CN116021794A - Nonmetal bulletproof helmet and manufacturing device and manufacturing method thereof - Google Patents
Nonmetal bulletproof helmet and manufacturing device and manufacturing method thereof Download PDFInfo
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Abstract
The invention provides a nonmetallic bulletproof helmet, a manufacturing device and a manufacturing method thereof, and provides a special nonmetallic helmet manufacturing device and method and a product, so as to realize improvement and optimization of bulletproof performance of the helmet; the problems of uneven thickness of the helmet, large front concave depression after being flicked and the like are solved, the production mode of the current mould pressing technology is optimized, the defect that the helmet cannot be uniformly pressed when being pressed is overcome, equal pressure is applied around a helmet mould, the thickness of the helmet in the mould is uniform, the mould is pressurized by surrounding oil medium liquid in a closed space, all parts of the helmet are subjected to equal high pressure according to the Pascal principle, the heat conduction process is conducted by liquid medium (compared with the traditional electric heating mode, the liquid heating mode is more uniform and stable), resin between helmet layers is uniformly melted, therefore, the isotropy of a finished product is good, the formed helmet shell is not stressed unevenly, the thickness distribution is uneven, the defect that the front concave depression of the helmet is large is overcome, and the integral anti-elastic performance of the helmet is improved.
Description
Technical Field
The invention belongs to the technical field of production and manufacture of non-woven fabrics, and particularly relates to a nonmetallic bulletproof helmet and a manufacturing device and a manufacturing method thereof.
Background
The bulletproof helmet is mainly used for protecting physical injuries such as pistol bullets, high-speed fragments, striking and explosion, absorbing the kinetic energy of the high-speed bullets through high-strength high-modulus materials, preventing penetration of the bullets and fragments, absorbing energy through a buffer system and protecting the safety of the head; at present, bulletproof helmets are mainly divided into metal bulletproof helmets and nonmetal bulletproof helmets according to material composition.
The metal bulletproof helmet is mainly produced by metal stretching or stamping forming, and because the metal bulletproof helmet is heavy, the metal bulletproof helmet can press the head to cause discomfort when being used, and cervical spondylosis can occur when the metal bulletproof helmet is worn for a long time; very poor (almost airtight) breathability; in addition, the phenomenon of 'flick' is easy to generate in the protection application process, secondary injury to the self and surrounding people can be generated, and the phenomenon of 'flick' is eliminated.
The nonmetallic bulletproof helmet is formed by hot-pressing a plurality of layers of high-performance fiber prepregs, and the helmet shell is mainly prepared from high-strength and high-modulus fibers such as aramid fiber II, aramid fiber III, ultra-high molecular weight polyethylene, PBO, carbon fibers, polyimide and the like by weaving woven fabrics with plain weave, twill weave, satin weave, square plain weave and other weave structures or non-woven fabrics which are prepared by uniformly spreading high-strength and high-modulus materials and bonding resin with a film by a loom; adding resin (such as modified phenolic resin, modified epoxy resin, polyurethane, polyolefin, acrylic acid, etc.) into the woven fabric or laid fabric, and finally making into helmet shell by cutting, layering, compression molding, etc.
The bulletproof performance of the traditional nonmetallic bulletproof helmet can meet the 2-level requirement in the GA 293-2012 standard, namely, a 54-type pistol is used for launching 51-type lead bullets, the bullet speed is 445+/-10 m/s, the helmet can not be penetrated under the effective hit condition, the heights of bullet marks at the side, rear and top parts are less than or equal to 25mm, and the heights of bullet marks at the front part are less than or equal to 30mm; the rupture protection requirement is generally simulated according to GJB 5115A-2012 by adopting 1.1g standard, and the V50 value of the rupture protection requirement is not less than 610m/s under the condition that the helmet is not penetrated.
In the existing nonmetallic bulletproof helmet manufacturing process, the bulletproof helmet is manufactured by cutting high-strength and high-modulus woven cloth or non-woven cloth (aramid fiber II, aramid fiber III, ultra-high molecular weight polyethylene, PBO, carbon fiber, polyimide and the like) according to a set shape (petal shape and impeller shape are mostly adopted), then stacking the layers at a rotating angle of the cut pieces, and finally performing hot-press molding by adopting a mold (research progress of the bulletproof helmet made of fiber reinforced resin matrix composite materials, weapon material science and engineering, 2022,45 (04): 125-132), and also manufacturing the bulletproof helmet by cutting the materials into wafer lamination, directly performing cold pressing to form blanks, performing the pre-molding and molding two procedures, and finally performing the procedures of trimming, spraying paint, hanging and the like to obtain the finished helmet (the bulletproof helmet shell of the patent: CN 206556513U).
In any shaping mode of the bulletproof helmet, the helmet needs to be molded; when the multilayer prepreg is stacked or the helmet blank body which is paved is molded, as the initial pressure only exists in the vertical direction in the long-time pressing process of a common hydraulic machine, component forces in other directions are generated after the material is contacted, uneven stress of the material in the circumferential direction of the mold is easy to occur, uneven thickness distribution of the helmet is caused, and the front part of the helmet has bullet mark height larger than that of the side, rear and top bullet mark height when the bulletproof helmet is subjected to a bullet impact test;
in the current domestic market, almost all bulletproof helmets are produced by a hydraulic press for compression molding, no matter an upward-compression hydraulic press or a downward-compression hydraulic press, the initial pressure born by the helmets in the compression molding process is limited in the vertical direction, a downward-compression type press carrying a convex mold is taken as an example, a helmet blank is placed in a female mold of a press base, a certain gap is reserved between the helmet blank and the female mold due to the fact that the helmet blank is loose and thick, the helmet blank cannot be tightly attached to the female mold, when the press is pressed down to the helmet blank, the male mold can slide downwards with the whole helmet blank, in the sliding process, the peripheral side surfaces of the helmets are worn and extruded by the female mold, the structure of side surface fibers of the helmets is damaged, and the protective performance of the side surfaces of the helmets is reduced; and because the slope of the front part of the helmet is slower than that of the side part and the rear part, the pressure applied in the mould pressing process is smaller, so that the thickness distribution in the mould pressing process of the helmet is uneven, the dent of the front part after being shot is larger, and the anti-elasticity performance is poor. Therefore, the existing manufacturing process is liable to cause poor overall ballistic performance of the ballistic helmet, especially poor front ballistic performance.
