FR2713327A1 - Ballistic, thermal and electromagnetic protection panel - Google Patents

Abstract

Panel, designed to give protection against ballistic, thermal and electromagnetic attack, esp. for a safety shelter, is made with an outer layer (4) of steel 1 - 7 mm thick, a first layer of thermal insulation (5) 10 - 20 mm thick, a ballistic protection layer 6 - 28 mm thick, and a second layer of thermal insulation 7 - 15 mm thick. All the inner layers are connected mechanically to the outer one.

Description

 The technical field of the present invention is that of construction panels for the production of partitions resistant to ballistic, thermal and electromagnetic attack while being endowed with structural resistance.

 There are numerous configurations of structural panels capable of stopping small or medium caliber projectiles, or of satisfactorily withstanding thermal aggression while ensuring a certain mechanical resistance.

As an indication, we will mention the FR Patent
A-2655413 which describes a ballistic protection shield, but does not offer any thermal protection. We will also cite Patent FR-A-2,649,095 describing a refractory composite material, which offers no ballistic protection. Mention will also be made of Patent FR-A-2 605 267 describing a ballistic protection panel comprising a layer of aluminum, a layer of laminated composite and a layer of ceramic. However, this panel does not resist thermal attack.

 The known state of the art shows that a panel with mechanical resistance resistant to ballistic and thermal attack has never been proposed. It is always possible to imagine various combinations of materials to obtain the three criteria indicated above, without however optimizing the assembly and above all responding to mass constraints, acceleration of vibrations, shocks, etc.

 The aim of the present invention is to provide a structural panel, endowed with mechanical resistance, resistant to thermal, ballistic and electromagnetic attacks on the one hand and to mass, acceleration and / or vibration stresses of somewhere else.

 Another object of the present invention is to provide a panel meeting the above characteristics while having a cost and a surface mass in accordance with the requirements of the user.

 Yet another object of the present invention is to provide a method of manufacturing partitions, walls, enclosures, allowing the various protective layers to be held in place.

The subject of the invention is therefore a panel for protection against ballistic, thermal and electromagnetic attack endowed with mechanical resistance and intended in particular for the manufacture of safety enclosures, characterized in that it is constituted from the outside towards the interior
- an outer steel skin 1 to 7 mm thick,
- a first layer of thermal insulation from 1 to 20 mm thick,
- a ballistic protective layer 6 to 28 mm thick,
- a second layer of thermal insulation 1 to 15 mm thick,
all the layers being connected by a mechanical fixing means to the external skin.

 According to another characteristic of the invention, the outer skin consists of a steel of very high hardness of the order of 500 HB.

 According to another characteristic of the invention, the first layer of thermal insulator is constituted by a refractory felt or a microporous micronized material or micronized silica.

 According to another characteristic of the invention, the ballistic protection layer consists of a ceramic layer and a layer of a glass or aramid-resin composite.

 According to yet another characteristic of the invention, the ballistic protective layer consists of a glass-resin or aramid-resin composite, or of a sandwich with a honeycomb core and a wooden plate.

 Finally, according to yet another characteristic of the invention, the second layer of thermal insulation consists of thin layers of silica wool separated by aluminum films, enclosed in an embossed metal box.

According to one embodiment of the invention, the protective panel according to the invention comprises
- approximately 3 mm from a very high hardness steel plate,
- approximately 13 to 16 mm of refractory felt or micronized silica,
- approximately 6 mm of ceramic and 12 to 15 mm of a glass-resin or aramid-resin composite,
- about 10 mm of thin layers of silica wool separated by aluminum films, the whole being enclosed in an embossed metal box.

According to another embodiment, said protective panel can be constituted by
- approximately 3 mm from a very high hardness steel plate,
- about 10 mm of refractory felt or micronized silica,
- 25 mm of glass-resin or aramideresin composite,
- about 10 mm of thin layers of silica wool separated by aluminum films, the whole being enclosed in an embossed metal box.

According to yet another embodiment, the protective panel according to the invention can comprise
- approximately 3 mm from a very high hardness steel plate,
- approximately 10 mm of micronized silica,
- about 10 mm from a sandwich with a honeycomb core,
- about 10 mm from a wooden plate,
- about 10 mm of thin layers of silica wool separated by aluminum films, the whole being enclosed in a metal box.

 The mechanical fixing means may consist of a set of stiffeners welded to the external skin and a metallic radial plate welded to the free end of each stiffener.

 A thermal protection blade can be placed on the radial metal plate so as to limit the thermal conduction through the fixing means.

The invention also relates to a method of panels intended for producing enclosures, characterized in that
- a set of stiffeners is welded to the outer skin,
radial plates are fixed at the free end of the stiffeners so as to constitute, with the stiffeners and the outer skin, receptacles for receiving at least two protective layers,
- the first thermal protection layer and the ballistic protection layer are put in place,
- the radial plates are isolated using thermal protection blades,
- there is an adhesive on the blades,
- The following plate (s) of the panel are applied to the assembly thus obtained.

