Method for preparing fiber hybrid composite bulletproof helmet and composite bulletproof helmet

Abstract

The present invention relates to the technical field of bulletproof protective equipment preparation, and provides a method for preparing a fiber hybrid composite bulletproof helmet and a composite bulletproof helmet. The method comprises: presetting cutting sizes, and sequentially cutting, pre-laying, and pre-pressing and shaping a multi-layer ultra-high molecular weight polyethylene fiber unidirectional fabric to obtain a pre-pressed helmet; placing the pre-pressed helmet into a molding mold for molding and pressing to obtain a bulletproof main body helmet; sequentially cutting, pre-laying, and molding and pressing a multi-layer reinforced fiber prepreg fabric to obtain a reinforced fiber helmet, wherein the fibers used in the multi-layer reinforced fiber prepreg fabric are reinforced fibers, and the reinforced fibers are one of or a combination of more of carbon fibers, aramid fibers, glass fibers, and PBO fibers; and subjecting the bulletproof main body helmet and the reinforced fiber helmet to hot-press laminating by using an adhesive film to obtain the fiber hybrid composite bulletproof helmet, wherein the hot-press laminating is a vacuum hot-pressing process. This improves the bulletproof performance of the fiber hybrid composite bulletproof helmet, which is beneficial for engineering applications.

Description

A method for preparing a fiber-blended composite bulletproof helmet and the composite bulletproof helmet Technical Field

[0001] This invention relates to the field of bulletproof protective equipment manufacturing technology, and in particular to a method for manufacturing a fiber hybrid composite bulletproof helmet and the composite bulletproof helmet. Background Technology

[0002] Bulletproof helmets are protective gear that shields the head from high-speed projectiles or shrapnel, playing a crucial role in improving soldiers' survivability, reducing casualties, and enhancing combat effectiveness. Since World War II, various countries have conducted in-depth research on the ballistic performance and wearing comfort of bulletproof helmets, including ballistic materials, helmet structure, composite structures, and molding processes. Through continuous technological innovation, traditional metal helmets have been gradually replaced.

[0003] Currently, the most widely used bulletproof helmets are aramid helmets and ultra-high molecular weight polyethylene (UHMWPE) helmets. However, aramid helmets are not light-resistant, have poor weather resistance, short lifespan, and high manufacturing costs, thus limiting their market application and engineering use. UHMWPE bulletproof helmets are not heat-resistant, and the bullet holes are high when bullets penetrate, easily causing blunt force trauma, resulting in lower bulletproof performance. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a fiber hybrid composite bulletproof helmet and a composite bulletproof helmet, thereby solving the problems of limited engineering applications and low bulletproof performance.

[0005] To address the aforementioned technical problems, the embodiments of the present invention provide the following technical solutions:

[0006] The first aspect of this invention provides a method for preparing a fiber hybrid composite bulletproof helmet, the method comprising:

[0007] Cut the multi-layer ultra-high molecular weight polyethylene fiber nonwoven fabric according to the preset cutting size;

[0008] Multi-layer cut ultra-high molecular weight polyethylene fiber non-woven fabric is layered and stacked together, and pre-laid in the cavity of the helmet negative mold to obtain a pre-laid helmet.

[0009] The pre-laid helmet is placed into a pre-compression mold for pre-compression and shaping to obtain a pre-compression helmet;

[0010] The pre-compressed helmet is placed into a molding mold for molding and pressing to obtain the bulletproof main helmet.

[0011] The multi-layer reinforcing fiber prepreg is cut and pre-laid in sequence to obtain a pre-laid reinforcing fiber helmet. The fiber used in the multi-layer reinforcing fiber prepreg is a reinforcing fiber, which is one or more of carbon fiber, aramid fiber, glass fiber, and PBO fiber.

[0012] The pre-laid reinforced fiber helmet is placed in a molding mold and pressed to obtain the reinforced fiber helmet;

[0013] The bulletproof main helmet and the reinforcing fiber helmet are hot-pressed together using an adhesive film to obtain a fiber hybrid composite bulletproof helmet. When the hot-pressing is vacuum hot-pressing, the vacuum hot-pressing temperature is 110~130℃, the holding pressure is 2~5MPa, and the holding time is 15~30min.

[0014] In some modified embodiments of the first aspect of the present invention, the fibers used in the ultra-high molecular weight polyethylene nonwoven fabric are ultra-high molecular weight polyethylene fibers, and the mixing ratio of ultra-high molecular weight polyethylene fibers to reinforcing fibers is 4:1 to 6.8:1.

