DESC:FIELD OF INVENTION

[0001] The present invention is directed to hybrid nanocomposite panels, and more particularly to hybrid nanocomposite panels for ballistic resistance application.

BACKGROUND OF INVENTION

[0002] Bullet Resistant (BR) Nanocomposite panels are most commonly used in wall assemblies, counters, doors, millwork, cubicles, and desks for many different architectural facility designs. Some of these facilities include Commercial, Schools, Financial, Government, Grid Security, Healthcare, Law Enforcement, Military, Residential, Safe Rooms and beyond.
[0003] Many attempts have been made in past to construct bullet proof panels with multiple layers. Additionally, bullet-resistant transparent panels have also been devised effectively that can block the penetration of a bullet when fired from one side of the panel, but not when fired from the other side of the panel. Other ballistic armor panels and armored glass structures are also proposed but all of the existing BR panels require additional structure to provide comfort for the user. Further, ordinarily the bullet energy is dissipated between fiber and resin, and also there is a limitation in energy absorption level. Thus, no proven design exists to absorb hard steel bullets.
[0004] Hence, in the background of foregoing limitations, there exists a need for bullet resistant panels that can provide comfort to the user, overcomes energy absorption issues and can effectively protect against attacks using guns of any type.
OBJECT OF THE INVENTION

[0005] The primary objective of the present disclosure is to provide hybrid nanocomposite panels with multiple layers for ballistic resistance.
[0006] In one other objective of the present disclosure, hybrid nanocomposite panels that are aesthetically appealing from outside is disclosed.
[0007] Another objective of the present disclosure is to provide core layers that are symmetrically designed to prevent bullet penetration at either side of firing.
[0008] In yet another objective of the present disclosure, the combination of nano and micro level reinforcement in polymer resin is capable of resisting bullet by absorbing energy in various modes.
[0009] Another objective of the present disclosure is to provide light weight BR panels.
[0010] In still another objective of the present disclosure, low cost BR panels resist bullets made of lead core, steel and hardened steel core.
[0011] In last objective of the present disclosure, surface of the panels is suitably designed to the need of end user.
SUMMARY OF THE INVENTION
[0012] In accordance with one aspect of present disclosure, a nanocomposite ballistic resistance structure is disclosed that comprises of: a first layer configured to be used as a surface layer of the structure; a second core layer provided on rear and front of the first surface layer configured to be reinforced with plurality of layers within a polymer matrix to prevent penetration of a fired bullet through the structure.

[0013] In accordance with another aspect of present disclosure, the nanocomposite ballistic resistance structure, the second core layer reinforced with nanoparticles provides mechanical strength, toughness, impact resistance and electrical or thermal conductivity to the structure.

BRIEF DESCRIPTION OF DRAWINGS
[0014] Fig. 1 illustrates nanocomposite ballistic resistance structure, in accordance with one exemplary embodiment of present disclosure.

[0015] Fig. 2 shows typical variety surface pattern design of hybrid nanocomposite structure, in accordance with one exemplary embodiment of present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] Before the present working principle of hybrid nanocomposite panels for ballistic resistance application is described, it is to be understood that this disclosure is not limited to the particular means and mode for achieving so, as described, since it may vary within the specification indicated. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present invention, which will be limited only by the appended claims. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. The disclosed embodiments are merely exemplary methods of the invention, which may be embodied in various forms.
[0017] In accordance with one general embodiment of present disclosure, reinforced structural composite materials that exhibit unique bullet resisting characteristics, is proposed. In accordance with one working embodiment, nano engineered ballistic resistance (BR) panels are developed to meet international standard UL 752 from levels 1 to 8. These BR panels can be custom designed as shelters to protect against attacks using guns of any type. Precisely, the bullet resisting panels are made using nano technology material that incorporate nanosized particles into polymer matrix of composite materials.
[0018] Nano engineered BR panels are light in weight compared to other international company’s products. In particular, near borders and hilly areas where creating permanent building or any other infrastructure is difficulty in short duration, these prefabricated panels can be cut and assembled to compact size as shelters for military personnel.

[0019] In accordance with one exemplary embodiment, the present disclosure overcomes energy absorption in various failure mechanisms within BR panels due to nano, micro and hard material surface interaction with continuous reinforcement and polymer resin. BR panels of the present disclosure will resist both light and hard metal bullets. Significantly, efforts have been invested in optimizing the nano reinforcement and thickness of BR panels to resist bullets of various ranges in ballistic test.