Disclosure of Invention
The invention aims to provide a nonmetal bulletproof helmet and a manufacturing device and a manufacturing method thereof, and provides a special nonmetal helmet manufacturing device and a method based on the existing helmet molding method and isostatic pressing concept, so as to realize improvement and optimization of bulletproof performance of the helmet; the problems of uneven thickness of the helmet, large front concave depression after being flicked and the like are solved, the production mode of the current mould pressing technology is optimized, the defect that the helmet cannot be uniformly pressed when being pressed is overcome, equal pressure is applied around a helmet mould, the thickness of the helmet in the mould is uniform, the mould is pressurized by surrounding oil medium liquid in a closed space, all parts of the helmet are subjected to equal high pressure according to the Pascal principle, the heat conduction process is conducted by liquid medium (compared with the traditional electric heating mode, the liquid heating mode is more uniform and stable), resin between helmet layers is uniformly melted, therefore, the isotropy of a finished product is good, the formed helmet shell is not stressed unevenly, the thickness distribution is uneven, the defect that the front concave depression of the helmet is large is overcome, and the integral anti-elastic performance of the helmet is improved.
A nonmetallic bulletproof helmet and a manufacturing device and a manufacturing method thereof, wherein:
A nonmetallic bulletproof helmet, comprising: a helmet body, a cushioning pad, and a suspension assembly; the buffer gasket and the suspension component are arranged on the inner side of the helmet body;
the helmet body includes: the helmet shell is made of nonmetallic materials, is produced by applying isostatic pressing to liquid which is uniformly pressed, achieves the integral homogenization of the helmet shell, and ensures high-efficiency anti-elastic performance; the helmet edge sealing ring is arranged around the lower part of the helmet shell; the helmet body coating is sprayed on the outer side of the helmet shell;
as an illustration, the nonmetallic material is a high-strength, high-modulus material with a tensile strength greater than 3GPa and a tensile modulus greater than 80GPa.
As one illustration, the high strength, high modulus materials include, but are not limited to: aramid II, aramid III, ultra high molecular weight polyethylene, PBO, carbon fiber or polyimide, or a combination thereof.
As one illustration, the high strength, high modulus materials include, but are not limited to: woven fabrics with plain, twill, satin or square plain weave structures, or laid fabrics made of high-strength, high-modulus materials uniformly and bonded with films through resins.
A device for manufacturing a nonmetallic bulletproof helmet, comprising: an isostatic press and a helmet shell oil pressure unit; the isostatic pressing machine is internally provided with a cylinder body, and hydraulic oil can be injected into or discharged out of the cylinder body through pressurization and depressurization operation, so that oil pressure operation is completed; the helmet shell oil pressure unit is arranged in the cylinder body;
further, the helmet shell oil pressure unit includes: the device comprises an outer die, an inner die, an upper fixing rod, a lower fixing rod, an upper end piston, a lower end piston, a liquid dividing ring and a vacuum pump;
the inner mold comprises: a female die and a male die;
as an illustration, in order to achieve better oil pressure effect, a plurality of exhaust holes are arranged above the convex mold.
One end of the upper fixing rod is connected with one end of the upper end piston, and the other end of the upper end piston is connected with the upper part of the outer die in a sealing way;
one end of the lower fixing rod is connected with one end of the lower end piston, a friction ring structure is arranged around the lower end piston, and when the negative pressure inside the outer die is guaranteed, the lower fixing rod can form good friction seal with the inner side wall of the lower end of the outer die, so that a closed space is formed between the upper end piston and the lower end piston and the inside of the outer die; the outer diameter size of the lower end piston is slightly smaller than the inner diameter size of the outer die;
The liquid dividing ring plays a role in opening and closing a valve and is used for injecting hydraulic oil and discharging the hydraulic oil and ensuring the clean and tidy effect of the prefabricated helmet shell;
as an illustration, the liquid dividing ring is of a double-layer sleeve structure, a plurality of groups of vertically arranged through holes are uniformly arranged around the outer ring and the inner ring at equal intervals, and the valve effect of opening and closing is achieved by rotating the outer ring or the inner ring; the diameter of the liquid dividing ring is slightly larger than that of the lower end piston;
as an illustration, the double-layer sleeve structure is adopted, so that the injection and the discharge of hydraulic oil can be ensured, and the large-amplitude deviation of an outer die caused by the excessively high hydraulic injection at one side can be avoided;
the lower part of the outer mold is in sealing connection with the upper part of the liquid dividing ring;
the upper fixing rod and the upper end piston are provided with a through exhaust channel which is communicated with the vacuum pump;
as an example, the upper end piston, the lower end piston, the outer mold, and the liquid dividing ring are all cylindrical structures.
As an illustration, the outer mold and the inner mold are fabricated from a soft, stretchable material.
As an illustration, the structural design of the helmet shell oil pressure unit not only ensures that the prefabricated helmet shell can bear equal pressure in all directions and the whole helmet shell after finished products are uniform, but also ensures that the hydraulic oil in the working procedure and the prefabricated helmet shell form good dry-wet separation, thereby avoiding the liquid pollution to products caused by the existing isostatic pressing machine oil pressure process;
A method of making a nonmetallic bulletproof helmet, comprising:
step one, cutting operation;
the cutting operation means: cutting the prepreg into a shape for paving helmets;
as one example, the shapes of the bunk-able helmets include, but are not limited to: one or a combination of a fan impeller type, a petal type, a four-leaf grass type or a six-leaf type;
as an illustration, the prepreg refers to: a high strength, high modulus material pre-infiltrated with a resin;
as one illustration, the resin includes, but is not limited to: one or a combination of modified phenolic, modified epoxy, polyurethane, polyolefin or acrylic;
as an illustration, the resin content is: 10% -30%. (by weight percent of the entire prepreg)
Step two, paving helmets;
the helmet laying operation means that: laying the cut prepreg layer by layer on a prepressing helmet die in a bottom-up sequence, and heating and adhering by means of resin on the surface of the prepreg to form a helmet blank body with a multi-layer prepreg structure;
as an example, for a nonmetallic protective material such as PE (ultra high molecular weight polyethylene) which does not resist high temperature, the heating adhesion operation should be omitted, and the material should be directly transferred to the pre-pressing step after being laid.