[0015] In some modified embodiments of the first aspect of the present invention, when hot pressing is non-vacuum hot pressing, the temperature of non-vacuum hot pressing is 110~130°C, the holding pressure is 5~15MPa, and the holding time is 15~30min.

[0016] In some modified embodiments of the first aspect of the present invention, the constant pressure holding temperature for molding and pressing the pre-pressed helmet is 128~133℃, the constant pressure holding time is 15~30min, and the constant pressure holding pressure is 15MPa.

[0017] In some modified embodiments of the first aspect of the present invention, the constant pressure holding temperature for molding and pressing the pre-laid reinforced fiber helmet is 135~155℃, the constant pressure holding time is 30~50min, and the constant pressure holding pressure is 3~7MPa.

[0018] In some modified embodiments of the first aspect of the present invention, multi-layered cut ultra-high molecular weight polyethylene fiber nonwoven fabric is layered and pre-laid in the mold cavity of a helmet negative mold to obtain a pre-laid helmet, comprising:

[0019] Obtain the first cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with a preset number of layers;

[0020] The first sharp corners of the first cut ultra-high molecular weight polyethylene fiber nonwoven fabrics of each layer are kept consistent, and the first cut ultra-high molecular weight polyethylene fiber nonwoven fabrics of each layer are interleaved at multiple inner shear lines and pre-laid in the mold cavity of the helmet negative mold.

[0021] Obtain the second cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with a preset number of layers;

[0022] Place the second sharp corner of each layer of second-cut ultra-high molecular weight polyethylene fiber nonwoven fabric into the corresponding first sharp corner position, and rotate the second sharp corner position by a preset angle;

[0023] The ultra-high molecular weight polyethylene fiber nonwoven fabrics cut into each layer are interleaved at multiple inner shear lines and pre-laid in the mold cavity of the helmet negative mold.

[0024] Return to the step of obtaining the second cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with the preset number of layers, and stop pre-laying when the preset number of pre-laying times is reached, to obtain the pre-laid helmet.

[0025] In some modified embodiments of the first aspect of the present invention, the preset number of layers is 2 to 4, the preset number of times is 10 to 30, and the preset angle is 30±5°.

[0026] In some modified embodiments of the first aspect of the present invention, multilayer ultra-high molecular weight polyethylene fiber nonwoven fabric is used as the bulletproof material, and the areal density of the bulletproof material is 80~160 g / m². 2 .

[0027] In some modified embodiments of the first aspect of the present invention, the adhesive film is a hot melt adhesive, and the surface density of the hot melt adhesive film is 60~120 g / m³. 2 .

[0028] The second aspect of the present invention provides a composite bulletproof helmet, which includes a bulletproof main helmet and a reinforcing fiber helmet. The bulletproof main helmet uses ultra-high molecular weight polyethylene fiber, and the reinforcing fiber helmet uses one or more of carbon fiber, aramid fiber, glass fiber, and PBO fiber. The mixing ratio of ultra-high molecular weight polyethylene fiber to reinforcing fiber is 4:1 to 6.8:1.

[0029] Compared to existing technologies, this invention provides a method for preparing a fiber-blended composite bulletproof helmet and the composite bulletproof helmet itself. The method involves cutting multiple layers of ultra-high molecular weight polyethylene (UHMWPE) fiber nonwoven fabric according to a preset cutting size, then layering these cut UHMWPE fiber nonwoven fabrics together and pre-laying them into the cavity of a helmet mold to obtain a pre-laid helmet. The pre-laid helmet is then placed in a pre-compression mold for pre-compression shaping to obtain a pre-compression helmet. Finally, the pre-compression helmet is placed in a molding mold for molding and pressing to obtain the main bulletproof helmet. Multiple layers of reinforcing fiber prepreg fabric are sequentially cut and pre-laid to obtain… The pre-laid reinforced fiber helmet, using multi-layered reinforced fiber prepreg, is made of one or more of the following fibers: carbon fiber, aramid fiber, glass fiber, and PBO fiber. The pre-laid reinforced fiber helmet is placed in a molding mold and pressed to obtain the reinforced fiber helmet. The bulletproof main helmet and the reinforced fiber helmet are then hot-pressed together using an adhesive film to obtain a fiber-hybrid composite bulletproof helmet. When the hot-pressing is done under vacuum, the temperature is 110-130℃, the holding pressure is 2-5 MPa, and the holding time is 15-30 minutes. By selecting ultra-high molecular weight polyethylene fiber, carbon fiber, aramid fiber, glass fiber, and PBO fiber as the hybrid fiber materials for the composite bulletproof helmet, the performance advantages of different fiber materials are comprehensively utilized, achieving a positive unity between the bulletproof performance and structural strength of the bulletproof helmet. This results in a smaller bullet wound height in the helmet made of hybrid fiber materials, effectively improving the bulletproof performance of the fiber-hybrid composite bulletproof helmet. The process of hot-pressing the interfacial adhesive film of the bulletproof main helmet and the reinforced fiber helmet adopts vacuum hot pressing to effectively improve the interfacial bonding strength and interfacial composite uniformity, while greatly improving production efficiency and facilitating engineering applications. Attached Figure Description

