Ballistic-resistant laminate comprising at least two pairs of unidirectional layers separated by a tie layer and wherein the fibers are parallel to each other

Abstract

The present invention relates to a structure for constructing a ballistic protection, which combines high projectile arresting and trauma reduction performance with high flexibility. A ballistic laminate is produced, which includes at least two pairs of unidirectional layers separated by a connecting layer, wherein the fibers are parallel to each other. In a preferred embodiment, the ballistic structure includes a plurality of unidirectional ballistic yarn sub-laminates. Each sub-laminate includes at least two unidirectional ballistic layers, the fibers of which are substantially parallel, i.e. oriented in the same direction; the two ballistic layers with parallel fibers are not in direct contact with each other, but are separated (and kept together) by a layer including, for example, a film that is also an adhesive. The sub-laminates are then coupled together so that the unidirectional fibers of each sub-laminate are substantially perpendicular to the unidirectional fibers of the adjacent sub-laminates.

Description

Technical Field

[0001] The present invention relates to structures for constructing ballistic protection which combine high bullet stopping and trauma reduction properties with high flexibility. Prior art

[0002] The scope of the present invention is a ballistic-resistant structure consisting of fibers or strips (hereinafter referred to as fibers) in the form of modules.

[0003] The first ballistic protectors were produced by superimposing fabrics with a traditional structure (warp-weft type) in which the weft threads passed through the warp threads; although some small modifications have been implemented over time, this type of fabric always has two groups of fibers (usually perpendicular to each other) that are also interspersed with some weaves, that is, different types of crossovers between the threads themselves.

[0004] These known textile structures have several disadvantages:

[0005] - acoustic reflection nodes responsible for absorbing the energy of the incident projectile are created at the intersections between the fibers; this reflection causes the fibers to experience stresses caused by the forces of both the incident and reflected waves, with a consequent weakening of the structure;

[0006] - The yarns used for the weft are woven into the fabric by a process (such as a "defiler") which imparts a torsional twist to the yarn, which causes the fibers to be non-parallel to the yarn direction; this misalignment reduces the anti-ballistic properties of the yarn.

[0007] A net improvement has been achieved by producing unidirectional fabrics; these fabrics consist of layers of yarns aligned and parallel to one another, partially or fully impregnated with different kinds of matrices.

[0008] The final structure of a unidirectional (UD) fabric consists of the superposition of several layers of unidirectional fibers, each of which is superimposed to the previous layer at an angle of generally about 90°. In this case, the cohesion of the structure is ensured by the use of a matrix / resin, since there is no crossing between the yarns belonging to the same layer.

[0009] The latter structure has the undoubted advantage that there is no crossing of the yarns, so that the sound waves can be absorbed without being reflected.

[0010] Likewise, these structures have the disadvantage of being deformable, as they must rely on the cohesion between the layers created by the use of a matrix, as they have no physical cross-linking between the yarns.

[0011] Due to this deformability, the outer surface of the fabric must be protected by additional elements (such as films) which also ensure acceptable wear resistance during use.

[0012] Further ballistic improvements have been achieved by using multiaxial fabrics in which the ballistic yarns are arranged unidirectionally at an angle to each other in overlapping layers and are then sewn together by a knitting process; in a higher performance variant, adjacent thread layers arranged perpendicular to each other are stabilized by the presence of an additional adhesive layer (film type). It should be noted that this feature (i.e. the presence of a film between the 0° layer and the 90° layer) has brought about a significant reduction in trauma.

[0013] As mentioned above, the ballistic performance of the structure is evaluated by means of two main parameters: the first is the so-called V50, i.e. the velocity at which 50% of the projectiles are stopped by the fabric; the second relates to the wound depth associated with the deformation (back face deformation BFD) experienced by the ballistic structure after the projectile has been stopped. The latter value is usually defined with reference to a standard (e.g. NiJ04) by measuring the depth of the indentation produced during a ballistic impact test in a piece of plasticine on which the ballistic package is placed.

[0014] To inhibit this trauma, it has been found that the introduction of an adhesive film between fiber layers arranged perpendicular to each other (including in UD and multi-axial structures) greatly reduces the trauma without a significant loss in V50.

[0015] Regardless of the ballistic structure, it is known that the part responsible for stopping the projectile is mainly the fibers; the fibers most widely used today are those based on polyethylene, polypropylene, glass, carbon, aramid-type fibers including in the form of copolymers, PVA fibers, etc.

