BALLISTIC MATERIALS
A ballistic impact resistant composite comprising a glass fiber and a resin, where the glass fiber consists essentially of fiber having a diameter of less than 9 microns, is provided. The ballistic impact resistant article or composite comprising fiber less than 9 micron yields a higher V50 value at the same areal density, or the same V50 value at a lower areal density, than an impact resistant article or composite comprising fiber of greater than 9 micron.
1 . A ballistic impact resistant article comprising a glass fiber of less than 9 micron filament diameter and a resin;
wherein the glass fiber consists essentially of:
SiO 2
56-66%
Al 2 O 3
10-26%
MgO
5-15%
CaO
0-10%
B 2 O 3
0-1%
alkali metal oxides
0-1%
Fe 2 O 3
0-0.5%
F 2
0-0.5%.
2 . The ballistic impact resistant article of claim 1 , wherein the glass fiber has a pristine fiber tensile strength of greater than 500 kpsi.
3 . The ballistic impact resistant article of claim 1 , wherein the glass fiber diameter is about 7 microns to less than 9 microns.
4 . The ballistic impact resistant article of claim 1 , wherein the glass fiber diameter is about 3.5 microns to about 7 microns.
5 . The ballistic impact resistant article of claim 1 , wherein the glass fiber is S-glass or R-glass.
6 . The ballistic impact resistant article of claim 1 , further comprising a hard strike face.
7 . The ballistic impact resistant article of claim 6 , wherein the hard strike face is ceramic.
8 . The ballistic impact resistant article of claim 1 , wherein the resin is selected from the group consisting of thermosetting resins, thermoplastic resins, and elastomeric resins.
9 . The ballistic impact resistant article of claim 1 , wherein the resin is a thermosetting resin.
10 . The ballistic impact resistant article of claim 1 , wherein the thermosetting resin is a phenolic resin.
11 . The ballistic impact resistant article of claim 1 , wherein the ballistic impact resistant article has a glass fiber weight fraction of about 80%.
12 . The ballistic impact resistant composite of claim 1 , wherein the glass fiber has a water resistant, impact debondable size coating thereon.
13 . The ballistic impact resistant composite of claim 12 , wherein the water resistant, impact debondable size coating comprises an epoxy based film former and a silane coupling agent.
14 . The ballistic impact resistant composite of claim 1 , wherein the article comprises one or more layers, wherein at least one of the layers is a woven or a non-woven network of the glass fiber.
15 . The ballistic impact resistant composite of claim 14 , wherein the network of glass fiber is non-woven chopped fibers.
16 . The ballistic impact resistant composite of claim 14 , wherein the woven network of glass fiber is selected from the group consisting of a plain weave, a twill weave, three-dimensional weave, a harness weave, a basket weave and a satin weave.
17 . The ballistic impact resistant composite of claim 14 , wherein the network of glass fiber comprises a sheet-like filament array in which the filaments are arranged substantially parallel to one another along a common filament direction.
18 . The ballistic impact resistant composite of claim 14 , wherein the composite comprises at least two layers, wherein each of the at least two layers comprises a sheet-like filament array, wherein each layer has the filaments arranged substantially parallel to one another along a common filament direction, and wherein the at least two layers are aligned at substantially 90 degree angles with their respective parallel glass filaments.
19 . A ballistic impact resistant article comprising a glass fiber having a diameter of less than 9 microns, wherein the glass fiber has the following characteristics:
a pristine fiber tensile strength at room temperature of greater than 500 kpsi;
a composition comprising about 64-66% by weight silica, about 24-26% by weight alumina, and about 9-11% by weight magnesia; and
at least one of the following:
i) a softening point of greater than 1900° F. as determined in accordance with ASTM C-338;
ii) a tensile modulus at room temperature of greater than 12.5 Mpsi as determined in accordance with ASTM D2101;
iii) a strain to failure of greater than 5.4% as determined in accordance with ASTM D2101; and
iv) a dimensional stability of less than 2.0×10 −6 in/in-degrees ° F.
20 . The ballistic impact resistant article of claim 19 , further comprising a hard strike face.
21 . The ballistic impact resistant article of claim 20 , wherein the hard strike face is ceramic.
22 . A process for constructing a ballistic impact resistant article, the process comprising
(i) providing at least one layer of a woven or fiber network, the woven or fiber network comprising a glass fiber of less than about 9 micron filament diameter;
(ii) impregnating the at least one layer of woven or fiber network with a resin;
(iii) stacking the at least one layer of woven or fiber network impregnated with resin; and
(iv) consolidating the stack of at least one layer of woven or fiber network impregnated with resin under compression;
wherein the glass fiber has a pristine fiber tensile strength of greater than 500 kpsi;
wherein a ballistic impact resistant article is constructed.
23 . A method of reducing a fragment projectile penetration threat comprising:
providing a ballistic impact resistant article comprising glass fibers having a diameter of less than 9 microns and a resin;
wherein the ballistic impact resistant article has a characteristic selected from the group consisting of:
an areal density of about 6.2 pounds per square foot at a thickness of about 0.58 inches and an average V50 value, protection ballistic limit in excess of about 4400 feet per second with 5.56 mm fragment simulating projectiles;
an areal density of about 5.2 pounds per square foot at a thickness of about 0.48 inches and an average V50 value, protection ballistic limit in excess of 2700 feet per second with 7.62 mm fragment simulating projectiles;
an areal density of about 12.4 pounds per square foot at a thickness of about 1.2 inches and an average V50 value, protection ballistic limit in excess of 3450 feet per second with 12.7 mm fragment simulating projectiles; and
an areal density of about 20.8 pounds per square foot at a thickness of about 2 inches and an average V50 value, protection ballistic limit in excess of 3800 feet per second with 20 mm fragment simulating projectiles.
24 . The method of claim 23 , wherein the ballistic impact resistant article further comprises a hard strike face.
25 . The method of claim 23 , wherein the hard strike face is ceramic.
26 . The method of claim 23 , wherein the glass fiber has the following characteristics:
a pristine fiber tensile strength at room temperature of greater than 500 kpsi;
a composition consisting essentially of about 64-66% by weight silica, about 24-26% by weight alumina, and about 9-11% by weight magnesia; and
at least one of the following:
i) a softening point of greater than 1900° F. as determined in accordance with ASTM C-338;
ii) a tensile modulus at room temperature of greater than 12.5 Mpsi as determined in accordance with ASTM D2101;
iii) a strain to failure of greater than 5.4% as determined in accordance with ASTM D2101; and
iv) a dimensional stability of less than 2.0×10 −6 in/in-degrees ° F.