KR20130054568A - Textile structure resistant to the impact of bullets and to the penetration of sharp and/or pointed elements and relative production method - Google Patents

Abstract

PURPOSE: A textile structure for withstanding an impact of a bullet and penetration of a sharp and/or pointed element and a manufacturing method thereof are provided to absorb and disperse a high energy, which is generated due to a collision with a projectile, by using elastic extensibility and delamination. CONSTITUTION: A textile structure at least partially includes a ballistic yarn and has resistance to penetration of a sharp element and to an impact of a bullet. The textile structure is at least partially impregnated with a homopolymer, a polycarbonate resin in a copolymer form, a homopolymer which is blended with another copolymer dissolved therein, or a polycarbonate resin in a copolymer form. The textile structure has a thickness which is at least 10% thinner after weaving. The polycarbonate resin is a mixture containing a polyester content of at least 10 wt% of the carbonic acid of bisphenol A.

Description

TEXTILE STRUCTURE RESISTANT TO THE IMPACT OF BULLETS AND TO THE PENETRATION OF SHARP AND / OR POINTED ELEMENTS AND RELATIVE PRODUCTION METHOD}

The present invention relates to a fabric structure that withstands penetration of sharp elements such as blades and / or pointed elements such as needles or ice picks and impingement of projectiles, and methods of making the same.

Structures of this type are mainly used to provide personal protective equipment such as, for example, clothing (outbreak and bulletproof vests).

In certain fields, two types of fabric structures are known, structures that withstand bullet collisions and structures that withstand the penetration of sharp and / or pointed elements.

Fabric structures of known type that provide the best antiballistic properties generally comprise unidirectional or semi-unidirectional structures.

Examples of these structures are Citio, EP1.595.105, DSM NV, WO97 / 00766, Allied Signal Inc., US 4,623,574. No. EP0191306B1 and US 5,354,605, US 7,148,162 B2 and EP0683374 B1 to Andrew D. Park. These structures are partially replaced by conventional weft and warp fabrics.

Yarns, so-called ballistic yarns, from which these structures are made are preferably elastomeric, plastomer-based, having an elastic modulus of less than 41 MPa, as described, for example, in US Pat. No. 5,354,605 (Columns 2-7). It consists of high-strength fibers that are at least partially impregnated or coated with a viscous or viscoelastic polymer.

In fact, the resistance to impact of the projectile is inversely proportional to the elastic modulus of the polymer coating and impregnating ballistic yarn fibers. In order to absorb and disperse the energy due to the impact of the projectile, the fibers forming the ballistic yarn must be deformed and stretched at the same time as possible. The low elastic modulus of the polymeric material causes the fibers to stretch and elastically deform to absorb more energy.

Although these fabric structures provide good resistance to impact of bullets, these fabrics, however, do not provide satisfactory resistance to penetration of sharp and / or pointed elements.

Currently known fabric structures that withstand the penetration of sharp and / or pointed elements generally consist of warp and weft fabrics having plain weave. Rigid polymeric materials with elastic modulus typically higher than 2,000 MPa are applied using conventional processes.

These polymeric materials are thermosetting polymers such as, for example, acrylics, epoxies, phenols and polyesters, as described, for example, in US 4,522,871.

Whether these fabric structures will provide good resistance to penetration of sharp and / or pointed elements, these fabric structures do not provide adequate resistance to impact of bullets. In fact, the polymeric material applied to the fabric structure fixedly bonds the fibers of the yarn that make the structure a substantially unitary structure. Sharp elements cannot separate fibers and pass through this structure. However, depending on the rigidity of the polymeric material applied, the fiber may be plastically deformed to absorb and disperse high energy due to the impact of the projectile.

In addition, rigid thermoset polymeric materials require a long time for complete polymerization. Due to these factors, the fabric structures to which these polymeric materials are applied are batch compressed into sheets having a standard dimension of about 150 x 250 cm, creating an indispensable piece of material in a subsequent process to form a template of a ballistic protective article. do.