[0016] In recent years, fibers characterized by very high values ​​of elastic modulus and tensile strength have been placed on the market; for example those based on UHMWPE (ultra-high molecular weight polyethylene), which have a tensile strength of more than 40 cN / dtex and a modulus of more than 135 GPa; these fibers are typically about 30% more resistant than the best aramid-based fibers.

[0017] However, resins (especially film types) have not experienced the same development in mechanical properties.

[0018] Therefore, attempting to use the same fiber / matrix textile configuration for high performance fibers and a matrix that does not have high performance does not result in the desired benefits.

[0019] Specifically, textile structures can absorb energy by the formula developed by Cunniff shown below (Cunniff, PM, "Dimensional Parameters for optimization of textile-based body armor systems" in the proceedings of the 18th International Ballistics Symposium, San Antonio, Texas, USA, November 15-19, 1999), which shows that the energy absorbed is proportional to the maximum elastic energy that can be stored per unit mass of fiber and the typical sound wave velocity of the fiber.

[0020]

[0021] In practice, it is necessary to try to absorb maximum energy by exploiting the fiber's ability to absorb elastic energy (which in turn depends on tensile strength and elongation at break), and equally to try to transmit the energy away from the projectile impact zone as quickly as possible (related to the speed of the sound waves in the fiber); it is for this reason that in today's textile structures, each unidirectional fiber layer is rotated 90 degrees relative to the previous layer; in this way the energy is removed from the projectile's impact point as quickly as possible.

[0022] In order to improve the ballistic response of the structure, it is therefore necessary for the fibers to have high tensile strength, high elongation, low density and high elastic modulus.

[0023] As mentioned above, UD fabrics and multiaxial fabrics require the application of a resin that guarantees structural stability and the greatest possible ability to keep the fibers in place during a ballistic event.

[0024] In the case where the layers consist of fibres and resin, Cunniff's formula remains valid, but account must be taken of the fact that, for the same mass, some of the fabric has been replaced by resin, which actually reduces the tensile strength of the fibres, their elastic modulus and, with it, the speed at which the energy is absorbed by the sound waves.

[0025] This has been confirmed experimentally.

[0026] As is known, resin increases the delamination surface area by holding the fibers in position where they work together; if the difference between the properties of the fibers and the resin is too great, the two materials work in completely inconsistent ways, thus reducing the ballistic arresting capabilities of the structure. In this case, the resin prevents the yarn fibers from working properly.

[0027] One skilled in the art might be tempted to reduce the amount of resin to remedy this problem, but this creates two problems:

[0028] - The amount of resin must be reduced to such an extent that the structure does not have sufficient cohesion;

[0029] - Currently produced membranes cannot be less than 6g / m at depths greater than 100cm 2 , however the depth of the fabric is usually 160cm.

[0030] In addition to the above, in warp and multiaxial weft UD type fabrics, it has been found that the lighter the individual unidirectional layers, the higher the V50 value and the less traumatic if the relative movement of the fibers in two adjacent layers rotating relative to each other is restricted.

[0031] Purpose of the Invention

[0032] The main object of the present invention is to provide an anti-ballistic protective element which alleviates the disadvantages of the known art. SUMMARY OF THE INVENTION

[0034] According to the invention, this result has been achieved by manufacturing a ballistic-resistant laminate for ballistic protection, the laminate comprising at least one first unidirectional textile sub-laminate and at least one second unidirectional textile sub-laminate, the first textile sub-laminate and the second textile sub-laminate each comprising a first textile layer having a first plurality of ballistic-resistant fibers arranged substantially in the α direction and a second textile layer comprising a second plurality of ballistic-resistant fibers arranged substantially in the α direction, the first textile layer and the second textile layer of each sub-laminate being separated by a connecting layer, the first textile sub-laminate and the second textile sub-laminate being in contact with each other and arranged in such a way that the fiber direction of the first sub-laminate and the fiber direction of the second sub-laminate form an angle of 90°+ / -10° relative to each other. The unidirectional textile layers are preferably pre-impregnated with a resin matrix comprising one or more of the following materials: acrylic, polyethylene, polybutylene, polyurethane or a resin based on block copolymers. The protective layer separating the first and second textile layers of each sub-laminate comprises one or more of the following materials: polyurethane, polyester, polyamide, polyethylene or polypropylene in the form of a (preferably adhesive) film or other structure (such as a mesh, felt or woven / non-woven fabric).

[0035] According to a preferred embodiment, the bulletproof fiber is made of aramid material, ultra-high molecular weight polyethylene material called UHMWPE, co-aramid, polybenzoxazole or polybenzothiazole material, liquid crystal, glass, carbon, etc., which are also mixed with each other. Preferably, the bulletproof laminate comprises a plurality of through holes with a diameter between 0.02 mm and 3 mm, which pass through the first sub-laminate and the second sub-laminate and have a density between 0.5 and 10 per square centimeter.

