High-impact-resistance composite bulletproof mask and preparation method thereof

Abstract

The invention discloses a high-impact-resistance composite bulletproof mask and a preparation method thereof, and relates to the technical field of bulletproof masks. The bulletproof mask comprises an outer layer, a middle layer and an inner layer, the outer layer is made of borosilicate glass, the middle layer is made of polymethyl methacrylate, the inner layer is made of polycarbonate, and after the multiple layers are bonded and compounded through acrylate bonding materials, the two ends of an inner layer polycarbonate plate are longer than the middle layer and outer layer materials. And the epitaxial part of the substrate is bonded with the borosilicate glass plate and the side plate of the polymethyl methacrylate plate at the same time to form a coated structure. The bulletproof mask can effectively fix the outer layer and the middle layer, when the bulletproof mask is impacted by bullets, the coating layer can provide reverse tensile stress, the layering phenomenon is reduced, the range of a center impact point fragmentation area is reduced, no fragments fly out, the problems of impact interface layering and fragment splashing are effectively solved, and the integrity and stability of the structure are improved.

Description

Technical Field

[0001] This invention relates to the field of bulletproof face shield technology, specifically to a high-impact-resistant composite bulletproof face shield and its preparation method. Background Technology

[0002] Statistics show that in typical conflicts of the 20th century, 75% to 80% of fatal injuries were caused by shrapnel from landmines, grenades, and other explosive devices, with 45% of these injuries occurring in the head. Protective face shields can prevent the penetration of projectiles and shrapnel, as well as the transmission of shockwave pressure to the brain, effectively protecting the head, eyes, and face without impairing the soldier's vision or tactical activities. Existing bulletproof face shields mostly employ a structure of organic or inorganic material layers with a polycarbonate backing plate. However, this approach results in problems such as fragmentation, easy delamination upon impact, and structural instability.

[0003] Chinese invention patent CN114383469A discloses a face shield for a bulletproof helmet, consisting of a face shield panel and a fragmentation protection lip. The face shield is made of multiple layers of materials bonded together, and the fragmentation protection lip is made of flame-retardant material and polyurethane, partially enclosing the edge of the face shield panel. However, the fragmentation protection lip does not effectively establish a connection mechanism with the various material layers. When impacted by a bullet, it can only prevent fragments from flying into the face, but cannot achieve interlayer stress wave transmission, and cannot effectively improve the overall structural strength of the face shield. Chinese invention patent CN102997755A discloses a bulletproof face shield that uses a high-temperature, high-pressure process to laminate a polycarbonate sheet as the inner and outer layers with an acrylic intermediate layer. The outer layer thickness is 0.5–2.5 mm, the intermediate layer thickness is 3–10 mm, and the inner layer thickness is 9–15 mm. It can maintain structural integrity after being hit by a bullet and can withstand secondary impacts. However, the outer layer of the mask is relatively thin. When it is hit by a bullet, the outer layer cannot effectively resist erosion. The bullet still carries a lot of energy after penetrating the outer layer. The normal tensile stress at the interface can easily exceed the normal bonding strength of the interface. The interface between the outer layer and the middle layer will be damaged by delamination, affecting the structural integrity. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides a high-impact-resistant composite bulletproof face shield and its preparation method. The invention involves hot-bending the edges of the inner panel and bonding it to the outer and middle layer side panels. When the bulletproof face shield is subjected to projectile impact, the impact generates normal tensile stress on the interface. The covering layer provides reverse tensile stress support to the interface, suppressing the tensile tendency between layers. Simultaneously, the covering layer provides radial constraint to the middle layer, reducing lateral deformation and suppressing interlayer slippage, thereby improving the overall structural strength. Furthermore, by adding nano-TiO2 powder to the acrylate, directional control of the adhesive is achieved, reducing optical distortion in the bulletproof face shield.

[0005] To achieve the above objectives, this invention provides a high-impact composite bulletproof face shield. The face shield comprises an outer layer, a middle layer, and an inner layer stacked sequentially from the outside in. The outer layer is a borosilicate glass plate, the middle layer is a polymethyl methacrylate (PMMA) plate, and the inner layer is a polycarbonate plate. The borosilicate glass plate and the PMMA plate are of the same size, while the polycarbonate plate is larger than both. After lamination, the outer extension of the polycarbonate plate is simultaneously bonded to the side plates of both the borosilicate glass plate and the PMMA plate, forming an encapsulated structure. The borosilicate glass plate and the PMMA plate, the PMMA plate and the polycarbonate plate, and the sides of the borosilicate glass plate and the PMMA plate are bonded to the polycarbonate plate using an acrylic adhesive. This acrylic adhesive can adapt to the refractive index changes between the layers, thereby reducing optical distortion.