[0030] The above and other objects, features, and advantages of exemplary embodiments of the present invention will become readily apparent upon reading the following detailed description with reference to the accompanying drawings. In the drawings, several embodiments of the invention are illustrated by way of example and not limitation, with the same or corresponding reference numerals denoteing the same or corresponding parts, wherein:

[0031] Figure 1 schematically shows a flowchart of the preparation method of the fiber hybrid composite bulletproof helmet;

[0032] Figure 2 schematically shows a diagram of the preset cutting size of ultra-high molecular weight polyethylene nonwoven fabric;

[0033] Figure 3 schematically shows a diagram of the cutting dimensions of the reinforcing fiber prepreg;

[0034] Figure 4 schematically shows the structure of a composite bulletproof helmet. Detailed Implementation

[0035] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0036] It should be noted that, unless otherwise stated, the technical or scientific terms used in this invention should have the ordinary meaning as understood by one of ordinary skill in the art.

[0037] The methods described in the embodiments of the present invention will be explained in detail below.

[0038] Figure 1 schematically illustrates a flowchart of the preparation method of the fiber hybrid composite bulletproof helmet according to an embodiment of the present invention. Referring to Figure 1, the preparation method may include:

[0039] S101. Cut the multi-layer ultra-high molecular weight polyethylene fiber nonwoven fabric according to the preset cutting size.

[0040] As an optional implementation, the fibers used in the ultra-high molecular weight polyethylene nonwoven fabric are ultra-high molecular weight polyethylene fibers, and the mixing ratio of ultra-high molecular weight polyethylene fibers to reinforcing fibers is 4:1 to 6.8:1.

[0041] As an optional implementation, multilayer ultra-high molecular weight polyethylene fiber (UHMWPEF) non-woven fabric is used as the bulletproof material, with an areal density of 80~160 g / m². 2 .

[0042] Specifically, the bulletproof material is processed through cutting, pre-laying, pre-pressing, and hot-pressing to produce the main body of the bulletproof helmet. The bulletproof material is a UHMWPEF non-woven fabric made by impregnating UHMWPEF with a thermoplastic resin binder, wherein the thermoplastic resin binder is polyurethane, with a content of 10% to 20%.

[0043] The cutting process involves laying up the UHMWPEF nonwoven fabric and then cutting it to a preset size using an automatic cutting machine. The radius of the circular portion of the preset-sized UHMWPEF nonwoven fabric is 260-350 mm, the length of the straight portion is 260-350 mm, the length of the inner shear line is 180-300 mm, and the distance between two inner shear lines on the same straight line is 142-232 mm.

[0044] Figure 2 schematically shows a diagram of the preset cutting size of ultra-high molecular weight polyethylene nonwoven fabric. As shown in Figure 2, the radius of the circular part of the ultra-high molecular weight polyethylene nonwoven fabric with the preset cutting size is 260 mm, the length of the straight part of the outer shape is 260 mm, the lengths of the inner shear lines are 189 mm and 297 mm, and the distance between the two inner shear lines on the same straight line is 143 mm.

[0045] S102. Layer by layer, cut ultra-high molecular weight polyethylene fiber nonwoven fabric is mixed and stacked, and pre-laid in the cavity of the helmet negative mold to obtain a pre-laid helmet.

[0046] Specifically, multiple layers of cut ultra-high molecular weight polyethylene fiber nonwoven fabric are interleaved and pre-laid into the cavity of the helmet mold to obtain a pre-laid helmet, including:

[0047] Step A1: Obtain the first cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with a preset number of layers.

