NL2029154A

NL2029154A - Protective vest

Info

Publication number: NL2029154A
Application number: NL2029154A
Authority: NL
Inventors: Fages Santana Eduardo; Ramón Martínez Guillén José; Gutiérrez Moscardó Óscar; Gisbert Gomis José
Original assignee: Asociacion De Investig De La Industria Textil Aitex
Priority date: 2021-04-29
Filing date: 2021-09-09
Publication date: 2022-09-19
Also published as: NL2029154B1; ES2927140A1

Abstract

A protective vest, characterized in that it comprises: an outer covering made of a non-ceramic material, an auxetic honeycomb inner structure having at least four layers with a plurality of 5 trapezoidal units, wherein each layer is made up internally of at least four sheets of a non- ceramic material, wherein the layers of the auxetic honeycomb inner structure are arranged in twos facing one another for the formation of inner cells having an auxetic conﬁguration, the trapezoidal units having a wall thickness of at least 0.6 mm and a height of at least 2.5 mm, and wherein the vertices of the trapezoidal units have an angle of 60°. 1 0 1 0

Description

PROTECTIVE VEST DESCRIPTION

OBJECT OF THE INVENTION The present invention relates to a protective vest, such as a bulletproof vest, made up of an outer covering made of a non-ceramic material and an auxetic honeycomb inner structure made of a non-ceramic material, wherein the geometry of the inner structure provides a deformation with a negative Poisson’s ratio. The object of the invention is to provide a protective garment which allows reducing the trauma generated by high-speed impacts concentrated in specific areas, such as bullet impacts.

BACKGROUND OF THE INVENTION Protective garments, such as vests, jackets, or suits, reducing the damage caused to the user’s body due to blows or impacts are known in the state of the art. Specifically, protective vests or bulletproof vests which allow reducing the trauma generated by a ballistic impact are known. The standards established by the NIJ (acronym of the National Institute of Justice) establish that protective vests must have a trauma value of less than 44 mm, where trauma in this context refers to the deformation of the material upon experiencing an impact. Therefore, trauma values greater than 44 mm may involve critical injuries or death of the user wearing the bulletproof vest. Known protective vests can be classified as flexible vests and rigid vests. Known flexible protective vests are usually made up of a flexible fabric made of a polymer material, where the fabric itself offers protection against an impact. However, protective garments of this type which lack a reinforcement structure offer a limited degree of protection. -1-

On the other hand, known rigid protective vests have, in addition to the flexible outer fabric, a rigid inner plate in contact with the body, commonly known as ‘backing’. This rigid inner plate is usually made up of viscoelastic foam. The degree of protection of garments of this type is greater than that of flexible garments; however, they are heavy garments which limit the user's freedom of movement.

Based on the foregoing, the applicant of the present utility model has detected the need for developing a protective vest with minimal weight which is comfortable for the user who must wear it for an extended time daily and offers a high degree of protection against high-speed, localized impacts, complying with the reference standards in relation to trauma.

DESCRIPTION OF THE INVENTION The proposed protective vest constitutes an effective solution for the problems described above, as it provides a comfortable, lightweight garment with an improved degree of protection as a result of the novel configuration that is described below. In that sense, the protective vest of the invention comprises an outer covering made of a non- ceramic material, the function of which is to absorb the impact first. The non-ceramic material is preferably para-aramid and/or ultra-high molecular weight polyethylene commonly known by its acronym UHMWPE. Ultra-high molecular weight polyethylene, hereinafter UHMWPE, is a polymer formed by long-chain repeating ethylene units having a molecular mass between 3.5 and 7.5 million unified atomic mass units. The UHMWPE has a Young’s modulus of about 110 GPa and a density of about 0.97 g/em?. Depending on the specific intended application of the protective vest, the outer covering can be a rigid UHMWPE plate, giving rise to a rigid protective vest, or alternatively, a combination of one or more UHMWPE and/or para-aramid fabrics, giving rise to a flexible protective vest.