[0006] Furthermore, the acrylate adhesive material is prepared through the following steps:

[0007] S1 Preparation of slurry: Nano-TiO2 powder is added to the dispersant polyethylene oxide (PEO), then added to a propylene glycol methyl ether acetate (PMA) solution and mixed thoroughly. The mixture is then ball-milled to obtain a TiO2 slurry.

[0008] S2 Binder Preparation: Add acrylate and propylene glycol methyl ether acetate to the reactor, and then slowly add the TiO2 slurry from S1 to the reactor. At this time, the TiO2 concentration in the system is 2-7.5 wt%.

[0009] S3 Degassing and Filtration: The S2 solution is degassed under vacuum and filtered through a 0.5μm filter cartridge to obtain the acrylate binder material.

[0010] Preferably, in step S1, the ball milling speed is 8000-10000 r / min, and the ball milling time is 20-25 min.

[0011] Preferably, in step S2, when mixing and stirring the acrylate and propylene glycol methyl ether acetate, the reactor speed is 500-550 r / min and the stirring time is 10-15 min; when adding the mixed solution from S1, the addition rate is less than or equal to 50 g / min, and stirring is maintained simultaneously.

[0012] Preferably, the borosilicate glass plate has a thickness of 6-8 mm, the polymethyl methacrylate plate has a thickness of 3-4 mm, the polycarbonate plate has a thickness of 1.5-2 mm, and the acrylate adhesive material has a thickness of 0.8-1.2 mm.

[0013] On the other hand, the present invention also provides a method for preparing the above-mentioned bulletproof face shield, comprising the following steps:

[0014] Step 1: Process the borosilicate glass plate, polymethyl methacrylate plate and polycarbonate plate according to the predetermined size, and use a mold to hot bend them to maintain a consistent curvature;

[0015] Step 2: Using a mold, heat-bend both sides of the polycarbonate sheet processed in Step 1 outward along the radius of curvature;

[0016] Step 3: Use an autoclave to laminate the plates processed in Step 1 and Step 2, laminating them in the order of borosilicate glass plate, polymethyl methacrylate plate and polycarbonate plate from top to bottom, and use acrylic adhesive to bond the layers together.

[0017] Preferably, in step 1, the hot bending temperature of the borosilicate glass plate is 700-850℃ and the holding time is 1-3h; the hot bending temperature of the polymethyl methacrylate plate is 120-160℃ and the holding time is 4-5h; and the hot bending temperature of the polycarbonate plate is 130-140℃ and the holding time is 2-3h.

[0018] Preferably, in step 2, the polycarbonate sheet is heat-bent outward along the radius of curvature at 14.0 to 14.5 mm from both ends.

[0019] Preferably, in step 3, the high-pressure reactor is maintained at a composite pressure of 0.5–0.8 MPa, the composite temperature is 125–130°C, and the pressure holding time is 0.5–1 h.

[0020] Compared with the prior art, the advantages of the high impact resistance composite bulletproof mask and its preparation method disclosed in this invention are:

[0021] 1. The bulletproof face shield prepared by this invention adopts a middle layer covering design, which can effectively fix the outer layer and the middle layer. The covering edge can form a barrier, providing radial constraint to the outer layer and the middle layer. When impacted by a bullet, the covering layer can provide reverse tensile stress, reducing the occurrence of delamination. Moreover, the fragmentation area at the center impact point is reduced, and no fragments fly out, effectively solving the problems of delamination at the impact interface and fragmentation, and improving the integrity and stability of the structure.

[0022] 2. The bulletproof mask prepared by this invention uses acrylate as the composite adhesive. By introducing nano-TiO2 powder into the acrylate, the refractive index of the acrylate adhesive can be effectively changed to match the refractive index of each layer material, thereby reducing optical distortion. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a high-impact composite bulletproof face shield according to some embodiments of the present invention.

[0024] Figure 2 This is a cross-sectional view of a high-impact composite bulletproof mask according to some embodiments of the present invention.

[0025] Figure 3 The image shows the spectral transmittance curve of the acrylate adhesive material prepared in Example 1.

[0026] Figure 4 This is a diagram showing the refractive index matching between the acrylic adhesive material and the refractive index of each layer of the bulletproof mask.

