Light and thin low-back-concave soft bulletproof vest chip and preparation method thereof

Abstract

The invention discloses a light and thin soft bulletproof chip with low back depression and a preparation method thereof, and particularly relates to the field of protective equipment. The bulletproof chip is composed of two parts, namely an aromatic polyamide film and a one-way belt manufactured by orthogonally overlapping n layers of ultra-high molecular weight polyethylene fibers at 0 / 90 degrees. Due to the fact that the high-strength and high-modulus thin film is added, impact stress is transmitted in the in-plane orthogonal direction, the transmission range of stress waves is expanded, in-plane deformation energy consumption of the body armor is increased, the deformation amount of the body armor in the bullet movement direction is reduced, and back sinking is reduced. Through live ammunition comparison experiments, the back depression is reduced by 42%.

Description

Technical Field

[0001] The present invention relates to bulletproof vest materials. Background Art

[0002] Soft bulletproof vests are characterized by lightness and flexibility. They are mainly made of high-strength directional polyamide fibers or ultra-high molecular weight polyethylene (UHMWPE) fibers. Ultra-high molecular weight polyethylene fibers are more widely used in the manufacture of bulletproof vests due to their lower density and better UV protection. However, due to the low lateral deflection, soft bulletproof vests made of this material are prone to large back sag (BFS) when subjected to impact, resulting in blunt trauma, fractures and organ ruptures, and in severe cases, life-threatening. According to relevant standard requirements, in addition to requirements for bullet penetration (V50), bulletproof vests also have clear requirements for BFS. BFS must be ≤25mm under different protection levels.

[0003] In order to reduce the BFS of soft bulletproof vests, many methods have been proposed, including fiber surface modification, fiber blending, improved weaving methods, and the addition of shear thickening fluid (STF). Among them, fiber surface modification can increase the friction between the fiber and the matrix and increase the friction energy consumption of fiber pull-out, but the surface modification of the fiber will reduce the fiber strength and affect the bulletproof performance. The use of shear thickening fluid can increase the friction between the yarns, thereby improving the energy absorption efficiency, but too much shear thickening fluid will cause excessive friction, causing the yarn failure mode to change from tensile to shear-based, resulting in reduced energy absorption efficiency. Shear thickening fluid not only makes the bulletproof vest bulky, but also has the risk of leakage. Fiber blending and cross-layer mixing are also methods to improve bulletproof performance, but this method requires a multi-angle layer structure to interfere with the propagation of shear waves. Not only is the manufacturing process complicated, but it also has no effect on reducing the weight of the bulletproof vest. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing a thin, low-back concave soft bulletproof vest chip, which is characterized by comprising the following steps:

[0005] (1) Spreading a nylon film on one or both sides of the ultra-high molecular weight polyethylene fiber unidirectional tape;

[0006] (2) pasting an aromatic polyamide film on a nylon film;

[0007] (3) The ultra-high molecular weight polyethylene fiber unidirectional tape, nylon adhesive film and aromatic polyamide film are heated and pressed to obtain a composite bulletproof vest chip.

[0008] Furthermore, the ultra-high molecular weight polyethylene fiber fabric is an ultra-high molecular weight polyethylene fiber unidirectional tape.

[0009] Furthermore, the ultra-high molecular weight polyethylene fiber unidirectional tape is composited with polyethylene with a molecular weight of 1.5 million to 9 million and a polyurethane adhesive. The single filament breaking strength of the ultra-high molecular weight polyethylene fiber unidirectional tape is 35 to 45 MPa. The thickness of the ultra-high molecular weight polyethylene fiber unidirectional tape is 0.11 mm to 0.50 mm.

[0010] Furthermore, the ultra-high molecular weight polyethylene fiber unidirectional tape is 0 / 90° orthogonally stacked 18-50 A thin, low-back concave soft bulletproof vest chip and its preparation method -1-

[0011] Unidirectional tape made of layers.

[0012] Furthermore, the aromatic polyamide film is selected from poly(p-phenylene terephthalamide) film, p-phenylene terephthalamide benzimidazole polymer film, and isophthalamide meta-phenylene diamine polymer film. The film has a tensile breaking strength of ≥275 MPa and a thickness of 8 to 24 um.

