Homogeneous bulletproof helmet shell and preparation method thereof

Abstract

The invention provides a homogeneous bulletproof helmet shell and a preparation method thereof, and the method comprises the following steps: carrying out the three-dimensional scanning of the outer surface of the helmet shell, and building a helmet shell three-dimensional curved surface model; drawing a plurality of parting lines on the three-dimensional curved surface model, intersecting the parting lines at the central point of the top of the helmet, and dividing the curved surface of the helmet into a plurality of equal parts; the segmented curved surface is subjected to two-dimensional plane unfolding along the corresponding segmentation lines, the top area is not segmented, and a cut-part shape is obtained; rotating the dividing line by different angles in sequence by taking the central point of the head top as the center, and repeating the dividing and unfolding steps to obtain a plurality of cutting piece shapes; the prepreg is cut according to the shapes of the multiple cut-parts, the multiple cut-parts are laid on a helmet mold in a butt joint mode according to the sequence, preforming and mold pressing curing forming are conducted, and the helmet shell is obtained. According to the preparation method, wrinkles caused by the fact that the shape of the cutting piece is not attached to the shape of the helmet can be avoided, the uniformity of the helmet shell can be improved, and therefore the bulletproof performance of the whole helmet is improved.

Description

Technical Field

[0001] The invention relates to the technical field of bulletproof protective equipment, in particular to a homogeneous bulletproof helmet shell and a preparation method thereof. Background Art

[0002] The existing method for preparing the shell of a bulletproof helmet is usually to first cut the prepreg into a circular, impeller or petal shape, then overlap and lay each layer of the cut pieces, and finally heat press and solidify them. The current prepreg cut pieces are drawn and trimmed based on experience, and cannot completely fit the shape of the helmet; and the overlapping and laying method of each layer of cut pieces will cause the prepreg to accumulate at the lower edge of the helmet, resulting in an uneven overall structure of the helmet, thereby affecting its bulletproof performance. There is still a lack of effective solutions.

[0003] Patent CN107289816A discloses a bulletproof helmet and a method for preparing the same, wherein the shell is formed by pressing a circular sheet of a non-woven fabric of a multi-layer ultra-high molecular weight polyethylene fiber or film. The bulletproof helmet prepared by this method has a certain deformation and slippage during the high-temperature pressing process, which can fill some of the missing parts, but this deformation and slippage are very limited, and many wrinkles will inevitably be generated, resulting in reduced bulletproof performance. Patent CN117341232A discloses a method for preparing a high-performance bulletproof helmet shell, which selects an ultra-high molecular weight polyethylene non-woven fabric with a molecular weight of 3 to 5 million as the bulletproof main body material, and selects a polyethylene plain prepreg fabric as the appearance material; and designs a variety of different sizes of cut pieces, and then uses the cut pieces of different sizes to lay the shell, and finally uses a mold to press the helmet shell. This invention adopts the method of overlapping and laying large and small pieces and circular reinforcement pieces on the top of the head, which to a certain extent compensates for the phenomenon of material shortage in the upper part of the helmet caused by the accumulation of pieces at the lower edge of the helmet, but the overall uniformity of the helmet still needs to be improved.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a homogeneous bulletproof helmet shell and a preparation method thereof, wherein the preparation method can improve the overall uniformity of the helmet shell, thereby improving the overall bulletproof performance of the helmet.

[0006] A first aspect of the present invention provides a method for preparing a homogeneous bulletproof helmet shell, comprising the following steps:

[0007] S1, performing a three-dimensional scan on the outer surface of the helmet shell to establish a three-dimensional curved surface model of the helmet shell;

[0008] S2. Draw a number of segmentation lines on the three-dimensional surface model, where the segmentation lines intersect at the center point of the top of the helmet, and divide the helmet surface into a number of equal parts;

[0009] S3, unfolding the segmented surface in a two-dimensional plane along the corresponding segmentation line, without segmenting the top of the head, to obtain a cut piece shape;

[0010] S4, rotating the dividing line with the center point of the top of the head at different angles in sequence, repeating the above steps S2-S3 to obtain a number of cut pieces;

[0011] S5, cutting the prepreg into a plurality of cut pieces, laying the plurality of cut pieces in sequence on a helmet mold by butt-jointing, preforming, and molding and curing to obtain a helmet shell.

