Ballistic protective textile structure and method for making it

Abstract

A composite ballistics protective textile structure comprises at least a textile element and one or more textile or thermoplastic matrix elements. The first textile element comprises unidirectional yarn fibers or flat strips. The second textile element comprises flat strip elements consisting of unidirectional yarns or thermoplastic films. Additional elements comprise thermoplastic matrix arrangements, based on rubber, elastomeric polymers or being laminated with thermoplastic films, for stabilizing the structure and reducing bullet trauma impacts.

Claims

1. A ballistics protective bullet-resistant textile structure providing a quick dissipation of an energy of a penetrating bullet, comprising: a first warp textile element comprising unidirectional matrix yarns or flat strips; a second weft textile element consisting of unidirectional flat strips of a thermoplastic material; said unidirectional yarns or flat strips of said first warp textile element being interleaved in a warp arrangement with said second weft textile element; said thermoplastic material of second weft textile element being partially softened or melted to rigidly bind said unidirectional matrix yarns or flat strips of said first warp textile element; and a third non-textile stabilizing element impregnated in said first warp textile element and said second weft textile element for stabilizing and reducing bullet impact traumas, said third non-textile stabilizing element comprising rubber or elastomeric polymer materials or a combination thereof laminated with thermoplastic films; said first warp textile element comprising para-aramid matrix yarns or flat strips, or yarns or flat strips of an ultra-high-molecular-weight polyethylene (UHMWPE) matrix; said second weft textile element consisting of flat strips of a para-aramid matrix, processed by glue, adhesive or thermoplastics matrix materials, or UHMWPE matrix flat strips, or thermoplastics films such as polyethylene (PE), polyurethane (PU), polypropylene (PP), polyamide (PA), ethylene-vinyl acetate (EVA), or any thermoplastics materials adapted to be extruded to a film form; and said weft flat strips having a height less than or equal to 2 cm.

2. A structure, according to claim 1, characterized in that said first warp element and second weft element are at least partially impregnated or laminated.

3. A method for making a ballistic protective bullet-resistant textile structure, according to claim 1, said method comprising the steps of: providing said first textile warp element comprising unidirectional matrix yarns or flat strips adapted to dissipate a portion of a bullet impact energy by breaking or fibrillating said matrix yarns or flat strips; providing said second textile thermoplastic material weft element comprising unidirectional matrix flat strips for further dissipating said bullet impact energy; arranging on a creel said first warp element; interweaving in a warp arrangement said first warp element with said second weft element; and partially melting said second weft element, thereby causing the thermoplastic material of said second weft element to rigidly bind said warp element matrix yarns or flat strips to one another; and impregnating said first warp textile element and said second weft textile element with said third non-textile element comprising rubber or elastomeric polymer materials or a combination thereof laminated with thermoplastic films for stabilizing and reducing traumas due to a bullet impact.

4. A method according to claim 3, characterized in that said partial melting of said second weft element is carried out by calendering.

5. A method, according to claim 3, characterized in that said partial melting of said second weft element is carried out by a hot laminating.

6. A method according to claim 3, characterized in that said partial melting of said second weft element is carried out by IR lamps.

7. A method according to claim 3, characterized in that said method further comprises the step of impregnating said structure by thermoplastics matrix materials comprising rubber or elastomeric polymers or a combination thereof, or laminating said structure by thermoplastics films selected from PE, PU, PP, PA, EVA, or any thermoplastics materials adapted to be extruded to a film form.

8. A method according to claim 3, characterized in that said method further comprises the step of molding to a compact condition one or more layers of said first warp element and second weft element.

9. A method according to claim 3, characterized in that said method is carried out on-line on a loom.

10. A method according to claim 3, characterized in that said method is carried out on parallel weaving systems.

11. A method according to claim 3, characterized in that said first warp textile element comprises para-aramid matrix yarns or flat strips, or yarns or flat strips of a UHMWPE matrix.

12. A method according to claim 3, characterized in that said second textile weft element consists of flat strips of a para-aramid matrix, processed by glue, adhesive or thermoplastics matrix materials, or UHMWPE matrix flat strips, or thermoplastics films such as PE, PU, PP, PA, EVA, or any thermoplastics materials adapted to be extruded to a film form.

13. A method according to claim 3, characterized in that said weft flat strips have a height less than or equal to 2 cm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Further characteristics and advantages of the present invention will become more apparent hereinafter from the following detailed disclosure of a preferred, though not exclusive, embodiment of the invention, which is illustrated, by way of an indicative but not limitative example, in the accompanying drawings, where:

(2) FIG. 1 is a perspective view of the ballistic protective textile structure according to the present invention;

(3) FIG. 2 is a cross-sectional view of the ballistic protective textile structure according to the invention;

(4) FIG. 3 is another cross-sectional view of the ballistic protective textile structure according to the invention; and

(5) FIGS. 4 and 5 show two further partially cross-sectioned perspective views of the ballistic protective textile structures according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) With reference to the number references of the above mentioned figures, the method according to the present invention comprises a first flat or plain weaving step, in which a first element, generally indicated by the reference number 1, comprising unidirectional warp fibers or flat strips is made.

(7) Said flat strips are arranged on suitable creels and are interleaved in a warp arrangement with a second element 2, consisting of like unidirectional thread flat strips, or a thermoplastic matrix film.