[0027] Figure 5 The images show the impact velocity-time diagrams of the high-impact-resistant composite bulletproof face shields and uncovered face shields prepared in Examples 1-2 and the comparative examples, respectively, under bullet impact.

[0028] In the figure, 1-borosilicate glass plate, 2-polymethyl methacrylate plate, 3-polycarbonate plate, 4-acrylate adhesive material. Detailed Implementation

[0029] The present invention will be further described below with reference to the accompanying drawings and related embodiments. The embodiments shown are only some, not all, of the embodiments.

[0030] like Figure 1 , 2 As shown, the bulletproof mask comprises an outer layer, a middle layer, and an inner layer stacked sequentially from the outside in. The outer layer is made of borosilicate glass, the middle layer is made of polymethyl methacrylate (PMMA), and the inner layer is made of polycarbonate (PC). The borosilicate glass plate 1 and the polymethyl methacrylate plate 2 are the same size, while the polycarbonate plate 3 is larger than both the borosilicate glass plate 1 and the polymethyl methacrylate plate 2. After lamination, the outer extension of the polycarbonate plate 3 is simultaneously bonded to the side plates of the borosilicate glass plate 1 and the polymethyl methacrylate plate 2, forming an encapsulated structure. The borosilicate glass plate 1 and the polymethyl methacrylate plate 2, the polymethyl methacrylate plate 2 and the polycarbonate plate 3, the side of the borosilicate glass plate 1 and the polycarbonate plate 3, and the side of the polymethyl methacrylate plate 2 and the polycarbonate plate 3 are all bonded with acrylate adhesive 4. The acrylate adhesive 4 can adapt to the refractive index changes between the layers, which can reduce the generation of optical distortion, and the acrylate adhesive 4 has extremely high transparency.

[0031] Example 1

[0032] The method for preparing the above-mentioned high-impact-resistant composite bulletproof face shield includes the following steps:

[0033] Step 1: Process the 6mm borosilicate glass plate 1, the 4mm polymethyl methacrylate plate 2, and the 2mm polycarbonate plate 3 according to the predetermined dimensions, and perform hot bending using a uniform mold to maintain consistent curvature. The hot bending temperature of the borosilicate glass plate 1 is 700℃, and the heat is maintained for 1 hour. The hot bending temperature of the polymethyl methacrylate plate 2 is 120℃, and the heat is maintained for 4 hours. The hot bending temperature of the polycarbonate plate 3 is 130℃, and the heat is maintained for 2 hours.

[0034] Step 2: Using a mold, heat-bend the polycarbonate sheet 3 treated in Step 1 at 14.4mm on both sides outward along the radius of curvature. The heat-bending temperature is 130℃, and the temperature is maintained for 2 hours.

[0035] Step 3: Use an autoclave to laminate the plates processed in Step 1 and Step 2, laminating them in the order of borosilicate glass plate 1, polymethyl methacrylate plate 2, and polycarbonate plate 3 from top to bottom, with 1.2mm acrylic adhesive 4 used for bonding between layers; the lamination pressure is 0.5 MPa, the lamination temperature is 125℃, and the pressure holding time is 0.5 h.

[0036] The acrylate adhesive material is prepared by the following steps:

[0037] S1 slurry preparation: 2g of nano TiO2 powder was added to 8g of dispersant polyethylene oxide, and then added to 17g of propylene glycol methyl ether acetate (PMA) solution and mixed thoroughly. The mixture was then ball-milled at a speed of 8000r / min for 25min to obtain TiO2 slurry.

[0038] S2 Binder Preparation: Add 62g of acrylate and 6g of propylene glycol methyl ether acetate to the reactor and mix and stir. The reactor speed is 500r / min and the stirring time is 11min. Then, add the TiO2 slurry from S1 to the reactor at an addition rate of 40g / min. At this time, the TiO2 concentration in the system is 2.10wt%.

[0039] S3 Degassing and Filtration: The S2 solution is transferred to a vacuum reactor for degassing under reduced pressure, and then filtered through a 0.5μm filter to obtain the acrylate binder.

[0040] The bulletproof face shield prepared in this embodiment was tested and found to have a transmittance of 89% with no significant optical distortion. The face shield was tested using a 1951-type 7.62mm round-nosed lead-core pistol bullet at a speed of 452 m / s. After testing, the face shield showed no delamination, a small glass shattering zone near the impact point, fragments were captured by polymethyl methacrylate (PMMA), and there was no large crack propagation; the overall integrity was good.

