An ultra-lightweight bulletproof cloth and a preparation method thereof

Abstract

This invention relates to the field of personal protective equipment materials technology, and in particular to an ultralight bulletproof fabric and its preparation method. The bulletproof fabric is composed of a protective outer layer and an anti-deformation inner layer, which are composited with thermoplastic resin. The protective outer layer is made of UHMWPE fiber with a linear density variation coefficient (CV) of <3% to form a non-woven fabric, which mainly absorbs impact energy efficiently. The anti-deformation inner layer is made of widened UHMWPE fiber non-woven fabric with a width of 6~10mm to effectively suppress back deformation. This structure achieves high bulletproof performance, low back protrusion, and good flexibility at an ultra-low areal density of 3.0~6.0kg / m², making it suitable for a new generation of high-performance soft bulletproof vests.

Description

Technical Field

[0001] This invention relates to the field of personal protective equipment materials technology, and in particular to an ultralight bulletproof fabric and its preparation method. Background Technology

[0002] Ultralight bulletproof fabric is a high-performance material for personal protective equipment. Its core objective is to achieve extreme lightweighting and good wearability while ensuring effective protection against ballistic threats. It is typically made of high-specific-strength fibers such as ultra-high molecular weight polyethylene, aiming to balance protective performance, weight, and comfort. It is an ideal core material for next-generation soft bulletproof vests, tactical vests, and other equipment.

[0003] However, existing bulletproof fabric technology struggles to simultaneously meet the three core requirements of "ultra-lightweight," "high protection," and "high flexibility." On one hand, to achieve higher protection levels, existing technologies typically employ complex composite structures, such as layering unidirectional non-woven fabric, tridirectional fabric, or even three-dimensional orthogonal non-woven fabric, and molding them into rigid or semi-rigid bulletproof plates under high temperature and pressure. While these different structural layers can address different stages of bullet penetration and thus achieve excellent ballistic performance, their fundamental flaw lies in the final product's thickness, high rigidity, and lack of flexibility. This renders it completely unsuitable for soft bulletproof vests that demand high levels of comfort and mobility, limiting its application to inserts. On the other hand, technological advancements also focus on improving the performance of the fibers themselves. By precisely controlling the spinning process, UHMWPE fibers with extremely high linear density consistency are produced, achieving a coefficient of variation (CV) of less than 3%, which is then used to manufacture unidirectional non-woven fabrics with more uniform ballistic performance. While this non-woven fabric made of high-performance fibers is lighter and thinner, as a single structural material, it still has inherent defects in resisting the impact of high-speed projectiles: local stress concentration at the point of impact can easily lead to rapid fiber breakage; the transmission and dissipation of stress waves between layers are not sufficient; more importantly, the material deforms and bulges on the back side after impact, and the structural damage is greater after the first impact, resulting in a significant decrease in resistance to multiple impacts.

[0004] In conclusion, neither complex rigid composite boards that sacrifice flexibility nor single high-performance nonwoven fabrics with performance shortcomings can simultaneously achieve excellent ballistic performance, superior resistance to back-side bulging, and good wearability at extremely low areal density.

[0005] Therefore, this application provides an ultralight bulletproof fabric and its preparation method to solve the problems mentioned in the background art. Summary of the Invention

[0006] The purpose of this invention is to provide an ultralight bulletproof fabric and its preparation method, which solves the problems of existing rigid composite boards being bulky and inflexible, and single high-performance non-woven fabric having poor impact resistance and severe back bulging, making it impossible to simultaneously achieve ultralightness, high bulletproofness and flexibility.

[0007] To solve the above-mentioned technical problems, the present invention provides an ultralight bulletproof cloth, wherein the bullet-faced side and the back side are respectively a protective outer layer and an anti-deformation inner layer, and are integrally bonded together by thermoplastic resin; The protective surface layer is composed of at least one layer of UHMWPE fiber nonwoven fabric, and the coefficient of variation (CV) of the linear density of the UHMWPE fiber in the nonwoven fabric is <3%. The deformation-resistant inner layer consists of at least one layer of expanded UHMWPE fiber nonwoven fabric, with the width of the expanded UHMWPE fiber being 6~10mm; The total surface density of bulletproof fabric is 3.0~6.0 kg / m².