Step three, a pre-pressing procedure;
the pre-pressing process refers to: putting the helmet blank into a pressing machine for relatively short and frequent mould pressing, wherein the pre-pressing temperature is 60-80 ℃, and the aim is to increase interlayer adhesive force between each layer of prepreg and to print the outline shape of the helmet shell on the surface of the helmet blank;
as an illustration, the shorter times are: no more than 1 minute.
As an illustration, the aim of using shorter time is not to destroy the structure of the side fiber of the helmet and not to reduce the whole protective performance of the helmet; but also can finish the outline shape of the helmet shell and prepare for the comprehensive pressing of the oil pressure process of the isostatic pressing machine in the next step.
Step four, trimming operation;
the trimming operation means: cutting according to the outline shape of the helmet shell developed in the pre-pressing procedure to obtain a prefabricated helmet shell, so that the prefabricated helmet shell is in a helmet shape consistent with the inner mold;
fifthly, an isostatic pressing machine oil pressure process;
the isostatic pressing machine oil pressure process adopts an isostatic pressing machine to carry out liquid mould pressing treatment on the prefabricated helmet shell, and specifically comprises the following steps:
(1) the prefabricated helmet shell is arranged between the concave die and the convex die (namely the inner die) of the helmet and then is closed, and then the whole inner die is fixed on the piston at the lower end of the isostatic pressing machine;
As an illustration, the inner mold is manufactured by processing soft rubber materials;
(2) the lower end piston is pushed by the lower fixing rod, the inner die is upwards sent into the outer die in the isostatic pressing machine cylinder body, the upper end piston and the lower end piston are respectively connected with the upper end and the lower end of the outer die in a sealing mode, at the moment, the liquid separation ring is in a locking state, and the hydraulic oil in the isostatic pressing machine is prevented from polluting the prefabricated helmet shell;
as an illustration, the outer mold is a hollow cylinder structure;
as an illustration, the outer mold is also fabricated from a soft rubber material;
(3) in the ascending process of the inner die, a vacuum pump is opened, gas in the outer die is discharged in real time through an exhaust channel penetrating through the upper piston and the upper fixing rod, and a small amount of gas in the inner die is also pumped out along with an exhaust hole on the convex die;
(4) when the upward-running inner die contacts the upper end piston, the lower fixing rod stops pushing, the isostatic press cylinder body closes and seals, and at the moment, the upper end piston, the lower end piston and the outer die form a sealing space;
(5) opening a liquid separation ring below the lower end piston, so that the hydraulic oil is uniformly diffused into the isostatic pressing machine cylinder body to carry out liquid supplementing operation, and setting temperature, pressure and oil pressure time after liquid supplementing is finished;
As an illustration, the temperature is: 120-165 ℃; the pressure is as follows: 15MPa to 25MPa; the oil pressure time is as follows: 10 min-30 min.
(6) Starting an isostatic press, wherein high-pressure and high-temperature hydraulic oil uniformly transmits pressure and temperature to the prefabricated helmet shell through an outer die and an inner die, so that the periphery of the prefabricated helmet shell can be subjected to the action of uniform pressure and temperature in all directions;
as an illustration, the hydraulic oil may be other liquid medium, such as pure water or the like;
as an illustration, hydraulic oil in the isostatic press cylinder body extrudes the outer die, the outer die generates extrusion deformation, the pressure generated by shrinkage of the outer die further generates extrusion deformation on the inner die, and finally the shrinkage deformation pressure of the inner die is transmitted to the prefabricated helmet shell to form equal pressure and temperature in all directions;
step six, shaping procedure;
the shaping procedure is as follows: after the oil pressure time is finished, cooling the hydraulic oil under the condition that the pressure is kept unchanged, keeping the pressure for 1-10 min to a set temperature, closing a vacuum pump, discharging the hydraulic oil in the isostatic pressing machine cylinder body, recovering the normal pressure in the isostatic pressing machine cylinder body, and finishing the solidification of the thermoplastic resin to generate a helmet shell;
As an illustration, the set temperature is: between 40 ℃ and 60 ℃;
and step seven, closing the liquid separation ring, driving the lower end piston to move downwards by the lower fixing rod, taking out the inner die by the lower end piston, leaving the outer die in the cylinder body, and waiting for putting in the next inner die to perform continuous operation.
As an example, the purpose of closing the liquid separating ring is to prevent the residual hydraulic oil in the isostatic press cylinder from causing oil pollution to the helmet shell.
As an example, if the pre-cast helmet shell material is a non-thermoplastic resin-based prepreg, the shaping process is omitted.
As an illustration, both the outer mold and the inner mold may be reusable.
The invention has the beneficial effects that:
1. compared with the traditional helmet manufacturing method, the invention has the following advantages:
(1) in the isostatic pressing machine oil pressure process, the side surfaces around the prefabricated helmet shell are not extruded by unidirectional force any more, abrasion is generated, the structure of side surface fibers is not damaged, all parts of the helmet are subjected to high pressure with equal each other, the structure is compact, the anti-breaking performance of the helmet is enhanced, and the breaking limit V50 value is remarkably improved.
(2) All parts of the helmet are subjected to equal pressure through hot pressing and shaping of an isostatic pressing machine, the heat conduction process is conducted by a liquid medium, in the traditional helmet hot pressing process, heat is provided by an electric heating system in a mold, electric heating pipes are distributed differently, so that the temperature of all points on the surface of the mold is uneven, the temperature of the heating pipes can far exceed the set temperature after the temperature of the mold is set, the heating pipes stop heating when the mold reaches the set temperature, the mold often exceeds the set temperature for a period of time, the instability of the temperature can be caused, the isostatic pressing machine conducts heat by the liquid medium, the mold is heated uniformly, the heat preservation is stable, therefore, resin between helmet layers is melted uniformly, the hot pressing state of each helmet is consistent, the fluctuation of the V50 value of a helmet fragment is reduced, the phenomenon of high penetration and low prevention is avoided, and the stability and consistency of the helmet fragment prevention performance are improved.