A further disadvantage associated with the impregnation of these fabric castings with rigid thermoset polymers is that they can be used in coolers at temperatures below 0 ° C to prevent undesired cure which impedes the required finishing after the structures have been impregnated with the resin. It must be deployed.

Among the various thermosetting resins, in particular phenol and polyester resins, leave undesirable odors in the fabric structures impregnated with these resins.

As provided by various standard regulations, in order to combine both the resistance to the penetration of sharp and / or pointed elements and the properties related to the resistance to projectile collisions, the characteristics of the resistance to projectile collisions are sharp and / or sharp. "Hybrid" structures are now being produced, including at least two structures having other resistance to penetration of the element.

However, these hybrid structures are heavy and rigid, and therefore, articles of clothing made from these hybrid structures are inconvenient to wear.

To overcome the aforementioned disadvantages, DuPont's document WO97 / 21334 proposes the use of thermoplastic ionomer resins in the form of a film having a tensile elastic modulus of about 1,000 MPa.

In this case however there are also two solutions, one of which is to apply the polymeric film to one of the opposite sides of the structure to provide resistance to the impact of the projectile and the other to It is applied to both opposite sides of the structure to provide resistance to the penetration of sharp and / or pointed elements.

In addition, these structures only provide resistance to the penetration of sharp / spiky elements or collision of projectiles only near room temperature, while at a temperature above room temperature, their properties are partially lost.

Finally, in EP1.102.958B1 of Teijin Twaron GmbH, a polycarbonate (PC) film of type LEXAN ^® 103 of GE plastic having a modulus of 2,500 Mpa is disclosed.

In this case, however, as described in this document, due to the high viscosity of the polycarbonate film upon exposure to high temperatures and pressures, sufficient portions of the fibers forming the yarns of the fabric may not be impregnated. Thus, the fibers are not sufficiently bonded to each other to provide reduced resistance to the penetration of sharp and / or pointed elements.

The scope of the present invention proposes a fabric structure that withstands the penetration of sharp and / or pointed elements and the impact of projectiles.

It is a further scope of the present invention to provide a fabric structure that can be used to make comfortable articles that protect people and that is more flexible than what is currently available on the market.

Another scope of the invention is to provide a fabric structure that retains its properties and characteristics over a wide temperature range and is substantially odorless.

Another scope of the invention is to provide a method of making a fabric structure which can be easily manufactured at a reduced cost and which is resistant to the penetration of sharp and / or pointed elements and the impact of projectiles.

These ranges according to the invention are implemented according to the fabric structure having resistance to the penetration of sharp and / or pointed elements and the impact of projectiles as specified in claim 1.

Further features are described in subclaim 2.

These ranges are also implemented according to the method of making a fabric structure having resistance to the penetration of sharp and / or pointed elements and the impact of projectiles as specified in claim 13.

Further features are described in the dependent claims 14-21.

The features of the present invention will become more apparent from the following illustrative non-limiting description in accordance with the accompanying illustrative drawings.

1 shows an example of weft and warp fabric structures that can be used to make a fabric structure according to the present invention.
FIG. 2 shows an example of a fabric structure in which two layers of unidirectional yarns overlapped at an angle of 90 ° +/− 5 ° are interconnected by the second structures 12-13 of the woven yarn.
3 and 4 illustrate exemplary cross-sectional views of the fabric structure of FIG. 1 before and after compression.

Referring to FIG. 1, at least a portion of the weft yarn 2 and / or warp yarn 3 in the fabric 1, in particular all of the weft yarns 2 and the warp yarn 3, consists of ballistic yarns.

Referring to FIG. 2, one or all layers of unidirectional yarns 14, 15 in the structure 10 are bulletproof, although the yarns 12 and 13 also at least partially comprise ballistic yarns.

As is known in the art, ballistic yarns have a tenacity and tensile modulus of the following values:

Strength ≥ 7 g / dtex (according to ISO-Norm 627-1-2)

Tensile modulus ≥ 200 g / dtex (according to ISO-Norm R527)

-Breaking energy ≥ 8 J / g (according to ASTMD Norm 2256)

For illustrative and non-limiting purposes only, these ballistic yarns are aramid based, copolyaramid based, polyvinyl alcohol, polybenzo-oxazole (PBO), polybenzothiazole (PBT), high molecular weight polyethylene, glass, bar It is the same as salt or carbon and includes fibers mixed with each other.

