Three-dimensional woven preform containing curable resin and bulletproof helmet

Abstract

The invention discloses a three-dimensional woven preform containing curable resin and a bulletproof helmet. The three-dimensional knitted prefabricated body is obtained by integrally forming and weaving by adopting a flat knitting machine for local knitting and a ring-holding needle retracting and releasing method; wherein the thermoplastic resin yarns are used as weaving yarns, the high-performance fibers are used as weft insertion yarns, and a single-side weft insertion structure is adopted; the thermoplastic resin yarns are at least one of polyester yarns, nylon yarns, polyethylene yarns, polypropylene yarns, polycarbonate yarns, polyformaldehyde yarns, polyphenylene sulfide yarns and polyether-ether-ketone yarns; the high-performance fibers are one or more of aramid fibers, PBO fibers, polyimide fibers or ultra-high molecular weight polyethylene fibers. According to the method, a mold pressing curing forming process is adopted, the process is simple, the forming time is short, the preparation efficiency is high, the curing forming pressure is large, and high-performance fibers bundled in the three-dimensional woven preform can be fully spread; the bulletproof helmet is uniform in structure and good in forming quality, and the bulletproof performance of the bulletproof helmet reaches the GA293-2012 police bulletproof helmet and mask second-level standard.

Description

Technical Field

[0001] The invention relates to a three-dimensional braided preform containing curable resin and a bulletproof helmet, belonging to the technical field of composite material protection. Background Art

[0002] The three-dimensional woven one-piece composite helmet has the characteristics of uniform structure, high material utilization rate, good impact resistance, etc. It can be used in bulletproof helmets and has broad application prospects.

[0003] Generally, the three-dimensional weaving technology of the flat knitting machine is used to prepare a three-dimensional woven helmet preform with continuous fiber distribution, one-piece weaving and uniform structure. The three-dimensional woven preform is then stacked and cured to obtain a bulletproof helmet.

[0004] Chinese patent applications (CN 111719225 B, CN 113085052 B) disclose a method for preparing a flat knitted three-dimensional shell preform and a helmet, which uses local knitting and loop-type retracting needles of a flat knitting machine to realize an integrally formed three-dimensional shell preform, and then uses a vacuum-assisted resin injection process to prepare a composite helmet from the knitted shell preform. This method is cumbersome, has a long curing time (more than 24 hours), the fiber volume content of the prepared helmet is low (about 45%), and the curing pressure is low, which is far from meeting the performance requirements of a bulletproof helmet.

[0005] Chinese patent application (CN 107475887 B) discloses a three-dimensional braided composite bulletproof helmet and its preparation method, which uses a three-dimensional four-way or three-dimensional five-way braided structure to weave a three-dimensional preform, and then uses a vacuum induction process to impregnate the preform with resin to prepare a bulletproof helmet. This method has a cumbersome preparation process, and the pressure during the preparation process is low (0.1MPa), the curing time is long (1-2h), the resin impregnation is insufficient and the distribution is uneven, which is not conducive to the bulletproof performance and large-scale production of the helmet.

[0006] Chinese patent application (CN201711414921) discloses a method for preparing a self-shaped pre-toughened fiber preform, which uses thermoplastic yarn to sew the reinforcing fibers to obtain a preform. The thermoplastic yarn can fix the reinforcing fibers and toughen the composite material. However, the suturing process is complicated and time-consuming, and may damage the reinforcing fibers. This method is also not suitable for preparing three-dimensional woven one-piece bulletproof helmets.

[0007] In summary, the three-dimensional woven one-piece composite helmet prepared by the prior art usually adopts the three-dimensional weaving technology, that is: first, a three-dimensional woven preform is prepared, and then a vacuum-assisted resin introduction curing molding technology is adopted. In a vacuum environment, the preform is impregnated with resin and cured to obtain a composite helmet. This results in a cumbersome preparation process of the helmet; the impregnated resin content is too high and difficult to control, the resin impregnation is insufficient and uneven, the curing molding pressure is small, the helmet is not compacted enough, and the high-performance fibers in the three-dimensional woven preform cannot be fully spread, which is far from meeting the performance requirements of the bulletproof helmet, and the preparation efficiency is low, and it cannot be mass-produced, and there is still a lack of effective solutions. The present invention is specially proposed. Summary of the invention

[0008] The purpose of the present invention is to provide a three-dimensional woven preform containing a curable resin and a bulletproof helmet, so as to solve the defects of the existing three-dimensional woven one-piece composite helmet, such as complicated process flow, high and difficult to control impregnation resin content, insufficient and uneven impregnation, low curing molding pressure, and insufficient compaction of the helmet, as well as the high-performance fibers in the three-dimensional woven preform cannot be fully spread, which is far from meeting the performance requirements of the bulletproof helmet, and the curing time is long and the preparation efficiency is low.

