Preparation method of high-performance anti-sinking buffer material and material

Abstract

The invention discloses a preparation method and material of a high-performance anti-sinking buffer material, and the method comprises the following steps: S1, mixing epoxy resin, a curing agent and a solvent according to a specific mass ratio to obtain an epoxy resin system; s2, impregnating aramid fibers in an epoxy resin system, and completing the impregnation process through a roller compound machine to obtain a prepreg; and S3, cutting the prepreg, performing lamination according to different angles, then performing hot press molding treatment on the laminated prepreg, and performing cooling to obtain the high-performance anti-sinking buffer material in a sheet form. According to the invention, innovative material and process design are adopted, and through reasonable fiber arrangement, impregnation formula and strict hot-pressing parameter control, the overall performance of the material is effectively improved, the anti-sinking capability is greatly improved, and the sinking value is obviously reduced, so that a more reliable safety guarantee is provided for a user; and meanwhile, a certain thickness is kept to improve the comfort of a wearer.

Description

Technical Field

[0001] The present invention relates to the field of material technology, and in particular to a preparation method and material of a high-performance anti-sag buffer material. Background Art

[0002] In today's society, especially in areas involving personal safety protection, such as bulletproof vest manufacturing, the demand for high-performance anti-dent buffer materials is showing an increasing trend. At present, the common bulletproof vest chips usually use a combination of 0.5mm PC board and 5mm EVA, the purpose of which is to achieve the dual goals of anti-dent and increased wearing comfort. However, in actual applications, when conducting gunshot tests based on the 3A.44 standard in the relevant NIJ 0101.06 standard, many problems were exposed. Although this combination can play an anti-dent role to a certain extent, the test results show that its dent value is between 32-40mm, which means that when subjected to the impact of a gunshot, a large dent will still occur, which will cause a large blunt injury, posing a certain threat to the safety of the user.

[0003] With the continuous development of science and technology and the continuous improvement of safety requirements, the existing combination of cushioning materials is obviously difficult to fully meet actual needs. On the one hand, higher anti-sag performance is the key to ensuring the safety of users. Smaller sag values ​​mean more effective resistance to impact and reduced injuries. On the other hand, while ensuring anti-sag performance, other properties of the material need to be taken into account, such as lightness and flexibility, to ensure that the wearer's activities are not restricted and have good comfort.

[0004] Through searching patent documents, it was found that CN202010724433 discloses a method for preparing an aramid fiber composite core by heat stretching and shaping aramid fibers. The method first uses secondary pipeline heating and five-roller traction equipment to perform heat stretching and shaping modification on the aramid fibers. After the heat stretching and shaping treatment is completed, the fibers are immersed in a dipping tank for dipping, and then cured by a curing mold. Finally, the fibers are pulled out and demolded by a traction device to obtain an aramid fiber composite core. However, the invention has some shortcomings: the use of impregnated resin makes the resin content uncontrollable, which affects the stability of the material properties; the unidirectional fiber arrangement leads to poor impact resistance and is difficult to cope with multi-directional impacts; and at the same time, it has not undergone multi-layer lamination and hot pressing molding and does not have bulletproof capabilities.

[0005] CN202110301267 discloses a long-storage-period, low-temperature-curing epoxy resin-based prepreg and a preparation method thereof, wherein the resin system is composed of a latent low-temperature curing agent, LycureM-10, and a mixture of solid epoxy resin and liquid epoxy resin. During preparation, a coating machine is used to prepare a resin film at 40°C, and then the resin film and reinforcing fiber are compounded at 40-45°C on a prepreg machine, and then cooled, trimmed, coated, and rolled to obtain a low-temperature-curing prepreg. This invention also has shortcomings: as a bearing material, the epoxy film has poor tensile properties and ductility, and is easily unable to spread during the fiber drawing process, affecting the uniformity of the material structure; and it is relatively brittle, and may cause the material to break after shooting, causing secondary damage.

[0006] In summary, in view of the many problems existing in the prior art, it is urgent to study a preparation method and material for a high-performance anti-sag buffer material. Summary of the invention

[0007] In view of the defects in the prior art, the present invention aims to study a preparation method and material of a high-performance anti-sag buffer material.