[0048] The preset number of layers is 2 to 4.

[0049] Obtain 2-4 layers of first-cut ultra-high molecular weight polyethylene fiber nonwoven fabric.

[0050] Step A2: Ensure that the first sharp corners of the first cut UHMWPE fiber nonwoven fabrics of each layer are aligned, and overlap the first cut UHMWPE fiber nonwoven fabrics of each layer at multiple inner cut lines, and pre-lay them in the mold cavity of the helmet negative mold.

[0051] Specifically, when laying out the first cut UHMWPE fiber nonwoven fabric (i.e., the cut pieces) of 2 to 4 layers together, the first sharp corners of each layer of the first cut UHMWPE fiber nonwoven fabric should be kept consistent, and the first cut UHMWPE fiber nonwoven fabric of each layer should be interleaved at the four inner cut lines to avoid material gaps or excessive overlap. This should be pre-laid in the mold cavity of the helmet negative mold to ensure that the pre-laid UHMWPE fiber nonwoven fabric of each layer conforms to the mold shape of the helmet negative mold.

[0052] Step A3: Obtain the second cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with a preset number of layers.

[0053] From the multi-layer cut ultra-high molecular weight polyethylene fiber nonwoven fabric of S101, obtain 2 to 4 layers of second-cut ultra-high molecular weight polyethylene fiber nonwoven fabric.

[0054] Step A4: Place the second sharp corner of each layer of second-cut ultra-high molecular weight polyethylene fiber nonwoven fabric into the corresponding first sharp corner position, and rotate the second sharp corner position by a preset angle.

[0055] The preset angle is 30±5°.

[0056] Place the second pointed corner of each layer of second-cut UHMWPE fiber nonwoven fabric at the corresponding first pointed corner position, that is, make the second pointed corner position coincide with the first pointed corner position. Rotate the second pointed corner position clockwise or counterclockwise by 30±5°. In other words, based on the first pointed corner position, rotate the corresponding second pointed corner position clockwise or counterclockwise by 30±5°. The pointed corner position after rotating clockwise or counterclockwise by 30±5° is the final pointed corner position of each layer of second-cut UHMWPE fiber nonwoven fabric.

[0057] Step A5: The ultra-high molecular weight polyethylene fiber nonwoven fabrics cut in the second cut of each layer are interleaved at multiple inner cut lines and pre-laid in the mold cavity of the helmet negative mold.

[0058] Specifically, when laying out 2 to 4 layers of second-cut UHMWPE fiber nonwoven fabric (i.e., cut pieces), the second pointed corners of each layer of second-cut UHMWPE fiber nonwoven fabric should be kept consistent, and the layers of second-cut UHMWPE fiber nonwoven fabric should be interleaved at the four inner cut lines to avoid material gaps or excessive overlap. This should be pre-laid in the mold cavity of the helmet negative mold to ensure that the pre-laid UHMWPE fiber nonwoven fabric of each layer conforms to the mold shape of the helmet negative mold.

[0059] Step A6: Return to the step of obtaining the second cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with the preset number of layers, and stop pre-laying when the preset number of pre-laying times is reached, to obtain the pre-laid helmet.

[0060] The preset number of times is 10 to 30.

[0061] Specifically, return to step A3 and continue executing steps A3, A4, and A5. This involves obtaining a preset number of layers of second-cut UHMWPE fiber nonwoven fabric, placing the second sharp corner of each layer of second-cut UHMWPE fiber nonwoven fabric at the corresponding first sharp corner position, and rotating the second sharp corner position by a preset angle. The layers of second-cut UHMWPE fiber nonwoven fabric are then interleaved at multiple inner shear lines and pre-laid in the mold cavity of the helmet negative mold. This pre-laying is stopped when the number of pre-layings reaches 10 to 30 times, resulting in a pre-laid helmet.

[0062] S103. Place the pre-laid helmet into the pre-compression mold for pre-compression and shaping to obtain the pre-compression helmet.

[0063] Specifically, the pre-compression process involves placing the pre-laid helmet into a pre-compression mold, ensuring the female mold is below and the male mold is above, and then starting the pre-compression and shaping process to obtain a pre-compressed helmet. The pre-compression process has a temperature of 25~55℃, a pressure of 10MPa, and a time of 5~15s.