[0013] Poly(p-phenylene terephthalamide)

[0014] p-Phenylene terephthalamide benzimidazole polymer

[0015] Isophthalamide-m-phenylenediamine polymer

[0016] Furthermore, the nylon film is one of nylon 6, nylon 66, and nylon 1010, and the film thickness is 4 to 8 um.

[0017] Furthermore, in step (3), the composite is carried out by a heat pressing process with a pressure of 20 to 50 MPa and a temperature of 120 to 125° C. for 10 to 15 minutes.

[0018] The present invention claims a method for preparing a soft bulletproof vest fabric based on the above-mentioned thin, low-back concave soft bulletproof vest chip, which is characterized by:

[0019] (A) cutting the composite bulletproof vest chip according to the size requirements of the bulletproof vest;

[0020] (B) using aromatic polyamide film as the bullet-facing surface, stacking several layers of composite bulletproof vest chips together;

[0021] (C) stitching the stacked composite bulletproof vest chips to obtain a soft bulletproof vest fabric. ≥10 layers (preferably 10-40 layers) of composite bulletproof vest chips can be loaded into a bulletproof vest jacket to form a soft bulletproof vest with a certain surface density.

[0022] The technical effect of the present invention is unquestionable. The present invention adopts an aromatic polyamide film and a unidirectional tape material made of n layers of ultra-high molecular weight polyethylene fiber stacked at 0 / 90 degrees orthogonally. Due to the addition of high-strength and high-modulus film, the impact stress is not only transmitted along the orthogonal direction in the plane, but also expands the transmission range of the stress wave, increases the in-plane deformation energy consumption of the bulletproof vest, and reduces the deformation of the bulletproof vest in the direction of bullet movement, reducing the back concavity. After a live ammunition comparison experiment, the back concavity was reduced by up to 42%. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the embodiments, but it should not be understood that the above subject matter of the present invention is limited to the following embodiments. Without departing from the above technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the art, which should all be included in the protection scope of the present invention.

[0025] Embodiment 1:

[0026] A method for preparing a thin, low-back concave soft bulletproof vest chip, characterized in that it comprises the following steps:

[0027] (1) Spreading a nylon film on one side of the ultra-high molecular weight polyethylene fiber unidirectional tape;

[0028] The nylon film is a nylon 66 film with a thickness of 8um, and the ultra-high molecular weight polyethylene fiber unidirectional tape is composited with polyethylene fiber with a molecular weight of 9 million and a polyurethane adhesive. The single fiber breaking strength of the ultra-high molecular weight polyethylene fiber unidirectional tape is 45MPa. The thickness of the ultra-high molecular weight polyethylene fiber unidirectional tape is 0.220mm to 0.230mm.

[0029] (2) pasting a biaxially oriented poly(p-phenylene terephthalamide) film on a nylon film;

[0030] The film has a tensile breaking strength of 472 MPa and a thickness of 12 um.

[0031] (3) The system of ultra-high molecular weight polyethylene fiber unidirectional tape-nylon adhesive film-aromatic polyamide film is composited by a hot pressing process to obtain a composite bulletproof vest chip. The heating temperature of the hot pressing process is 120° C. and the pressure is 20 MPa, and the temperature and pressure are maintained for 10 minutes.

[0032] When applying:

[0033] (A) The assembled materials are cut into a certain size along the fiber stacking direction using electric scissors with tungsten steel blades;

[0034] (B) Using aromatic polyamide film as the bullet-facing surface, 19 layers of composite bulletproof vest chips are stacked together;

[0035] (C) The stacked composite bulletproof vest chips are stitched together to obtain a soft bulletproof vest fabric with a density of 4 kg / m2.

[0036] Preparation of the comparative example of Example 1

[0037] The chip in the comparative example is composed of 6 layers of ultra-high molecular weight polyethylene fiber unidirectional tapes (the material and specifications are the same as those used in low BFS soft bulletproof vests); 22 layers of chips are stacked and assembled into a comparative example sample using the same vacuuming or sewing method.

[0038] Performance Test of Example 1

[0039] 1. Use an electronic balance to weigh the prepared bulletproof vest chip.

[0040] 2. Calculate the surface density: Divide the weight of the chip by the area, and the surface density is 4kg / m 2 .

[0041] 3. Tested according to the GA141-2010 Level 2 bulletproof standard to verify the protective performance of the bulletproof vest chip.