In a preferred embodiment, the ballistic yarns are composed of continuous filament fibers parallel to one another, but may also use twisted, texturized and taslanized yarns mixed with each other.

Bulletproof yarns can be used to modify the adhesive properties of polycarbonate-based polymers according to the present invention to polymers known in the art, such as silicon, or fluorocarbon polymers, for example, to provide water repellency, or fibers of yarn, for example. Other polymers such as butenes, polyacrylates, poly-iso-butylene and polyesters can be pretreated by impregnation.

Bulletproof yarns have a count of 25 dtex to 10,000 dtex, preferably 250 dtex to 4,400 dtex.

By controlling the number of yarns per centimeter and the number of ballistic yarns used in the structures described above, the weight of the fabric is between 50 g / m ² and 1,000 g / m ² , preferably between 100 g / m ² and 500 g / m. Can be ²

One of the characteristics of the present invention is a method of applying a polycarbonate-based polymer to a fabric. The polycarbonate-based polymer is dissolved in a suitable solvent, and this solution is then applied to the fabric structure described above by conventional processes.

Impregnation may also be only partial, ie it comprises only part of the fiber present in the fabric structure, for example even only 10% of the fiber, so that the amount of fiber in the fabric structure impregnated with the polycarbonate-based resin is total Varying from 10% to 100% of the fiber.

The polycarbonate-based resin dissolved in a solvent may be applied to only one of two opposite sides of the fabric structure, for example, in a process known to those skilled in the art.

For the purposes of the present invention, the polycarbonate resin

a) a mixture containing at least 10% by weight of polyester of carbonic acid of bisphenol-A, wherein the remaining part of the mixture is, for example, polystyrene, polyester, polyamide, poly-iso-butylene, polybutene, polyphenol , Resins such as ABS;

b) a copolymer in which repeating units are constituted for at least 10% of the esters of carbonic acid of bisphenol-A.

The polycarbonate-based resin should have the following mechanical properties:

Elongation at break> 100%, according to ISO-Norm RS27;

Tensile modulus ≥ 1500 MPa, according to ISO-Norm R527;

-No impact failure in accordance with the Charpy test at a temperature of 30 ° C, according to standard ISO-Norm 179-1 EU.

In a preferred embodiment, for example, if the polycarbonate-based resin consists of a copolymer (case b), the remaining repeating units thereof are 1,1-bis (4-hydroxy) even if other polymers thereon are not excluded. Phenyl) -3,3,5-trimethylcyclohexane (BPTMC).

For purposes of illustration, the following products may be used as additional components of polycarbonate-based copolymers, siloxanes, succinic anhydrides, diphenylcarbonates, poly (alkylene terephthalates).

The polycarbonate-based resin is dissolved in a suitable solvent selected according to the properties of the resin itself. For example, solvents such as acetone, methyl-ethyl-ketone, ethyl acetate, perchloro-ethylene, water can be used.

The solvent is present in amounts ranging from 10% to 90%.

Mineral fillers such as boron carbide, silicon carbide, silicon oxide or the like in powder form may be added to the solution thus obtained.

In addition, other polymeric materials, which have already been dissolved, may also be present in solution, such as, for example, fluorocarbons or silicone polymers to obtain water repellency.

The solution of the polycarbonate-based resin can be applied to the fabric structure using known methods such as, for example, foulard, spraying, immersion, and the like.

Upon drying, the amount of polycarbonate based resin is 5 g / m ² to 200 g / m ² , preferably 50 g / m ² to 100 g / m ² .

In a preferred embodiment, the viscosity of the solution of the polycarbonate-based resin is set so as to completely impregnate all the fibers of the yarn forming the structure itself.