[0008] A further improvement of the technical solution of the present invention is that the protective surface layer is composed of 1 to 5 layers of UHMWPE fiber non-woven fabric stacked in a 0° / 90° orthogonal manner.

[0009] A further improvement of the technical solution of the present invention is that the UHMWPE fiber of the protective surface has a linear density of 800~1200D, a breaking strength ≥36.9cN / dtex, and an initial modulus ≥1395cN / dtex.

[0010] A further improvement of the technical solution of the present invention is that the non-woven fabric of the anti-deformation inner layer is a twill weave with a fabric surface density of 100~250g / m².

[0011] A further improvement to the technical solution of the present invention is that the twill weave is a 2 / 2 twill weave and the satin weave is a five-end satin weave.

[0012] A further improvement of the technical solution of the present invention is that the broadened UHMWPE fiber is obtained by broadening UHMWPE fiber with a linear density of 400~800D.

[0013] A further improvement of the technical solution of the present invention is that the thermoplastic resin is at least one of low-density polyethylene, linear low-density polyethylene, thermoplastic polyurethane or ethylene-vinyl acetate copolymer, and its total content accounts for 8% to 20% of the total mass of the bulletproof fabric.

[0014] A method for preparing ultralight bulletproof fabric includes the following steps: S1: Preparation of high-consistency UHMWPE fibers: UHMWPE resin with a weight-average molecular weight (Mw) of 4 million to 10 million and an average particle size of d is selected and mixed with a solvent to prepare a spinning solution. The spinning solution concentration C and the average particle size d of the resin are controlled to satisfy: C×d²<20000. After swelling, dissolution, spinning and post-stretching, UHMWPE fibers with a linear density variation coefficient (CV) value of <3% are obtained. S2: Preparation of broadened UHMWPE fibers: Broadened UHMWPE fibers with a linear density of 400~800D are formed into flat fiber bundles with a width of 6~10mm. S3: Prepare the protective surface layer: Make the fibers obtained in step S1 into a single layer of non-woven fabric, and then stack them in an orthogonal manner at 0° / 90° according to the required number of layers; S4: Preparation of anti-deformation inner layer: The broadened fibers obtained in step S2 are used as warp and weft yarns and woven into a non-woven fabric with a twill weave. S5: Composite: The protective outer layer, thermoplastic resin layer and anti-deformation inner layer are combined in sequence and then hot-pressed to obtain the composite.

[0015] A further improvement to the technical solution of the present invention is that the conditions for hot pressing composite in step S5 are: temperature 130~150℃, pressure 2~4MPa, and time 0.5~2 hours.

[0016] A further improvement of the technical solution of the present invention lies in the application of ultralight bulletproof cloth or bulletproof cloth prepared by the preparation method in soft bulletproof vests.

[0017] By adopting the above technical solution, the present invention has the following beneficial effects: 1. This invention provides an ultralight bulletproof fabric that integrates a protective outer layer composed of highly uniform fibers with a deformation-resistant inner layer composed of expanded fiber non-woven fabric, achieving functional zoning and synergistic effects. The protective outer layer is made of high-performance UHMWPE fibers with extremely low linear density variation coefficient, orthogonally layered to ensure high uniformity of fiber properties and high-speed, uniform transmission of stress waves, thereby efficiently absorbing the main impact energy of the bullet. The deformation-resistant inner layer is made of twill non-woven fabric woven from expanded UHMWPE fibers of a specific width. Its flat fiber morphology increases the bonding area with resin, and its interwoven structure provides excellent shear resistance and overall deformation resistance, effectively suppressing back bulge after bullet penetration and preventing non-penetrating injuries. This combination of "high-efficiency energy-absorbing surface layer" and "deformation-resistant and toughened inner layer" fundamentally overcomes the shortcomings of traditional single non-woven fabric structures, such as poor resistance to back bulge and rapid decay of ballistic performance after repeated ballistic protection. It also avoids the problem of insufficient flexibility in complex rigid composite boards, achieving high protection level, low back deformation and good overall ballistic safety at extremely low areal density.