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Moreover, the protective vest additionally has an auxetic honeycomb inner structure which is arranged in direct contact with the user’s body and formed by at least four layers with a plurality of trapezoidal units. Preferably, the trapezoidal units have a wall thickness of at least

0.6 mm and a height of at least 2.5 mm, whereas the vertices of the trapezoidal units preferably have an angle of 60°. Each of the layers forming the auxetic honeycomb inner structure is made up internally of at least four sheets of a non-ceramic material, such as UHMWPE or para-aramid. These sheets of non-ceramic material are introduced in a mold having an auxetic geometry to obtain the layers making up the inner honeycomb structure by means of thermal compression. Alternatively, the layers are obtained by introducing the sheets of non-ceramic material in a mold having an auxetic geometry filled therein with a polymer resin, such as an epoxy resin, which impregnates the sheets of non-ceramic material.

The layers making up the auxetic honeycomb inner structure are arranged in twos facing one another, forming inner cells having an auxetic configuration. The auxetic honeycomb inner structure thereby offers a negative Poisson’s ratio value when a force, such as a bullet impact, is applied thereon. Therefore, the greater the force applied on a point of the auxetic honeycomb inner structure, the greater the force generated in the opposite direction at said point will be. This opposing force is caused mainly by the deformation of the material which accumulates at the force or impact application point.

Advantageously, this material accumulation effect together with the presence of the outer covering of non-ceramic material reduces the advancing speed of the bullet, minimizing damage to the user’s body. Therefore, a protective vest that is as lightweight as possible, but ensures compliance with the NIJ reference standard, with a trauma value of less than 44 mm, is obtained, allowing the user to wear it for the whole day, if necessary.

Lastly, it should be pointed out that the protective vest object of the present invention offers an air permeability of at least 190 mm/s, greatly exceeding the air permeability values of the known protective garments.

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In conclusion, the protective vest that is described offers a lightweight and safe protective garment that can be configured as a rigid or flexible vest with improved impact resistance.

BRIEF DESCRIPTION OF THE DRAWINGS To complement the description that will be made below and for the purpose of helping to better understand the features of the invention according to respective preferred practical embodiments thereof, a set of drawings is attached as an integral part of said description in which the following is depicted in an illustrative and non-limiting manner: Figure 1 shows a section view of one of the layers making up the auxetic honeycomb inner structure according to a preferred embodiment of the object of the present invention.

Figure 2 shows a section view of the four layers making up the auxetic honeycomb inner structure according to a preferred embodiment of the object of the present invention.

Figure 3 shows a perspective view of the auxetic honeycomb inner structure according to a preferred embodiment of the object of the present invention.

Figure 4 shows a section view of a portion of the protective vest according to a first preferred embodiment of the invention, in which the outer covering is a rigid UHMWPE plate, giving rise to a rigid protective vest.

Figure 5 shows a section view of a portion of the protective vest according to a second preferred embodiment of the invention, in which the outer covering is made up of a UHMWPE fabric and a para-aramid fabric, giving rise to a flexible protective vest.

PREFERRED EMBODIMENT OF THE INVENTION In view of the mentioned figures, it can be seen how the protective vest of the invention is made up of an outer covering (1) made of a non-ceramic material combined with an auxetic honeycomb inner structure (2).

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The auxetic honeycomb inner structure (2) of the protective vest has at least four layers (3) with a plurality of trapezoidal units (4), as observed in Figures 1, 2, and 3. The trapezoidal units (4) have a wall thickness of at least 0.6 mm and a height of at least 2.5 mm, whereas the vertices (6) of the trapezoidal units have an angle of 60°.

Figure 3 illustrates one of the layers (3) forming the auxetic honeycomb inner structure (2) of the protective vest, the mentioned layer (3) being made up of at least four sheets of a non- ceramic material, such as UHMWPE or para-aramid. However, the present invention is in no case limited to these materials or to the dimensions of the trapezoidal units (4) making up the auxetic honeycomb inner structure (2).

Moreover, Figures 2 and 3 show how the layers (3) of the auxetic honeycomb inner structure (2) of the protective vest are arranged in twos facing one another for the formation of inner cells (5) having an auxetic configuration. As described in detail above, this configuration enables the production of an opposing force leading to material accumulation in the auxetic honeycomb inner structure (2) upon applying a force such as a bullet impact on a point of the protective vest, reducing the bullet speed, such that damage to the body of the user wearing the protective vest is minimized.