Alternatively, if higher flexibility is the goal, the viscosity of the solution is increased by changing the solvent / polycarbonate ratio. The increased viscosity of the solution prevents all fibers of the yarns from being wetted, so that some fibers remain in the non-impregnated state. Some of the fibers that are not impregnated with the solution of the polycarbonate-based resin may be further impregnated with additional resins of different compositions. This additional resin may, for example, also be elastomeric, thermoset, thermoplastic or viscoelastic in the mixture.

This additional resin preferably has a tensile elastic modulus at least 10% less than the tensile elastic modulus of the polycarbonate-based resin.

Also in this case these polymers are blended into the filler.

This additional resin can also be appropriately dissolved in the solvent in an amount to obtain a solution having the desired viscosity, and can be applied by known methods similar to those described above.

The amount of this second resin is 5 g / m ² to 100 g / m ² in the dry state.

The additional resin may also be applied in the form of films, nets, powders, felts that may be laminated or applied to one or both surfaces of the fabric structure.

After each impregnation of the fabric structure with a polycarbonate-based resin or additional resin, the solvent is removed, for example, by known methods in certain ovens.

The fabric structure after treatment, i.e. after removal of the solvent, is thus calendered or pressed, preferably continuously pressed so that its thickness is reduced by at least 10% relative to the value corresponding to the woven state.

With this intention, the impregnated fabric structure is exposed to a pressure of at least 10 bar at ≥ 200 ° C. In a preferred embodiment, a pressure of at least 80 bar is applied at a temperature of 200 ° C. for several tens of seconds so that the thickness of the fabric structure is reduced by at least 15%.

This application of high pressure also increases what is known in the art as a "coverage factor".

3 and 4 show a cross-sectional view of the fabric 1 before and after deforming the cross section of the yarn from a circle to a substantially “flat” shape to enhance stretching.

By this method, the ballistic performance of the structure against bullets and sharp and / or pointed elements is increased.

Surprisingly, polycarbonate-based resins have been found to have limited adhesion to the fibers of ballistic yarns used to make textile structures within the scope of the present invention.

Low adhesion values of polycarbonate-based resins are surprisingly useful for the purposes of the present invention. In this way, in fact, upon impact with the bullet, the fibers of the ballistic yarn can absorb and disperse high energy due to the impact of the projectile by elastic elongation and delamination.

It has also been found that polycarbonate-based resins provided in solution in accordance with the present invention provide adequate resistance to the penetration of sharp and / or pointed elements to the material impregnated with the resin.

The energy due to the penetration of sharp and / or pointed elements is generally 50 J, which is considerably less than other energies in the impact of projectiles greater than 1,000 J. The energy resulting from the penetration of sharp and / or pointed elements is not sufficient to separate the fibers bound to each other by the matrix, so that the fabric is brought to an integral surface that cannot be easily penetrated by the sharp and / or pointed elements. Is formed.

Thus, by applying a self-rigid polycarbonate-based resin to a fabric structure made at least partially of ballistic yarn, it is possible to provide a fabric structure that provides excellent resistance to penetration of sharp and / or pointed elements and impact of the projectile. It turns out that there is.

The fabric structure provides greater flexibility as the thickness of the fabric structure is reduced to at least 10% less than the woven thickness.

For example, in a fabric structure having a thickness of 0.25 mm, for example, a 15% reduction in thickness increases the flexibility by more than 50% according to well known mechanical laws.

Thus, the fabric structures of the present invention maintain flexibility and resistance properties that are substantially unchanged at -30 ° C to + 100 ° C.

In addition, the fabric structure according to the invention is preferably odorless.

The fabric structure according to the invention can be combined with other materials such as foams, wovens, nonwovens, felts, polymeric films, for example, in certain articles to protect people against bullets and sharp and / or pointed elements. Or may be used alone.

Fabric structures and methods within the scope of the invention are illustrated with reference to the following non-limiting examples.

Example 1 Weft and warp fabrics having polycarbonate-based resin in copolymer form

The weft and warp fabrics are woven with ballistic yarns of number 550 dtex.

This fabric weighs 155 g / m ² , has a thickness of 0.23 mm, has a density of 13.2 yarn / cm in the weft and a density of 13.2 yarn / cm in the warp yarn.