[0018] 2. This invention provides a method for preparing the ultralight bulletproof fabric. This method ensures reliable product performance and production feasibility through control of process steps and core parameters. First, in the step of preparing highly uniform fibers, controlling the spinning solution concentration C and the average resin particle size d to satisfy the core relationship C×d²<20000 is crucial for obtaining UHMWPE fibers with a linear density variation coefficient CV value <3%. This ensures that the UHMWPE resin particles can swell and dissolve uniformly and fully in the solvent, forming a highly uniform spinning solution. This eliminates bulletproof weaknesses caused by fiber performance dispersion at the source, laying a material foundation for preparing a high-performance protective surface layer. Second, the preparation steps are clearly divided into the separate preparation of the protective surface layer and the deformation-resistant inner layer. This modular process design allows each functional layer to be processed independently under its optimal process conditions, ensuring the high orientation of the surface layer fibers and the stable structure of the inner layer fabric. Finally, by setting the temperature to 130~150℃, the pressure to 2~4MPa, and the time to 0.5~2 hours for hot pressing composite process, the selected thermoplastic resin is ensured to fully melt and flow, and to uniformly penetrate between fibers and between layers, so as to achieve a firm and uniform interface bond between the protective outer layer and the deformation-resistant inner layer, thereby integrating the performance advantages of the two materials into a whole, while avoiding damage to the mechanical properties of the fibers due to excessive temperature or pressure. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A schematic diagram of the structure of an ultralight bulletproof fabric; Figure 2 for Figure 1 Cross-sectional view; Figure 3 for Figure 1 Schematic diagram of the structure of the middle protective layer; Figure 4 for Figure 3 An enlarged schematic diagram of part A in the middle; Figure 5 for Figure 1 Schematic diagram of the fabric structure of the deformation-resistant inner layer; Figure 6 for Figure 5 Enlarged diagram of part B.

[0021] Reference numerals: 1-protective outer layer; 2-deformation resistant inner layer. Detailed Implementation

[0022] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] The present invention will be further explained below with reference to specific embodiments.

[0026] like Figure 1-6 As shown, the ultralight bulletproof fabric provided by the present invention is a double-layer composite fabric with functional partitions from the bullet surface to the back surface; specifically, the bulletproof fabric is composed of a protective outer layer 1 and an anti-deformation inner layer 2, which are bonded together by heat pressing through an intermediate thermoplastic resin composite layer.

[0027] The protective outer layer 1 is the main energy absorption and dispersion layer, which is composed of at least one, preferably two to three, layers of UHMWPE fiber non-woven fabric orthogonally stacked in the 0° / 90° direction. The coefficient of variation (CV) of the linear density of the UHMWPE fiber in the non-woven fabric is <3%. The performance of each bundle of fibers used in the outer layer is extremely uniform, eliminating bulletproof weak points that may be formed due to uneven strength of monofilaments from the source. Preferably, the linear density of the fiber is in the range of 800~1200D, with a high breaking strength of ≥36.9cN / dtex and a high initial modulus of ≥1395cN / dtex, providing a material basis for efficiently absorbing the kinetic energy of bullet impact. The orthogonal layup design allows the layer to quickly and uniformly transmit and diffuse stress waves in two mutually perpendicular directions when impacted, maximizing the conversion of the bullet's kinetic energy into the strain energy of the fiber.