(3) All parts of the helmet are subjected to equal pressure, the heat conduction process is also uniformly conducted by a liquid medium, resin between helmet layers is melted uniformly, so that the isotropy of a finished product is good, and as all the pressure is equal, the thickness of the helmet is uniform, even if the gradient of the front part of the helmet is slower, the pressure with the same size as that of a side surface can be received, the anti-elasticity performance of the helmet is increased, the heights of front, rear, side and top bullet marks of the helmet are reduced, particularly the front part is obviously reduced, and the dent after the bullet is greatly reduced, so that the safety of wearing personnel is greatly protected.
(4) The metal mould that traditional mould pressing adopted, not only weight is big, inner structure is complicated, still needs built-in heating cooling etc. device in its concave, the terrace die utensil, and the helmet mould that adopts in the isostatic pressing machine uses the elastomer rubber material, need not to increase heating device, mould light in weight, simple structure, preparation convenience, realizes the mixed quick production of helmet of different specifications easily, whole low price.
Drawings
Fig. 1 is a schematic diagram showing an exemplary set of shapes for a helmet during a cutting operation in a method for manufacturing a nonmetallic bulletproof helmet according to the present invention.
Fig. 2 is a schematic view showing the overall structure of a device for manufacturing a nonmetallic bulletproof helmet according to the present invention.
Fig. 3 is a perspective view showing the overall structure of an apparatus for manufacturing a nonmetallic bulletproof helmet according to the present invention.
Fig. 4 is an exploded view of the inner mold of a device for manufacturing a nonmetallic bulletproof helmet of the present invention.
Fig. 5 is a schematic view showing a closed state of a prefabricated helmet shell of a method for manufacturing a nonmetallic bulletproof helmet according to the present invention, which is placed between a concave mold and a convex mold.
Fig. 6 is a schematic view of the overall structure of an outer mold of a device for manufacturing a nonmetallic bulletproof helmet according to the present invention.
Fig. 7 is a schematic diagram of the isostatic pressing hydraulic process flow of a method of making a nonmetallic bulletproof helmet of the present invention.
Fig. 8 is a schematic view of the exhaust design of a device for manufacturing a nonmetallic bulletproof helmet of the present invention.
Fig. 9 is a schematic view of the outer and inner ring designs of the liquid separation ring of a non-metallic ballistic helmet manufacturing apparatus of the invention.
Detailed Description
The preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
Referring to the drawings in the specification, a nonmetallic bulletproof helmet and a manufacturing device and a manufacturing method thereof are shown, wherein:
a nonmetallic bulletproof helmet, comprising: a helmet body, a cushioning pad, and a suspension assembly; the buffer gasket and the suspension component are arranged on the inner side of the helmet body;
The helmet body includes: the helmet shell is made of nonmetallic materials, is produced by applying isostatic pressing to liquid which is uniformly pressed, achieves the integral homogenization of the helmet shell, and ensures high-efficiency anti-elastic performance; the helmet edge sealing ring is arranged around the lower part of the helmet shell; the helmet body coating is sprayed on the outer side of the helmet shell;
as an illustration, the nonmetallic material is a high-strength, high-modulus material with a tensile strength greater than 3GPa and a tensile modulus greater than 80GPa.
As one illustration, the high strength, high modulus materials include, but are not limited to: aramid II, aramid III, ultra high molecular weight polyethylene, PBO, carbon fiber or polyimide, or a combination thereof.
As one illustration, the high strength, high modulus materials include, but are not limited to: woven fabrics with plain, twill, satin or square plain weave structures, or laid fabrics made of high-strength, high-modulus materials uniformly and bonded with films through resins.
An apparatus for manufacturing a nonmetallic bulletproof helmet, as shown with reference to fig. 2, includes: an isostatic press 101 and a helmet shell oil pressure unit; the isostatic press is internally provided with a cylinder body 102, and hydraulic oil can be injected into or discharged out of the cylinder body 102 through pressurization and depressurization operation, so that oil pressure operation is completed; the helmet shell oil pressure unit is arranged inside the cylinder body 102;
Further, the helmet shell oil pressure unit includes: an outer die 103, an inner die, an upper fixing rod 104, a lower fixing rod 105, an upper end piston 106, a lower end piston 107, a liquid dividing ring 108, and a vacuum pump 114;
the inner mold comprises: a female die 109 and a male die 110;
as an example, in order to achieve a better oil pressure effect, a plurality of exhaust holes 111 are provided above the male die 110.
One end of the upper fixing rod 104 is connected with one end of the upper end piston 106, and the other end of the upper end piston 106 is connected with the upper part of the outer mold 103 in a sealing manner;
one end of the lower fixing rod 105 is connected with one end of the lower end piston 107, and a friction ring structure is arranged around the lower end piston 107, so that when the internal negative pressure of the outer mold 103 is ensured, good friction sealing fixation can be formed with the inner side wall of the lower end of the outer mold 103, and a closed space is formed between the upper end piston 106, the lower end piston 107 and the inner side of the outer mold 103; the outer diameter dimension of the lower end piston 107 is slightly smaller than the inner diameter dimension of the outer mold 103;
the liquid dividing ring 108 has the functions of opening and closing a valve, injecting hydraulic oil, discharging the hydraulic oil and ensuring the cleanliness of the prefabricated helmet shell 112;
As an illustration, the liquid dividing ring 108 has a double-layer sleeve structure, and a plurality of groups of vertically arranged through holes are equidistantly arranged around the outer ring 115 and the inner ring 116, so that the valve effect of opening and closing is achieved by rotating the outer ring 115 or the inner ring 116; the diameter of the liquid dividing ring 108 is slightly larger than the diameter of the lower end piston 107; referring to fig. 9;
as an illustration, the double-layer sleeve structure is adopted, so that the injection and the discharge of hydraulic oil can be ensured, and the large deviation of the outer die 103 caused by the excessively high hydraulic injection at one side can not be generated;
the lower part of the outer mold 103 is in sealing connection with the upper part of the liquid dividing ring 108;
the upper fixing rod 104 and the upper end piston 106 are provided with a through exhaust channel 113, and the exhaust channel 113 is communicated with the vacuum pump 114;
as an example, the upper piston 106, the lower piston 107, the outer mold 103, and the liquid split ring 108 are all cylindrical structures.