[0041] Example 2

[0042] The method for preparing a high-impact-resistant composite bulletproof face shield includes the following steps:

[0043] Step 1: Process the 8mm borosilicate glass plate 1, the 3mm polymethyl methacrylate plate 2, and the 1.5mm polycarbonate plate 3 according to the predetermined dimensions, and perform hot bending using a uniform mold to maintain consistent curvature. The hot bending temperature of the borosilicate glass plate 1 is 850℃, and the holding time is 3h; the hot bending temperature of the polymethyl methacrylate plate 2 is 160℃, and the holding time is 5h; the hot bending temperature of the polycarbonate plate 3 is 140℃, and the holding time is 3h.

[0044] Step 2: Using a mold, heat bend the polycarbonate sheet 3 processed in Step 1 outwards along the radius of curvature at 14.1mm on both sides;

[0045] Step 3: Use an autoclave to laminate the plates processed in Step 1 and Step 2, laminating them in the order of borosilicate glass plate 1, polymethyl methacrylate plate 2, and polycarbonate plate 3 from top to bottom, with 0.8mm acrylic adhesive 4 used for bonding between layers; the lamination pressure is 0.8 MPa, the lamination temperature is 130℃, and the pressure holding time is 1 hour.

[0046] The acrylate adhesive material is prepared by the following steps:

[0047] S1 slurry preparation: 7g of nano TiO2 powder was added to 4g of dispersant polyethylene oxide, and then added to 18g of propylene glycol methyl ether acetate (PMA) solution and mixed thoroughly. The mixture was then ball-milled at a speed of 10000r / min for 20min to obtain TiO2 slurry.

[0048] S2 Binder Preparation: Add 60g of acrylate and 7g of propylene glycol methyl ether acetate to the reactor and mix and stir. The reactor speed is 550r / min and the stirring time is 10min. Then, add the TiO2 slurry from S1 to the reactor at an addition rate of 50g / min. At this time, the TiO2 concentration in the system is 7.29wt%.

[0049] S3 Degassing and Filtration: The S2 solution is transferred to a vacuum reactor for degassing under reduced pressure, and then filtered through a 0.5μm filter to obtain the acrylate binder.

[0050] The bulletproof face shield prepared in this embodiment was tested and found to have a transmittance of 87% with no significant optical distortion. The face shield was tested using a 1951-type 7.62mm round-nosed lead-core pistol bullet at a velocity of 449 g / s. After testing, the face shield showed no delamination, a small glass shattering zone near the impact point, fragments were captured by polymethyl methacrylate (PMMA), and there was no large crack propagation; the overall integrity was good.

[0051] Example 3

[0052] The method for preparing a high-impact-resistant composite bulletproof face shield includes the following steps:

[0053] Step 1: Process the 7mm borosilicate glass plate 1, the 3.5mm polymethyl methacrylate plate 2, and the 2mm polycarbonate plate 3 according to the predetermined dimensions. Use a uniform mold for hot bending to maintain consistent curvature. The hot bending temperature of the borosilicate glass plate 1 is 850℃ and the holding time is 3h. The hot bending temperature of the polymethyl methacrylate plate 2 is 160℃ and the holding time is 5h. The hot bending temperature of the polycarbonate plate 3 is 140℃ and the holding time is 3h.

[0054] Step 2: Using a mold, heat bend the polycarbonate sheet 3 processed in Step 1 outwards along the radius of curvature at 14.5mm on both sides;

[0055] Step 3: Use an autoclave to laminate the plates processed in Step 1 and Step 2, laminating them in the order of borosilicate glass plate 1, polymethyl methacrylate plate 2, and polycarbonate plate 3 from top to bottom, with 1mm acrylic adhesive 4 used for bonding between layers; the lamination pressure is 0.6 MPa, the lamination temperature is 128℃, and the pressure holding time is 1 hour.

[0056] The acrylate adhesive material is prepared by the following steps:

[0057] S1 slurry preparation: 4g of nano TiO2 powder was added to 6g of dispersant polyethylene oxide, and then added to 20g of propylene glycol methyl ether acetate (PMA) solution and mixed thoroughly. The mixture was then ball-milled at a speed of 10000r / min for 20min to obtain TiO2 slurry.

[0058] S2 Binder Preparation: Add 61g of acrylate and 6g of propylene glycol methyl ether acetate to the reactor and mix and stir. The reactor speed is 500r / min and the stirring time is 11min. Then, add the TiO2 slurry from S1 to the reactor at an addition rate of 45g / min. At this time, the TiO2 concentration in the system is 4.12wt%.

