FR2537502A1 - COMPOSITE MATERIAL COMPRISING A STRAPPED SHAPE OF A WOVEN TABLE, IMPREGNATED WITH PLASTIC MATERIAL AND PROVIDED WITH AT LEAST ONE EXTERNAL COATING LAYER - Google Patents

Abstract

THE INVENTION CONCERNS A COMPOSITE MATERIAL HAVING MODULE RELATIONSHIPS OF ELASTICITY AND RESISTANCE TO BREAKAGE THAT ARE HIGHER THAN THOSE OF METALS AND IN PARTICULAR OF STEEL AND TITANIUM. THIS MATERIAL INCLUDES A TABLECLOTH 10 OF YARNS OR FIBERS 12 WEAVES, WHICH IS IMPREGNATED WITH A PLASTIC MATERIAL 14 AND OF WHICH AT LEAST ONE FACE IS COVERED WITH A LAYER 16 OF A MATERIAL FORMED OF FIBERS AND IMPREGNATED WITH A PLASTIC MATERIAL. THE INVENTION APPLIES IN PARTICULAR TO THE REALIZATION OF BULLET VESTS AND PROTECTIVE OR SHIELDING WALLS.

Description

INDUSTRIAL PLASTIC

MECHANICAL

  The invention relates to a novel composite material having

  in particular a modulus of elasticity / density ratio and a ratio

  higher tensile strength / density than metals, in particular steel and titanium, as well as its applications, for example in the production of bulletproof vests, shielding and protective walls, beams, tennis rackets, skis, etc. In such applications, traditional materials such as metals and metal alloys have already been replaced by composite materials which are much lighter and more easily conformable.

example by molding.

  In particular, laminate materials formed from

  coated or resin-impregnated boron borers, which have quite satisfactory mechanical performances, but of which

  the extremely high cost price limits the applications.

  It is also known that a material such as fried boron carbide

  té offers a very high resistance to impacts, but presents a behavior of the type called "fragile" to the shock waves, its

  rupture resulting in its total and instantaneous collapse

  In addition, this material must be molded at a temperature above 15000 C and its cost is extremely high.

high.

  Layered materials including

  high-quality carbon fibers coated with resin or

  which have elastic modulus ratios / den-

  sity and very high tensile strength / density

  However, the impact resistance of these materials is mediocre

  and their break-up is of the so-called "fragile" type.

  a very high cost price.

  Also on the market for some time, laminate materials formed of aramid fibers commercially available under the trademark "XEVLAR", but which have a

  high cost price and which have inadequate resistance

  These compounds of aramid fibers and of plastic or resin are currently used in the form of flexible sheets for the production of bullet-proof vests. However, these flexible sheets do not in themselves prevent the penetration of the fibers. piercing bullets and age pretty quickly when

  they are subjected to ultraviolet radiation.

  Composite materials formed from two plates of ductile material (metal or metal alloy) which are bonded to a core of plastic material are also known. However, this bonding does not always ensure the homogeneity of the whole

  when the composite material is subject to

  or significant increases in temperature, in particular

  because of the significant differences in mechanical characteristics

  and coefficients of dilation between the plates of

  ductile material and the core of plastic material.

  The subject of the invention is a light composite material,

  mechanical characteristics at least comparable to those of competing composite materials (for example

  based on aramid fibers), which has a very low cost price

  compared to competing composite materials and

  does not have the disadvantages mentioned above.

  The composite material according to the invention is characterized in that it comprises a framework formed of at least one woven layer of son or metal or synthetic fibers, which is impregnated with a plastic material, and at least one layer of coating outer integral with a face of the web. According to the applications for which this composite material is intended, the plastic material that impregnates the woven sheet

  can be rigid, semi-rigid or flexible, the coating layer

  outer part formed on one side of the web may be of a material having a high surface hardness (for example alumina or ceramic) or be formed of fibers embedded in a plastic material identical to or compatible with that which impregnates the woven web, fibers of this outer coating layer which may be, for example,

  boron, carbon, glass or aramid fibers.