[0028] The deformation-resistant inner layer 2 is a crucial deformation-inhibiting and toughening layer. It is a non-woven fabric composed of broadened UHMWPE fibers with a width of 6-10 mm. A 2 / 2 twill weave is preferred. Conventional UHMWPE fibers have an approximately circular cross-section, but the broadening process treats them into flat strips, which significantly increases the fiber surface area, thereby forming a stronger interfacial bond with the thermoplastic resin during subsequent lamination and greatly enhancing the interlayer shear resistance. The interwoven structure of the non-woven fabric gives this layer excellent integrity and deformation resistance. When the areal density is controlled at 100-250 g / m², this layer, while maintaining lightweight properties, can effectively "catch" the residual impact force after penetrating the outer layer, significantly suppressing the bulging of the back material caused by bullet impact and preventing serious non-penetrating blunt force trauma to the wearer.

[0029] The thermoplastic resin composite layer serves as both an adhesive and a stress-transfer medium. Low-density polyethylene and thermoplastic polyurethane are preferred materials, existing in film or powder form between the layers. Through a hot-pressing process, the resin melts and permeates between the fibers, firmly bonding the protective outer layer 1 and the deformation-resistant inner layer 2 into a single unit, ensuring effective transfer and synergistic dissipation of impact energy between the two layers. The total resin content is controlled at 8%–20% of the total mass of the bulletproof fabric, ensuring sufficient bonding strength while avoiding excessive resin that would increase weight or reduce material flexibility.

[0030] Through the specific double-layer structure design of the protective outer layer 1 and the deformation-resistant inner layer 2, the present invention combines the advantages of the two fiber forms, and finally produces a bulletproof fabric that achieves an excellent balance of protective performance, anti-back protrusion ability and wearing flexibility in a "super light" state with a total surface density of only 3.0~6.0 kg / m².

[0031] Example 1 This embodiment details the preparation and properties of an ultralight bulletproof fabric with an areal density of approximately 3.7 kg / m².

[0032] S1. Preparation of highly consistent UHMWPE fibers: Raw materials: UHMWPE resin powder with a weight-average molecular weight (Mw) of 5.5 million, a molecular weight distribution (Mw / Mn) of 5.0, and an average particle size (d) of 152 μm was selected. The solvent was No. 68 industrial white oil.

[0033] Key process control: Prepare the spinning solution and precisely control its mass concentration C=0.5wt%. Calculate C×d²=0.5×152²=11552, which meets the core control condition C×d²<20000. This step is a prerequisite for ensuring the consistency of subsequent fibers.

[0034] Process: The resin and white oil are fully swollen and mixed at 100℃. The swollen mixture is then fed into a co-rotating twin-screw extruder, where it undergoes low-temperature shearing and dissolution at a barrel temperature of 100℃ and a screw speed of 350 rpm to form a uniform spinning solution. After extrusion via a metering pump and spinneret, the solution is rapidly cooled and solidified in a low-temperature water bath to obtain nascent gel fibers. These nascent fibers undergo multi-stage hot stretching, achieving a total stretch ratio of 57.8 times, ultimately yielding the finished fiber.

[0035] Fiber properties: The linear density of the produced fiber is 800D. Sampling tests showed that its coefficient of variation (CV) was 2.3% (<3%), its breaking strength was 36.9 cN / dtex, and its initial modulus was 1480 cN / dtex, fully meeting the high performance and high consistency requirements of fibers for protective surface layer 1.

[0036] S2. Preparation of expanded UHMWPE fibers: Commercially available UHMWPE fibers with a linear density of 400D were selected as raw materials.

[0037] The fibers are processed using a mechanical roller pressing device under suitable temperature and tension to form flat, ribbon-like fiber bundles with a width of 8mm for weaving.

[0038] S3. Preparation of the protective surface layer 1 preform: The highly consistent UHMWPE fibers obtained in step S1 are processed on a dedicated non-woven fabric production line. The fibers undergo unwinding, tension control, and reed threading to achieve a strictly parallel arrangement of all fibers within a single layer.