[0009] The present invention first provides a three-dimensional braided preform containing a curable resin, which is obtained by integrally forming and weaving by using a method of partial braiding of a flat knitting machine and a method of holding and releasing the loops and releasing the needles;

[0010] Among them, thermoplastic resin yarn is used as weaving yarn, high-performance fiber is used as weft yarn, and a single-sided weft structure is adopted.

[0011] The thermoplastic resin yarn is any one of polyester yarn, nylon yarn, polyethylene yarn, polypropylene yarn, polycarbonate yarn, polyoxymethylene yarn, polyphenylene sulfide yarn and polyetheretherketone yarn, or a composite yarn thereof.

[0012] Wherein, the high-performance fiber is one or more of aramid fiber, PBO fiber, polyimide fiber or ultra-high molecular weight polyethylene fiber.

[0013] The fabric surface density of the three-dimensional braided preform prepared by the present invention is 300-480 g / m 2 ;

[0014] In the three-dimensional braided preform, the mass percentage of the thermoplastic resin yarn is 15% to 35%.

[0015] Based on the three-dimensional braided preform, the present invention further provides a bulletproof helmet containing a curable resin, which is obtained by laminating and paving the three-dimensional braided preform and then forming it into one piece by molding.

[0016] The ply angle of the three-dimensional braided preform is a 0 / 90° orthogonal structure, and the side of each layer of the three-dimensional braided preform with the weft yarns is always ply-laid in one direction.

[0017] Wherein, the compression molding includes compression preforming and compression curing molding;

[0018] The conditions of the compression molding preforming are as follows:

[0019] The curing process is pre-molding at 60-100°C, the pre-molding pressure is 5-10MPa, and the time is 5-10min;

[0020] The conditions of the compression molding are as follows:

[0021] The temperature is 120-360°C, the pressure is 10-30MPa, and the time is 30-45min;

[0022] Preferably, after the compression molding and curing, the temperature is lowered to 25 to 90° C. under a pressure of 10 to 30 MPa and then demoulded.

[0023] The present invention adopts a single-sided weft-insertion structure, uses thermoplastic resin yarn as weaving yarn, and high-performance fiber as weft-insertion yarn, and three-dimensional weaving is integrated into one. During the subsequent molding of the three-dimensional woven preform of the present invention, the high temperature will melt the thermoplastic resin yarn and bond the high-performance fiber together, solving the problem that the traditional three-dimensional woven preform needs secondary processing and impregnation with resin, and the thermoplastic resin yarn is evenly distributed, and the resin content can be precisely controlled;

[0024] The front schematic diagram of the single-sided weft insertion structure used in the present invention is as follows Figure 1 As shown, the schematic diagram on the back is as follows Figure 2 As shown, the schematic diagram of the three-dimensional braided preform structure provided by the present invention is as follows Figure 3 shown.

[0025] The invention adopts a compression curing molding process to prepare a bulletproof helmet, which has a simple process, a short molding time, a high preparation efficiency, and a high curing molding pressure, so that the high-performance fibers bundled in the three-dimensional woven preform can be fully spread. The bulletproof helmet of the invention has a uniform structure, good molding quality, and the bulletproof performance reaches the GA 293-2012 police bulletproof helmet and mask level 2 standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a front schematic diagram of the single-sided weft-inserted fabric structure.

[0027] Figure 2 This is a schematic diagram of the back side of the single-sided weft-inserted fabric structure.