[0012] Preferably, step S1 comprises: using a 3D scanner to perform a 3D scan on the outer surface of the helmet shell to obtain a point cloud map, and then using software for reverse modeling to establish a 3D curved surface model of the helmet shell.

[0013] Preferably, in step S2, the helmet curved surface is divided into 4 to 8 equal parts.

[0014] Preferably, step S3 includes: unfolding the segmented curved surface in a two-dimensional plane along the corresponding segmentation line, and then forming the central area of ​​the unfolded figure into a circular area with the center point of the top of the head as the center, to obtain a cut piece shape.

[0015] Preferably, the radius of the circular area is 50-70 mm.

[0016] Preferably, in step S4, the angle is 10-25°; more preferably, it is rotated clockwise by 10 to 25°.

[0017] Preferably, in step S5, the number of layers of the ply is 17-24.

[0018] Preferably, in step S5, the prepreg is an aramid woven prepreg (preferably a plain weave structure), which is made of phenolic resin coated on one side and has a surface density of 200 to 500 g / m 2 The mass percentage of the phenolic resin is between 8-15%.

[0019] Preferably, in step S5, the preforming temperature is 90±3°C, the pressure is 10±1 MPa, and the time is 120±5s.

[0020] Preferably, the compression molding temperature is 145±3° C., the pressure is 23±1 MPa, and the time is 900±5 s.

[0021] The second aspect of the present invention provides a homogeneous bulletproof helmet shell, which is prepared by the above-mentioned preparation method of the homogeneous bulletproof helmet shell.

[0022] The present invention has at least the following beneficial effects:

[0023] (1) The present invention establishes a three-dimensional curved surface model of the shell of the bulletproof helmet according to the outer shape of the shell of the bulletproof helmet, divides the curved surface by a dividing line and unfolds it into a planar shape to form a cut piece, and the central area of ​​the cut piece forms an undivided area, which can avoid wrinkles caused by the mismatch between the cut piece shape and the helmet shape, while ensuring the bulletproof performance of the top of the bulletproof helmet.

[0024] (2) The present invention lays a plurality of cut pieces formed by dividing lines at different angles on a helmet mold in sequence by a butt-jointed manner, preforms, and finally performs molding and curing. The butt-jointed laying method avoids the phenomenon of material piling up at the lower edge of the helmet due to overlapping of the cut pieces, further improving the overall uniformity of the bulletproof helmet, thereby improving the overall bulletproof performance of the bulletproof helmet. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 A top view of the three-dimensional curved surface model of the helmet shell provided by the present invention Figure 1 .

[0027] Figure 2 A top view of the three-dimensional curved surface model of the helmet shell provided by the present invention Figure 2 .

[0028] Figure 3 This is a front view of the three-dimensional curved surface model of the helmet shell provided by the present invention.

[0029] Figure 4 The shape of the cut piece provided by the present invention is schematically shown Figure 1 .

[0030] Figure 5 The shape of the cut piece provided by the present invention is schematically shown Figure 2 .

[0031] Explanation of reference numerals: 1. three-dimensional surface model of helmet shell; 2. dividing line; 3. center point of the top of the head; 4. circular area. DETAILED DESCRIPTION

[0032] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] Example 1

[0036] like Figures 1 to 5As shown, a 3D scanner is used to perform a 3D scan on the outer surface of the shell of the MICH bulletproof helmet to obtain a point cloud map, and then CATIA software is used for reverse modeling to establish a 3D curved surface model 1 of the shell of the bulletproof helmet; 3 segmentation lines 2 are drawn on the 3D curved surface model, and the 3 segmentation lines 2 intersect at the center point 3 of the top of the helmet, and the angle between adjacent segmentation lines 2 is 60°, so that the curved surface of the helmet is divided into 6 equal parts; the segmented curved surface is respectively unfolded in a two-dimensional plane along the corresponding segmentation lines 2, and then the central area of ​​the unfolded figure is optimized to a circular area 4 with a radius of 60 mm and a center point 3 of the top of the head as the center, so as to obtain a cut piece shape; the segmentation line 2 is rotated 12° clockwise with the center point 3 of the top of the head as the center, and the above segmentation curve and two-dimensional plane unfolding surface operations are repeated to obtain all the cut piece shapes required for the bulletproof helmet; all the cut piece graphics are exported and numbered and typeset in the CAD software.