[0042] 4. From the analysis of the live-fire test data, it can be found that compared with the comparative example, the back concavity of the bulletproof vest obtained in Example 1 is reduced by up to 42%.

[0043] Table 1 Live-fire test results

[0044] Group Back Frustration (BFS) Sample No. 1 of Example 1 18mm Sample No. 2 of Example 1 18mm Sample No. 3 of Example 1 16mm Sample No. 1 of the comparative example of Example 1 28mm Sample No. 2 of the comparative example of Example 1 28mm Sample No. 3 of the comparative example of Example 1 27mm

[0045] Embodiment 2:

[0046] A method for preparing a thin, low-back concave soft bulletproof vest chip, characterized in that it comprises the following steps:

[0047] (1) Spreading a nylon film on one side of the ultra-high molecular weight polyethylene fiber unidirectional tape;

[0048] The nylon film is a nylon 6 film with a thickness of 8um, and the ultra-high molecular weight polyethylene fiber fabric is composited with polyethylene fiber with a molecular weight of 6 million and a polyurethane adhesive. The single-filament breaking strength of the ultra-high molecular weight polyethylene fiber unidirectional tape is 40MPa. The thickness of the ultra-high molecular weight polyethylene fiber unidirectional tape is 0.5mm.

[0049] (2) pasting a p-phenylenediamine benzimidazole polymer film on a nylon film;

[0050] The film has a tensile breaking strength of 490 MPa and a thickness of 8 um.

[0051] (3) The system of ultra-high molecular weight polyethylene fiber unidirectional tape-nylon adhesive film-aromatic polyamide film is composited by a hot pressing process to obtain a composite bulletproof vest chip. The heating temperature of the hot pressing process is 120° C. and the pressure is 40 MPa, and the temperature and pressure are maintained for 10 minutes.

[0052] When applying:

[0053] (A) The assembled materials are cut into a certain size along the fiber stacking direction using electric scissors with tungsten steel blades;

[0054] (B) Using aromatic polyamide film as the bullet-facing surface, 9 layers of composite bulletproof vest chips are stacked together;

[0055] (C) The stacked composite bulletproof vest chips are stitched together to obtain a soft bulletproof vest fabric with a density of 4.9 kg / m2.

[0056] Comparative example of embodiment 2:

[0057] Step 1: Material preparation

[0058] Ultra-high molecular weight polyethylene fiber unidirectional tape: same as in the embodiment.

[0059] Step 2: Preparation of bulletproof vest chip

[0060] 1. Cut the unidirectional tape in the same way, stack and assemble 10 layers to form a comparative sample.

[0061] 2. Assemble using the same vacuuming or sewing method.

[0062] Step 3: Performance Testing

[0063] 1. Use an electronic balance to weigh the comparative sample.

[0064] 2. Calculate the surface density: Divide the weight of the sample by the area, and the surface density obtained is also 5kg / ㎡.

[0065] 3. Tests were conducted according to the second level bulletproof standard of GA141-2010 to compare the protective performance of the embodiment and the comparative example.

[0066] 4. From the analysis of the live-fire test data, it can be found that compared with the comparative example, the back concavity of the bulletproof vest obtained in Example 2 is reduced by up to 28%.

[0067] Performance Test of Example 2

[0068] Table 2 Live-fire test results

[0069]

[0070]

[0071] Embodiment 3:

[0072] A method for preparing a thin, low-back concave soft bulletproof vest chip, characterized in that it comprises the following steps:

[0073] (1) Spreading a nylon film on one side of the ultra-high molecular weight polyethylene fiber unidirectional tape;

[0074] The nylon film is a nylon 1010 film with a thickness of 4um, and the ultra-high molecular weight polyethylene fiber unidirectional tape is composited with polyethylene fiber with a molecular weight of 1.5 million and a polyurethane adhesive. The single fiber breaking strength of the ultra-high molecular weight polyethylene fiber unidirectional tape is 35MPa. The thickness of the ultra-high molecular weight polyethylene fiber unidirectional tape is 0.10mm.

[0075] (2) pasting a meta-phenylene isophthalamide polymer film on a nylon film;

[0076] The film has a tensile breaking strength of 275 MPa and a thickness of 24 μm.