[0036] Preferably, the first textile sub-laminate and the second textile sub-laminate are joined together by pressing. When through holes are present, they are preferably made after the pressing stage. In a preferred embodiment, the first textile sub-laminate and the second textile sub-laminate are joined together by sewing. At least some of the through holes can be made during the sewing stage. Sewing is preferably carried out using a needle having a diameter at least 20% larger than the diameter of the thread used for sewing. Alternatively, the holes can be drilled by a system equipped with a roller or cylinder with a plurality of punches to create holes when the roller (or cylinder) rolls on the laminate.

[0037] The weight of each textile element is preferably 10 g / m 2 and 500g / m 2 between.

[0038] In a second aspect of the present invention, there is provided a method for producing a ballistic-resistant laminate as described above. The production method comprises the following steps:

[0039] - placing at least a first unidirectional textile layer, an adhesive film and at least a second unidirectional textile layer in contact with each other in such a way that the adhesive film is placed between the textile layers and holds the textile layers together. The first textile layer and the second textile layer comprise a plurality of ballistic-resistant fibers arranged in substantially the same direction (+ / - 10°);

[0040] - bonding together at least the first textile layer, the adhesive film and at least the second textile layer by pressure to produce a textile sub-laminate;

[0041] - placing the first textile sublaminate and the second textile sublaminate in contact with each other so that the direction of the fibers of the first textile sublaminate and the direction of the fibers of the second textile sublaminate are at an angle of 90°+ / -10° relative to each other;

[0042] - bonding together at least the first textile sub-laminate and at least the second textile sub-laminate at a pressure between 1 and 200 bar.

[0043] According to another aspect of the present invention, there is provided a ballistic protection comprising at least one layer of the above-described ballistic-resistant laminate.

[0044] According to another aspect of the invention, there is provided a hybrid ballistic-proof packaging comprising at least one ballistic-proof laminate as described above, based on UHMW polyethylene fibers having a tenacity greater than 30 cN / dtex, a modulus greater than 120 GPa and an elongation greater than 2%, and at least one layer of fabric based on aramid copolymer having a fiber tenacity greater than 26 cN / dtex, a modulus greater than 100 GPa and an elongation greater than 2%, so that: the specific energy absorbed by 55 gr fsp is higher than 35 j / kg / m 2 ; According to standard NIJ0.101.06, for weight less than 4.6kg / m 2 The ratio between the V50 obtained with the .44 Magnum Speer HP projectile and the maximum trauma recorded according to the same NIJ 0.101.06 standard is greater than or equal to 11 (m / s) / mm. According to a preferred embodiment, when through holes are present, the through holes will have a diameter between 0.02 mm and 3 mm. Preferably, the number of through holes per square centimeter will be between 0.5 and 10.

[0045] With the structure according to the invention, ballistic performance superior to existing products on the market is achieved, as well as high flexibility, durability and long-term stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] These and further advantages, objects and features of the present invention will be better understood by those skilled in the art from the following description and the accompanying drawings relating to illustrative embodiments of the features, but not to be understood in a limiting sense, in which:

[0048] Figure 1 A perspective view showing a structure for a ballistic protection according to a possible embodiment of the invention before drilling;

[0049] Figure 2 Shows Figure 1 A side view of the structure in FIG.

[0050] Figure 3 The inflection (or discontinuity) of a unidirectional fiber in a straight direction caused by a through hole is diagrammatically shown.

[0051] Detailed Description

[0052] According to a preferred embodiment of the present invention, there is provided a structure comprising a plurality of unidirectional ballistic yarn sub-laminates. Each sub-laminate comprises at least two unidirectional ballistic layers having substantially parallel fibers, i.e. oriented in the same direction; the two ballistic layers having parallel fibers are not in direct contact with each other, but are separated (and held together) by a layer comprising, for example, a film, which may be an adhesive.

[0053] The sub-laminates are then joined together such that the unidirectional fibers of each sub-laminate are substantially perpendicular to the unidirectional fibers of adjacent sub-laminates.