  In general, the composite material according to the invention

  prevents transmission through it of shock waves

  such as the impact of a projectile, while preventing, in some embodiments, the penetration of the

  projectile This composite material according to the invention also

  advantage of not having a brittle type break

  when it experiences shock waves or impacts, and pre-

  to have a relatively high elongation rate at break. According to other features of the invention, aimed at producing bulletproof vests, the material comprises a superposition of woven sheets of the aforementioned type, which are

  in solidarity with each other, and between which are

  terposées rigid and hard material plates, such as boron carbide, alumina, ceramics, titanium, etc., these rigid plates arranged between two sheets being separated from each other by intervals filled with plastic and being offset with respect to

  on both sides of a layer, so as to overlap

  expensive partially on each side of the tablecloth.

  Thus, depending on the dimensions of the plates, a more or less flexible structure is obtained which is suitable for

  wearing a bulletproof vest or garment.

  According to another characteristic of the invention, the density

  threads or fibers forming said woven web are

  in the thickness of the web and for example increases

  from the median plane of it to its outer faces.

  This structure makes it possible, on the one hand, to reduce the weight of the

  material and, on the other hand, to maintain an elasticity

  cited in bending and a modulus of inertia in flexion and in tor-

particularly effective.

  According to other features of the invention, the composite material is produced in the form of a hollow section with a circular, oblong or polygonal section, the outer face of which

  comprises a superficial hardness plastic layer

  These characteristics are more particularly aimed at

  the realization of beams, rods, bars, frames, etc. According to yet another characteristic of the invention, which

  more specifically, the production of skis,

  material comprises a middle layer of a plastic material

  such as an epoxy resin interposed between two layers of

  of the aforementioned type, the outer faces of which are covered

  a layer of fibers coated with plastics material.

  In the following description, given by way of example,

  refers to the accompanying drawings, in which Figure 1 is a schematic sectional view of a first embodiment of the composite material according to the invention; Figure 2 is a schematic sectional view illustrating the application of the invention to the realization of a vest defenses; Figure 3 is a schematic sectional view illustrating another application of the invention to the realization of a reinforcement piece of a bulletproof vest of a known type; Figure 4 is a schematic sectional view of a shielding wall or protection; Figure 5 is a schematic sectional view of an alternative embodiment of the invention for bulletproof vests; Figure 6 is a schematic sectional view of a honeycomb beam using the composite material according to the invention; Figures 7, 8 and 9 are cross-sectional views of structures of circular, rectangular and oblong section respectively, using the material according to the invention;

  FIG. 10 is a sectional view of a ski sole used in

  reading the material according to the invention.

  Reference is first made to Figure 1, which is a schematic

  only partially in section of one embodiment of the material

composite according to the invention.

  This composite material comprises a web 10 formed by

  wise wire or metal or synthetic fibers 12,

  which is impregnated throughout its thickness and all its

  due to a plastic material 14 which can be of the rigid type,

  semi-rigid or flexible, depending on the intended applications of the

  terial. At least one face of the ply 10 is covered with a layer

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  16 of a fiber material 19 coated with a plastics material which is identical to or compatible with the material

  plastic 14 impregnating the web 10 In the example shown

  the other side of the web 10 is also covered with a layer 18 of a fiber material coated with a plastic material which may be identical to the plastic material impregnated with or compatible with the web ci, as in the case of the layer 16 covering the other side of the other layer Depending on the case, the material of the layer 18 may be identical to that of the layer 16 or may be formed of different fibers L ' thickness of the layer 18 can be

  equal to that of layer 16, or else different; the den-

  of these two layers may be equal or different

different from each other.

  Thanks to the plastic material with which they are impregnated, the ply 10 and the layers 16 and 18 are intimately connected.

  to each other and are thus united without risk of

  or separation when the composite material is

  subjected to very severe mechanical stresses.

  This composite material can be formed by hot molding,

  cold or under pressure, or by injection of the

  plastic mold in a mold containing the cloth tablecloth 10

  metal or synthetic and plates or tablecloths

  fibers to form layer 16 and / or

che 18.

  The web 10 may be formed of several layers of a metal or synthetic fabric or be formed by weaving

  three-way wire or metal fiber or synthetic

  The yarns or fibers forming the web 10 may be stainless steel wires having a diameter of 0.2 mm or less, or light metal alloy wires with high mechanical characteristics, or be a mixture or a combination of wire or metal fibers and

yarns or synthetic fibers.