[0008] To achieve the above object, the present invention discloses a method for preparing a high-performance anti-sag buffer material, comprising the following steps:

[0009] Step S1, mixing epoxy resin, curing agent and solvent according to a specific mass ratio to obtain an epoxy resin system;

[0010] Step S2, impregnating the aramid fiber in an epoxy resin system, completing the impregnation process through a roller laminating machine to obtain a prepreg;

[0011] Step S3, cutting the prepreg, laminating them at different angles, and then hot pressing and cooling the laminated prepreg to obtain a high-performance anti-sag buffer material in the form of a sheet.

[0012] Preferably, in step S1, the mass ratio of epoxy resin, curing agent and solvent is (98-100):(1-1.2):(10-15).

[0013] Preferably, the impregnation process of step S2 includes: placing the aramid fiber roll on the reel of the drum laminating machine and stretching and arranging it, attaching the PE film to the drum of the drum laminating machine and flattening it, fixing one end of the arranged aramid fiber on the drum with the PE film laid on it, adding the epoxy resin system to the glue tank of the drum laminating machine, rotating the drum with the PE film laid on it, so that the fixed aramid fiber is infiltrated and stacked in the epoxy resin system, so that the aramid fiber is stacked in one direction, and after stacking is completed, it is cut along the center axis to obtain a prepreg.

[0014] Preferably, in step S2, the aramid fibers are stretched and arranged by roller winding.

[0015] Preferably, in step S2, the rotation speed of the drum is set to 28-30 r / min, the horizontal axis speed is set to 13-14 r / min, the drum is started, and the horizontal speed is turned on after winding 1-3 turns.

[0016] Preferably, in step S3, the size of the cut prepreg is (1.6±0.02)m×(1.6±0.02)m.

[0017] Preferably, step S3 comprises: laminating the cut prepreg in four directions according to 0° / 45° / 90° / 135° to obtain laminated prepreg.

[0018] Preferably, the hot pressing molding process in step S3 includes: placing the laminated prepreg into a flat vulcanizer, setting the pressing temperature to 130-135°C, setting the pressure to 15-23Mpa, pressing for 10-30 minutes, and cooling to 35°C-40°C after hot pressing to obtain a high-performance anti-sag buffer material in the form of a sheet.

[0019] Preferably, the thickness of the buffer material is 2-3 mm.

[0020] The present invention also provides a high-performance anti-dent buffer material, which is prepared by the above-mentioned preparation method, contains 85-90% of aramid fiber and 10-15% of epoxy resin, and is used for the manufacture of bulletproof vests.

[0021] Compared with the prior art, the technical solution of this application has the following beneficial technical effects:

[0022] 1. The present invention has made innovations in material and process design. First, in terms of materials, aramid fiber is impregnated with epoxy resin to prepare prepreg, with aramid fiber accounting for 85-90% and epoxy resin accounting for 10-15%. Then, the prepreg is cut and laminated into a 0° / 45° / 90° / 135° four-way structure, and then hot-pressed to form a 2-3mm thick sheet.

[0023] 2. In the process, attention is paid to the reasonable arrangement of fibers, the optimization of the impregnation formula (mass ratio in the epoxy resin system) and the strict control of the hot pressing parameters. Through these measures, the overall performance of the material is effectively improved. In order to verify the improvement effect of the material performance, especially its anti-sag ability, a gunfire performance test of the bulletproof material was carried out. During the test, it was found that the material's anti-sag ability has been greatly improved, and its sag value has been significantly reduced to the range of 25-30mm. Compared with the prior art, the performance has been improved by more than 10%. The standard requirement here is that the sag value is qualified within 44mm, while the general test results in the industry usually have a sag value of about 35mm. This shows that the material of the present invention not only meets the standard requirements in terms of anti-sag performance, but also exceeds the general level of the industry, showing obvious advantages and improvements.

[0024] 3. This not only provides users with more reliable safety protection, but also improves the comfort of the wearer while maintaining a certain thickness, making it more applicable and advantageous in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0026] Figure 1 The present invention is a flowchart of a method for preparing a high-performance anti-sag buffer material in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0028] The present invention uses aramid fiber as the main material and impregnates it in a specific proportion of epoxy resin to form a prepreg. Then, the prepreg is cut and laminated at a specific angle. Then, the laminated prepreg is processed by a hot pressing molding process. After this series of process steps, a sheet is finally produced. This sheet has very excellent anti-sag performance and can play an important role in practical applications.

[0029] Embodiment 1:

[0030] Figure 1 The present invention is a flowchart of a method for preparing a high-performance anti-sag buffer material in an embodiment of the present invention.