[0054] like Figure 1 As shown, the structure includes an overlay of layers consisting of:

[0055] - a unidirectional fiber layer 101 in direction α (eg 0°), which is preferably impregnated with a matrix (eg a matrix with low modulus and high elongation);

[0056] - an adhesive polymer structural layer 105, such as a film, a mesh, etc.;

[0057] a unidirectional fiber layer 101 impregnated with a matrix (e.g. with low modulus and high elongation) in direction α (parallel and not in direction β perpendicular to the α direction (90° in this example) as in solutions of the known art);

[0058] - a unidirectional fiber layer 103 in a direction β perpendicular to the direction α;

[0059] - an adhesive polymer structural layer 105, such as a film, a mesh, etc.;

[0060] - A unidirectional fiber layer 103 impregnated with a matrix in the β direction (rather than in the α direction perpendicular to the β direction).

[0061] exist Figure 1 In the structure in, the three upper layers 101, 105 and 101 constitute a first sub-laminate, in which the fibers (in layer 101) are all oriented in the same direction α; the three lower layers 103, 105 and 103 constitute a second sub-laminate, in which the bulletproof fibers (in layer 103) are all oriented in the β direction perpendicular to α.

[0062] One feature of this structure is that the unidirectional anti-ballistic fiber layers are arranged so that they form subset layers with parallel fibers (in pairs in our example, but there can be more than two; first layer 101 and second layer 101; first layer 103 and second layer 103) and the parallel pairs are separated by an adhesive element 105 (e.g. an adhesive film). In contrast, in a preferred embodiment of the invention, pairs of adjacent layers with fibers perpendicular to each other (preferably second layer 101 and first layer 103 impregnated with a matrix) are in direct contact with each other, without a protective film in between. This direct contact feature improves the anti-ballistic performance of the structure.

[0063] For simplicity, in this specification we refer to exact measurements and definitions (such as 0° and 90° or parallel and perpendicular), but for the purposes of the present invention, it is intended that such measurements and definitions should be approximated to a certain degree, so that 0° means 0°+ / -10°; 90° means 90°+ / -10°, parallel means "substantially parallel", and perpendicular means "substantially perpendicular".

[0064] Figure 2 The side view shows Figure 1 The same structure, in which the order of the layers can be seen (101+105+101+103+105+103), and again showing that the adhesive film separates the layers having fibers that are parallel (or more precisely substantially parallel) to each other, but does not separate the layers having fibers that are perpendicular (substantially perpendicular) to each other.

[0065] The bulletproof layer according to a preferred embodiment of the present invention is made of bulletproof yarns, which are arranged unidirectionally in the above-mentioned direction. Small plates or monofilaments can be used as substitutes for yarns usually composed of many filaments. The yarn count of these yarns (plates, monofilaments) is advantageously between 20 and 6500 d / tex, their toughness is higher than 10 cN per d / tex, the modulus is higher than 40 GPa, and the tensile elongation is between 1% and 10%; for example, Produced under the trade name Aramid yarns belong to these categories.

[0066] In addition to aramid yarns, ultra-high molecular weight PE yarns can also be used, for example, Produced under the trade name and The yarn may also be known under the trade name or in the form of a board. Produced by Artec's co-aramid yarns are known under the name Artec. These yarns are characterized by a dynamic tensile strength that is at least twice as high as the static strength, thus allowing high anti-ballistic properties.

[0067] Preferably, the layers of ballistic yarn constituting the ballistic-resistant structure according to the invention are pre-impregnated with thermoplastic resins and thermosetting resins, including mixtures thereof; the mechanical properties of these resins may be elastic, plastic, viscoelastic, etc. Among them, acrylic resins, polyethylene, polybutylene, polyurethane, resins based on block copolymers (styrene-butadiene-styrene type) (also known under the trade name of ) is particularly useful. The amount applied is between 3% and 30%. The purpose of applying the resin is to promote the bonding between the layers of unidirectionally deposited and superimposed yarns. In addition, the resin brings the various fibrils of the yarn into close contact, thereby forming a continuity that is beneficial for ballistic purposes. As mentioned above, in each pair of unidirectional "parallel" ballistic layers (e.g. Figure 1 and Figure 2 An additional element (105) is applied between 101 and 101 in order to stabilize the structure and protect the yarn fibrils from the mechanical effects generated by the mutual friction of the layers during use. Element 105 can also be a discontinuous film, felt, net and non-woven fabric.

[0068] The composition of these layers 105 (e.g. films) must allow adhesion between the layers. Therefore, elements based on thermoplastic polymers and thermosetting polymers (including mixtures thereof) are used. The mechanical properties of these resins can be elastic, plastic, viscoelastic, etc. For example, polyethylene, polyurethane, polycarbonate, polyamide, polypropylene, and polyester films (also in the form of copolymers) are particularly useful. Advantageously, the weight of these additional elements should be as low as possible, ideally around 3 g / m 2 The structure thus obtained is subjected to the effects of pressure and temperature. The pressure is advantageously between 2 and 200 bar, and more advantageously between 20 and 40 bar. The pressing temperature is between 20° C. and 200° C., and more advantageously between 30° C. and 110° C. The pressure / temperature combination is applied using processes known to those skilled in the art, and both can be continuous and discontinuous. The laminate thus obtained undergoes further processing stages, including the formation of discontinuities throughout the entire structure of the laminate.