[0064] S104. Place the pre-compressed helmet into the molding mold for molding and pressing to obtain the bulletproof main helmet.

[0065] As an optional implementation method, the constant pressure holding temperature for the molding and pressing of the pre-compression helmet is 128~133℃, the constant pressure holding time is 15~30min, and the constant pressure holding pressure is 15MPa.

[0066] Specifically, step S104 is a hot pressing process, in which the pre-pressed helmet is placed into the molding mold and hot-pressed. The constant pressure holding temperature is 128~133℃, the constant temperature holding time is 15~30min, the constant temperature holding pressure is 15MPa, and the mold opening temperature is 30~50℃. During the molding and pressing process, 3~6 venting operations are performed, the venting temperature is 50~100℃, and the helmet mold is raised 30~50mm during venting.

[0067] S105. Cut and lay the multi-layer reinforcing fiber prepreg in sequence to obtain the pre-laid reinforcing fiber helmet.

[0068] Among them, the fibers used in the multi-layer reinforced fiber prepreg are reinforcing fibers, which are one or more of carbon fiber, aramid fiber, glass fiber, and PBO fiber.

[0069] Multi-layer reinforced fiber prepreg is a composite material made from resin-based reinforcing fiber materials. Reinforced fiber helmets are produced by sequentially cutting, pre-laying, and hot-pressing the multi-layer reinforced fiber prepreg.

[0070] Resin-based materials include epoxy resin, acrylic resin, and polyimide resin.

[0071] The composite material is a prepreg made of carbon fiber, aramid fiber, and glass fiber impregnated with resin, with a resin content of 30-50%.

[0072] The cutting process of multi-layer reinforced fiber prepreg involves cutting the reinforced fiber prepreg into a prepreg with a set cutting size, which includes a circle with a preset radius, and four inner cutting lines within the circle.

[0073] Figure 3 schematically shows a diagram of the cutting dimensions of the reinforcing fiber prepreg. As shown in Figure 3, the cutting process of the multi-layer reinforcing fiber prepreg is to cut the reinforcing fiber prepreg into a circle with a radius of 250 mm, and at the same time cut four inner cut lines with a length of 170 mm.

[0074] Specifically, the pre-laying process involves placing the cut reinforcing fiber prepreg fabric (i.e., the cut pieces) onto a pre-laying mold, with each piece overlapping the others at the inner cut line to ensure they adhere tightly to the mold surface. Based on the mixing ratio of ultra-high molecular weight polyethylene fiber to reinforcing fiber, after all pieces have been laid, they are removed from the pre-laying mold and shaped to ensure no openings at the inner cut line seams and a tight fit between the pieces.

[0075] Pre-lay molds are designed according to mixed structures. They can be the female or male mold of the forming mold, or other objects whose forming surfaces conform to the female or male mold.

[0076] S106. Place the pre-laid reinforced fiber helmet into the molding mold and press it to obtain the reinforced fiber helmet.

[0077] Specifically, step S106 is a hot pressing process, which involves placing the pre-laid reinforced fiber helmet into a molding mold and starting the molding and pressing process. The constant pressure holding temperature for molding and pressing the pre-laid reinforced fiber helmet is 135~155℃, the constant temperature holding pressure is 30~50min, the constant temperature holding pressure is 3~7MPa, and the mold opening temperature is 30~50℃.

[0078] S107. The bulletproof main helmet and the reinforced fiber helmet are hot-pressed together using an adhesive film to obtain a fiber hybrid composite bulletproof helmet.

[0079] When hot pressing is performed as vacuum hot pressing, the temperature is 110~130℃, the holding pressure is 2~5MPa, and the holding time is 15~30min.

[0080] As an optional implementation method, when hot pressing is performed as non-vacuum hot pressing, the temperature of non-vacuum hot pressing is 110~130℃, the holding pressure is 5~15MPa, and the holding time is 15~30min.

[0081] As an optional implementation, the adhesive film is a hot melt adhesive with a film surface density of 60~120 g / m³. 2 .

[0082] Specifically, the formed bulletproof helmet and the reinforced fiber helmet are hot-pressed together, and the interlayer interface between the bulletproof helmet and the reinforced fiber helmet is bonded together using an adhesive film.

[0083] Hot pressing can be done in a vacuum or in a non-vacuum mold. Vacuum hot pressing is preferred because it can improve the uniformity of the adhesive at the interlayer interface.