[0037] The surface density is 350g / m 2 , the aramid woven prepreg with a resin percentage content of 10% is cut and numbered according to the above-mentioned piece layout diagram to obtain each layer of aramid prepreg pieces. According to the surface density requirements of the bulletproof helmet, the resin-containing side of the aramid prepreg piece is always facing down, and 24 layers are laid in sequence on the positive mold of the molding machine according to the shape of the helmet mold by butt-laying; at 90°C and 10MPa pressure, the molding is carried out for 120s to complete the preforming; then, at 145°C and 23MPa pressure, the molding is carried out for 900s to complete the molding curing molding; demolding can obtain the bulletproof helmet shell.

[0038] Example 2

[0039] A 3D scanner is used to perform a 3D scan on the outer surface of the shell of the MICH bulletproof helmet to obtain a point cloud map, and then CATIA software is used for reverse modeling to establish a 3D curved surface model 1 of the shell of the bulletproof helmet; 3 segmentation lines 2 are drawn on the 3D curved surface model, and the 3 segmentation lines 2 intersect at the center point 3 of the top of the helmet, and the angle between adjacent segmentation lines 2 is 60°, so that the curved surface of the helmet is divided into 6 equal parts; the segmented curved surface is respectively unfolded in a two-dimensional plane along the corresponding segmentation lines 2, and then the central area of ​​the unfolded figure is optimized to a circular area 4 with a radius of 60 mm and a center point 3 of the top of the head as the center, so as to obtain a cut piece shape; the segmentation line 2 is rotated 12° clockwise with the center point 3 of the top of the head as the center, and the above segmentation curve and two-dimensional plane unfolding surface operations are repeated to obtain all cut piece shapes required for the bulletproof helmet; all cut piece graphics are exported and numbered and typeset in the CAD software.

[0040] The surface density is 500g / m 2, the aramid woven prepreg with a resin percentage content of 12% is cut and numbered according to the above-mentioned piece layout diagram to obtain each layer of aramid prepreg pieces. According to the surface density requirements of the bulletproof helmet, the resin-containing side of the aramid prepreg piece is always facing down, and 17 layers are laid in sequence on the positive mold of the molding machine according to the shape of the helmet mold by butt-laying; at 90°C and 10MPa pressure, the molding is carried out for 120s to complete the preforming; then, at 145°C and 23MPa pressure, the molding is carried out for 900s to complete the molding curing molding; demolding can obtain the bulletproof helmet shell.

[0041] Example 3

[0042] A 3D scanner is used to perform a 3D scan on the outer surface of the shell of the MICH bulletproof helmet to obtain a point cloud map, and then CATIA software is used for reverse modeling to establish a 3D curved surface model 1 of the shell of the bulletproof helmet; 4 segmentation lines 2 are drawn on the 3D curved surface model, and the 4 segmentation lines 2 intersect at the center point 3 of the top of the helmet, and the angle between adjacent segmentation lines 2 is 45°, so that the curved surface of the helmet is divided into 8 equal parts; the segmented curved surface is respectively unfolded in a two-dimensional plane along the corresponding segmentation lines 2, and then the central area of ​​the unfolded figure is optimized to a circular area 4 with a radius of 60 mm and a center point 3 of the top of the head as the center, so as to obtain a cut piece shape; the segmentation line 2 is rotated 20° clockwise with the center point 3 of the top of the head as the center, and the above segmentation curve and two-dimensional plane unfolding surface operations are repeated to obtain all the cut piece shapes required for the bulletproof helmet; all the cut piece graphics are exported and numbered and typeset in the CAD software.

[0043] The surface density is 350g / m 2 , the aramid woven prepreg with a resin percentage content of 10% is cut and numbered according to the above-mentioned piece layout diagram to obtain each layer of aramid prepreg pieces. According to the surface density requirements of the bulletproof helmet, the resin-containing side of the aramid prepreg piece is always facing down, and 24 layers are laid in sequence on the positive mold of the molding machine according to the shape of the helmet mold by butt-laying; at 90°C and 10MPa pressure, the molding is carried out for 120s to complete the preforming; then, at 145°C and 23MPa pressure, the molding is carried out for 900s to complete the molding curing molding; demolding can obtain the bulletproof helmet shell.