[0039] The immersion method is used to apply adhesive by passing parallel fiber bundles through a tank containing thermoplastic polyurethane adhesive.

[0040] After drying, cooling, and winding, a non-woven fabric with a single width and a single layer density of 100g / m² is produced, in which the thermoplastic polyurethane resin content is 15wt%.

[0041] After cutting, the two layers of this non-woven fabric are orthogonally overlapped at 0° / 90° to obtain the protective surface layer 1 prefabricated body, whose total surface density is about 200g / m².

[0042] S4. Preparation of the deformation-resistant inner layer 2 non-woven fabric: The 8mm wide expanded UHMWPE fiber obtained in step S2 is used as warp and weft yarn.

[0043] The weaving is performed on a rapier loom using a 2 / 2 twill weave. The warp and weft densities are both set at 40 ends / 10cm.

[0044] After weaving, a widened fiber twill nonwoven fabric with an areal density of 150 g / m² is obtained.

[0045] S5, Lamination and Hot-Pressure Composite: Layering sequence: In a flat mold, lay the materials in the following order: First, place two orthogonally stacked protective surface layer 1 non-woven fabric preforms, then lay a thermoplastic polyurethane film with a surface density of 20g / m², and finally cover with a layer of twill non-woven fabric obtained in step S4.

[0046] Hot pressing process: The above-described laminated assembly is placed in a hot press. A segmented heating program is used, culminating in a constant temperature of 140°C and a pressure of 3.0 MPa, followed by hot pressing and holding for 1 hour. These process conditions ensure that the thermoplastic polyurethane resin fully melts, flows, and penetrates between fibers and at interlayer interfaces.

[0047] Cooling and Demolding: After hot pressing, the material is held under pressure and cooled to below room temperature before demolding to obtain the final product of this embodiment: double-layer composite ultralight bulletproof fabric. Its total areal density is calculated to be approximately 370 g / m² (0.37 kg / m²).

[0048] Example 2 This embodiment demonstrates an ultralight bulletproof fabric with a higher protection level and a total areal density of approximately 4.8 kg / m². Its manufacturing process parameters have been adjusted to verify the process window and performance adjustability of the present invention.

[0049] S1. Preparation of highly consistent UHMWPE fibers: UHMWPE resin with a higher molecular weight was selected, with a Mw of 8 million and an average particle size of d=108μm.

[0050] To prepare a higher concentration spinning solution, C = 0.9 wt%. Verification showed that C × d² = 10497 < 20000, indicating the condition was met.

[0051] After swelling, dissolving, spinning, and a higher thermal stretch of 79.4 times, a fiber with a linear density of 800D was obtained. Its CV value was further improved to 1.5%, its breaking strength reached 39.5 cN / dtex, and its initial modulus reached 1752 cN / dtex.

[0052] S2. Preparation of expanded UHMWPE fibers: 600D UHMWPE fiber is selected as raw material and spread to a width of 10mm.

[0053] S3. Preparation of the protective surface layer 1 preform: The above-mentioned high-performance fibers are used to make a single-layer non-woven fabric with a density of 80 g / m², and low-density polyethylene is used as the bonding resin with a content of 12 wt%.

[0054] Three layers are stacked in a 0° / 90° / 0° manner to obtain the protective surface layer 1 prefabricated body with a total surface density of approximately 240 g / m².

[0055] S4. Preparation of the deformation-resistant inner layer 2 non-woven fabric: Five-end satin weave non-woven fabric made of 10mm wide spreadable fibers, with a surface density of 200g / m².

[0056] S5, Lamination and Hot-Pressure Composite: Low-density polyethylene powder is evenly sprinkled between each layer of material, and the total resin content is controlled at 18wt%.

[0057] The hot pressing process parameters were adjusted to: temperature 135℃, pressure 2.5MPa, and time 1.5 hours. After cooling, the finished product was obtained with a total surface density of approximately 495g / m².