As an illustration, the outer mold 103 and the inner mold are fabricated from a soft, stretchable material.
As an illustration, the structural design of the helmet shell oil pressure unit not only ensures that the prefabricated helmet shell 112 can bear equal pressure in all directions and the whole helmet shell after finished products are uniform, but also ensures that the hydraulic oil in the working procedure and the prefabricated helmet shell 112 form good dry-wet separation, thereby avoiding the liquid pollution to products caused by the existing isostatic pressing oil pressure process;
A method of making a nonmetallic bulletproof helmet, comprising:
step one, cutting operation;
the cutting operation means: cutting the prepreg into a shape for paving helmets;
as one example, the shapes of the bunk-able helmets include, but are not limited to: one or a combination of a fan impeller type, a petal type, a four-leaf grass type or a six-leaf type; see in detail figure 1.
As an illustration, the prepreg refers to: a high strength, high modulus material pre-infiltrated with a resin;
as one illustration, the resin includes, but is not limited to: one or a combination of modified phenolic, modified epoxy, polyurethane, polyolefin or acrylic;
as an illustration, the resin content is: 10% -30%. (by weight percent of the entire prepreg)
Step two, paving helmets;
the helmet laying operation means that: laying the cut prepreg layer by layer on a prepressing helmet die in a bottom-up sequence, and heating and adhering by means of resin on the surface of the prepreg to form a helmet blank body with a multi-layer prepreg structure;
as an example, for a nonmetallic protective material such as PE (ultra high molecular weight polyethylene) which does not resist high temperature, the heating adhesion operation should be omitted, and the material should be directly transferred to the pre-pressing step after being laid.
Step three, a pre-pressing procedure;
the pre-pressing process refers to: putting the helmet blank into a pressing machine for relatively short and frequent mould pressing, wherein the pre-pressing temperature is 60-80 ℃, and the aim is to increase interlayer adhesive force between each layer of prepreg and to print the outline shape of the helmet shell on the surface of the helmet blank;
as an illustration, the shorter times are: no more than 1 minute.
As an illustration, the aim of using shorter time is not to destroy the structure of the side fiber of the helmet and not to reduce the whole protective performance of the helmet; but also can finish the outline shape of the helmet shell and prepare for the comprehensive pressing of the oil pressure process of the isostatic pressing machine in the next step.
Step four, trimming operation;
the trimming operation means: cutting according to the outline shape of the helmet shell which is developed in the pre-pressing procedure to obtain a prefabricated helmet shell 112, so that the prefabricated helmet shell is in a helmet shape which is consistent with the inner mold;
fifthly, an isostatic pressing machine oil pressure process; referring to fig. 7;
the isostatic pressing machine oil pressure process adopts an isostatic pressing machine to carry out liquid mould pressing treatment on the prefabricated helmet shell, and specifically comprises the following steps:
(1) the prefabricated helmet shell is closed after being placed between a helmet concave die 109 and a helmet convex die 110, as shown in fig. 5 in detail, and then the whole inner die is fixed on a piston 107 at the lower end of an isostatic press;
As an illustration, the inner mold is manufactured by processing soft rubber materials;
(2) the lower end piston 107 is pushed by the lower fixing rod 105, the inner die is sent upwards into the outer die 103 in the cylinder 102, the upper end piston 106 and the lower end piston 107 are respectively connected with the upper end and the lower end of the outer die 103 in a sealing way, at the moment, the liquid separation ring 108 is in a locking state, and the hydraulic oil in the isostatic press is ensured not to pollute the prefabricated helmet shell 112;
as an illustration, the outer mold 103 is a hollow cylinder structure;
as an illustration, the outer mold 103 is also manufactured by processing soft rubber material;
(3) in the process of ascending the inner mold, a vacuum pump 114 is opened, the gas in the outer mold 103 is discharged in real time through an exhaust channel 113 penetrating the upper piston 106 and the upper fixing rod 104, and a small amount of gas in the inner mold is simultaneously pumped out along with the exhaust hole 111 on the convex mold 110; see in detail fig. 8;
(4) when the upward-running inner die 109 contacts the upper end piston 106, the lower fixing rod 105 stops pushing, the isostatic press cylinder 102 closes the seal, and at this time, the upper end piston 106, the lower end piston 107 and the outer die 103 form a sealed space;
(5) Opening a liquid separation ring 108 below the lower end piston 107, so that the hydraulic oil is uniformly diffused to the periphery of the isostatic press cylinder 102 to carry out fluid infusion operation, and after fluid infusion is finished, setting temperature, pressure and oil pressure time;
as an illustration, the temperature is: 120-165 ℃; the pressure is as follows: 15MPa to 25MPa; the oil pressure time is as follows: 10 min-30 min.
(6) Starting an isostatic press, wherein high-pressure and high-temperature hydraulic oil uniformly transmits pressure and temperature to the prefabricated helmet shell 112 through the outer die 103 and the inner die, so that the periphery of the prefabricated helmet shell 112 can be subjected to the action of uniform pressure and temperature in all directions;
as an illustration, the hydraulic oil may be other liquid medium, such as pure water or the like;
as an illustration, the hydraulic oil in the isostatic press cylinder body extrudes the outer mold 103, the outer mold 103 generates extrusion deformation, the pressure generated by shrinkage of the outer mold 103 further generates extrusion deformation on the inner mold, and finally the shrinkage deformation pressure of the inner mold is transmitted to the prefabricated helmet shell 112 to form equal pressure and temperature in all directions;
step six, shaping procedure;
the shaping procedure is as follows: after the oil pressure time is finished, cooling the hydraulic oil under the condition that the pressure is kept unchanged, keeping the pressure for 1-10 min to a set temperature, closing a vacuum pump 114, discharging the hydraulic oil in the isostatic pressing machine cylinder 102, recovering the normal pressure in the isostatic pressing machine cylinder 102, and completing the solidification of the thermoplastic resin to generate a helmet shell;
As an illustration, the set temperature is: between 40 ℃ and 60 ℃;
step seven, closing the liquid separation ring 108, driving the lower end piston 107 to move downwards by the lower fixing rod 105, taking out the inner mold by the lower end piston 107, leaving the outer mold 103 in the cylinder 102, and waiting for the next inner mold to be put in for continuous operation.