[0028] Figure 3Schematic diagram of the three-dimensional braided preform structure. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0030] Embodiment 1,

[0031] The MICH bulletproof helmet was 3D modeled using CATIA software and a 2D unfolded view was obtained; then the 3D woven preform was structurally designed, programmed and woven using Stoll's computerized flat knitting machine.

[0032] 100D low melting point nylon hot melt yarn (melting point is 90-100℃) is selected as the weaving yarn, 1500D aramid yarn is used as the weft yarn, and a single-sided weft structure is designed with a weaving surface density of 340g / m 2 , a three-dimensional braided preform with a nylon mass percentage of 16%.

[0033] The aramid weft-lined side of the three-dimensional woven preform is always facing upward, and 25 layers are orthogonally stacked at 0 / 90° on the male mold of the molding machine; then, the preform is molded at 85°C and a pressure of 10MPa for 10 minutes, and the preform is completed and the edges are trimmed; then, the preform is molded at 130°C and a pressure of 20MPa for 40 minutes, and the curing molding is completed; then, the pressure of 20MPa is maintained, the temperature is reduced to 85°C, and the bulletproof helmet is demolded.

[0034] According to the GA 293-2012 police bulletproof helmet and mask standard test, the back convex value is 22mm, reaching the GA Level 2 standard.

[0035] Embodiment 2,

[0036] The MICH bulletproof helmet was 3D modeled using CATIA software and a 2D unfolded view was obtained; then the 3D woven preform was structurally designed, programmed and woven using Stoll's computerized flat knitting machine.

[0037] 100D low melting point nylon hot melt yarn (melting point is 90-100℃) is selected as the weaving yarn, 1500D aramid yarn is used as the weft yarn, and a single-sided weft structure is designed. The weaving surface density is 410g / m 2 , a three-dimensional braided preform with a nylon mass percentage of 29%.

[0038] The aramid weft-lined side of the three-dimensional woven preform is always facing upward, and 21 layers are orthogonally stacked at 0 / 90° on the positive mold of the molding machine; the preform is molded for 10 minutes at 85°C and a pressure of 10 MPa, and the preform is completed and the edges are trimmed; then, the preform is molded for 40 minutes at 130°C and a pressure of 20 MPa, and the curing molding is completed; then, the pressure of 20 MPa is maintained, the temperature is reduced to 85°C, and the bulletproof helmet is demolded.

[0039] According to the GA 293-2012 police bulletproof helmet and mask standard test, the back convex value is 18mm, reaching the GA Level 2 standard.

[0040] Embodiment 3,

[0041] The MICH bulletproof helmet was 3D modeled using CATIA software and a 2D unfolded view was obtained; then the 3D woven preform was structurally designed, programmed and woven using Stoll's computerized flat knitting machine.

[0042] 100D polyethylene yarn with a molecular weight of 800,000 to 1,000,000 (melting point of 130 to 140°C) was selected as the braiding yarn, 1500D aramid yarn was used as the weft yarn, and a single-sided weft structure was designed with a weaving surface density of 385g / m 2 , a three-dimensional braided preform with a polyethylene mass percentage of 25%.

[0043] The aramid weft-lined side of the three-dimensional woven preform is always facing upward, and 22 layers are orthogonally stacked at 0 / 90° on the positive mold of the molding machine; the preform is molded for 10 minutes at 90°C and a pressure of 10MPa, and the preform is completed and the edges are trimmed; then, the preform is molded for 40 minutes at 150°C and a pressure of 20MPa, and the curing molding is completed; then, the pressure of 20MPa is maintained, the temperature is reduced to 90°C, and the bulletproof helmet is demolded.

[0044] According to the GA 293-2012 police bulletproof helmet and mask standard test, the back convex value is 19mm, reaching the GA Level 2 standard.

[0045] Comparative Example 1

[0046] The MICH bulletproof helmet was 3D modeled using CATIA software and a 2D unfolded view was obtained; then the 3D woven preform was structurally designed, programmed and woven using Stoll's computerized flat knitting machine.

[0047] Select 100D low melting point nylon hot melt yarn (melting point is 90-100℃) as the weaving yarn, 1500D aramid yarn as the weft yarn, design a single-sided weft structure, and the weaving surface density is 500g / m 2 , a three-dimensional braided preform with a nylon mass percentage of 12.5%.