[0058] Comparison and performance testing To objectively evaluate the advantages of the present invention, the following comparative examples were set up and comparative tests were conducted.

[0059] Comparative Example 1: The same high-consistency fibers and thermoplastic polyurethane resin as in Example 1 were used. However, the structure was changed to a pure fiber non-woven fabric. Four layers of single-layer non-woven fabric were stacked at 0° / 90° / 0° / 90° and then hot-pressed to control the total areal density to approximately 400 g / m². This comparative example was used to verify the performance limitations of a single high-performance non-woven fabric structure.

[0060] Comparative Example 2: The same broadened fibers and 2 / 2 twill inner layer as Example 1 were used. However, the protective outer layer 1 was replaced with a two-layer non-woven fabric made of commercially available UHMWPE fibers (CV value approximately 5%). The total areal density was approximately 380 g / m². This comparative example was used to verify the critical impact of fiber consistency on the overall performance of the bilayer structure.

[0061] Comparison sample: A mainstream commercially available UHMWPE soft bulletproof cloth product that meets the GA141-2010 Level II protection requirements was selected as the market benchmark, with a typical areal density of approximately 5.0 kg / m².

[0062] Standardized tests were performed on Examples 1 and 2, Comparative Examples 1 and 2, and commercially available products: Ballistic performance (V50): According to the GA141-2010 standard, the V50 ballistic limit test was conducted using a 5.56mm steel core bullet (M193 bullet).

[0063] Back Surface Deformation (BFS): The depth of the indentation formed by the plastic material on the back of the bulletproof material at the V50 test velocity described above, measured in mm. The BFS value is directly related to the risk of non-penetrating injury.

[0064] Bending stiffness: Tested according to GB / T18318.1 standard. The smaller the value, the softer the material and the better the wearing comfort.

[0065] Areal density: calculated by direct measurement.

[0066] The test results are summarized in the table below:

[0067] Results Analysis Based on the data in the table above, the technical effects of the present invention are analyzed as follows: Significant lightweight advantages: The areal density of Examples 1 and 2 (3.7, 4.8 kg / m²) is significantly lower than that of similar products on the market with 5.0 kg / m², achieving a weight reduction of more than 20%, reflecting the core feature of "ultra-light".

[0068] Leading in all aspects of bulletproof performance: V50 values: The V50 values ​​of Example 1 (715 m / s) and Example 2 (740 m / s) are both higher than those of Comparative Example 1 (700 m / s) and commercially available products (680 m / s), proving that the double-layer structure of the present invention is superior to the traditional single non-woven fabric structure in terms of energy absorption efficiency. The performance of Example 2 is particularly outstanding.

[0069] Back Fiber Spread (BFS): This is one of the most significant improvements of this invention. The BFS values ​​of Examples 1 and 2 (18.5, 16.2 mm) are significantly lower than those of Comparative Example 1 (25.1 mm) and commercially available products (28 ± 2 mm), representing a reduction of 34%-42%. This demonstrates the irreplaceable role of the "broadened fiber anti-deformation inner layer 2" in suppressing deformation after impact and improving safety. Even in Comparative Example 2, due to the presence of the broadened inner layer, its BFS (22.3 mm) is superior to that of Comparative Example 1, which uses pure non-woven fabric, further confirming the functionality of this inner layer structure.

[0070] Excellent flexibility: Examples 1 and 2 have the lowest bending stiffness values, indicating the softest materials. Comparative Example 1, being entirely composed of rigid, non-woven fabric layers, exhibits the highest stiffness. This demonstrates that the structure of the present invention successfully retains fabric-like softness and bendability while achieving high-strength protection, perfectly meeting the comfort requirements of soft bulletproof vests.

[0071] Structural synergy verification: Comparison of the examples and comparative examples shows that: Comparative Example 1 shows that only high-consistency non-woven fabric, although light, is resistant to back unevenness and is relatively stiff, indicating that a single optimized fiber cannot solve all the problems.