[0020] In accordance with another exemplary embodiment, the present disclosure provides hybrid nanocomposite panels with multiple layers for ballistic resistance (BR). It comprises surface layer to provide aesthetic outside surface. Next, the second layer from both front and rear surface is reinforced with three types of reinforcements, continuous high aspect ratio, micro and nano scale in polymer matrix. The core layers between these second layers are designed symmetrically to prevent bullet penetration at either side of firing. Significantly, the nano particles act as nano level secondary reinforcement to matrix materials. The result of the addition of nanoparticles is a drastic improvement in properties that include mechanical strength, toughness, impact resistance and electrical or thermal conductivity.

[0021] In accordance with one example embodiment, the core layers are made as hybrid with Kevlar/Glass/UHMWPE (ultra-high molecular weight polyethylene) continuous woven bidirectional fibers/hardened inserts wetted/bonded using polymer resin with other layers. The number of hybrid layers is designed according to threat levels of weapon. The kinetic energy of the bullet is absorbed by second layer by fracture of continuous fibre, the compression of micro and nano scale reinforcement. The energy transfer from micro and nano scale reinforcement to surrounding matrix and reinforcement is high due to large surface area interactions. The hard metal inserts/boron carbide micro reinforcement is able to do micro level damage to the front nose of bullet and thus it offers reasonable amount of frictional force for further penetration. Also, the second layer is stiff due to multiple hard material reinforcement and this creates high contact force which resists and fails in higher threat levels of bullet.

[0022] However, with the high contact force during further penetration of the bullet in core layers, makes a reasonable amount of energy balance with reference to kinetic energy of the bullet. The type of resin system and number of layers can be optimized according to threat levels of bullet and cost. For low-cost economical hybrid nanocomposite panels, the low cost WRM glass fiber is used with more number of layers having increase in thickness and weight of the panels. For light weight hybrid nanocomposite panels, high performance expensive Kevlar and carbon fiber layers are used to make the panels.

[0023] The Hybrid Nanocomposite panels are designed with multilayers having reinforced with nano and micro scale fillers to meet design requirement. Figure 1 shows the front 10, rear 20 of surface layer 30 and core layers 40 of Hybrid Nanocomposite panel 50. The core layers 30 are made using multiple layers kevlar/glass/UHMWPE (ultra-high molecular weight polyethylene) fiber layers embedded in nano scale material reinforced polymer matrix. The front and rear layers reinforced with hardest materials in micro scale and nano scale having largest surface level interaction with matrix system for steel core bullets resistance.

[0024] Front layer is designed to provide hard, tough and stiff. The micro filler will interact with fired bullet 5 to create a damage and nano filler will dissipate projectile kinetic energy by vibration, bending and twisting to enhance resistance level of panels. The continuous micro size reinforcement will fracture by tensile and shear plugging. High contact force with small displacement within front 30 and core layers 40 make large work done to make equilibrium of bullet 5 kinetic energy. The panels 50 are designed to absorb bullet energy in multiple mechanisms which cannot be possible in conventional composite materials.

[0025] Specifically, the hybrid nanocomposite panels of size 30 mm x 30 mm are prepared and the same panels are tested to meet UL 752 standard requirements. The testing room temperature is 25ºC and humidity is 50% RH. Table 1 below provides summary of weapon levels and hybrid nanocomposite panel’s thickness and density.

UL 752 STD level Velocity of test (m/s)
(+/-15 m/s) Weapon & shots Hybrid nanocomposite panels
Thickness(mm) and density
01 376 9mmx19mm, 3 shots 6.35
10 kg/m2
02 400 0.357 Magnum,
3 shots 9.5
15.2 kg/m2
03 430 0.44 Magnum,
3 shots 10
16kg/m2
04 812 0.30 Rifle,
1 shot 32
51.2 kg/m2
05 878 7.61x51,
1 shot
32
51.2 kg/m2
06 430 9x19,
5 shots 10
16 kg/m2
07 986 5.56x45,
5 shots 32
51.2 kg/m2
08 878 7.61x51,
5 shots 32
51.2 kg/m2

[0026] Fig. 1 shows the front 10, rear 20 and core layers 40 of Hybrid Nanocomposite panel 50. The core layers 40 are made using multiple layers Kevlar/glass/UHMWPE fiber layers embedded in nano scale material reinforced polymer matrix. Fig. 2 shows the typical design pattern of Hybrid Nanocomposite panels 50. This thin surface mat is layered at outer surface of the Hybrid Nanocomposite panels and a thin layer of clear coating to protect this surface mat against environment. The bond strength of this surface mat with adjacent layer is equal to interlaminar strength of the layers. Also, it will be possible custom designed surface pattern, if the quantity of panel is large. The color of surface layers can be chosen by the customers.