[0059] S3 Degassing and Filtration: The S2 solution is transferred to a vacuum reactor for degassing under reduced pressure, and then filtered through a 0.5μm filter to obtain the acrylate binder.

[0060] The bulletproof face shield prepared in this embodiment was tested and found to have a transmittance of 87% with no significant optical distortion. The face shield was tested using a 7.62mm round-nosed lead-core pistol cartridge (Type 1951) at a speed of 454 m / s. After testing, the face shield showed no delamination, a small glass shattering zone near the impact point, fragments were captured by polymethyl methacrylate (PMMA), and there was no large crack propagation; the overall integrity was good.

[0061] Figure 3 The spectral transmittance curve of the acrylate adhesive material prepared in Example 1 shows high transmittance in the visible light range of 400 nm to 780 nm, which can improve the visibility of the mask. Simultaneously, it has low transmittance in the ultraviolet region below 400 nm, providing UV protection. The spectral transmittance curves of the acrylate adhesive materials prepared in Examples 2-3 are similar to those in Example 1.

[0062] Figure 4 This diagram shows the refractive index matching between the acrylate binder and the refractive indices of each layer of the bulletproof mask. As the amount of TiO2 added increases, the refractive index of the acrylate binder gradually rises. By adjusting the amount of TiO2 added to match the refractive indices of adjacent interface materials, optimal optical performance can be achieved.

[0063] Comparative Example

[0064] Step 1: Process 7mm borosilicate glass, 3.5mm polymethyl methacrylate, and 1.8mm polycarbonate sheets according to predetermined dimensions, and perform hot bending using a uniform mold to maintain consistent curvature. The hot bending temperature of the borosilicate glass sheet is 800℃, and the holding time is 2 hours; the hot bending temperature of the polymethyl methacrylate sheet is 140℃, and the holding time is 4.5 hours; the hot bending temperature of the polycarbonate sheet is 135℃, and the holding time is 0.7 hours.

[0065] Step 2: Use an autoclave to laminate the plates processed in Step 1, laminating them in the order of borosilicate glass plate, polymethyl methacrylate plate, and polycarbonate plate from top to bottom, with 1.0mm acrylic adhesive used between the layers; the lamination pressure is 0.6 MPa, the lamination temperature is 128℃, and the pressure holding time is 0.8h.

[0066] The acrylate adhesive material is prepared by the following steps:

[0067] S1 slurry preparation: 5g of nano TiO2 powder was added to 7g of dispersant polyethylene oxide, and then added to 14g of propylene glycol methyl ether acetate (PMA) solution and mixed thoroughly. The mixture was then ball-milled at a speed of 9000r / min for 23min to obtain TiO2 slurry.

[0068] S2 Binder Preparation: Add 62g of acrylate and 7g of propylene glycol methyl ether acetate to the reactor and mix and stir. The reactor speed is 550r / min and the stirring time is 10min. Then add the slurry in S1 to the reactor at an addition rate of 45g / min. The TiO2 concentration in the solution is 5.26wt%.

[0069] S3 Degassing and Filtration: The S2 solution is transferred to a vacuum reactor for degassing under reduced pressure, and then filtered through a 0.5μm filter to obtain the acrylate binder.

[0070] The bulletproof face shield prepared in this embodiment was tested and found to have a transmittance of 89% with no significant optical distortion. The face shield was tested using a 1951-type 7.62mm round-nosed lead-core pistol bullet at a speed of 450 m / s. After testing, the face shield showed obvious delamination between the outer and middle layers, with a large fractured area in the outer layer, long propagating cracks, and a loss of overall integrity. Furthermore, the effective stopping time against projectiles was prolonged.

[0071] Figure 5 The images show the impact velocity-time diagrams of the high-impact-resistant composite bulletproof face shields and the uncovered face shield prepared in Examples 1-2 and the comparative example, respectively, under bullet impact. A bullet radar velocimeter was used at room temperature (28°C) and humidity (75%) to analyze the velocity decay of a 7.62mm pistol bullet. In the examples, the covered structure effectively extends the deformation time of the core material and prevents premature collapse, allowing the intermediate layer to fully dissipate energy and thus increasing the upper limit of energy absorption, effectively blocking higher-velocity projectiles. In contrast, the comparative example, lacking interlayer constraint, is prone to localized fracture and delamination under bullet impact, failing to form a sustained secondary barrier and posing a risk of localized penetration.