 A very first advantage lies in the simplicity of production of the panel according to the invention for obtaining ballistic, thermal and electromagnetic characteristics.

 Another advantage of the invention lies in the surface mass of the panel of the order of 30 to 85 kg / m2 offering the user a wide range of use.

Other characteristics and advantages of the invention will be better understood on reading the additional description given for information with reference to the appended drawings in which
FIG. 1 is a sectional view of a first embodiment of the panel according to the invention,
FIG. 2 is a sectional view of a second embodiment of the panel according to the invention,
FIG. 3 is a sectional view of a third embodiment of the panel according to the invention,
- Figure 4 illustrates an embodiment of a means of fixing the different layers.

 The panel according to the invention is mainly intended for the construction of partitions, cases of security vehicles, enclosures, chests, usable for the transport or the storage of precious objects of the civil or military type. These requirements are met with panels 1, 2, and 3 according to Figures 1 to 3 which can be combined at the option of the user.

 The panel according to FIG. 1 consists of a set of layers, five in total, offering the maximum of ballistic protection. It comprises from the outside, that is to say on the side from which the aggression can occur, towards the inside, an outer skin 4 made of very high strength steel, for example with a hardness of 500 HB. This skin 4 can have a thickness of 1 to 7 mm, in particular approximately 3 mm. This skin participates in resistance to ballistic aggression and provides structural resistance. In addition, even in the event of aggression with small or medium caliber projectiles, this skin 4 can be pierced but is not disorganized at the point of impact. This skin 4 is followed by a first layer 5 of thermal insulation 10 to 20 mm thick. Preferably, micronized silica was chosen, which is in a commercial form which is easy to use, from 13 to 16 mm approximately. This layer 5 is followed by a layer 6 of a material ensuring ballistic protection. It is composed of a ceramic layer 6a of approximately 6 mm thick and a layer 6b of a glass-resin or aramid-resin composite of approximately 12 to 15 mm. The role of this layer is to completely stop a projectile having passed through the skin 4. Finally, there is a layer 7 of thermal insulation approximately 10 mm thick.

This layer 7 is composed of thin layers of silica wool separated by aluminum films, the whole being enclosed in an embossed metal box. All of these layers are commercially available and need not be described more fully.

 A panel conforming to FIG. 1 has a 2 surface mass of the order of 70 to 85 kg / m and resists ballistic attacks by small or medium caliber projectiles of any known type and all thermal attacks liable to occur. during storage or transport.

 Another example of panel 2 according to the invention is illustrated by FIG. 2 consisting of four layers including layers 4 and 5 of panel 1. Layer 5 is followed here by a layer 8 of a glass-resin composite or aramid-resin about 25 mm thick. In combination with skin 4, it provides ballistic protection. A layer 9 of thermal insulation of approximately 10 mm is applied to layer 8 consisting of thin layers of silica wool separated by aluminum films, enclosed in an embossed metal box.

Panel 2 has a surface mass of 65 to 80 kg / m2 and offers thermal protection identical to panel 1 but slightly lower ballistic protection. Panel 2 can be used whenever the maximum ballistic protection provided by panel 1 is not necessary.

 Another example of a panel 3 is shown diagrammatically in FIG. 3. It includes the outer skin 4 and the adjacent thermal protection layer 5 of the panel 1. To this latter, a layer 10 of approximately 10 mm thick is applied, consisting of a sandwich with metallic, synthetic or cardboard honeycomb core and light metal alloy skin. Then there is a plate 11 of about 10 mm of wood to ensure in combination with the skin 4 and the layer 10 ballistic protection and structural strength.

 Finally, there is a layer 12 of about 10 mm of thermal insulation identical to the layer 9 described above. Layers 5 and 12 of panel 3 provide thermal protection in combination.

 Panel 3 has a surface mass of 35 to 45 kg / m2. The ballistic protection conferred by this panel is less than that offered by panel 2. The panel 3 although offering lower ballistic protection is endowed with a very high compressive strength and can therefore be used for receiving loads large mass where maximum ballistic protection is not required.

 FIG. 4 shows an example of a means of mounting the different layers on the outer skin 4. It consists of a stiffener 13 fixed by a weld 14 to the skin 4. At the free end of this stiffener, a radial plate 15 is welded on both sides. This cooperates with the stiffener 13 and the skin 4 to delimit a housing in which at least two layers of panels 1, 2 or 3 are inserted. On this plate 15, a blade 16 of thermal insulation is made up of mica agglomerated by a silicone resin. The role of this blade 16 is to limit any transmission of heat to the internal side of the panel by the metallic elements 4, 13 and 15. Finally, an adhesive 17 is applied to the blade 16 to ensure the adhesion of the adjacent layer of the panel. .