As a polycarboentic resin, the BPA + BPTMC copolymer is dissolved in ethyl acetate at a rate of 25%-75%.

The fabric is impregnated entirely with this solution and then dried.

The amount of dry resin applied to the fabric was 45 g / m ² .

The fabric thus obtained is compressed at 80 bar at a temperature of 220 ° C. for about 30 seconds.

The final thickness was 0.19 mm (fabric 1).

Thirty-four layers of a fabric (1) of size 40x40 mm simply laid down on top and bottom were tested according to HOSDB standard level HG ₂ KR ₂ and the results are as follows:

-Test with knife = passed

-Test = pass with bullet

Example  2

The same fabric as in Example 1 was impregnated with a solution of 50% polycarbonate and 50% solvent to adjust the viscosity to wet only 70% of the fibers.

The final amount of dry resin was 31 g / m ² .

After compression at 80 bar at 220 ° C. for 30 seconds, the thickness was 0.18 mm (fabric 2).

3434 layers of fabric ₂ were tested according to HOSDB standard level HG ₂ KR ₂ and the results are as follows:

-Test with knife = passed

-Test = pass with bullet

Example  3

As in Example 1, the weft and warp fabrics were totally impregnated with a mixture of a resin composed of 10% polybutene and 90% copolymer of polycarbonate dissolved in a suitable solvent, and the dry weight of the applied resin was 45 after evaporating the solvent. g / m ² .

34 layers of fabric laid up and down were tested according to HOSDB standard level HG ₂ KR ₂ :

-Test with knife = passed

-Pass test = 9 mm bullet

-Pass the test = 0,375 bullets

Example 4 (comparative)

A warp and weft plain weave with a density of 12.2 × 12.2 with a yarn count of 440 dtex was impregnated with phenolic resin. 43 layers of fabric area density of 6,800 kg / m ² were tested in the same manner and the results are as follows.

-Test with knife = passed

-Test = failure with 9 mm bullet

-Test with 0,375 SP = failed

Example 5 (comparative)

Lay both sides of a flat weave warp and weft fabric with a weight of 190 g / m ² , density 8.6x8.6 and yarn number of 1100 with 45 g / m ² ionomer film for a total weight of 90 g / m ² The results are as follows:

-Test with knife = passed

-Test with 0,375 SP = failed

Example 6 (comparative)

80 g / m ² of PC film is inserted between the two layers and 140 g / m ² of Density and Fabric structures consisting of two plain weave warp and weft fabrics with 7.4 × 7.4 yarn / cm were laminated to each other. 6.800 kg / m Total weight HOSDB same test level the floor 19 for the ² HG ₂ Tested according to KR ₂ and the results are as follows:

-Test with knife = passed

-Test = failure with 9 mm bullet

-Test = failed with 0,375 bullets

Claims (21)

