UD cloth is a unidirectional tape prepared from polyethylene spun fibers with a molecular weight of 4.5 million. The single-filament breaking strength of the ultra-high molecular weight polyethylene fiber UD cloth is 35 cn / dtex. The thickness of the ultra-high molecular weight polyethylene fiber UD cloth is 0.110 mm to 0.150 mm.

[0054] (2) Continuously lay a poly(p-phenylene terephthalamide benzimidazole) polymer film on the nylon adhesive film in step (1)

[0055] The tensile breaking strength of the film is 375 MPa and the thickness is 12 um.

[0056] (3) Lay the nylon adhesive film described in step (1) on the biaxially stretched poly(p-phenylene terephthalamide) in step (2).

[0057] (4) Lay the poly(p-phenylene terephthalamide benzimidazole) polymer film described in step (1) on the nylon adhesive film in step (3).

[0058] (5) Lay the nylon adhesive film described in step (1) on the poly(p-phenylene terephthalamide benzimidazole) polymer film in step (4).

[0059] (6) Lay a layer of the ultra-high molecular weight polyethylene fiber UD cloth described in step (1) on the nylon adhesive film in step (5).

[0060] (7) The system of ultra-high molecular weight polyethylene UD cloth - nylon film - aromatic polyamide film - nylon adhesive film - aromatic polyamide film - nylon adhesive film - ultra-high molecular weight polyethylene UD cloth obtained in step (6) is hot-pressed and compounded to obtain a composite sheet AF2UD. During hot pressing, the heating temperature is 120 °C, the pressure is 20 MPa, and heat preservation and pressure holding are carried out for 10 minutes.

[0061] (8) According to the bullet penetration direction, 22 layers of UD cloth without film are placed on the upper layer and 23 layers of composite UD cloth are placed on the lower layer, and they are stacked together according to the areal density of 9.7 kg / m 2 The surface density is stacked together.

[0062] (9) The stacked materials are put into a vulcanizer for hot pressing to obtain a composite laminate. During hot pressing, the temperature is 120 °C ± 5 °C, and the pressure is 2 MPa.

[0063] (10) In the order from bottom to top, boron carbide ceramics, polyurethane adhesive film, and composite laminate are stacked in sequence and then put into a hot press can for hot pressing and laminating. Hot pressing time: 4 h, pressure: 1 MPa, temperature: 95 °C.

[0064] The boron carbide ceramics have a strength of 380 MPa, an HV hardness greater than 2900, a thickness of 6 ± 5 mm, and an areal density of 12 kg / m2. The polyurethane adhesive film has a thickness of 5 μm and an areal density of 50 g / m 2 .

[0065] Comparative example of Example 2

[0066] The material of the pe laminate in the comparative example is composed of 6 layers of ultra-high molecular weight polyethylene fiber UD cloth (the material and specifications are the same as those used in the lightweight and low-back concave hard bulletproof vest); according to 9.7 kg / m 2 The areal density (about 54 layers) is stacked and then hot-pressed into a pe laminate under the same working conditions, and the same ceramic and adhesive film are used to laminate it into a hard insert.

[0067] Bulletproof performance test of Example 2

[0068] 1. Use an electronic balance to weigh the weight of the prepared hard bulletproof insert.

[0069] 2. Calculate the areal density: Divide the weight of the chip by the area, and the obtained areal density is 21.7 kg / m 2 .

[0070] 3. Arrange the experimental device according to the Class III bulletproof standard in GJB 4300A-2012, and use a ballistic gun to fire a 56-type armor-piercing bullet at the center of the bulletproof insert to verify the protective performance of the bulletproof vest chip.

[0071] 4. From the analysis of the live firing test data, compared with the comparative example, the back depression of the bulletproof vest obtained in Example 1 was reduced by up to 12%

[0072] Table 2 Live firing test results

[0073]

[0074]

[0075] Example 3

[0076] A preparation method of a thin and low-back-depression rigid bulletproof insert, characterized by comprising the following steps:

[0077] (1) Spread a nylon adhesive film on the ultra-high molecular weight polyethylene fiber UD cloth

[0078] The nylon adhesive film is a nylon 66 adhesive film with a thickness of 8 um, and the ultra-high molecular weight polyethylene fiber UD cloth is a unidirectional tape prepared from polyethylene spun fibers with a molecular weight of 6 million. The single filament breaking strength of the ultra-high molecular weight polyethylene fiber UD cloth is 40 cn / dtex. The thickness of the ultra-high molecular weight polyethylene fiber UD cloth is 0.110 mm to 0.150 mm.

[0079] (2) Continue to lay a meta-aramid polymer film on the nylon adhesive film in step (1). The tensile breaking strength of the film is 270 MPa and the thickness is 20 um.

[0080] (3) Lay the nylon adhesive film described in step (1) on the meta-aramid polymer film in step (2).

[0081] (4) Lay the meta-aramid polymer film described in step (1) on the nylon adhesive film in step (3).

[0082] (5) Lay the nylon adhesive film described in step (1) on the meta-aramid polymer film in step (4).

[0083] (6) Lay a layer of the ultra-high molecular weight polyethylene fiber UD cloth described in step (1) on the nylon adhesive film in step (5).

[0084] (7) Thermally press and compound the system of ultra-high molecular weight polyethylene UD cloth - nylon film - aramid film - nylon adhesive film - aramid film - nylon adhesive film - ultra-high molecular weight polyethylene UD cloth obtained in step (6) to obtain a composite sheet AF2UD. When thermally pressing, heat the temperature to 120 °C, the pressure is 20 MPa, and keep warm and press for 10 minutes.