[0044] Comparative Example 1

[0045] The surface density is 350g / m 2, the aramid woven prepreg with a resin percentage content of 10% is cut and numbered according to the traditional wind impeller-shaped cutting pattern to obtain each layer of aramid prepreg cutting pieces. According to the surface density requirements of the bulletproof helmet, the resin-containing side of the aramid prepreg cutting piece is always facing down, and 22 layers are laid in sequence on the positive mold of the molding machine according to the shape of the helmet mold in an overlapping layer manner; at 90°C and 10MPa pressure, the molding is carried out for 120s to complete the preforming; then, at 145°C and 23MPa pressure, the molding is carried out for 900s to complete the molding curing molding; demolding can obtain the bulletproof helmet shell.

[0046] Comparative Example 2

[0047] A 3D scanner is used to perform a 3D scan on the outer surface of the shell of the MICH bulletproof helmet to obtain a point cloud map, and then CATIA software is used for reverse modeling to establish a 3D curved surface model 1 of the shell of the bulletproof helmet; 3 segmentation lines 2 are drawn on the 3D curved surface model, and the 3 segmentation lines 2 intersect at the center point 3 of the top of the helmet, and the angle between adjacent segmentation lines 2 is 60°, so that the curved surface of the helmet is divided into 6 equal parts; the segmented curved surface is respectively unfolded in a two-dimensional plane along the corresponding segmentation lines 2, and then the central area of ​​the unfolded figure is optimized to a circular area 4 with a radius of 60 mm and a center point 3 of the top of the head as the center, so as to obtain a cut piece shape; the segmentation line 2 is rotated 12° clockwise with the center point 3 of the top of the head as the center, and the above segmentation curve and two-dimensional plane unfolding surface operations are repeated to obtain all cut piece shapes required for the bulletproof helmet; all cut piece graphics are exported and numbered and typeset in the CAD software.

[0048] The surface density is 560g / m 2 , the aramid woven prepreg with a resin percentage content of 20% is cut and numbered according to the above-mentioned piece layout diagram to obtain each layer of aramid prepreg pieces. According to the surface density requirements of the bulletproof helmet, the resin-containing side of the aramid prepreg piece is always facing down, and 15 layers are laid in sequence on the positive mold of the molding machine according to the shape of the helmet mold by butt-laying; at 90°C and 10MPa pressure, the molding is carried out for 120s to complete the preforming; then, at 145°C and 23MPa pressure, the molding is carried out for 900s to complete the molding curing molding; demolding can obtain the bulletproof helmet shell.

[0049] Comparative Example 3

[0050] A 3D scanner is used to perform a 3D scan on the outer surface of the shell of the MICH bulletproof helmet to obtain a point cloud map, and then CATIA software is used for reverse modeling to establish a 3D curved surface model 1 of the shell of the bulletproof helmet; 6 segmentation lines 2 are drawn on the 3D curved surface model, and the 6 segmentation lines 2 intersect at the center point 3 of the top of the helmet, and the angle between adjacent segmentation lines 2 is 30°, so that the curved surface of the helmet is divided into 12 equal parts; the segmented curved surface is respectively unfolded in a two-dimensional plane along the corresponding segmentation lines 2, and then the central area of ​​the unfolded figure is optimized to a circular area 4 with a radius of 60 mm and a center point 3 of the top of the head as the center, so as to obtain a cut piece shape; the segmentation line 2 is rotated 30° clockwise with the center point 3 of the top of the head as the center, and the above segmentation curve and two-dimensional plane unfolding surface operations are repeated to obtain all cut piece shapes required for the bulletproof helmet; all cut piece graphics are exported and numbered and typeset in the CAD software.

[0051] The surface density is 350g / m 2 , the aramid woven prepreg with a resin percentage content of 10% is cut and numbered according to the above-mentioned piece layout diagram to obtain each layer of aramid prepreg pieces. According to the surface density requirements of the bulletproof helmet, the resin-containing side of the aramid prepreg piece is always facing down, and 24 layers are laid in sequence on the positive mold of the molding machine according to the shape of the helmet mold by butt-laying; at 90°C and 10MPa pressure, the molding is carried out for 120s to complete the preforming; then, at 145°C and 23MPa pressure, the molding is carried out for 900s to complete the molding curing molding; demolding can obtain the bulletproof helmet shell.