[0031] like Figure 1 As shown, this embodiment provides a method for preparing a high-performance anti-sag buffer material, comprising the following steps:

[0032] Step S1, mixing epoxy resin, curing agent and solvent according to a specific mass ratio to obtain an epoxy resin system.

[0033] The mass ratio of the epoxy resin, curing agent and solvent of the present invention is (98-100):(1-1.2):(10-15); in this embodiment, the mass ratio of the epoxy resin, curing agent and solvent is 98:1.2:15.

[0034] In this embodiment, the solvent is acetone and the curing agent is ethylenediamine.

[0035] Step S2, impregnating the aramid fiber in an epoxy resin system, completing the impregnation process through a roller compounding machine to obtain a prepreg.

[0036] In this embodiment, the impregnation process is completed by a roller laminating machine, wherein the reel of the roller laminating machine is used to place the aramid fiber roll, and the glue groove of the roller laminating machine is used to contain the epoxy resin system. When the roller of the roller laminating machine rotates, the aramid fiber can be stained with the epoxy resin system through the glue groove.

[0037] Specifically, the impregnation process of step S2 includes: placing the aramid fiber roll on the reel of the drum laminating machine and stretching and arranging it, attaching the PE film to the drum of the drum laminating machine and laying it flat, fixing one end of the arranged aramid fiber on the drum on which the PE film is laid, adding the epoxy resin system to the glue tank of the drum laminating machine, rotating the drum on which the PE film is laid, so that the fixed aramid fiber is infiltrated and laid in the epoxy resin system, so that the aramid fiber is unidirectionally laid, and after the laying is completed, it is cut along the central axis to obtain the prepreg:

[0038] In this embodiment, the proportion of aramid fiber in the prepreg (filament content) is 88%, and the thickness of a single sheet of prepreg is 0.1 mm. The aramid fiber is stretched and arranged by winding around a roller. Specifically, first, the untwisted fiber (aramid fiber in an untwisted form) is drafted and impregnated with resin. Then, through the action of the laying roller, a uniform plane with a certain width is formed. Then, by winding the upper wire, the fibers are laid as evenly as possible on the surface of the drum one by one, so as to achieve no gaps and as small an overlap as possible. Such a fiber arrangement method can ensure that the fibers are evenly stressed during subsequent processing.

[0039] Further, the rotation speed of the drum is set to 28-30r / min, the horizontal axis speed is set to 13-14r / min, the drum is started, and the horizontal speed is turned on after winding 1-3 turns. In this embodiment, the rotation speed of the drum is specifically set to 28r / min, the horizontal axis speed is 13r / min, the drum is started, and the horizontal speed is turned on after winding three turns to ensure that the wire head is fixed.

[0040] Step S3, cutting the prepreg, laminating them at different angles, and then hot pressing and cooling the laminated prepreg to obtain a high-performance anti-sag buffer material in the form of a sheet.

[0041] Specifically, the size of the cut prepreg is (1.6±0.02) m×(1.6±0.02) m. In this embodiment, the size of the prepreg is 1.62 m×1.62 m.

[0042] In this embodiment, the cut prepreg is laminated in four directions according to 0° / 45° / 90° / 135° to obtain laminated prepreg.

[0043] The hot pressing forming process of the present invention comprises:

[0044] Step M1, cutting the laminated prepreg into a size of 1.62x1.62m, ensuring edge alignment.

[0045] Step M2, weighing the prepreg, the weight range is 11.3±0.05kg, the number of layers corresponds to 21 layers±1 layer, and then the neatly stacked prepreg is placed in a flat vulcanizer.

[0046] Step M3, the pressing temperature is set to 130-135°C, the pressure is set to 15-23Mpa, and the pressing time is set to 10-30min. In this embodiment, the pressing temperature is set to 130°C, the pressure is set to 15Mpa, and the pressing time is set to 30min.

[0047] Step M4, close the mold, apply pressure, and start heat preservation and pressure maintenance for 30 minutes when the temperature reaches 130°C. After completion, open the mold to take out the parts, and after cooling to 35°C-40°C, obtain a high-performance anti-sag cushioning material in sheet form; the thickness of the cushioning material is 2-3mm.

[0048] In this embodiment, when a refrigerator is used for cooling, a suitable temperature needs to be set. When the temperature is cooled to a range of 35°C-40°C, the prepared high-performance anti-sag buffer material can reach the required solidification strength.