[0072] Comparative Example 2, which uses a double-layer structure but has poor surface fiber consistency, has the lowest V50 value, indicating that if the performance of the base material is uneven, the overall protective performance will be greatly reduced.

[0073] This invention successfully breaks through the bottleneck of traditional technology by synergistically combining "highly consistent fibers" and "expanded fibers" in a specific "double-layer composite structure".

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ultralight bulletproof fabric, characterized in that, The outer surface of the bullet consists of a protective outer layer (1) and an anti-deformation inner layer (2), which are bonded together by thermoplastic resin. The protective surface layer (1) is composed of at least one layer of UHMWPE fiber nonwoven fabric, and the coefficient of variation (CV) of the linear density of the UHMWPE fiber in the nonwoven fabric is <3%; The deformation-resistant inner layer (2) is at least one layer of expanded UHMWPE fiber nonwoven fabric, and the width of the expanded UHMWPE fiber is 6~10mm; The total surface density of bulletproof fabric is 3.0~6.0 kg / m².

2. The ultralight bulletproof fabric according to claim 1, characterized in that, The protective surface layer (1) is made of 1 to 5 layers of UHMWPE fiber nonwoven fabric stacked in a 0° / 90° orthogonal manner.

3. The ultralight bulletproof fabric according to claim 1, characterized in that, The protective outer layer (1) is made of UHMWPE fiber with a linear density of 800~1200D, a breaking strength of ≥36.9cN / dtex, and an initial modulus of ≥1395cN / dtex.

4. The ultralight bulletproof fabric according to claim 1, characterized in that, The anti-deformation inner layer (2) is a twill weave with a fabric surface density of 100~250g / m².

5. The ultralight bulletproof fabric according to claim 4, characterized in that, The twill weave is a 2 / 2 twill, and the satin weave is a five-end satin.

6. The ultralight bulletproof fabric according to claim 1, characterized in that, Expanded UHMWPE fibers are obtained by expanding UHMWPE fibers with a linear density of 400~800D.

7. The ultralight bulletproof fabric according to claim 1, characterized in that, The thermoplastic resin is at least one of low-density polyethylene, linear low-density polyethylene, thermoplastic polyurethane, or ethylene-vinyl acetate copolymer, and its total content accounts for 8% to 20% of the total mass of the bulletproof fabric.

8. A method for preparing ultralight bulletproof fabric as described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Preparation of high-consistency UHMWPE fibers: UHMWPE resin with a weight-average molecular weight (Mw) of 4 million to 10 million and an average particle size of d is selected and mixed with a solvent to prepare a spinning solution. The spinning solution concentration C and the average particle size d of the resin are controlled to satisfy: C×d²<20000. After swelling, dissolution, spinning and post-stretching, UHMWPE fibers with a linear density variation coefficient (CV) value of <3% are obtained. S2: Preparation of broadened UHMWPE fibers: Broadened UHMWPE fibers with a linear density of 400~800D are formed into flat fiber bundles with a width of 6~10mm. S3: Preparation of protective surface layer (1): The fibers obtained in step S1 are made into a single layer of non-woven fabric, and then stacked in an orthogonal manner at 0° / 90° according to the required number of layers; S4: Preparation of anti-deformation inner layer (2): The broadened fibers obtained in step S2 are used as warp and weft yarns to weave a non-woven fabric with a twill weave structure; S5: Composite: The protective outer layer (1), thermoplastic resin layer and anti-deformation inner layer (2) are combined in sequence and then hot-pressed to obtain the composite.

9. The method for preparing an ultralight bulletproof fabric according to claim 8, characterized in that, The conditions for hot pressing composite in step S5 are: temperature 130~150℃, pressure 2~4MPa, and time 0.5~2 hours.

10. The use of the ultralight bulletproof fabric according to any one of claims 1-7 or the bulletproof fabric prepared by the method according to any one of claims 8-9 in soft bulletproof vests.

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