As an example, the purpose of closing the liquid divider ring 108 is to prevent oil contamination of the helmet shell by residual hydraulic oil in the isostatic press cylinder 102.
As an example, if the raw material of the prefabricated helmet shell 112 is a non-thermoplastic resin-based prepreg, the shaping process is omitted.
As an illustration, both the outer mold 103 and the inner mold may be reusable.
For a better understanding of the principle design of a method of manufacturing a nonmetallic bulletproof helmet of the present invention, examples are now presented;
example 1:
aramid fiber II woven fabric prepreg is used as a raw material of a nonmetallic bulletproof helmet, the specification of the adopted aramid fiber II yarn is 1100dtex, the resin is modified phenolic resin, and the surface density of the prepreg is 405g/m 2 The resin content was 15% (by weight percent of the entire prepreg);
cutting the prepreg of the aramid fiber II woven fabric into six sheets, and performing helmet paving operation on a pre-pressing helmet die, wherein each layer of prepreg is staggered by 5 degrees, and the total paving layer number is 23; in the process of paving the helmet, a hot air gun is used for heating to soften and bond resin between prepreg layers to form a helmet blank, and the helmet blank is taken off from a pre-pressing helmet die after the paving is finished;
Putting the helmet blank into a down-pressing press for mould pressing, setting the temperature to 80 ℃, the pressure to 20MPa, and the time to 50 seconds, and taking out the helmet blank after the pre-pressing is finished;
as an illustration, whether the indentation generated by the mould is within the range of the inner surface of the helmet blank or not can be observed, and if the indentation is out of the range, the prepressing is carried out again;
cutting the helmet blank by using a saw blade cutting machine according to the helmet shell marks generated in the pre-pressing process, so that the blank forms a prefabricated helmet shell 112 which is consistent with the model of the mould;
placing the prefabricated helmet shell 112 into a female die 109 and a male die 110 which are made of rubber, closing the female die, fixing the whole inner die on a lower end piston 107, feeding the lower end piston into a cylinder 102 for sealing, opening a vacuum pump 114 after sealing, pumping out residual air in an outer die 103 and the inner die through the vacuum pump 114, opening a liquid separation ring 108 through rotation control, performing liquid supplementing operation, wherein a medium is glycerin, the set temperature is 155 ℃, the pressure is 25MPa, and the pressure maintaining time is 20min;
after the oil pressure is over, cooling the hydraulic oil to 50 ℃ under the condition that the pressure is kept unchanged, maintaining the pressure for minutes after the temperature reaches the set temperature, closing a vacuum pump, simultaneously discharging the hydraulic oil in the isostatic pressing machine cylinder body 102, recovering the normal pressure in the isostatic pressing machine cylinder body 102, and completing the solidification of the thermoplastic resin to generate a helmet shell;
The liquid separation plate 108 is closed, the bottom sealing plate of the cylinder 102 is opened, the inner mold is carried out by the lower piston, the lower piston 107 presses the liquid back during carrying out, and at the same time, the liquid separation ring 108 is closed, and the outer mold 103 is left in the cylinder 102 and is not taken out.
The prepared helmet is detected according to the method of grade 2 in GA 293-2012 bulletproof helmet and face mask for police, a 51-type lead core bullet is launched by a 54-type pistol, and the bullet mark height is tested, compared with the conventional technology, the helmet prepared by the special method has the advantages that the maximum bullet mark height at the front part of the helmet is reduced by about 15mm, and the maximum bullet mark height at other parts is reduced by about 8mm;
according to the requirement of breaking prevention in GJB 5115A-2012' requirement on safety technical performance of bulletproof helmet for military use, 17 grains (1.1 g) standard is adopted to simulate breaking, and the limit V50 value of breaking prevention of the helmet is tested, compared with the helmet produced by the conventional process, the performance of the helmet prepared by the special method in the invention is improved by 25m/s on average; the maximum and minimum V50 difference of the 10-top helmet is reduced from 44m/s to 21m/s, and the product stability is improved.
Example 2:
PE (ultra-high molecular weight polyethylene) laid fabric prepreg is used as a raw material of a nonmetallic bulletproof helmet, the adopted PE yarn has the specification of 1100dtex, the resin is aqueous polyurethane, and the surface density of the prepreg is 110g/m 2 The resin content is 18%;
cutting PE laid fabric prepreg into four-leaf grass type 57 layers, aligning and stacking according to filament directions in the laid fabric, then placing the PE laid fabric prepreg into an oven, setting the temperature to 90 ℃ (non-high temperature), heating for 10 minutes, softening the prepreg, and taking out the laminated prepreg after heating is completed;
pulling and fixing four corners of the laminated prepreg, horizontally laying the laminated prepreg on a pressing press die, starting prepressing, setting the temperature to 80 ℃, the pressure to 10MPa, and the time to 1min, and taking out a helmet blank after prepressing;
cutting the helmet blank body by using a saw blade cutting machine according to the contour generated by the pre-pressing, so that the helmet blank forms a prefabricated helmet shell 112 which is consistent with the model of the mould;
placing the prefabricated helmet shell into a rubber concave die 109 and a male die 110, closing the rubber concave die, fixing the inner die on a lower end piston 107, sending the lower end piston 107 into a cylinder 102 for sealing, opening a vacuum pump 114 after sealing, pumping out residual air in an outer die 103 and the inner die, opening a liquid separation ring 108 through rotation, performing liquid supplementing operation, wherein the medium is glycerin, the set temperature is 125 ℃, the pressure is 25MPa, and the oil pressure time is 20min;
after the oil pressure time is over, the vacuum pump 114 is turned off, hydraulic oil in the isostatic press cylinder 102 is discharged, normal pressure in the isostatic press cylinder is restored, and the thermoplastic resin is solidified to generate a helmet shell;
The liquid separating ring 108 is closed, the lower end piston 107 is driven by the lower fixing rod 105 to move downwards, the inner mold is carried out by the lower end piston, the outer mold is left in the cylinder body and is not taken out, and the next inner mold is waited to be put in, so that continuous operation can be carried out.