(8) The warp components can comprise either warp yarns or flat strips made of a para-aramid matrix, such as KEVLAR (poly-paraphenylene terephthalamide), TWARON (p-phenylene terephthalamide) or the like, as commercially available, or warp yarns or flat strips of a ultra-high-molecular-weight polyethylene (UHMWPE) matrix, such as SPECTRA (gel-spun UHMWPE), DYNEEMA (gel-spun UHMWPE), TENSYLON (UHMWPE material), or the like as commercially available.

(9) The weft yarns advantageously comprises high toughness yarns.

(10) In this connection, it should be pointed out that the yarns used do not have any linear density limitations.

(11) The weft yarns, in turn, comprise flat strip elements of a para-aramid matrix, such as KEVLAR, TWARON or other commercially available para-aramid matrix arrangements, as suitably processed by glue, adhesive or thermoplastic materials, or further flat strip elements of a UHMWPE matrix, such as SPECTRA, DYNEEMA, TENSYLON, or other commercially available arrangements, or further thermoplastic films such as PE, PU, PP, polyamide (PA), ethylene-vinyl acetate (EVA), or, in principle, any desired or target thermoplastic material suitable for extruding a film.

(12) The most suitable condition for holding such a yarn/thermoplastic material ratio without negatively affecting the end energy or power dispersion properties, is achieved by using, as a weft pick or yarn arrangements, flat strip elements of a height less than or equal to 2 cm.

(13) The material thus made is subject to a further stabilizing process, comprising partially melting the thermoplastic matrix by hot calendering or laminating, or by IR lamps, operating under operative conditions varying depending on the thermoplastic material used.

(14) The stabilizing method can be carried out both in-line on the loom, and in parallel on dedicated systems.

(15) The above material combination can be further impregnated by additional elements, indicated by the reference number 3, such as thermoplastic matrixes based on rubber or elastomeric polymers or a combination thereof, or being laminated by different thermoplastic films such as PE, PU, PP, PA, EVA or, in principle, by any thermoplastic materials providing an extruded film.

(16) The above mentioned additional components facilitate an impact energy distribution through the underlying support, owing to a viscoelastic fiber deforming, breaking or fibrillating.

(17) The thermoplastic impregnation moreover properly compacts either one or more support layers, including the above mentioned elements 1 and 2, by a molding method.

(18) With reference to FIGS. 4 and 5, examples of the subject textile structures are herein shown, the reference number 1 showing a thermoplastic film or yarn flat strip having a high toughness, and the reference number 2 indicating high toughness yarns, the reference number 3 also indicating high toughness yarns and 4 a thermoplastic filmwebnon-woven fabric.

(19) Ballistic data show that the above structure does not provide results like those which can be achieved by individual layers.

(20) In fact, the presence of a gap or discontinuity, facilitates a reduction of traumas deriving from a bullet impact, and an improved energy distribution.

(21) Said discontinuity or gap can comprise air, or any other desired materials, such as different density and thickness felt or foamed materials.

(22) The examples mentioned hereinbelow have been achieved by experimental tests performed by the Applicant and are herein shown only by way of an illustrative and not limitative purpose.

(23) The tests shown, in particular, are related to packages having a weight from 5.10 kg/m2 and 5.2 kg/m2, depending on the individual layer weights.

(24) The packages have been applied to a plasticine block designed to verify traumas of bullets fired with a firing speed according to the NIJ standard, that is Cal. 9 mm FMJ RN and 44 Mag. JHC bullets, to measure the VO value.

(25) For each package three shots have been fired.

Example 1

(26) 28 layers of a 0/90 crossed unidirectional fabric comprising a 930 dtex multifilament para-aramid fiber warp (element 1) and a middle toughness 2 cm TENSYLON flat strip (element 2) being stabilized by a PE base thermoplastic film.

(27) The speed and trauma data are shown in the following table:

(28) TABLE-US-00001 Shot Bullet speed Trauma Panel weight Average trauma No. (m/s) mm Kg/m2 (mm) Cal. 9 mm FMJ RN 1 444 30 5.12 29.7 2 437 31 3 429 28 Cal. 44 Mag. 1 439 48 5.13 48.6 2 435 44 3 439 54

Example 2

(29) 38 layers of a 0/90 crossed unidirectional fabric comprising a 930 dtex multifilament para-aramid fiber warp (element 1) and a 2 cm ionomeric polyethylene film flat strip (element 2).

(30) The speed and trauma data are shown in the following table:

(31) TABLE-US-00002 Shot Bullet speed Trauma Panel weight Average trauma No. (m/s) mm Kg/m2 (mm) Cal. 9 mm FMJ RN 1 439 34 5.12 35.7 2 444 38 3 437 35 Cal. 44 Mag. JHC 1 436 63 5.12 60 2 445 58 3 440 59

Example 3

(32) 54 layers of a 0/90 crossed unidirectional fabric comprising a 670 dtex multifilament para-aramid fiber warp (element 1) and a 2 cm ionomeric polyethylene film flat strip (element 2).

(33) The speed and trauma data are shown in the following table:

(34) TABLE-US-00003 Shot Bullet speed Trauma Panel weight Average trauma No. (m/s) mm Kg/m2 (mm) Cal. 9 mm FMJ RN 1 436 32 5.20 33.0 2 441 35 3 439 32 Cal. 44 Mag. JHG 1 428 51 5.10 52.7 2 445 55 3 444 52

(35) It has been found that the invention fully achieves the intended aim and objects.

(36) In practicing the invention, the chosen details may be different both with respect to the individual constructional layer of the package, and with respect to the individual layer component elements.