In that sense, the protective vest of the invention, provided with the configuration described in detail above, can be configured in different preferred embodiments as a rigid or flexible protective vest, according to the intended application.

In that sense, according to a first preferred embodiment of the invention depicted in Figure 4, the protective vest is configured as a rigid vest, also known as a plate carrier vest, in which the outer covering (1) is rigid and made up of UHMWPE, having a thickness of 14 mm, and the vest being completed with the auxetic honeycomb inner structure (2).

An experimental test performed on this first preferred embodiment of the invention allowed verifying that the rigid protective vest that is described allows the trauma caused by the bullet on the user’s body to be reduced by 27.5% compared with known protective vests having the same weight as the vest of the first embodiment but lacking an auxetic honeycomb inner structure (2).

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In the mentioned test, the trauma that is caused and the speed of the bullet were measured according to international reference standards, the test being described as an NIJ 0101.06 test (Rifles 7.62 mm, FMJ 9.6 g (847 + 9.1 m/s), where:

- NIJ stands for the National Institute of Justice, a reference institution for tests of this type. - 0101.06 is the number of the NIJ standard. - Rifles refers to the type of weapon fired to perform the test, in this case, a rifle. - 7.62 mm is the diameter of the bullet fired in the test. - FMI stands for Full Metal Jacketed, which refers to the shell of the bullet fired in the test. - 9.6 gis the weight of the bullet fired in the test. - 847 +£9.1 m/s is the speed at which the bullet is fired in the test. - Test result: 27.5% reduction of the trauma caused with respect to the results of the trauma caused by other known vests having the same weight.

Alternatively, Figure 5 illustrates a detail of the section of a second preferred embodiment of the invention, wherein the protective vest is provided with the configuration described in detail above, and wherein the outer covering (1) is flexible and made up of a UHMWPE fabric (17), combined with a para-aramid fabric (1°), giving rise to a flexible protective vest.

In this second preferred embodiment, the para-aramid fabric (177) receives the bullet impact first.

Two experimental tests were performed on this second embodiment of the invention illustrated in Figure 5, the results of which are described in detail below.

In that sense, in a first experimental test of the second preferred embodiment of the invention, described as NIJ 0101.06 (9 x 19 mm FMJ 8.0 g (436 + 9.1) m/s), it can be verified that the reduction of trauma caused by the bullet on the user’s body is 12.8% compared with known protective vests having the same weight as the flexible protective vest of the second embodiment but lacking an auxetic honeycomb inner structure (2). Advantageously, the test that was performed additionally determined that, with the trauma generated by the impact -6-

being the same, the protective vest of the second embodiment has a weight that is 7% less than known vests having no auxetic honeycomb inner structure (2). The parameters of the NIJ

0101.06 test (9 x 19 mm FMJ 8.0 g (436 + 9.1) m/s) are defined below: - NIJ stands for National Institute of Justice. - 0101.06 is the number of the NIJ standard. - 9x 19 mm is the diameter (first figure) and the length of the bullet (second figure) fired in the test. - FM) stands for Full Metal Jacketed, which refers to the shell of the bullet fired in the test. - 8.0 g is the weight of the bullet fired in the test. - 436+9.1 m/s is the speed at which the bullet is fired in the test. - Test result: 12.8% reduction of the trauma caused with respect to the results of the trauma caused by other known vests having the same weight. - Test result: with the trauma caused being the same, the vest of the invention has a 7% weight reduction with respect to other known vests. A second experimental test of the second preferred embodiment of the invention, described as NIJ 0101.06 (44 MAG JHP Speer 15.6 g (436 + 9.1) m/s), shows that the reduction of the trauma caused by the bullet for the flexible vest of the second preferred embodiment is 20% compared with known vests having the same weight but lacking an auxetic honeycomb inner structure (2). The parameters of the NIJ 0101.06 test (44 MAG JHP Speer 15.6 g (436 £9.1) m/s) are defined below: - NIJ stands for National Institute of Justice. - 0101.06 is the number of the NIJ standard. - 44 MAG is the type of bullet fired in the test. - JHP Speer stands for Jacketed Hollow Point Speer and refers to the type of point of the bullet fired in the test. - 15.6 g is the weight of the bullet fired in the test. - 436+9.1 m/s is the speed at which the bullet is fired in the test. - Test result: 20% reduction of the trauma caused with respect to the results of the trauma caused by other known vests having the same weight. -7-