  The fibers used to form the layers 16 and 18 may be boron, carbon, glass fibers, aramid fibers, etc. The materials used to impregnate the sheet

  and layers 16 and 18 may be polymeric resins.

  riseable hot or cold under pressure, a silicone elastomer, polyurethane, etc.

  The composite material according to the invention has the property es-

  to have elastic modulus / density ratios

  and breaking strength / density which are largely superior

  metal, and in particular steel and titanium, especially when the ply 10 is a steel wire fabric, to have a very good damping coefficient of the mechanical and acoustic vibrations, to have a

  very high elongation at rupture, the rupture being

gressive and partial.

  Referring now to FIG. 2, which represents a

  application of the invention to the production of a protective vest

balls.

  The structure shown in FIG. 2 comprises a number of plies 20 of composite material according to the invention, which here are five in number and which each comprise a layer or ply of woven wire or metal fibers impregnated with a flexible plastic material and possibly comprising on one or both sides a layer of fibers impregnated with the same material

  flexible plastics Between the plies 20 are arranged

  22 of a very hard material such as boron carbide or titanium which are spaced from each other between two plies 20 and which are offset with respect to

  on both sides of a sheet 20 so as to

  partially overlap each side of the tablecloth.

  22 have for example a length or a vertical dimension of between 10 and 20 centimeters, and a width or a horizontal dimension of between 4 and 8 centimeters.

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  intervals 24 separating the wafers 22 between two sheets are lined with the same flexible plastic material during the molding of the entire structure The thickness of the structure shown enfigure 2 is for example about 4 mm The flexible plastic material that permeates the webs 20 and which fills the gaps 24 ensures the connection between the different components of this structure The assembly thus obtained can be placed between two textile fabrics forming the

outer and inner faces of the vest.

  The structure shown in FIG. 2 is of the semi-rigid type and is ready for the radii of curvature of the chest and the back.

  This semi-rigidity also makes it possible to absorb

  part of the kinetic energy of a projectile, by

  deformation and movement of the vest in the impact zone.

  In addition, the structure of the composite material according to the invention

  forming the webs 20 avoids a trans-

  of the shockwave resulting from the impact, which

  of this shock wave sensitive parts or organs

  of the body and also avoids the destruction of one or more

  platelets 22 which are not submitted directly to

this shock wave.

  FIG. 3 shows a structure intended to reinforce bullet-proof vests of a known type. This structure is in the form of a corrugated plate 26 made of composite material according to the invention, which is placed for example in a pocket formed, on the outer side or the impact side, by a number of superimposed layers 28 of aramid fibers and, on the body side, by a hand cloth 30 The corrugated plate 26 comprises a woven sheet of metal son impregnated with a plastic material semi-rigid and whose outer face is provided with a coating 32 of very hard material, such as ceramic or alumina, which can be deposited on this outer face by any suitable means, for example by a torch to Plasma or metallization Advantageously, the corrugated plate 26 is formed of a superposition of layers

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  composite material according to the invention, which may have

  different densities from one layer to another, and

  The dulations of this plate which are in contact with the retaining cloth 30 form enlarged bases 340. This structure makes it possible to replace the steel plates which

  are usually placed in pockets of protective vests

  Known balls made of aramid fibers These steel plates

  disadvantages of having too much weight

  both and allow the transmission of shock waves, which

  are very dangerous for the sensitive organs of the body.

  Referring now to Figure 3 which is a schematic

  partial cut of a shielding or protective wall

  protection, for example for a vehicle, for a shield of

  close, etc. This wall includes an outer plate 36 in

  titanium or any other material with

  very high canicles, an inner plate 38 of

  posite according to the invention, and an intermediate corrugated plate

  40 also composite material according to the invention

  internal 38 is formed of a woven metal sheet impregnated with a rigid plastic material and at least one side of which comprises a layer of an impregnated fiber-based material

  of the same rigid plastic material

  medium 40 is formed of an impregnated woven metal web

  of a semi-rigid plastic material.

  Under the effect of a shock on the outer plate 36, the plate

  corrugated 40 tends to flatten by absorbing some of the energy

  kinetics of shock or impact and to dampen the wave of

  shock, while preventing or limiting its transmission to the

  that internal 38 which itself tends to absorb the shock wave

possibly transmitted.