[0084] The composite adhesive film used at the interlayer interface can be a vinyl-based, polyethylene-based, or other type of hot melt adhesive. Preferred adhesives are those with high affinity for materials such as polyethylene and aramid, and excellent resistance to high and low temperatures, weathering, and damp heat aging. The film surface density is 60~120 g / m³. 2 The dimensions are 500×500mm. The size of the adhesive film is flexible and can be adjusted to cover the entire composite interface of the helmet.

[0085] This invention, based on the overall structure and ballistic performance requirements of bulletproof helmets, selects different hybrid fiber materials, fiber hybrid structures, and fiber hybrid ratios for different modes of damage, in order to comprehensively leverage the performance advantages of each fiber material and achieve a hybrid positive effect and optimal ballistic performance. This includes the selection of the main bulletproof fiber and hybrid reinforcing fibers, as well as the hybrid structure and hybrid ratio of each fiber. The bulletproof fiber is UHMWPE fiber, and the reinforcing fibers are one or more combinations of carbon fiber, aramid fiber, glass fiber, and PBO fiber.

[0086] The hybrid structure of bulletproof fiber and reinforcing fiber can be designed such that the bulletproof surface is bulletproof fiber and the back surface is reinforcing fiber; or the bulletproof surface is reinforcing fiber and the back surface is bulletproof fiber; or the bulletproof surface and the back surface are one or two of the reinforcing fibers, with bulletproof fiber in the middle.

[0087] Through steps S101 to S107, a fiber hybrid composite helmet made of one or more of the following composite materials can be obtained. This fiber hybrid composite helmet has excellent ballistic protection performance and structural rigidity, and can withstand Type 51 7.62mm lead-core bullets fired from a Type 54 pistol, with a bullet hole height of less than or equal to 25mm.

[0088] This invention, based on the manufacturing process of ultra-high molecular weight polyethylene (UHMWPE) bulletproof helmets, comprehensively utilizes fiber hybridization technology, multi-structure material composite technology, and vacuum hot pressing technology to propose a method for preparing fiber hybrid composite bulletproof helmets. Using this method, composite bulletproof helmets that combine structural stiffness and ballistic protection performance can be manufactured, improving ballistic protection performance while reducing product weight.

[0089] As an optional embodiment: Step 1, select ultra-high molecular weight polyethylene fiber as the main bulletproof material and carbon fiber as the reinforcing hybrid fiber material. The hybrid structure has an ultra-high molecular weight polyethylene material on the projectile-facing side and a carbon fiber material on the projectile-receiving side, with a fiber mixing ratio of 6.5:1.

[0090] Step 2: Select an areal density of 160 g / m³ 2Ultra-high molecular weight polyethylene (UHMWPE) non-woven fabric with a resin content of 15% was used as the bulletproof material and cut into pre-cut pieces of a predetermined size. Three pieces were taken and repeatedly overlapped to pre-lay the helmet, repeating this process 15 times, for a total of 45 pieces. The pre-laid helmet was then placed in a pre-compression mold for pre-compression at 50℃, 10MPa, and 5s. Subsequently, it was transferred to a molding mold for hot pressing, with a constant pressure and holding temperature of 128℃, a holding time of 800s, and a holding pressure of 15MPa. The mold opening temperature was 40℃, and four venting processes were performed during the pressing process at an venting temperature of 80℃. After pressing, the UHMWPE bulletproof helmet shell was obtained.

[0091] Step 3: Select an areal density of 200 g / m³ 2 Three sheets of 3K carbon fiber prepreg with 30% epoxy resin content were cut into pre-cut pieces. Following a method of overlapping the pieces at the inner cut line, three sheets of carbon fiber prepreg were laid flat on the helmet male mold. After laying and shaping, high-temperature resistant polytetrafluoroethylene (PTFE) release fabric was selected as the release material, and pressing began. The pressing temperature was 140℃, with a constant temperature and pressure holding time of 30 minutes and a constant pressure of 5 MPa. The mold opening temperature was 40℃. After hot pressing, a carbon fiber reinforced helmet shell with a frosted surface was obtained.