[0069] Ballistic tests have shown that, for the same mass of ballistic protection, the lower the weight of the individual layers of protection, the better the performance obtained.

[0070] Therefore, the ideal bulletproof structure should have the following characteristics:

[0071] 1. Fibers with high tensile properties (high toughness, high elongation, high modulus),

[0072] 2. A single layer with a defined weight,

[0073] 3. Impregnate a single unidirectional fiber with a suitable resin,

[0074] 4. A low weight membrane placed between adjacent layers wherein the fibers are parallel to one another to restrict relative movement between the fibers of adjacent layers, the layers having a tenacity of at least 20 MPa and an elongation at break exceeding 500%,

[0075] For example, the total weight is 100g / m 2Ballistic fabric, including 4 pieces of approximately 22g / m 2 unidirectional layers, between which 3g / m 2 membrane.

[0076] As mentioned above, the best way to prevent movement between fibers in adjacent layers having fibers parallel to each other during use is to use an adhesive film.

[0077] While individual layers can be made nearly as light as desired, there is a limit to how light a film can be, beyond which it may be prohibitive due to production problems.

[0078] The above invention can be used to produce any low-weight unidirectional fiber layers, which are connected to each other, for example, by a membrane; the membrane connecting unidirectional layers that do not rotate relative to each other provides a weak interaction compared to the case where the membrane is placed between layers that rotate relative to each other; contrary to what might be imagined, the effect of this "weak" interaction is positive.

[0079] The membrane stability of the non-rotating unidirectional fiber layers also makes it possible to avoid the application of further membranes on the external surface of the final structure, since the strength is provided by the membrane (or other separation element) itself present between the layers.

[0080] The above-mentioned structure, which is theoretically contrary to the general rule of construction according to the known technology, instead provides the performance of combining high V50 with low trauma.

[0081] If through holes are made through the entire structure to provide greater flexibility to the unidirectional laminate, undulations and thus deflections (or discontinuities) will be created in the straight path of the ballistic yarn, such as Figure 3 As shown. It has been surprisingly confirmed that, by the presence of these deflections, the flexibility characteristics of the structure are greatly improved, and the permeability characteristics are also improved, without compromising the ballistic properties in terms of arresting resistance and the degree of trauma caused by impact energy. The number of these through holes and their diameter can be adjusted to suit the needs of each individual structure (to increase or decrease flexibility and permeability). Advantageously, the holes preferably have a substantially circular shape (but they can also be other shapes, such as elliptical); in a preferred embodiment of the invention, the diameter of these holes is between 0.02 mm and 3 mm, preferably between 0.5 mm and 2 mm. The number of such through holes (i.e. their density) is preferably between 0.1 and 10 per square centimeter, more preferably between 0.5 and 10 per square centimeter.

[0082] In a preferred embodiment, the various layers of the laminate are sewn together and it is the sewing operation that creates the through-holes.

[0083] It is preferred that the diameter of the suture is 20% to 90% smaller than the diameter of the through hole produced by the needle or needle tongue providing this type of suture. This suture is selected according to the structure and weight of the laminate to be manufactured. The suture count is advantageously between 20d / tex and 300d / tex. Threads based on organic polymers (such as polyester, polyamide, polyethylene, polypropylene) or inorganic threads (such as basalt, carbon fiber, glass) are used. The nature of the suture is not critical to the performance of the laminate. In some cases, when the diameter of the suture is much smaller than the diameter of the hole / channel produced and especially in certain types of suture, the thread is not locked and is therefore easily "removable", thereby ceasing to play its role. In this case, a bicomponent monofilament is used for the suture itself, wherein the outer part can be melted more easily than the inner part, the melting point of the inner part being higher so that it remains intact at its temperature during the pressing stage. In a preferred form of embodiment, the needle (eg crochet hook) is fed by a non-ballistic thread which passes perpendicularly through all the layers of the laminate, thus improving the cohesion between the layers of the laminate after being suitably knotted with a knitted or chain knot.

[0084] The length of the binding stitches is advantageously between 1 and 20 millimeters, and the distance between the various seams in the longitudinal direction is advantageously between 1 and 20 millimeters.