A fabric structure composed at least partially of ballistic yarns, having a resistance to penetration of sharp or pointed elements and resistance to impacts from bullets,
The fabric structure is at least partially impregnated with a polycarbonate resin in the form of a homopolymer or copolymer or a polycarbonate resin in the form of a homopolymer or copolymer blended with other polymers dissolved in a solvent, the structure being after weaving Woven constructions having a thickness of at least 10% thinner. The fabric structure according to claim 1, wherein the polycarbonate-based resin is a mixture containing at least 10% by weight of polyester of carbonic acid of bisphenol-A. The fabric structure according to claim 1, wherein the resin is a copolymer in which the repeating unit consists of at least 10% ester of carbonic acid of bisphenol-A. 4. The fabric structure of claim 3 wherein the residual repeat units of the copolymer are represented by 1-1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (BPTMC). The resin according to any one of claims 1 to 4, wherein the resin is
Elongation at break> 100%, measured according to ISO-Norm RS27;
Tensile modulus ≥ 1500 MPa when measured according to ISO-Norm R527;
Fabric structure characterized by the absence of impact fracture according to the Charpy test at a temperature of-30 ° C, measured according to ISO-Norm 179-1 EU. 6. The fabric structure according to claim 1, wherein the thickness of the fabric structure is at least 10% thinner than the thickness corresponding to the weaving condition after applying a pressure of at least 10 bar. 7. The method of claim 1, wherein the weft and warp fabrics are at least partially formed of ballistic yarns, or two layers of unidirectional yarns are interconnected by a second structure, and two of unidirectional yarns. And the layers are mutually arranged at an angle of 90 ° +/− 5%, at least a portion of the unidirectional yarns are ballistic yarns, and at least a portion of the yarns of the second structure comprise ballistic sinusoidal structures. The fabric structure according to any one of claims 1 to 7, wherein the number of fibers impregnated with the polycarbonate resin is at least 10% of the total number of fibers. The fabric structure according to any one of claims 1 to 8, comprising an amount of said polycarbonate-based resin in a dry state of 5 g / m ² to 200 g / m ² . 10. The portion of the fiber of claim 1, wherein the portion of the fiber that is not impregnated with the polycarbonate resin is impregnated with an additional resin of an elastomeric, plastomer-based, thermoset or viscoelastic polymer in the mixture therebetween. Fabric structure, characterized in that. 11. The fabric structure of claim 10, comprising an amount of said resin comprised between 5 g / m ² and 100 g / m ² in a dry state. 12. The ballistic yarn according to any one of the preceding claims, wherein the ballistic yarns are twisted, textured, and translated mixed with each other and are continuous yarns having a number of 25 dtex to 10000 dtex,
Tensile strength ≥ 7 g / dtex (according to ISO-Norm 627-1-2)
Tensile modulus ≥ 200 g / dtex (according to ISO-Norm R527)
Fabric structure characterized by having mechanical properties of breaking energy ≧ 8 J / g (according to ASTMD Norm 2256). 13. A method of making a fabric structure according to any one of claims 1 to 12, which has a resistance to the penetration of sharp and / or pointed elements and resistance to the impact of bullets.
a) forming a fabric structure composed at least partially of ballistic yarn,
b) at least partially impregnating the fabric structure with a polycarbonate-based resin or other polymer dissolved in a solvent in the form of a homopolymer or copolymer,
c) removing the solvent used for the solution from the impregnated fabric structure,
d) compacting the impregnated and dried structure such that at least 10% thickness is reduced. The method of claim 13, further comprising impregnating the fabric structure with additional resin after step c) prior to the step d) of removing the solvent. 15. The method of claim 14, wherein the additional resin is dissolved in a solvent and applied to the fabric structure, wherein the additional step of removing the solvent used for the solution of the additional resin from the impregnated fabric structure further comprises the compression step d). Provided in the. 16. The method of any one of claims 13-15, wherein the method of manufacturing comprises overlapping two layers of unidirectional yarns at an angle of 90 [deg.] +/- 5 [deg.], At least a portion of the yarn of the additional structure and the unidirectional. Interconnecting two layers having additional structures of the weft and warp type, wherein at least a portion of the yarn consists of ballistic yarn. The polycarbonate-based resin according to any one of claims 13 to 16, wherein the polycarbonate-based resin is composed of at least 10% by weight of polyester of carbonic acid of bisphenol-A or the repeating unit consists of at least 10% of ester of carbonic acid of bisphenol-A. It is a mixture containing a copolymer. 20. The method of claim 19, wherein the polycarbonate-based resin is a copolymer whose residual repeating unit is represented by 1-1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane (BPTMC). How to. The method according to any one of claims 13 to 18, wherein the polycarboenitic resin
Elongation at break> 100%, measured according to ISO-Norm RS27;
Tensile modulus ≥ 1500 MPa when measured according to ISO-Norm R527;
A method characterized by the fact that there is no collision fracture in the sample according to the Charpy test at a temperature of-30 ° C., measured according to ISO-Norm 179-1 EU. 20. The method of claim 13, wherein the compressing step consists in applying a pressure of at least 10 bar at a temperature of at least 200 ° C. such that the thickness is reduced by at least 10%. The method of claim 13, wherein the compressing step consists in applying a pressure of at least 80 bar at a temperature of at least 220 ° C. such that the thickness is reduced by at least 15%.

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