[0092] Step 4: Use the ultra-high molecular weight polyethylene (UHMWPE) bulletproof helmet prepared in Step 2 as the frontal surface and the carbon fiber reinforced helmet prepared in Step 3 as the rearal surface. Select an interfacial adhesive with a surface density of 120 g / m² for the two helmet materials. 2 A 500×500mm vinyl film was used as the base material. The three components, arranged in a "bullet-facing surface + film + bullet-repellent surface" configuration, were placed in a molding die and hot-pressed. The process parameters were: temperature 130℃, pressure 15MPa, and time 15min. This resulted in a bulletproof helmet made of a blend of ultra-high molecular weight polyethylene fiber and carbon fiber, balancing ballistic performance and structural rigidity, with a bare helmet weight of 1040g.

[0093] Live-fire tests were conducted using 7.62mm lead-core bullets (Type 51) fired from the Type 54 pistol. The test results are shown in Table 1. It can be seen that the bullet hole height is less than or equal to 25mm, meeting the requirements of GA 293-2012, Level 2 standard.

[0094] Table 1 Test Results of Protective Performance of Fiber-Mixed Bulletproof Helmet Shells

[0095]

[0096] In this embodiment of the invention, multi-layer ultra-high molecular weight polyethylene fiber non-woven fabric is cut according to a preset cutting size. The multi-layer cut ultra-high molecular weight polyethylene fiber non-woven fabric is then layered and pre-laid in the cavity of a helmet mold to obtain a pre-laid helmet. The pre-laid helmet is placed in a pre-pressing mold for pre-pressing and shaping to obtain a pre-pressed helmet. The pre-pressed helmet is then placed in a molding mold for molding and pressing to obtain a bulletproof main helmet. Multi-layer reinforcing fiber prepreg is cut and pre-laid sequentially to obtain a pre-laid reinforcing fiber helmet. The fibers used in the multi-layer reinforcing fiber prepreg are reinforcing fibers, which are one or more combinations of carbon fiber, aramid fiber, glass fiber, and PBO fiber. The pre-laid reinforcing fiber helmet is placed in a molding mold for molding and pressing to obtain a reinforcing fiber helmet. The bulletproof main helmet and the reinforcing fiber helmet are then hot-pressed together using an adhesive film to obtain a fiber hybrid composite bulletproof helmet. When the hot-pressing is done in vacuum, the vacuum hot-pressing temperature is 110~130℃, the holding pressure is 2~5MPa, and the holding time is 15~30min. By selecting ultra-high molecular weight polyethylene fiber, carbon fiber, aramid fiber, glass fiber, and PBO fiber as hybrid fiber materials for the composite bulletproof helmet, the performance advantages of different fiber materials are comprehensively utilized, achieving a positive unity between the bulletproof performance and structural strength of the bulletproof helmet. This results in a smaller bullet hole height value for the helmet made of hybrid fiber materials, effectively improving the bulletproof performance of the fiber-hybrid composite bulletproof helmet. The step-by-step process of molding the main bulletproof helmet, the reinforcing fiber helmet, and the composite molding of the main bulletproof helmet and the reinforcing fiber helmet ensures the quality stability of the helmet molding process for different materials. The hot-pressing process for bonding the interfacial adhesive films of the main bulletproof helmet and the reinforcing fiber helmet, using vacuum hot pressing, effectively improves the interfacial bonding strength and interfacial composite uniformity, while significantly increasing production efficiency, which is beneficial for the engineering application of this invention.

[0097] Figure 4 schematically shows the structure of a composite bulletproof helmet, which includes a bulletproof main helmet and a reinforcing fiber helmet. The bulletproof main helmet uses ultra-high molecular weight polyethylene fiber, and the reinforcing fiber helmet uses one or more of carbon fiber, aramid fiber, glass fiber, and PBO fiber. The mixing ratio of ultra-high molecular weight polyethylene fiber to reinforcing fiber is 4:1 to 6.8:1.

[0098] It should be noted that the description of the above composite bulletproof helmet embodiments is similar to the description of the above fiber-hybrid composite bulletproof helmet preparation method embodiments, and has similar beneficial effects as the fiber-hybrid composite bulletproof helmet preparation method embodiments. For technical details not disclosed in the embodiments of the composite bulletproof helmet of the present invention, please refer to the description of the fiber-hybrid composite bulletproof helmet preparation method embodiments of the present invention for understanding.