The prepared helmet is detected according to the method of grade 2 in GA 293-2012 bulletproof helmet and face mask for police, a 51-type lead core bullet is launched by a 54-type pistol, and the bullet mark height is tested, compared with the conventional technology, the helmet prepared by the special method has the advantages that the maximum bullet mark height at the front part of the helmet is reduced by about 22mm, and the maximum bullet mark height at other parts is reduced by about 13mm; according to the requirement of breaking prevention in GJB 5115A-2012' requirement on safety technical performance of bulletproof helmet for military use, 17 grains (1.1 g) standard is adopted to simulate breaking, and the limit V50 value of breaking prevention of the helmet is tested, compared with the helmet produced by the conventional process, the performance of the helmet prepared by the special method in the invention is improved by 21m/s on average by the measured V50 value; the maximum and minimum V50 difference of the 10-top helmet is reduced to 23m/s from 39m/s originally, and the product stability is improved.
In the process of the isostatic pressing machine oil pressure technology, the side surfaces around the prefabricated helmet shell are not extruded by unidirectional force any more, abrasion is generated, the structure of side surface fibers is not damaged, all parts of the helmet are subjected to high pressure with equal each other, the structure is compact, the breakage resistance of the helmet is enhanced, and the breakage limit V50 value is remarkably improved.
All parts of the helmet are subjected to equal pressure through hot pressing and shaping of an isostatic pressing machine, the heat conduction process is conducted by a liquid medium, in the traditional helmet hot pressing process, heat is provided by an electric heating system in a mold, electric heating pipes are distributed differently, so that the temperature of all points on the surface of the mold is uneven, the temperature of the heating pipes can far exceed the set temperature after the temperature of the mold is set, the heating pipes stop heating when the mold reaches the set temperature, the mold often exceeds the set temperature for a period of time, the instability of the temperature can be caused, the isostatic pressing machine conducts heat by the liquid medium, the mold is heated uniformly, the heat preservation is stable, therefore, resin between helmet layers is melted uniformly, the hot pressing state of each helmet is consistent, the fluctuation of the V50 value of a helmet fragment is reduced, the phenomenon of high penetration and low prevention is avoided, and the stability and consistency of the helmet fragment prevention performance are improved.
All parts of the helmet are subjected to equal pressure, the heat conduction process is also uniformly conducted by a liquid medium, resin between helmet layers is melted uniformly, so that the isotropy of a finished product is good, and as all the pressure is equal, the thickness of the helmet is uniform, even if the gradient of the front part of the helmet is slower, the pressure with the same size as that of a side surface can be received, the anti-elasticity performance of the helmet is increased, the heights of front, rear, side and top bullet marks of the helmet are reduced, particularly the front part is obviously reduced, and the dent after the bullet is greatly reduced, so that the safety of wearing personnel is greatly protected.
The metal mould that traditional mould pressing adopted, not only weight is big, inner structure is complicated, still needs built-in heating cooling etc. device in its concave, the terrace die utensil, and the helmet mould that adopts in the isostatic pressing machine uses the elastomer rubber material, need not to increase heating device, mould light in weight, simple structure, preparation convenience, realizes the mixed quick production of helmet of different specifications easily, whole low price.
The foregoing description of the preferred embodiments of the present invention has been presented only to facilitate the understanding of the principles of the invention and its core concepts, and is not intended to limit the scope of the invention in any way, however, any modifications, equivalents, etc. which fall within the spirit and principles of the invention should be construed as being included in the scope of the invention.
Claims (10)
1. A nonmetallic bulletproof helmet, comprising: a helmet body, a cushioning pad, and a suspension assembly; the buffer gasket and the suspension component are arranged on the inner side of the helmet body;
the helmet body includes: the helmet shell is made of nonmetallic materials, is produced by applying isostatic pressing to liquid which is uniformly pressed, achieves the integral homogenization of the helmet shell, and ensures high-efficiency anti-elastic performance; the helmet edge sealing ring is arranged around the lower part of the helmet shell; the helmet body coating is sprayed on the outer side of the helmet shell.
2. The nonmetallic bulletproof helmet of claim 1, wherein the nonmetallic material is a high-strength, high-modulus material, the tensile strength is greater than 3GPa, and the tensile modulus is greater than 80GPa; the high-strength and high-modulus material is as follows: aramid II, aramid III, ultra high molecular weight polyethylene, PBO, carbon fiber or polyimide, or a combination thereof.
3. The nonmetallic bulletproof helmet of claim 1, wherein the high strength, high modulus material comprises: woven fabrics with plain, twill, satin or square plain weave structures, or laid fabrics made of high-strength, high-modulus materials uniformly and bonded with films through resins.
4. A device for manufacturing a nonmetallic bulletproof helmet, comprising: an isostatic press and a helmet shell oil pressure unit; the isostatic pressing machine is internally provided with a cylinder body, and hydraulic oil can be injected into or discharged out of the cylinder body through pressurization and depressurization operation, so that oil pressure operation is completed; the helmet shell oil pressure unit is arranged in the cylinder body;
the helmet shell oil pressure unit includes: the device comprises an outer die, an inner die, an upper fixing rod, a lower fixing rod, an upper end piston, a lower end piston, a liquid dividing ring and a vacuum pump;
The inner mold comprises: a female die and a male die; a plurality of exhaust holes are formed above the convex die;
one end of the upper fixing rod is connected with one end of the upper end piston, and the other end of the upper end piston is connected with the upper part of the outer die in a sealing way;
one end of the lower fixing rod is connected with one end of the lower end piston, a friction ring structure is arranged around the lower end piston, and when the negative pressure inside the outer die is guaranteed, the lower fixing rod can form good friction seal with the inner side wall of the lower end of the outer die, so that a closed space is formed between the upper end piston and the lower end piston and the inside of the outer die; the outer diameter size of the lower end piston is slightly smaller than the inner diameter size of the outer die;
the liquid dividing ring plays a role in opening and closing a valve and is used for injecting hydraulic oil and discharging the hydraulic oil and ensuring the clean and tidy effect of the prefabricated helmet shell;
the lower part of the outer mold is in sealing connection with the upper part of the liquid dividing ring;
the upper fixing rod and the upper end piston are provided with a through exhaust channel which is communicated with the vacuum pump;
the diameter of the liquid dividing ring is slightly larger than that of the lower end piston.