[0049] Embodiment 2:

[0050] This embodiment provides a method for preparing a high-performance anti-sag buffer material, comprising the following steps:

[0051] Step S1, weighing according to the corresponding ratio, epoxy resin: curing agent: solvent = 100:1:10, epoxy resin weighing 5kg, curing agent weighing 0.05kg, solvent weighing 0.5kg, using an electronic stirrer to stir, stir evenly and set aside.

[0052] Step S2, pour glue into the glue tank of the drum machine, weigh the fiber 3.98kg, put it on the unwinding device, cover the drum surface with PE film, stretch the fiber through the glue tank, and fix it on the drum through the laying roller. Set the rotation speed of the drum to 30r / min and the horizontal axis speed to 13.5r / min, start the drum, and turn on the horizontal speed after winding three times to make the aramid fiber unidirectionally stacked. After stacking, cut it along the center axis to obtain unidirectional prepreg.

[0053] Step S3, weigh the fiber weight to 3.07kg, weigh the aramid UD cloth weight to 1.05kg, according to the formula: fiber weight m = 3.98-3.07 = 0.91kg, resin weight = 1.05-0.91 = 0.14kg, fiber accounts for 86.7%, and resin accounts for 13.3%.

[0054] The cut prepreg was laminated in four directions at 0° / 45° / 90° / 135° to obtain laminated prepreg. After observation, the fibers on the surface were fixed without any excess floating fibers, and the interlayer composite strength was good after lamination.

[0055] Embodiment 3:

[0056] This embodiment provides a method for preparing a high-performance anti-sag buffer material. Compared with the solution of Example 2, the rotation speed and the horizontal axis speed of the drum in step S2 of this embodiment are improved.

[0057] Specifically, in step S2, the rotation speed of the drum is set to 32 r / min and the horizontal axis speed is set to 14.5 r / min.

[0058] In step S3, the fiber weight is weighed as 3.14 kg, and the aramid UD cloth weight is weighed as 1.05 kg. According to the formula: fiber weight m = 3.14-2.21 = 0.93 kg, resin weight = 1.05-0.93 = 0.12 kg, the fiber accounts for 88.6% and the resin accounts for 11.4%.

[0059] The cut prepreg was laminated in four directions at 0° / 45° / 90° / 135° to obtain laminated prepreg. After observation, the fibers on the surface were fixed without any excess floating fibers, and the interlayer composite strength was good after lamination.

[0060] By carrying out the experimental process of Example 2 and Example 3 and analyzing the corresponding results, it is clarified that when the aramid fiber accounts for 85-90% and the epoxy resin accounts for 10-15%, it is the optimal proportion range of the high-performance anti-dent buffer material. When judging the material properties, the gunshot test method is adopted. Through this test, it is found that the material within the above-mentioned proportion range can show high anti-dent ability, and at the same time has good mechanical strength and buffering effect, thereby providing a scientific basis for the preparation of high-performance anti-dent buffer materials.

[0061] Embodiment 4:

[0062] This embodiment provides a high-performance anti-dent buffer material, which is prepared by the preparation method in the above-mentioned embodiment 1, contains 85-90% aramid fiber and 10-15% epoxy resin, and is used for the manufacture of bulletproof vests.

[0063] In order to emphasize that the hot pressing process in the present invention needs to be strictly controlled, different hot pressing process parameters are set and the results are analyzed. First, the basic hot pressing process parameters are determined: the pressing temperature range is 130-135°C, the pressure per unit area is set to 15Mpa, and the pressing is 10 minutes.

[0064] Comparative Example 1:

[0065] The prepreg after lamination is prepared by the steps in the above embodiment, and hot pressing is performed. The hot pressing process is as follows:

[0066] Step M1, cutting the laminated prepreg into a size of 1.62x1.62m, ensuring edge alignment.

[0067] Step M2, weighing the prepreg, the weight range is 11.3±0.05kg, the number of layers corresponds to 21 layers±1 layer, and then the neatly stacked prepreg is placed in a flat vulcanizer.

[0068] Step M3, lay release paper on top and bottom, set the pressure value of the flatbed vulcanizer to 15 MPa, the temperature to 129° C., and the time to 10 min.

[0069] Step M4, close the mold, apply pressure, and start heat preservation and pressure maintenance for 10 minutes when the temperature reaches 129°C. After completion, open the mold and take out the parts.