[0085] Equipment and machines known to those skilled in the art, such as quilting machines or multi-head sewing machines, may be used to make the seams, which equipment and machines may be appropriately modified.

[0086] As mentioned above, the stitching of the structure is optional and is not necessarily related to the presence of the above-mentioned through holes. However, the presence of the through holes provides the above-mentioned advantages of increased flexibility and air permeability, and if there is no stitching operation, the through holes can be obtained by alternative methods. An alternative method for producing the through holes and the relative discontinuity in the linear direction of the fibers (i.e., without a stitching stage) includes subjecting the laminate to the action of a series of punches placed on a rotating cylinder, which is appropriately loaded to apply the pressure required to puncture the laminate so that the punches penetrate the entire thickness of the laminate.

[0087] In an alternative embodiment of the invention, it is also possible that both techniques, ie stitching and punching (or other techniques for producing through holes) coexist: in this case, some holes will have stitching lines in them, while others will not.

[0088] In order to better describe the content of the present invention, Figure 3The undulations produced in a yarn placed unidirectionally after being pierced by a needle, punch or needle latch are shown. These discontinuities must be produced without causing any damage to the ballistic fiber. Therefore, the punch, hook or needle that produces such discontinuities must have no sharp edges or sharp parts, but must be appropriately rounded.

[0089] The structure of the laminate comprises at least two sub-laminates, each sub-laminate comprising a pair of layers of pre-impregnated yarns, each layer having fibers parallel to each other and separated from each other by a protective film; the at least two sub-laminates are stacked, wherein the direction of the unidirectional yarns in each sub-laminate is oriented at an angle of 90°+ / -10° relative to the adjacent sub-laminate.

[0090] In a preferred embodiment, the number of layers in a single laminate is 4 (2 layers per sub-laminate), but may be more, such as any multiple of 2 (eg 8).

[0091] A ballistic protection made from a laminate according to the invention may comprise a variable number of the above-described laminate structures, preferably ranging from a minimum of 1 to a maximum of 50.

[0092] The structure that is the subject of the invention can be further improved by applying an additional treatment that greatly increases the flexibility of the structure; this improvement is produced during the optional stage of sewing the layers together, resulting from an orderly reduction in thickness along the entire length of the segment.

[0093] These reductions in thickness may be in the same direction as the segment, or at 45° to the direction of the length of the segment, or a combination thereof.

[0094] The best performances are obtained when the reduction in thickness is discontinuous, interrupted by holes through which the bonding element e) is inserted; these holes also have the valuable effect of deflecting the straightness of the anti-ballistic fiber, having a favorable effect on the elongation at break of the fiber itself and increasing its anti-ballistic properties (Cunniff formula for elongation).

[0095] The channel has a width between 0.1 and 1 mm and a length between 1 and 30 mm.

[0096] The reduction in thickness is obtained by subjecting the assembly to further pressing, in which the sewing threads make impressions in the fabric, leaving channels. Pressing causes a reduction in thickness alternating with holes through which the thread e) is passed. The channels / thread holes are effectively alternating.

[0097] In order to achieve this in the case of unidirectional polyethylene-based fiber layers, it is necessary that the bonding element should have a higher softening temperature than the ballistic fibers and that the ballistic fibers should allow themselves to be plastically deformed.

[0098] It is also preferred that there should be no bonding between the bonding element and the thickness reduction (otherwise the ballistic fibres are locked), and there should be bonding between the membrane and the bonding element between two adjacent layers of unidirectional fibres pointing in the same direction. This ensures that the bonding element is cohesive to the structure and does not slip out during subsequent cutting into the vest shape.

[0099] This application also provides the following terms:

[0100] 1. A ballistic-proof laminate for ballistic protection, the laminate comprising at least a first unidirectional textile sub-laminate and at least a second unidirectional textile sub-laminate, each of the first textile sub-laminate and the second textile sub-laminate comprising a first textile layer and a second textile layer, the first textile layer having a first plurality of ballistic-proof fibers arranged in a direction α, the second textile layer comprising a second plurality of ballistic-proof fibers arranged substantially in the direction α, the first textile layer and the second textile layer of each sub-laminate being separated by a connecting layer, the first sub-laminate and the second sub-laminate being in direct contact with each other and being arranged so that the direction of the fibers of the first sub-laminate and the direction of the fibers of the second sub-laminate form a relative angle of 90°+ / -10°.

[0101] 2. The ballistic-resistant laminate according to clause 1, wherein the textile layer is pre-impregnated with a resin matrix comprising one or more of the following materials: acrylic resin, polyethylene, polybutylene, polyurethane, block copolymer-based resins.