 When the mounting means described above is applied to a panel 1 according to FIG. 1, the assembly is carried out as follows. The layers 5 and 6 are engaged under the plate 15, with a suitable local cutting of the plate 6 to receive the plate 15 and the blade 16 so as to ensure a surface flatness. The internal layer 7 is then retained by the adhesive 17 and the assembly thus obtained can be used as for the manufacture of an enclosure.

 Applied to the panel of Figure 2, the production method is as follows. The layers 5 and 8 are engaged under the plate 15, with, as previously, an adequate cutting of the plate 8 to integrate the plate 15 and the blade 16 so as to ensure surface continuity.

The internal layer 9 is retained by the adhesive 17 and the assembly can be used such as to manufacture an enclosure.

 Applied to a panel 3 in FIG. 3, the production method is as follows. One can for example engage layers 5 and 10 under the plate 15 with an adequate cutout of the plate 10 to ensure surface continuity. The last two plates 11 and 12 are placed and held in place by simple gravity. We will then use the panel 3, in this configuration, mainly to make the floor of an enclosure, a box or a chest, etc. which does not require a rigid configuration of all of the layers of the panel 3.

Claims (14)

 1. Panel for protection against ballistic, thermal and electromagnetic attacks endowed with mechanical resistance and intended in particular for the manufacture of safety enclosures, characterized in that it consists of the exterior towards the interior  - an outer skin (4) of steel 1 to 7 mm thick,  - a first layer of thermal insulation (5) 10 to 20 mm thick,  - a ballistic protection layer  (6; 8; 10,11) from 6 to 28 mm thick,  - a second layer of thermal insulation  (7; 9; 12) from 7 to 15 mm thick,  all of the layers being connected by mechanical fixing means (13,14) to the external skin.  2. Protective panel according to claim 1, characterized in that the outer skin (4) consists of a very high hardness steel of the order of 500 HB.  3. Protective panel according to claim 1 or 2, characterized in that the first layer of thermal insulator (5) consists of a refractory felt or a microporous micronized material or by micronized silica.  4. Protection panel according to any one of claims 1 to 3, characterized in that the ballistic protection layer consists of a ceramic  (6a) and / or by a composite (6b) glass-resin or aramideresin.  5. Protective panel according to one of claims 1 to 3, characterized in that the ballistic protective layer consists of a sandwich with a honeycomb core (10) and a wooden plate (11) .  6. Protective panel according to one of claims 1 to 6, characterized in that the second layer (7; 9; 12) of thermal insulation consists of thin layers of silica wool separated by aluminum films, the whole being enclosed in an embossed metal box.  7. Protective panel according to claim 4, characterized in that it comprises  - approximately 3 mm of very high hardness steel,  - approximately 13 to 16 mm of refractory felt or micronized silica,  - approximately 6 mm of ceramic and 12 to 15 mm of a glass-resin or aramid-resin composite,  - about 10 mm of thin layers of silica wool separated by aluminum films, the whole being enclosed in an embossed metal box.  8. Protection panel according to claim 4, characterized in that it comprises  - approximately 3 mm of very high hardness steel,  - about 10 mm of refractory felt or micronized silica,  - 25 mm of glass-resin or aramideresin composite,  - about 10 mm of thin layers of silica wool separated by aluminum films, the whole being enclosed in an embossed metal box.  9. Protective panel according to claim 6, characterized in that it comprises  - approximately 3 mm of very high hardness steel,  - about 10 mm of refractory felt or micronized silica,  - about 10 mm from a sandwich with a honeycomb core,  - about 10 mm of wood,  - about 10 mm of thin layers of silica wool separated by aluminum films, the whole being enclosed in an embossed metal box.  10. Protection panel according to any one of the preceding claims, characterized in that the mechanical fixing means (13, 15) consists of a set of stiffeners (13) welded to the external skin (4) and a radial plate metal (15) welded to the free end of each stiffener.  11. Protective panel according to claim 10, characterized in that a thermal protection blade (16) is disposed on the metal plate  (15) so as to limit the thermal conduction through the fixing means.  12. Protective panel according to claim 11, characterized in that the blade (16) of thermal protection consists of mica coated with a silicone resin.  13. Protective panel according to claim 12, characterized in that an adhesive (17) is stuck on the blade (16).  14. A method of manufacturing a panel according to any one of the preceding claims, characterized in that  - a set of stiffeners (13) is welded to the outer skin (4),  - the free end of the stiffeners is fixed  (13) radial plates (15) so as to form, with the stiffeners and the outer skin, receptacles for receiving at least two protective layers,  the first thermal protection layer and the ballistic protection layer are put in place by introducing them under the radial plates (15),  - the radial plates (15) are isolated using bonded thermal protection blades,  - there is an adhesive on the blades,  - The following plate (s) of the panel are applied to the assembly thus obtained.