U.S. patent application number 14/379812 was filed with the patent office on 2015-02-05 for ballistic composite containing a thermoplastic overlay.
The applicant listed for this patent is E I DU PONT DE NEMOURS AND COMPANY. Invention is credited to Thomas D. Boyer, Carmen A. Covelli, Bryce Vanarsdalen.
Application Number | 20150033935 14/379812 |
Document ID | / |
Family ID | 49624477 |
Filed Date | 2015-02-05 |
United States Patent
Application |
20150033935 |
Kind Code |
A1 |
Boyer; Thomas D. ; et
al. |
February 5, 2015 |
BALLISTIC COMPOSITE CONTAINING A THERMOPLASTIC OVERLAY
Abstract
Ballistic composite articles comprising a fabric section, an
overlay section disposed on the strikeface of the composite article
and comprising a thermoplastic resin, and optionally an adhesive
layer disposed between the fabric section and the overlay section
are described. The ballistic composite articles can provide
comparable or improved protection against projectile threats
relative to conventional ballistic composites consisting only of a
same-type fabric section having comparable area density, as
evidenced by comparable V50 values and/lower backface deformation
values when tested under the same conditions.
Inventors: |
Boyer; Thomas D.; (Smyrna,
DE) ; Covelli; Carmen A.; (Chadds Ford, PA) ;
Vanarsdalen; Bryce; (Cherry Hill, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
E I DU PONT DE NEMOURS AND COMPANY |
Wilmington |
DE |
US |
|
|
Family ID: |
49624477 |
Appl. No.: |
14/379812 |
Filed: |
February 28, 2013 |
PCT Filed: |
February 28, 2013 |
PCT NO: |
PCT/US13/28260 |
371 Date: |
August 20, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61604763 |
Feb 29, 2012 |
|
|
|
Current U.S.
Class: |
89/36.02 |
Current CPC
Class: |
B32B 27/36 20130101;
B32B 2307/52 20130101; B32B 7/12 20130101; B32B 5/022 20130101;
B32B 27/365 20130101; B32B 2307/54 20130101; B32B 2274/00 20130101;
B32B 5/08 20130101; B32B 2307/536 20130101; B32B 27/12 20130101;
B32B 2571/02 20130101; F41H 1/04 20130101; B32B 2262/0253 20130101;
B32B 2262/0238 20130101; B32B 2307/558 20130101; B32B 3/04
20130101; F41H 5/0478 20130101 |
Class at
Publication: |
89/36.02 |
International
Class: |
F41H 5/04 20060101
F41H005/04; F41H 1/04 20060101 F41H001/04 |
Claims
1. A ballistic composite article having a strikeface and a
backface, the ballistic composite article comprising: a) a fabric
section comprising two or more fibrous fabric layers; b) an overlay
section comprising one or more layers, the overlay section being
disposed on the strikeface and comprising a thermoplastic resin,
wherein the weight percent of the overlay section relative to the
composite article is between about 1% and about 50%; and c) an
optional first adhesive layer disposed between the fabric section
and the overlay section; whereby the composite article, when tested
according to MIL-STD-662-F using a 16 grain right circular cylinder
fragment-simulating projectile, has a V50 value comparable to or
greater than that of an article consisting only of a same-type
fabric section having an area density that is about the same as the
area density of the composite article.
2. The composite article of claim 1, wherein the overlay section is
additionally disposed on the backface of the composite article, and
optionally on at least a portion of at least one edge of the
composite article, with the proviso that the majority of the
overlay section is disposed on the strikeface.
3. The composite article of claim 1, wherein the thermoplastic
resin comprises polycarbonate, a thermoplastic elastomeric
polyester having poly(1,4-butylene terephthalate) and poly(alkylene
ether)glycol blocks, polybutylene terephthalate, a polyacetal, a
blend of polyamide and an ethylene/.alpha.,.beta.-unsaturated C3-C8
carboxylic acid copolymer partially neutralized with metal ions, or
combinations thereof.