[0072] The above description is merely a specific embodiment of the present invention, but the specific protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the protection scope of the present invention.

Claims

1. A high-impact composite bulletproof face shield, comprising an outer layer, a middle layer, and an inner layer stacked sequentially from the outside in, characterized in that, The outer layer is a borosilicate glass plate (1), the middle layer is a polymethyl methacrylate plate (2), and the inner layer is a polycarbonate plate (3). The borosilicate glass plate (1) and the polymethyl methacrylate plate (2) are the same size, and the polycarbonate plate (3) is larger than the borosilicate glass plate (1) and the polymethyl methacrylate plate (2). After the composite, the outer extension of the polycarbonate plate (3) is simultaneously bonded to the side plates of the borosilicate glass plate (1) and the polymethyl methacrylate plate (2) to form an encapsulated structure. The borosilicate glass plate (1) and the polymethyl methacrylate plate (2), the polymethyl methacrylate plate (2) and the polycarbonate plate (3), the side of the borosilicate glass plate (1) and the side of the polymethyl methacrylate plate (2) and the polycarbonate plate (3) are all bonded with acrylate adhesive material (4). The acrylate adhesive material (4) can adapt to the refractive index changes between the layers, thereby reducing the generation of optical distortion.

2. The high impact-resistant composite bulletproof face shield according to claim 1, characterized in that, The acrylate adhesive material (4) is prepared by the following steps: S1: Add nano-TiO2 powder to the dispersant polyethylene oxide, then add it to the propylene glycol methyl ether acetate solution and mix thoroughly. Ball mill to obtain TiO2 slurry. S2: Add acrylate and propylene glycol methyl ether acetate to the reactor, and then slowly add the TiO2 slurry from S1 to the reactor. At this time, the TiO2 concentration in the system is 2-7.5 wt%. S3: The S2 solution is degassed under vacuum and filtered through a 0.5μm filter to obtain the acrylate adhesive.

3. The high impact-resistant composite bulletproof face shield according to claim 2, characterized in that, In step S1, the ball milling speed is 8000-10000 r / min, and the ball milling time is 20-25 min.

4. The high impact-resistant composite bulletproof face shield according to claim 2, characterized in that, In step S2, when mixing and stirring the acrylate and propylene glycol methyl ether acetate, the reactor speed is 500-550 r / min and the stirring time is 10-15 min; when adding the slurry in S1, the addition rate is less than or equal to 50 g / min, and stirring is maintained.

5. A high-impact composite bulletproof face shield according to claim 1, characterized in that, The borosilicate glass plate (1) has a thickness of 6-8 mm, the polymethyl methacrylate plate (2) has a thickness of 3-4 mm, the polycarbonate plate (3) has a thickness of 1.5-2 mm, and the acrylate adhesive material (4) has a thickness of 0.8-1.2 mm.

6. A method for preparing a high-impact composite bulletproof face shield according to any one of claims 1 to 5, characterized in that, The preparation process includes the following steps: Step 1: Process the borosilicate glass plate (1), polymethyl methacrylate plate (2) and polycarbonate plate (3) according to the predetermined size, and use a mold to hot bend them to maintain a consistent curvature; Step 2: Using a mold, heat-bend both sides of the polycarbonate sheet (3) processed in Step 1 outward along the radius of curvature; Step 3: Composite the plates processed in Step 1 and Step 2 in the order of borosilicate glass plate (1), polymethyl methacrylate plate (2) and polycarbonate plate (3) from top to bottom, and bond the layers with acrylic adhesive material (4).

7. The method for preparing a high-impact composite bulletproof face shield according to claim 6, characterized in that, In step 1, the hot bending temperature of the borosilicate glass plate (1) is 700-850℃ and the heat preservation time is 1-3h; the hot bending temperature of the polymethyl methacrylate plate (2) is 120-160℃ and the heat preservation time is 4-5h; and the hot bending temperature of the polycarbonate plate (3) is 130-140℃ and the heat preservation time is 2-3h.

8. The method for preparing a high-impact composite bulletproof face shield according to claim 6, characterized in that, In step 2, the polycarbonate sheet (3) is heat-bent outward along the radius of curvature at 14.0 to 14.5 mm from both ends.

9. The method for preparing a high-impact composite bulletproof face shield according to claim 6, characterized in that, In step 3, the high-pressure reactor is maintained at a pressure of 0.5–0.8 MPa, the composite temperature is 125–130°C, and the pressure holding time is 0.5–1 h.

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