[0099] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing a fiber hybrid composite bulletproof helmet, characterized in that, The preparation method includes: Cut the multi-layer ultra-high molecular weight polyethylene fiber nonwoven fabric according to the preset cutting size; Multi-layer cut ultra-high molecular weight polyethylene fiber non-woven fabric is layered and stacked together, and pre-laid in the cavity of the helmet negative mold to obtain a pre-laid helmet. The pre-laid helmet is placed into a pre-compression mold for pre-compression and shaping to obtain a pre-compression helmet; The pre-compressed helmet is placed into a molding mold for molding and pressing to obtain the bulletproof main helmet. The multi-layer reinforcing fiber prepreg is cut and pre-laid in sequence to obtain a pre-laid reinforcing fiber helmet. The fiber used in the multi-layer reinforcing fiber prepreg is a reinforcing fiber, which is one or more of carbon fiber, aramid fiber, glass fiber, and PBO fiber. The pre-laid reinforced fiber helmet is placed in a molding mold and pressed to obtain the reinforced fiber helmet; The bulletproof main helmet and the reinforced fiber helmet are hot-pressed together using an adhesive film to obtain a fiber hybrid composite bulletproof helmet. When the hot-pressing is a vacuum hot-pressing process, the temperature of the vacuum hot-pressing is 110~130℃, the holding pressure is 2~5MPa, and the holding time is 15~30min.

2. The preparation method according to claim 1, characterized in that, The fibers used in the ultra-high molecular weight polyethylene nonwoven fabric are ultra-high molecular weight polyethylene fibers, and the mixing ratio of the ultra-high molecular weight polyethylene fibers to the reinforcing fibers is 4:1 to 6.8:

1.

3. The preparation method according to claim 1, characterized in that, When the hot-pressing composite is non-vacuum hot-pressing, the temperature of the non-vacuum hot-pressing is 110~130℃, the holding pressure is 5~15MPa, and the holding time is 15~30min.

4. The preparation method according to claim 1, characterized in that, The constant pressure holding temperature for the molding and pressing of the pre-compression helmet is 128~133℃, the constant pressure holding time is 15~30min, and the constant pressure holding pressure is 15MPa.

5. The preparation method according to claim 1, characterized in that, The pre-laid reinforced fiber helmet is formed and pressed under constant pressure at a temperature of 135~155℃, a constant pressure holding time of 30~50min, and a constant pressure holding pressure of 3~7MPa.

6. The preparation method according to claim 1, characterized in that, The process of layering and stacking multiple layers of cut ultra-high molecular weight polyethylene fiber nonwoven fabric and pre-laying them into the mold cavity of a helmet negative mold to obtain a pre-laid helmet includes: Obtain the first cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with a preset number of layers; The first sharp corners of each layer of first-cut ultra-high molecular weight polyethylene fiber non-woven fabric are kept consistent, and the first-cut ultra-high molecular weight polyethylene fiber non-woven fabrics of each layer are interleaved at multiple inner shear lines and pre-laid in the mold cavity of the helmet negative mold. Obtain the second cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with the preset number of layers; Place the second sharp corner of each layer of second-cut ultra-high molecular weight polyethylene fiber nonwoven fabric into the corresponding first sharp corner position, and rotate the second sharp corner position by a preset angle. The ultra-high molecular weight polyethylene fiber nonwoven fabrics of each layer of second cut are inter-stitched at multiple inner cut lines and pre-laid in the mold cavity of the helmet negative mold; Return to the step of obtaining the second cut of ultra-high molecular weight polyethylene fiber nonwoven fabric with the preset number of layers, and stop pre-laying when the preset number of pre-laying times is reached, to obtain the pre-laid helmet.

7. The preparation method according to claim 6, characterized in that, The preset number of layers is 2 to 4, the preset number of times is 10 to 30, and the preset angle is 30±5°.

8. The preparation method according to claim 1, characterized in that, The multilayer ultra-high molecular weight polyethylene fiber nonwoven fabric is used as a bulletproof material, and the areal density of the bulletproof material is 80~160 g / m². 2 .

9. The preparation method according to claim 1, characterized in that, The adhesive film is a hot melt adhesive, and the surface density of the hot melt adhesive film is 60~120 g / m³. 2 .

10. A composite bulletproof helmet, characterized in that, The composite bulletproof helmet includes a bulletproof main helmet and a reinforcing fiber helmet. The bulletproof main helmet uses ultra-high molecular weight polyethylene fiber, and the reinforcing fiber helmet uses one or more of carbon fiber, aramid fiber, glass fiber, and PBO fiber. The mixing ratio of ultra-high molecular weight polyethylene fiber to the reinforcing fiber is 4:1 to 6.8:1.

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