[0070] Experimental results and analysis: Through interlayer peeling, it was found that part of the PE film was not fully melted, the interlayer interface adhesion was insufficient, and it was easy to delaminate by hand. Although increasing the hot pressing time has improved the effect to a certain extent, there are still PE film residues in some areas, affecting the quality of the final product. After the gun test, the dents are large and easy to delaminate.

[0071] Comparative Example 2:

[0072] The hot pressing process steps are the same as those in Comparative Example 1, with the only difference being step M3 and step M4.

[0073] In step M3, the temperature was increased to 136°C to explore the effect of temperature on the hot pressing effect.

[0074] In step M4, when the temperature reaches 136°C, the heat and pressure are kept for 10 minutes, and after the temperature is reached, the mold is opened and the parts are taken out.

[0075] Experimental results and analysis: Through interlayer peeling, it was found that the PE film was fully melted and the interlayer interface was strong enough. However, the high temperature brought problems. The surface of the board turned yellow because the resin was not resistant to high temperature, which affected the strength of the board. Moreover, the board was brittle when the temperature was too high, and it was easy to break or even penetrate after being shot.

[0076] In summary, it can be seen from these two comparative examples that the selection of hot pressing process parameters is very critical. Only by strictly controlling the hot pressing process can we obtain products with good performance. Too low or too high temperature will lead to various quality problems. It is necessary to find a suitable range of hot pressing process parameters to ensure the quality and performance of the product.

[0077] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for preparing a high-performance anti-sag buffer material, characterized in that: The steps include: Step S1, mixing epoxy resin, curing agent and solvent according to a specific mass ratio to obtain an epoxy resin system; Step S2, impregnating the aramid fiber in the epoxy resin system, completing the impregnation process through a roller laminating machine to obtain a prepreg; Step S3, cutting the prepreg, laminating them at different angles, and then hot pressing and cooling the laminated prepreg to obtain a high-performance anti-sag buffer material in the form of a sheet.

2. The method for preparing a high-performance anti-sag buffer material according to claim 1, characterized in that: In the step S1, the mass ratio of the epoxy resin, the curing agent and the solvent is (98-100):(1-1.2):(10-15).

3. The method for preparing a high-performance anti-sag buffer material according to claim 1, characterized in that: The impregnation process of step S2 includes: placing the aramid fiber roll on the reel of the drum laminating machine and stretching and arranging it, attaching a PE film to the drum of the drum laminating machine and flattening it, fixing one end of the arranged aramid fiber on the drum with the PE film laid on it, adding the epoxy resin system into the glue tank of the drum laminating machine, rotating the drum with the PE film laid on it, so that the fixed aramid fiber is infiltrated and stacked in the epoxy resin system, so that the aramid fiber is stacked in one direction, and after stacking is completed, it is cut along the central axis to obtain a prepreg.

4. The method for preparing a high-performance anti-sag buffer material according to claim 3, characterized in that: In the step S2, the aramid fibers are stretched and arranged by winding around a roller.

5. The method for preparing a high-performance anti-sag buffer material according to claim 3, characterized in that: In step S2, the rotation speed of the drum is set to 28-30 r / min, the horizontal axis speed is set to 13-14 r / min, the drum is started, and the horizontal speed is turned on after winding 1-3 turns.

6. The method for preparing a high-performance anti-sag buffer material according to claim 1, characterized in that: In the step S3, the size of the prepreg after cutting is (1.6±0.02)m×(1.6±0.02)m.

7. The method for preparing a high-performance anti-sag buffer material according to claim 6, characterized in that: The step S3 comprises: laminating the cut prepreg in four directions according to 0° / 45° / 90° / 135° to obtain laminated prepreg.

8. The method for preparing a high-performance anti-sag buffer material according to claim 7, characterized in that: The hot pressing molding process in step S3 includes: placing the laminated prepreg into a flat vulcanizer, setting the pressing temperature to 130-135°C, setting the pressure to 15-23Mpa, pressing for 10-30 minutes, and cooling to 35°C-40°C after hot pressing to obtain a high-performance anti-sag buffer material in the form of a sheet.

9. The method for preparing a high-performance anti-sag buffer material according to claim 8, characterized in that: The thickness of the buffer material is 2-3 mm.

10. A high performance anti-sag cushioning material, characterized in that: The invention is prepared by the preparation method according to any one of claims 1 to 9, contains 85-90% of aramid fiber and 10-15% of epoxy resin, and is used for the manufacture of bulletproof vests.

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