  FIG. 5 represents a partial schematic sectional view of an embodiment variant of a bulletproof vest according to

  The structure shown comprises a web of

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  diane 42 of yarns or woven metal fibers which is -

  impregnated with a flexible plastic material, for example a silicone elastomer, or a high polyurethane foam

  density The two faces of the median ply 42 are covered by

  of a series of flexible webs 44 of fibers such as glass or aramid fibers, which are impregnated with

  flexible plastic material, for example the same elastomer

  The density of the wires or metal fibers forming the woven web 42 varies from the plane

  median of this layer up to its external faces, advantageously

  The density of the ply is, for example, of the order of 0.6 in the median plane and 3 on the external faces, with an average density of between 1 and 2. The number of plies 44 is advantageously between 10 and 1 S 20, the thickness of each ply being between about 0.2 and 0.4 mm. The outermost plies 44 may be formed of fibers different from those forming the innermost plies, the latter being for example fiberglass while the outer layers are made of fiberglass

  carbon, aramid or metal fibers.

  The structure of FIG. 5 has a modulus of elasticity in flexion and a modulus of inertia in flexion and torsion which are at least equal to those of equivalent structures made solely of aramid fibers or of carbon fibers,

  the overall density or the mass of the structure being sensi-

  The structure according to the invention shown in FIG. 5 has a cost price much lower than that of the equivalent fiber structures.

carbon or aramid fibers.

  The composite material according to the invention can also be used for producing tubes, beams, frames, etc. For example, the material of FIG.

  square, rectangular, polygonal, circular section

  oblong and then includes, at least on its ex-

  a preferably rigid plastic coating such as high density polyurethane

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1 l

  skin, that is to say with a relatively superficial hardness

  Such a profile may be hollow or filled with

  light plastic material, for example polyurethane foam

high density rethane.

  FIG. 6 represents, by way of example, a schematic section

  transversal tick of a honeycomb beam of composite material

posite according to the invention.

  This beam is formed by the juxtaposition of two sections of composite material according to the invention, the section of which

  rectangular cross-section is shown partly in

  6, and which each comprise a metallized woven web

  50 impregnated with a rigid plastic material such as high density polyurethane, the two faces of this sheet 50 being covered with a layer of this plastic material optionally comprising (for the outer face of the sheets

  ) glass and / or carbon fibers, for example

sprayed.

  The two sections 50 are juxtaposed along one of their longitudinal vertical faces, and their horizontal faces

  upper and lower are covered with

  metal shaft 52 impregnated with the same rigid plastic material and extending over the entire extent of the beam.

  the junction between the two sections, each woven mat

  metal 52 is also covered with a metal woven strip 54 also impregnated with said plastic material which forms an outer surface layer 56 of relatively high hardness. The sections forming the beam may be empty or filled with a polyurethane or phenolic foam if desired improve thermal and acoustic insulation

  A beam according to the invention may also have a structure

  of the honeycomb type and then be formed of a plurality of

  of sections juxtaposed and assembled to each other

  as described with reference to FIG.

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  Figures 7, 8 and 9 show tubular structures

  composite material according to the invention which comprise each

  cune a framework 60 formed of a woven web of son or metal or synthetic fibers, impregnated with a rigid plastic material such as polyurethane, and whose two faces are covered with a layer 62, 64 of the same plastic material, the outer layer 62 being skin-effect, that is to say having a relatively high surface hardness. Optionally, a sheet 66 of fibers impregnated with plastic material may be provided between the outer face of the woven sheet 60 and the outer layer 62 of plastic, this sheet 66 consisting of a tube or

  two strips wound on the woven web 60 in crossing

  with an angle between 10 and 45 O

  In FIG. 8, the inner layer of plastics material 64

  Stiffening ribs 68 which also have the effect of promoting the delivery of the plastic material by injection. Similarly, the structure of FIG. 9 comprises a stiffener 70 made of plastic material, at the minor axis.

  of the oblong cross section of this structure.

  The structure of Figure 7 is applicable, for example, to

  ski poles, sailboats, pipes.