5. The manufacturing device of the nonmetal bulletproof helmet according to claim 4, wherein the liquid dividing ring is of a double-layer sleeve structure, a plurality of groups of vertically arranged through holes are formed in the periphery of the outer ring and the periphery of the inner ring at equal intervals, and the opening and closing valve effect is achieved by rotating the outer ring or the inner ring; the double-layer sleeve structure is adopted, so that the injection and the discharge of hydraulic oil can be ensured, and the large-amplitude deviation of the outer die caused by overhigh hydraulic injection at one side can be avoided.
6. The apparatus for manufacturing a nonmetallic bulletproof helmet according to claim 4, wherein the upper piston, the lower piston, the outer mold, and the liquid dividing ring are all cylindrical structures.
7. The apparatus for manufacturing a nonmetallic bulletproof helmet according to claim 4, wherein the outer mold and the inner mold are manufactured by soft and stretchable materials.
8. A method of making a nonmetallic bulletproof helmet, comprising:
step one, cutting operation;
the cutting operation means: cutting the prepreg into a shape for paving helmets; the prepreg refers to: a high strength, high modulus material pre-infiltrated with a resin;
step two, paving helmets;
the helmet laying operation means that: laying the cut prepreg layer by layer on a prepressing helmet die in a bottom-up sequence, and heating and adhering by means of resin on the surface of the prepreg to form a helmet blank body with a multi-layer prepreg structure;
step three, a pre-pressing procedure;
the pre-pressing process refers to: putting the helmet blank into a pressing machine for relatively short and frequent mould pressing, wherein the pre-pressing temperature is 60-80 ℃, and the aim is to increase interlayer adhesive force between each layer of prepreg and to print the outline shape of the helmet shell on the surface of the helmet blank;
Step four, trimming operation;
the trimming operation means: cutting according to the outline shape of the helmet shell developed in the pre-pressing procedure to obtain a prefabricated helmet shell, so that the prefabricated helmet shell is in a helmet shape consistent with the inner mold;
fifthly, an isostatic pressing machine oil pressure process;
the isostatic pressing machine oil pressure process adopts an isostatic pressing machine to carry out liquid mould pressing treatment on the prefabricated helmet shell, and specifically comprises the following steps:
(1) the prefabricated helmet shell is arranged between the concave die and the convex die (namely the inner die) of the helmet and then is closed, and then the whole inner die is fixed on the piston at the lower end of the isostatic pressing machine;
(2) the lower end piston is pushed by the lower fixing rod, the inner die is upwards sent into the outer die in the isostatic pressing machine cylinder body, the upper end piston and the lower end piston are respectively connected with the upper end and the lower end of the outer die in a sealing mode, at the moment, the liquid separation ring is in a locking state, and the hydraulic oil in the isostatic pressing machine is prevented from polluting the prefabricated helmet shell;
(3) in the ascending process of the inner die, a vacuum pump is opened, gas in the outer die is discharged in real time through an exhaust channel penetrating through the upper piston and the upper fixing rod, and a small amount of gas in the inner die is also pumped out along with an exhaust hole on the convex die;
(4) when the upward-running inner die contacts the upper end piston, the lower fixing rod stops pushing, the isostatic press cylinder body closes and seals, and at the moment, the upper end piston, the lower end piston and the outer die form a sealing space;
(5) Opening a liquid separation ring below the lower end piston, so that the hydraulic oil is uniformly diffused into the isostatic pressing machine cylinder body to carry out liquid supplementing operation, and setting temperature, pressure and oil pressure time after liquid supplementing is finished;
(6) starting an isostatic press, wherein high-pressure and high-temperature hydraulic oil uniformly transmits pressure and temperature to the prefabricated helmet shell through an outer die and an inner die, so that the periphery of the prefabricated helmet shell can be subjected to the action of uniform pressure and temperature in all directions;
step six, shaping procedure;
the shaping procedure is as follows: after the oil pressure time is finished, cooling the hydraulic oil under the condition that the pressure is kept unchanged, keeping the pressure for 1-10 min to a set temperature, closing a vacuum pump, discharging the hydraulic oil in the isostatic pressing machine cylinder body, recovering the normal pressure in the isostatic pressing machine cylinder body, and finishing the solidification of the thermoplastic resin to generate a helmet shell;
and step seven, closing the liquid separation ring, driving the lower end piston to move downwards by the lower fixing rod, taking out the inner die by the lower end piston, leaving the outer die in the cylinder body, and waiting for putting in the next inner die to perform continuous operation.
9. The method of manufacturing a nonmetallic bulletproof helmet of claim 8, wherein the shape of the spreadable helmet comprises: one or a combination of a fan impeller type, a petal type, a four-leaf grass type or a six-leaf type.
10. The method of manufacturing a nonmetallic bulletproof helmet of claim 8, wherein the outer mold and the inner mold are reusable.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211612349.1A CN116021794A (en) | 2022-12-15 | 2022-12-15 | Nonmetal bulletproof helmet and manufacturing device and manufacturing method thereof |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211612349.1A CN116021794A (en) | 2022-12-15 | 2022-12-15 | Nonmetal bulletproof helmet and manufacturing device and manufacturing method thereof |
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| CN116021794A true CN116021794A (en) | 2023-04-28 |
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| CN202211612349.1A Pending CN116021794A (en) | 2022-12-15 | 2022-12-15 | Nonmetal bulletproof helmet and manufacturing device and manufacturing method thereof |
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