4. The composite article of claim 1, wherein the weight percent of
the overlay section is between about 1% and about 40%.
5. The composite article of claim 1, wherein the first adhesive
layer is present and comprises a plant-based glue, a solvent-type
glue, a synthetic monomer glue, a synthetic polymer glue, an epoxy
resin, a polyurethane, or combinations thereof.
6. The composite article of claim 1, wherein one or more of the
fibrous fabric layers comprises a woven fabric.
7. The composite article of claim 1, wherein one or more of the
fibrous fabric layers comprises a non-woven fabric.
8. The composite article of claim 7, wherein the non-woven fabric
comprises a unidirectionally oriented tape structure.
9. The composite article of claim 1, wherein the fabric layers
comprise a polymer selected from the group consisting of aramid,
ultra-high molecular weight polyethylene, ultra-high molecular
weight polypropylene, polyvinyl alcohol, polyazole,
polybenzoxazole, polybenzothiazole, and combinations or blends
thereof.
10. The composite article of claim 1, wherein the fabric section
further comprises a polymeric resin disposed between at least two
of the fibrous fabric layers, and the polymeric resin and the
overlay section comprise the same thermoplastic resin.
11. The composite article of claim 1, wherein the areal density is
between about 2.5 lbs/ft.sup.2 and 1.0 lbs/ft.sup.2.
12. A panel comprising the composite article of claim 11.
13. A helmet comprising the composite article of claim 11.
14. A ballistic composite article having a strikeface and a
backface, the ballistic composite article comprising: a) a fabric
section comprising two or more fibrous fabric layers; b) an overlay
section comprising one or more layers, the overlay section being
disposed on the strikeface and comprising a thermoplastic resin,
wherein the weight percent of the overlay section relative to the
composite article is between about 1% and about 50%; and c) an
optional first adhesive layer disposed between the fabric section
and the overlay section; whereby the composite article, when tested
according to HP White HPW-TP-0401.01B using a 9 mm Full Metal
Jacket projectile, has a back face deformation value lower than
that of an article consisting only of a same-type fabric section
having an areal density about the same as the areal density of the
composite article.
15. The composite article of claim 14, wherein the weight percent
of the overlay section is between about 1% and about 40%, and
wherein the thermoplastic resin comprises polycarbonate, a
thermoplastic elastomeric polyester having poly(1,4-butylene
terephthalate) and poly(alkylene ether)glycol blocks, polybutylene
terephthalate, a polyacetal, a blend of polyamide and an
ethylene/.alpha.,.beta.-unsaturated C3-C8 carboxylic acid copolymer
partially neutralized with metal ions, or combinations thereof.
Description
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) from, and claims the benefit of, U.S. Provisional
Application No. 61/604,763 filed Feb. 29, 2012 and U.S. Provisional
Application No. 61/604,741 filed Feb. 29, 2012; both of which are
by this reference incorporated in their entirety as a part hereof
for all purposes.
FIELD OF THE INVENTION
[0002] Rigid armor composite structures comprising a fabric section
and an overlay section comprising a thermoplastic resin are
provided.
BACKGROUND
[0003] Ballistic articles such as bulletproof vests, helmets,
tactical plates, structural members of helicopters, vehicle armor,
and other military equipment containing high strength fibers are
known. Fibers conventionally used include aramid fibers such as
poly(phenylenediamine terephthalamide), glass fibers, nylon fibers,
ceramic fibers, and the like. For many applications, such as vests,
or parts of vests, the fibers are used in a woven or knitted
fabric. For hard armor applications the fibers may be encapsulated
or embedded in a matrix material. Phenolic or modified polyester
resin can also be added to these high strain ballistic fabrics in
order to form composites in which the resin does little more than
keep out water.
[0004] Published Patent Application GB 2,124,887 discloses a
protective shield to be used in front of a person's body to protect
the person from injury by a bullet or other missile comprising at
least one layer of plastics sheet material and a plurality of
layers of woven fabric formed from aramid fibers, in which use of
the plastics sheet material is on that side of the aramid fabric
layers which faces away from the person's body. The sheet plastics
can be of high impact absorbing plastics, for example rigid poly
vinyl chloride, acrylonitrile butadiene styrene, or
polycarbonate.