  The structure of Figure 8 is applicable, for example, to tennis racket frames, as well as to skis when

  it has an appropriate height / width ratio The structure

  FIG. 9 is applicable, for example, to hydraulic turbine blades and wind turbine blades. In these structures, the internal space may be empty or provided with a

  light material having a density of the order of 0.2.

  FIG. 10 is a partial sectional view of a composite material structure according to the invention, which comprises a middle layer 72 of a plastic material such as a resin

  epoxy, placed between two woven webs 74 of threads or

  made of plastic, impregnated with plastic

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  outer faces are each covered with a layer 76 of

  plastic material such as an epoxy resin, itself

  covered with a layer 78 of material formed of

  resin, the fibers being fiberglass, carbon, aramid, etc. This structure is applicable to the production of walls, in particular of motor vehicle bodies, and to the production of the upper and lower flanges of a ski. In this case, the structure of FIG. 10 has a thickness of between 2 and 3 mm and extends all along the ski Such structures forming the upper and lower flanges of a ski allow a very good damping of bending and torsional vibration, and a very large

  stiffness enecrsion, favorable to the catch of edges.

Claims (15)

claims   1 Composite material having a modulus of elasticity ratio   density, and a higher tensile strength / density ratio than metals and in particular steel and   titanium, characterized in that it comprises a structural framework   web of at least one web (10) woven of metallic or synthetic yarns or fibers (123) which is impregnated with a plastics material (14), and at least one outer coating layer   (16, 18) secured to one side of the web (10).   Material according to claim 1, characterized in that said outer coating layer (16, 18) is formed of fibers (19) embedded in a plastics material identical to or   compatible with that which permeates said woven web (10).   Material according to claim 2, characterized in that the fibers are boron, carbon, glass or aramid fibers.   4. Material according to one of the preceding claims,   characterized in that both sides of the web (10) are   provided with a coating layer (16, 18) of the aforementioned type.   Material according to one of the preceding claims,   characterized in that the plastic material (14) impregnating the   said ply (10) is of the rigid, semi-rigid or flexible type.   6 Material according to claim 1, characterized in that the outer coating layer (32) integral with one side of the woven web (26) is a layer of material with a large   hardness such as ceramic or alumina.   Material according to one of the preceding claims,   characterized in that the woven and impregnated web forms a corrugated plate (26, 40).   Material according to one of claims 1 to 5, characterized   rised in that it includes a superposition of woven webs   (20) of the aforementioned type, integral with each other.   Material according to claim 8, characterized in that   plates (22) of rigid and hard material, such as   bure boron, are interposed between two woven webs (20) of the aforementioned type.   Material according to claim 9, characterized in that it comprises at least three superimposed woven plies <20) between which said rigid plates (22) are arranged, these plates arranged between two plies (20) being separated from each other by gaps (24) filled with plastic material and being offset relative to each other on both sides of a web (20) so as to overlap   partially on each side of the web.   Material according to one of claims 1 to 10, characterized   in that the density of the yarns or fibers (12) forming   said web (10) is substantially uniform throughout the entire thickness of the tablecloth.   Material according to one of claims 1 to 10, characterized   characterized in that the density of the yarns or fibers forming said woven web (42) is variable in the thickness of the web and increases from the median plane thereof to its outer faces.   Material according to claim 12, characterized in that   said woven web (42) is impregnated with plastic material   that flexible such as a silicone elastomer or a foam of high density polyurethane.   14 Material according to claim 12 or 13, characterized in that said woven web (42) is secured, by its outer faces, a series of plies (44) of woven fibers such as glass fibers, carbon fiber or aramid   impregnated with a flexible plastic material.   Composite material according to one of Claims 1 to   5, characterized in that, the woven web (50, 60) being impregnated with a rigid plastic material, it is produced in the form of a hollow profile with circular section, oblong or polygonal.   Composite material according to one of claims 1 to   characterized in that it comprises a middle layer (72)   of a plastic material such as an epoxy resin, interpolated   between two woven sheets (74) of the aforementioned type, impregnated with a rigid plastic material, and whose external faces   are each covered with a layer (78) of impregnated fibers   with a rigid plastic material   Protective structure against impacts or shocks, such as for example a bulletproof vest or a shielding wall, characterized in that it is formed from a   composite material according to one of claims 1 to 14.