[0077] (3) The system of ultra-high molecular weight polyethylene fiber unidirectional tape-nylon adhesive film-aromatic polyamide film is composited by a hot pressing process to obtain a composite bulletproof vest chip. The heating temperature of the hot pressing process is 120° C. and the pressure is 50 MPa, and the temperature and pressure are maintained for 15 minutes.

[0078] When applying:

[0079] (A) The assembled materials are cut into a certain size along the fiber stacking direction using electric scissors with tungsten steel blades;

[0080] (B) Using aromatic polyamide film as the bullet-facing surface, 36 layers of composite bulletproof vest chips are stacked together;

[0081] (C) The stacked composite bulletproof vest chips are stitched together to obtain a soft bulletproof vest fabric with a density of 4.5 kg / m2.

[0082] The performance test of Example 2 is similar to that of Example 1.

[0083] Step 1: Material preparation

[0084] Ultra-high molecular weight polyethylene fiber unidirectional tape: same as in the embodiment.

[0085] Step 2: Preparation of bulletproof vest chip

[0086] 1. Cut the unidirectional tape in the same way, stack and assemble 10 layers to form a comparative sample.

[0087] 2. Assemble using the same vacuuming or sewing method.

[0088] Step 3: Performance Testing

[0089] 1. Use an electronic balance to weigh the comparative sample.

[0090] 2. Calculate the surface density: Divide the weight of the sample by the area, and the surface density obtained is also 4.5kg / ㎡.

[0091] 3. Tests were conducted according to the second level bulletproof standard of GA141-2010 to compare the protective performance of the embodiment and the comparative example.

[0092] 4. From the analysis of the live-fire test data, it can be found that compared with the comparative example, the back concavity of the bulletproof vest obtained in Example 2 is reduced by up to 21.4%.

[0093] Table 3 Live-fire test results

[0094] Group Back Frustration (BFS) Sample No. 1 of Example 3 22mm Sample No. 2 of Example 3 23mm Sample No. 2 of Example 3 22mm Sample No. 1 of the comparative example of Example 3 28mm Sample No. 2 of the comparative example of Example 3 28mm Sample No. 3 of the comparative example of Example 3 27mm

Claims

1. A method for preparing a thin, low-back concave soft bulletproof vest chip, characterized in that: The following steps are involved: (1) spreading a nylon film on the ultra-high molecular weight polyethylene fiber unidirectional tape (UD cloth) fabric; (2) pasting an aromatic polyamide film on a nylon film; (3) The system of ultra-high molecular weight polyethylene fiber unidirectional tape-nylon adhesive film-aromatic polyamide film is heated and pressed to obtain a composite bulletproof vest chip.

2. The method for preparing a thin, low-back concave soft bulletproof vest chip according to claim 1, characterized in that: The ultra-high molecular weight polyethylene fiber fabric is an ultra-high molecular weight polyethylene fiber unidirectional tape.

3. The method for preparing a thin, low-back concave soft bulletproof vest chip according to claim 1, characterized in that: The ultra-high molecular weight polyethylene fiber unidirectional tape is composited from polyethylene fibers with a molecular weight of 1.5 million to 9 million and a polyurethane adhesive.

4. The method for preparing a thin, low-back concave soft bulletproof vest chip according to claim 1, characterized in that: The aromatic polyamide film is selected from poly (p-phenylene terephthalamide) film, p-phenylene terephthalamide benzimidazole polymer film, and isophthalamide (m-phenylene terephthalamide) polymer film. The film has a tensile breaking strength of ≥275 MPa and a thickness of 8 to 24 μm.

5. The method for preparing a thin, low-back concave soft bulletproof vest chip according to claim 1, characterized in that: The nylon film is one of nylon 6, nylon 66 and nylon 1010.

6. The method for preparing a thin, low-back concave soft bulletproof vest chip according to claim 1, characterized in that: In step (3), the composite is carried out by a hot pressing process with a pressure of 20 to 50 MPa and a temperature of 120 to 125° C. for 10 to 15 minutes.

7. A method for preparing a soft bulletproof vest fabric based on a thin, low-back concave soft bulletproof vest chip according to claims 1 to 6, characterized in that: (A) cutting the composite bulletproof vest chip according to the bulletproof vest size requirements; (B) using aromatic polyamide film as the bullet-facing surface, stacking several layers of composite bulletproof vest chips together; (C) The stacked composite bulletproof vest chips are stitched together to obtain a soft bulletproof vest fabric.

Images