[0052] The bulletproof helmet shells prepared in the embodiment and the comparative example were respectively tested for V50 value according to the standard GJB 5115A-2012 "Technical Performance Requirements for Safety of Military Bulletproof Helmets" and for back convexity value according to the Level 2 standard GA 293-2012 "Police Bulletproof Helmets and Masks", and the results are compared as shown in Table 1.

[0053] Table 1

[0054]

[0055] It can be seen from the results in Table 1 that the bulletproof helmet prepared by the present invention has better bulletproof performance than the bulletproof helmet prepared by the traditional method, and the bulletproof performance of the front, back, left, right and top of the helmet is almost the same, indicating that the shell of the bulletproof helmet of the present invention is a homogeneous structure.

[0056] In summary, the present invention establishes a three-dimensional curved surface model of a bulletproof helmet shell according to the shape of the bulletproof helmet shell, divides the curved surface by a dividing line and unfolds it in a plane to form a piece shape, and the central area of ​​the piece forms an undivided area, which can avoid wrinkles caused by the mismatch between the piece shape and the helmet shape, and at the same time ensure the bulletproof performance of the bulletproof helmet on the top of the head; the present invention lays a plurality of pieces formed by dividing lines at different angles on a helmet mold in sequence, pre-forms, and finally molds and solidifies them. The butt-laying method avoids the phenomenon of piling up the lower edge of the helmet due to overlapping of the pieces, further improves the overall uniformity of the bulletproof helmet, and thus improves the overall bulletproof performance of the bulletproof helmet.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a homogeneous bulletproof helmet shell, characterized in that: The steps include: S1, performing a three-dimensional scan on the outer surface of the helmet shell to establish a three-dimensional curved surface model of the helmet shell; S2. Draw a number of segmentation lines on the three-dimensional surface model, where the segmentation lines intersect at the center point of the top of the helmet, and divide the helmet surface into a number of equal parts; S3, unfolding the segmented surface in a two-dimensional plane along the corresponding segmentation line, without segmenting the top of the head, to obtain a cut piece shape; S4, rotating the dividing line with the center point of the top of the head at different angles in sequence, repeating the above steps S2-S3 to obtain a number of cut pieces; S5, cutting the prepreg into a plurality of cut pieces, laying the plurality of cut pieces in sequence on a helmet mold by butt-jointing, preforming, and molding and curing to obtain a helmet shell.

2. The method for preparing a homogeneous bulletproof helmet shell according to claim 1, characterized in that: Step S1 includes: using a 3D scanner to perform a 3D scan on the outer surface of the helmet shell to obtain a point cloud map, and then using software for reverse modeling to establish a 3D curved surface model of the helmet shell.

3. The method for preparing a homogeneous bulletproof helmet shell according to claim 1, characterized in that: In step S2, the helmet curved surface is divided into 4 to 8 equal parts.

4. The method for preparing a homogeneous bulletproof helmet shell according to claim 1, characterized in that: Step S3 includes: unfolding the segmented curved surface in a two-dimensional plane along the corresponding segmentation line, and then forming the central area of ​​the unfolded figure into a circular area with the center point of the top of the head as the center, to obtain a cut piece shape.

5. The method for preparing a homogeneous bulletproof helmet shell according to claim 4, characterized in that: The radius of the circular area is 50-70 mm.

6. The method for preparing a homogeneous bulletproof helmet shell according to claim 1, characterized in that: In step S4, the angle is 10-25°.

7. The method for preparing a homogeneous bulletproof helmet shell according to claim 1, characterized in that: In step S5, the prepreg is an aramid woven prepreg, which is made of phenolic resin coated on one side and has a surface density of 200 to 500 g / m 2 The mass percentage of the phenolic resin is between 8-15%.

8. The method for preparing a homogeneous bulletproof helmet shell according to claim 1, characterized in that: In step S5, the preforming temperature is 90±3°C, the pressure is 10±1 MPa, and the time is 120±5s.

9. The method for preparing a homogeneous bulletproof helmet shell according to claim 1, characterized in that: The compression molding temperature is 145±3° C., the pressure is 23±1 MPa, and the time is 900±5 s.

10. A homogeneous bulletproof helmet shell, characterized in that: The homogeneous bulletproof helmet shell is prepared by the preparation method of any one of claims 1 to 9.

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