[0102] 3. Ballistic-resistant laminate according to one of the preceding clauses, wherein the connecting layer comprises one or more of the following materials: polyurethane, polyester, polyamide, polyethylene, polypropylene in the form of a film or other structure such as a mesh, felt or woven / non-woven fabric.

[0103] 4. The ballistic-resistant laminate according to one of the preceding clauses, wherein the ballistic-resistant fibers comprise one or more of the following materials: aramid, polyamide, high molecular weight polyethylene UHMWPE, co-aramid, polybenzoxazole, polybenzothiazole, liquid crystal, glass, carbon.

[0104] 5. The ballistic-resistant laminate according to one of the preceding clauses, comprising a plurality of through holes with a diameter between 0.02 mm and 3 mm passing through the first sub-laminate and the second sub-laminate and having a density between 0.5 and 10 per square centimeter.

[0105] 6. Ballistic-resistant laminate according to one of the preceding clauses, wherein the first sub-laminate and the second sub-laminate are joined to each other by a pressing action.

[0106] 7. A ballistic resistant laminate according to clause 6, wherein the through holes are produced after the pressing action.

[0107] 8. A ballistic resistant laminate according to any of clauses 5-7, wherein the first sub-laminate and the second sub-laminate are joined together by sewing, and at least a portion of the through holes are formed during the sewing.

[0108] 9. The ballistic-resistant laminate according to clause 8, wherein the seams are made by needles having a diameter at least 20% greater than the diameter of the yarn used for stitching.

[0109] 10. Ballistic protection comprising at least one ballistic-resistant laminate according to one of clauses 1 to 9.

[0110] 11. A method for producing a ballistic-resistant laminate according to one of the preceding clauses, comprising the following steps:

[0111] - arranging at least a first unidirectional textile layer, a connecting element and at least a second unidirectional textile layer in contact with each other, such that the connecting element is inserted between the textile layers and keeps the textile layers bound together, the first textile layer and the second textile layer comprising a plurality of anti-ballistic fibers arranged in substantially the same direction (+ / - 10°);

[0112] - bonding said at least first textile layer, said connecting element and said at least second textile layer to each other by pressure, obtaining a textile sub-laminate;

[0113] - arranging a first textile sublaminate and a second textile sublaminate in contact with each other so that the direction of the fibers of the first textile sublaminate and the direction of the fibers of the second textile sublaminate have a relative angle of 90°+ / -10°;

[0114] - joining together said at least first sub-laminate and said at least second sub-laminate by a pressure between 1 and 200 bar.

[0115] 12. A hybrid ballistic-proof package comprising: at least one ballistic-proof laminate according to one of clauses 1 to 9, based on polyethylene UHMW fibers having a tenacity (tenacity) higher than 30 cN / dtex, a modulus higher than 120 GPa and an elongation higher than 2%; and at least one layer of fabric based on an aramid copolymer having a fiber tenacity (tenacity) greater than 26 cN / dtex, a modulus greater than 100 GPa, and an elongation greater than 2%, such that:

[0116] -Specific energy absorbed by 55gr FSP is higher than 35j / kg / m 2 ;

[0117] - According to NIJ0.101.06 standard, for weight less than 4.6kg / m 2 For packaging, the ratio between V50 of the .44 Magnum Speer HP bullet and the maximum trauma recorded according to the NIJ 0.101.06 standard is greater than or equal to 11 (m / s) / mm.

Claims

1. A ballistic laminate for ballistic protection, the ballistic laminate comprising at least a first unidirectional textile sub-laminate and at least a second unidirectional textile sub-laminate, each of the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate comprising a first textile layer and a second textile layer, the first textile layer having a first plurality of ballistic fibers arranged in a direction α, the second textile layer having a second plurality of ballistic fibers arranged in the same direction α, the first textile layer and the second textile layer of each of the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate being separated by a connecting layer, the connecting layer being inserted between the first textile layer and the second textile layer, the connecting layer being an adhesive, the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate being in direct contact with each other and being arranged so that the direction of the fibers of the at least first unidirectional textile sub-laminate and the direction of the fibers of the at least second unidirectional textile sub-laminate form a relative angle of 90°+ / -10°.

2. The ballistic-resistant laminate according to claim 1, wherein the first textile layer and the second textile layer are pre-impregnated with a resin matrix comprising one or more of the following materials: acrylic resin, polyethylene, polybutylene, polyurethane, block copolymer-based resins.

3. The ballistic resistant laminate according to claim 1, wherein the tie layer comprises one or more of the following materials: polyurethane, polyester, polyamide, polyethylene, polypropylene in film form.