[0027] The selection of nano particle is according to the property improvement expected in composite materials. The effectiveness of the nanoparticles is such that the amount of material added is normally only between 0.5% and 5% by the weight of matrix. Nanoparticles have an extremely high surface to volume ratio which dramatically changes their properties when compared with their bulk sized equivalent materials. It also changes the way in which the nanoparticles bond with the bulk material. There is no limit for application range for nanocomposites. Energy absorbed by the bullet 5 resistance nanocomposite panels is such example of nanocomposites. The high surface area between nano particles and polymer matrix enhances the dissipation of bullet 5 kinetic energy to stop penetration into nano composite bullet resisting panels.

[0028] The current combination of nano and micro level reinforcement in polymer resign is to resist bullet 5 by absorbing energy in various modes such as bending, twisting, shearing. Hard material inserts make the deformation of the backend laminate at high contact force to absorb energy in bending mode. The front layers absorb energy in tensile failure and shear plugging. The summation of these energies will make equilibrium with kinetic energy of bullet to balance and to prevent penetration.

[0029] Thus, as a physical result, the hard surface and toughness of the material cause the bullet 5 to distort and flatten the bullet as it penetrates, the layers of reinforcement within the laminate pull apart in a controlled manner such that the energy of the bullet 5 is dissipated within the laminate. More energy is consumed as the bullet 5 penetrates the high-strength nano and micro scale reinforcements.

[0030] Appropriate bullet resistant panels 50 in areas with high threat potential has become a key element in designer' specifications for day-to-day operations in the public realm. Nano Technology is the precise and controlled fabrication or as-assembly of atoms and molecules at Nanometer (10^-9m) dimension, into materials and devise with unique properties. 1 Nanometer is equivalent to 1/1000th of a human hair.

[0031] The foregoing description is a specific embodiment of the present disclosure. It should be appreciated that this embodiment is described for purpose of illustration only, and that numerous alterations and modifications may be practiced by those skilled in the art without departing from the spirit and scope of the invention. It is intended that all such modifications and alterations be included insofar as they come within the scope of the invention as claimed or the equivalents thereof.
,CLAIMS:We Claim:

1) A nanocomposite ballistic resistance structure (50), comprising:

a first layer (30) configured to be used as a surface layer of the structure;
a second core layer (40) provided on rear (20) and front (10) of the first surface layer (30) configured to be reinforced with plurality of layers within a polymer matrix to prevent penetration of a fired bullet (5) through the structure (50).

2) The nanocomposite ballistic resistance structure (50), as claimed in claim 1, wherein the second core layer (40) reinforced with nanoparticles provides mechanical strength, toughness, impact resistance and electrical or thermal conductivity to the structure (50).

3) The nanocomposite ballistic resistance structure (50), as claimed in claim 1, wherein the second core layer (40) reinforced with Kevlar/glass/UHMWPE, continuously woven bidirectional fibres or ultra-high molecular weight polyethylene along with hardened inserts or a combination thereof is configured to absorb kinetic energy of the fired bullet (5).

4) The nanocomposite ballistic resistance structure (50), as claimed in claim 3, wherein the second core layer (40) reinforcements are bonded using polymer resins to other layers of the structure (50).

5) The nanocomposite ballistic resistance structure (50), as claimed in claim 3, wherein the hardened inserts comprises of boron carbide micro reinforcements configured to provide frictional force to the fired bullet (5) as it makes deformation of backend laminate at high contact force to absorb energy in bending mode.

6) The nanocomposite ballistic resistance structure (50), as claimed in claim 1, wherein the second core layer (40) comprising of the plurality of reinforced layers is designed based on threat levels of firing weapon.

7) The nanocomposite ballistic resistance structure (50), as claimed in claim 3, wherein the front layer (10) and the rear layer (20) are reinforced with hard material comprising micro fillers and nano fillers to have largest surface level interaction with the polymer matrix for bullet resistance.

8) The nanocomposite ballistic resistance structure (50), as claimed in claim 7, wherein the micro fillers are configured to cause damage to the fired bullet (5) by tensile and shear plugging.

9) The nanocomposite ballistic resistance structure (50), as claimed in claim 7, wherein the nano fillers are configured to dissipate projectile kinetic energy by vibration, bending and twisting to enhance resistance towards the fired bullet (5).

10) The nanocomposite ballistic resistance structure (50), as claimed in claim 1, wherein thickness of the structure (50) varies between 6.35 mm to 32 mm.

11) The nanocomposite ballistic resistance structure (50), as claimed in claim 1, wherein density of the structure (50) varies between 10kg/m2 to 51.2 kg/m2.
12) The nanocomposite ballistic resistance structure (50), as claimed in claim 2, wherein nanoparticles constituting the second core layer (40) is 0.5% to 5% by weight of the polymer matrix such that high surface area between the nanoparticles and the polymer matrix enhances dissipation of kinetic energy of the fired bullet (5).