[0085] (8) In the direction of bullet penetration, 23 layers of AF2UD fabric are on the top and 22 layers of UD fabric without added film are on the bottom, and they are stacked together according to the areal density of 9.7 kg / m 2 The areal density is stacked together.

[0086] (9) The stacked materials are put into a vulcanizer for hot pressing to obtain a composite laminate. During hot pressing, the temperature is 120°C ± 5°C and the pressure is 2 MPa.

[0087] (10) In the order from bottom to top, silicon carbide ceramics, polyurethane film, and the composite laminate are stacked in sequence and then put into a hot press for hot pressing and bonding. Hot pressing time: 4 h, pressure: 1 MPa, temperature: 95°C.

[0088] The boron carbide silicon porcelain has a strength of 380 MPa, a hardness greater than 28 GPa, a thickness of 6 ± 5 mm, and an areal density of 18 kg / m2. The polyurethane film has a thickness of 5 μm and an areal density of 50 g / m 2 .

[0089] Comparative example of Example 3

[0090] The material of the pe laminate in the comparative example is composed of 6 layers of ultra-high molecular weight polyethylene fiber UD fabric (the material and specifications are the same as those used in the light and low-back concave hard bulletproof vest); they are stacked according to the areal density of 9.7 kg / m 2 The areal density (about 54 layers) is hot pressed into a pe laminate under the same working conditions, and the same ceramics and films are used to bond into a hard insert.

[0091] Ballistic performance test of Example 3

[0092] 1. Use an electronic balance to weigh the weight of the prepared hard bulletproof insert.

[0093] 2. Calculate the areal density: Divide the weight of the chip by the area, and the obtained areal density is 27.7 kg / m 2 .

[0094] 3. Arrange the experimental device according to the Class III bulletproof standard in GJB 4300A-2012, and use a ballistic gun to fire a 56-type armor-piercing bullet at the center of the bulletproof insert to verify the protection performance of the bulletproof vest chip.

[0095] 4. It can be obtained from the analysis of the live ammunition shooting test data that, compared with the comparative example, the maximum back depression of the bulletproof vest obtained in Example 1 is reduced by 16%

[0096] Table 3 Live ammunition test results

[0097] Group Back Flattening (BFS) Sample No. 1 of Example 3 21mm Sample No. 2 of Example 3 21mm Sample No. 3 of Example 3 22mm Sample No. 1 of the Comparative Example of Example 3 25mm Sample No. 2 of the Comparative Example of Example 3 24mm Sample No. 3 of the Comparative Example of Example 3 25mm

Claims

1. A preparation method of a low-back concave, thin and hard bulletproof insert plate, characterized in that: (1) Lay a nylon adhesive film on the ultra-high molecular weight polyethylene UD cloth, and the obtained composite material is denoted as UD1 composite material; (2) Lay an aromatic polyamide film on the nylon adhesive film of the UD1 composite material, and the obtained composite material is denoted as UD2 composite material; (3) Lay a nylon adhesive film on the aromatic polyamide film of UD2, and the obtained composite material is denoted as UD3 composite material; (4) Lay an ultra-high molecular weight polyethylene UD cloth on the nylon adhesive film of the UD3 composite material, and the obtained composite material is denoted as UD4 composite material; (5) Heat the UD4 composite material, and the obtained composite sheet is denoted as composite sheet AFUD; (6) Stack a number of cut composite sheets AFUD; (7) Put the stacked composite sheets AFUD into a vulcanizer for hot pressing to obtain a composite laminate; (8) Stack ceramics, polyurethane adhesive film, and composite laminate in order from bottom to top, and then put them into a hot press can for hot pressing and laminating.

2. The lightweight and low-back concave hard bulletproof insert plate according to claim 1 and its preparation method are characterized in that: In step (2), the aromatic polyamide film is selected from poly(p-phenylene terephthalamide) film, p-phenylene terephthalamide benzimidazole polymer film, and m-phenylene isophthalamide polymer film.

3. A thin and light low-back concave hard bulletproof insert plate and its preparation method according to claim 1, characterized in that: In step (3), the nylon adhesive film is one of nylon 6, nylon 66, and nylon 1010.

4. A thin and light low-back concave hard bulletproof insert plate and a preparation method thereof according to claim 1, characterized in that: In step (5), composite is carried out by a hot pressing process, with a pressure of 20 - 50 MPa and a temperature of 120 - 125 °C.

5. A thin and light low-back concave hard bulletproof insert plate and a preparation method thereof according to claim 1, characterized in that: In step (6), the surface density range after stacking is 8 kg / m 2 ~ 12 kg / m 2 .

6. A thin and light low-back concave hard bulletproof insert plate and a preparation method thereof according to claim 1, characterized in that: In step (7), the hot pressing pressure of the vulcanizer is 2 - 5 MPa, the hot pressing temperature is 120 °C ± 5 °C, and the pressure holding time is 10 - 20 minutes.

7. According to claim 1, a thin and light low-back concave hard bulletproof insert plate and its preparation method - 1 - A preparation method, characterized in that: In step (8), the ceramics are one of silicon carbide ceramics and boron carbide ceramics.

8. A thin and light low-back concave hard bulletproof insert panel and its preparation method according to claim 1, characterized in that: In step (8), the pressure of the hot press can is 1 - 2 MPa.

9. A low-back concave, thin and hard bulletproof insert plate prepared by the method according to any one of claims 1 to 8.

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