[0048] The aramid weft-lined side of the three-dimensional woven preform is always facing upward, and 17 layers are orthogonally stacked at 0 / 90° on the male mold of the molding machine; the preform is molded for 10 minutes at 85°C and a pressure of 10 MPa, and the preform is completed and the edges are trimmed; then, the preform is molded for 40 minutes at 130°C and a pressure of 20 MPa, and the curing molding is completed; then, the pressure of 20 MPa is maintained, the temperature is reduced to 85°C, and the bulletproof helmet is demolded.

[0049] According to the GA 293-2012 standard test for police bulletproof helmets and masks, the bulletproof helmet was penetrated and did not meet the bulletproof standard.

[0050] Comparative Example 2

[0051] The MICH bulletproof helmet was 3D modeled using CATIA software and a 2D unfolded view was obtained; then the 3D woven preform was structurally designed, programmed and woven using Stoll's computerized flat knitting machine.

[0052] 100D low melting point nylon hot melt yarn (melting point is 90-100℃) is selected as the weaving yarn, 1500D aramid yarn is used as the weft yarn, and a single-sided weft structure is designed. The weaving surface density is 445g / m 2 , a three-dimensional braided preform with a nylon mass percentage of 38%.

[0053] The aramid weft-lined side of the three-dimensional woven preform is always facing upward, and 19 layers are orthogonally stacked at 0 / 90° on the positive mold of the molding machine; the preform is molded for 10 minutes at 85°C and a pressure of 10 MPa, and the preform is completed and the edges are trimmed; then, the preform is molded for 40 minutes at 130°C and a pressure of 20 MPa, and the curing molding is completed; then, the pressure of 20 MPa is maintained, the temperature is reduced to 85°C, and the bulletproof helmet is demolded.

[0054] According to the GA 293-2012 standard test for police bulletproof helmets and masks, the bulletproof helmet was penetrated and did not meet the bulletproof standard.

Claims

1. A three-dimensional braided preform containing a curable resin, which is obtained by integrally forming and weaving by using a knitting machine for partial weaving and a method of holding and releasing the needles; in, Thermoplastic resin yarn is used as weaving yarn, high-performance fiber is used as weft inlay yarn, and a single-sided weft inlay structure is adopted.

2. The three-dimensional braided preform according to claim 1, characterized in that: The thermoplastic resin yarn is any one of polyester yarn, nylon yarn, polyethylene yarn, polypropylene yarn, polycarbonate yarn, polyoxymethylene yarn, polyphenylene sulfide yarn and polyetheretherketone yarn, or a composite yarn thereof.

3. The three-dimensional braided preform according to claim 1 or 2, characterized in that: The high-performance fiber is one or more of aramid fiber, PBO fiber, polyimide fiber or ultra-high molecular weight polyethylene fiber.

4. The three-dimensional braided preform according to any one of claims 1 to 3, characterized in that: The fabric surface density of the three-dimensional braided preform is 300-480 g / m 2 ; In the three-dimensional braided preform, the mass percentage of the thermoplastic resin yarn is 15% to 35%.

5. A bulletproof helmet containing a curable resin, which is obtained by laminating and paving the three-dimensional braided preforms according to any one of claims 1 to 4 and then forming them into one piece by compression molding.

6. The bulletproof helmet according to claim 5, characterized in that: The plying angle of the three-dimensional braided preform is a 0 / 90° orthogonal structure, and the side of each layer of the three-dimensional braided preform with the weft yarns inserted therein is always ply-laid in one direction.

7. The bulletproof helmet according to claim 5 or 6, characterized in that: The compression molding includes compression preforming and compression curing molding.

8. The bulletproof helmet according to claim 7, characterized in that: The conditions of the compression molding preforming are as follows: The curing process is pre-molding at 60-100° C., the pre-molding pressure is 5-10 MPa, and the time is 5-10 minutes.

9. The bulletproof helmet according to claim 7, characterized in that: The conditions of the compression molding are as follows: The temperature is 120-360°C, the pressure is 10-30MPa, and the time is 30-45min.

10. The bulletproof helmet according to claim 7, characterized in that: After the molding is cured and formed, the temperature is lowered to 25 to 90° C. under a pressure of 10 to 30 MPa and then demoulded.

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