BALLISTIC IMPACT RESISTANT NANO-DENIER FIBROUS WOVEN SHEET
I. TECHNICAL FIELD OF INVENTION
This invention relates to the field of ultra-lightweight high performance ballistic impact resistant material.
DESCRIPTION OF RELATED ART
Ballistic resistant fibrous woven materials, such as those made from aramid fibers (Kevlar) or polyethylene fibers (Spectra) are well-known. However, these materials are heavy, require lamination to optimize ballistic performance are not flexible and do not perform well against high velocity lightweight ballistic rounds such as a .270 cal. Furthermore, these materials, once laminated, have a large cross section, typically .40 inches to .60 inches for NIJ Level Ilia protection. Also of importance, the polyethylene fibers (Spectra) have a very low melting point, 150°, at which ballistic performance degrades significantly and is very susceptible to burning.
Both the aramid fibers and polyethylene fiber laminates are found to exhibit sequential delamination, cut-out of a plug induced by through-the-thickness shear, and combined modes of shear and tensile failure of fibers. When subjected to the repeated impact of a constant striking ballistic velocity, a progressive growth of local delamination including gross failure of the composite will occur. In summary, these materials do not provide protection from multiple (2 or more) ballistic impacts in a localized area before failure.
As these materials are relied on to provide ballistic protection for a wide variety of applications including but not limited to vests; helmets; vehicles including but not limited to cars, trucks, aircraft, mass transit vehicles, and architecture structures. It is important to have a lightweight, flexible product that is capable of providing continuous ballistic protection even after receiving numerous localized ballistic impacts.
π. BACKGROUND ART
Refer to Drawings attached.
HI. DISCLOSURE OF INVENTION
Summary
The present invention relates to a thin, ultra lightweight, flexible ballistic impact resistant material that can withstand multiple ballistic impacts within a localized area without failure. The material is comprised of fibrous structures containing nano-fibrils and other textile fibers. Nano-fibers are produced having a diameter of 4A to 1 nm, and a nano-denier of about 10"9.
These nano-fibrils are converted into linear assemblies (yams) and joined by weaving. The resulting textile material is layered in accordance with the design schematic formulated for the specific ballistic threat or threats that the application calls for. The woven sheet is actually comprised of multiple plies of the nano-fibril derived woven fabric layers, the variation of energy dissipating layers combined with impact resistant layers, and the unique process of joining these layers using multi-directional overlapping sewn seams and a high shear joining filament that contributes to the material's superior performance.
The complex architecture described above also allows this material to be designed, developed and assembled to provide ballistic threat protection for a large variety of threat levels. By varying materials, densities, and woven assembly, the product can be optimized for high velocity lightweight ballistic rounds, lower velocity heavyweight ballistic rounds, and an equal number of variations of small shaped charge events.
IV. BRIEF DESCRIPTION OF DRAWINGS
Figure X is the Final Assembly Stitch Pattern 1. Figure Y is the Core Stitch Pattern 2.
A = Puncture resistant woven nano-fibers
B = Puncture resistant woven nano-fibers
C = Puncture resistant woven nano-fibers
E = Separately assembled core blanket
F & D = Energy dissipating nano-fibers
V. BEST MODE FOR CARRYING OUT INVENTION
The best mode for carrying out this invention is in a properly equipped facility. The nano-fibrils will require specialized equipment necessary to process the linear assemblies (yarns). This is accomplished using an electro-spinning process that joins the hybrid fibers to a core filament. These yarns are then woven together using varying weaves and material densities. The core of the sheet is comprised of a number of layers of these textile materials joined by sewing with the high shear filament. The inner core is then encapsulated by a number of outer layers. This entire assembly is then joined using high shear filament and high strength tightly sewn pattern. Using the detailed design drawings, specialized equipment, and personnel suitably trained to execute the assembly, the process has proven to be very efficient.
VI. INDUSTRIAL APPLICABILITY
This invention is specifically applicable to any and all applications that require or would benefit from a lightweight, infinitely adjustable, ballistic impact resistant thin, flexible sheet.
(1) Aerospace
(2) Automotive
(3) Mass Transit
(4) Architectural
(5) Military