4. The ballistic resistant laminate according to claim 2, wherein the tie layer comprises one or more of the following materials: polyurethane, polyester, polyamide, polyethylene, polypropylene in film form.

5. The ballistic resistant laminate according to any one of claims 1-4, wherein the first plurality of ballistic resistant fibers and the second plurality of ballistic resistant fibers comprise one or more of the following materials: polyamide, ultra high molecular weight polyethylene, polybenzoxazole, polybenzothiazole, glass, carbon.

6. The ballistic resistant laminate according to claim 5, wherein: The polyamide includes aromatic polyamide.

7. The ballistic resistant laminate according to claim 5, wherein: The polyamide includes co-aramid.

8. The ballistic resistant laminate according to claim 6, wherein The polyamide includes co-aramid.

9. The ballistic resistant laminate according to any one of claims 1-4 and 6-8, comprising a plurality of through holes having a diameter between 0.02 mm and 3 mm, the through holes passing through the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate and having a density between 0.5 and 10 per square centimeter.

10. The ballistic resistant laminate of claim 5, comprising a plurality of through holes having a diameter between 0.02 mm and 3 mm, the through holes passing through the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate and having a density between 0.5 and 10 per square centimeter.

11. The ballistic resistant laminate according to any one of claims 1-4 and 6-8, wherein the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate are joined to each other by a pressing action.

12. The ballistic resistant laminate of claim 5, wherein the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate are joined to each other by a pressing action.

13. The ballistic resistant laminate of claim 9, wherein the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate are joined to each other by a pressing action.

14. The ballistic resistant laminate of claim 10, wherein the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate are joined to each other by a pressing action.

15. The ballistic resistant laminate of claim 13, wherein the through holes are produced after the pressing action.

16. The ballistic resistant laminate of claim 14, wherein the through holes are produced after the pressing action.

17. The ballistic resistant laminate of claim 9, wherein the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate are joined together by sewing, and at least a portion of the through-holes are formed during the sewing.

18. The ballistic resistant laminate of claim 10, wherein the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate are joined together by sewing, and at least a portion of the through-holes are formed during the sewing.

19. The ballistic resistant laminate according to any one of claims 13-16, wherein the at least first unidirectional textile sub-laminate and the at least second unidirectional textile sub-laminate are joined together by sewing, and at least a portion of the through holes are formed during the sewing.

20. A ballistic resistant laminate according to claim 17 or 18, wherein the seams are made by needles having a diameter at least 20% greater than the diameter of the yarn used for stitching.

21. The ballistic resistant laminate of claim 19, wherein the seams are made by needles having a diameter at least 20% greater than the diameter of the yarn used for stitching.

22. Ballistic protection comprising a ballistic laminate according to any one of claims 1 to 21.

23. A method for producing a ballistic resistant laminate according to any one of claims 1 to 21, comprising the following steps: - arranging at least a first textile layer, a connecting layer and at least a second textile layer in contact with each other, such that the connecting layer is interposed between the first textile layer and the second textile layer and keeps the first textile layer and the second textile layer joined together, the first textile layer and the second textile layer comprising a plurality of anti-ballistic fibers arranged in the same direction; - bonding the at least first textile layer, the connecting layer and the at least second textile layer to each other by pressure, obtaining a unidirectional textile sub-laminate; - arranging a first unidirectional textile sublaminate and a second unidirectional textile sublaminate in contact with each other so that the direction of the fibers of the first unidirectional textile sublaminate and the direction of the fibers of the second unidirectional textile sublaminate have a relative angle of 90°+ / -10°; - bonding together at least the first unidirectional textile sublaminate and at least the second unidirectional textile sublaminate by means of a pressure between 1 and 200 bar.

24. A mixed bulletproof packaging comprising: Ballistic-resistant laminate according to any one of claims 1 to 21, based on ultra-high molecular weight polyethylene fibers having a tenacity higher than 30 cN / dtex, a modulus higher than 120 GPa and an elongation higher than 2%; and at least one layer of fabric based on an aramid copolymer having a fiber tenacity greater than 26 cN / dtex, a modulus greater than 100 GPa, and an elongation greater than 2%, such that: - Specific energy absorbed by 55 gr fsp is higher than 35 j / kg / m 2 ; - According to NIJ0.101.06 standard, for weight less than 4.6 kg / m 2 For packaging, the ratio between the V50 of the .44 Magnum Speer HP bullet and the maximum trauma recorded according to the NIJ 0.101.06 standard is greater than or equal to 11 (m / s) / mm.

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