Lastly, it should be pointed out that as a result of the presence of the auxetic honeycomb inner structure (2), the preferred embodiments of the invention described and illustrated in Figures 4 and 5 offer an air permeability of 192 mm/s, which constitutes a significant improvement with respect to known flexible or rigid protective vests which offer an air permeability of 0.11 mm/s and 0 mm/s, respectively. -8-

Claims

ConclusiesConclusions

1. Beschermend vest, met het kenmerk, dat dit omvat: - een buitenbekleding (1) die is gemaakt van een niet-keramisch materiaal, - een auxetische honingraat-binnenstructuur (2) die ten minste vier lagen (3) heeft met een veelheid trapezoidale eenheden (4), waarbij elke laag (3) intern bestaat uit ten minste vier bladen van een niet-keramisch materiaal, waarbij de lagen (3) van de auxetische honingraat-binnenstructuur (2) per twee zijn aangebracht, die naar elkaar toe wijzen voor de vorming van binnenste cellen (5) die een auxetische configuratie hebben; waarbij de trapezoïdale eenheden (4) een wanddikte van ten minste 0,6 mm en een hoogte van ten minste 2,5 mm hebben, en waarbij de hoekpunten (6) van de trapezoidale eenheden een hoek van 60° hebben.A protective vest, characterized in that it comprises: - an outer covering (1) made of a non-ceramic material, - an auxetic honeycomb inner structure (2) having at least four layers (3) with a plurality of trapezoidal units (4), wherein each layer (3) internally consists of at least four sheets of a non-ceramic material, wherein the layers (3) of the auxetic honeycomb inner structure (2) are arranged in pairs, facing each other ways of forming inner cells (5) having an auxetic configuration; wherein the trapezoidal units (4) have a wall thickness of at least 0.6 mm and a height of at least 2.5 mm, and wherein the vertices (6) of the trapezoidal units have an angle of 60°.

2. Beschermend vest volgens conclusie 1, met het kenmerk, dat de bladen van niet- keramisch materiaal die de lagen (3) van de auxetische honingraat-binnenstructuur (2) vormen een polyethyleen weefsel met ultrahoog moleculair gewicht of een para-aramide weefsel zijn.Protective vest according to claim 1, characterized in that the sheets of non-ceramic material constituting the layers (3) of the auxetic honeycomb inner structure (2) are an ultra-high molecular weight polyethylene fabric or a para-aramid fabric. .

3. Beschermend vest volgens conclusie 1, met het kenmerk, dat de bladen van niet- keramisch materiaal die de lagen (3) van de auxetische honingraat-binnenstructuur (2) vormen een polyethyleen weefsel met ultrahoog moleculair gewicht of een para-aramide weefsel zijn die zijn geïmpregneerd met een epoxyhars.Protective vest according to claim 1, characterized in that the sheets of non-ceramic material forming the layers (3) of the auxetic honeycomb inner structure (2) are an ultra-high molecular weight polyethylene fabric or a para-aramid fabric. which are impregnated with an epoxy resin.

4. Beschermend vest volgens conclusie 1, met het kenmerk, dat het niet-keramische materiaal van de buitenbekleding (1) star is en bestaat uit polyethyleen met ultrahoog moleculair gewicht.Protective vest according to claim 1, characterized in that the non-ceramic material of the outer covering (1) is rigid and consists of ultra-high molecular weight polyethylene.

5. Beschermend vest volgens conclusie 1, met het kenmerk, dat het niet-keramische materiaal van de buitenbekleding (1) flexibel is en bestaat uit een polyethyleen weefsel (1) met ultrahoog moleculair gewicht gecombineerd met een para-aramide weefsel (1).Protective vest according to claim 1, characterized in that the non-ceramic material of the outer covering (1) is flexible and consists of an ultra-high molecular weight polyethylene fabric (1) combined with a para-aramid fabric (1).

6. Beschermend vest volgens één van de voorgaande conclusies, met het kenmerk, dat het een luchtdoorlatendheid van ten minste 190 mm/s heeft.Protective vest according to any one of the preceding claims, characterized in that it has an air permeability of at least 190 mm/s.

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