[0005] U.S. Pat. No. 7,608,322 discloses a composite for resisting
impact from an oncoming projectile having a front strike face and a
back wear face comprising: an elastomer; and an impact resistive
substrate wherein at least a portion of the impact resistive
substrate is coated by the elastomer to provide the composite
having a front strike face coating and a back wear face coating and
wherein a ratio of weight of front strike face coating to back wear
face coating ranges from 1:1.2 to 1:100.
[0006] There is a continuing need for ballistic composites and
articles comprising such composites which provide comparable or
improved protection against projectile threats while being more
cost effective than conventional ballistic composites.
SUMMARY
[0007] Described herein are ballistic composite articles having a
strike face, the composite articles comprising: a fabric section,
an overlay section comprising one or more layers, and an optional
adhesive layer disposed between the fabric section and the overlay
section. The fabric section comprises two or more fibrous fabric
layers. The overlay section comprises a thermoplastic resin and is
disposed on the strikeface of the composite article. The composite
articles provide ballistic performance, with regard to V50 values
as determined under test conditions specified herein, comparable to
or greater than the ballistic performance of an article consisting
only of a same-type fabric section and having an areal density
equal to, or about the same as, the areal density of the composite
article. The composite articles provide reduced back face
deformation as determined under test conditions specified herein,
compared to that of an article consisting only of a same-type
fabric section and having an areal density equal to, or about the
same as, the areal density of the composite article.
[0008] In one embodiment, a ballistic composite article having a
strikeface and a backface is disclosed, the ballistic composite
article comprising:
[0009] a) a fabric section comprising two or more fibrous fabric
layers;
[0010] b) an overlay section comprising one or more layers, the
overlay section being disposed on the strikeface of the composite
article and comprising a thermoplastic resin, wherein the weight
percent of the overlay section relative to the composite article is
between about 1% and about 50%; and
[0011] c) an optional first adhesive layer disposed between the
fabric section and the overlay section;
[0012] whereby the composite article, when tested according to
MIL-STD-662-F using a 16 grain right circular cylinder
fragment-simulating projectile, has a V50 value comparable to or
greater than that of an article consisting only of a same-type
fabric section having an areal density equal to, or about the same
as, the areal density of the composite article.
[0013] In one embodiment, a ballistic composite article having a
strikeface and a backface is disclosed, the ballistic composite
article comprising:
[0014] a) a fabric section comprising two or more fibrous fabric
layers;
[0015] b) an overlay section comprising one or more layers, the
overlay section being disposed on the strikeface and comprising a
thermoplastic resin, wherein the weight percent of the overlay
section relative to the composite article is between about 1% and
about 50%; and
[0016] c) an optional first adhesive layer disposed between the
fabric section and the overlay section;
[0017] whereby the composite article, when tested according to HP
White HPW-TP-0401.01B using a 9 mm Full Metal Jacket projectile,
has a back face deformation value lower than that of an article
consisting only of a same-type fabric section having an areal
density equal to, or about the same as, the areal density of the
composite article.
[0018] By "equal to, or about the same as" it is meant that the
areal densities of articles being compared are intended to be about
the same for purposes of meaningful comparison, not necessarily
equal,
BRIEF DESCRIPTION OF THE FIGURES
[0019] The ballistic composite articles described herein are
described with reference to the following figures.
[0020] FIG. 1 provides a cross-sectional view of one embodiment of
the ballistic composite article described herein.
[0021] FIG. 2 provides a cross-sectional view of another embodiment
of the ballistic composite article described herein.
[0022] FIG. 3 provides a cross-sectional view of yet another
embodiment of the ballistic composite article described herein.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0023] The ballistic composite articles disclosed herein are
described with reference to the following terms.
[0024] As used herein, where the indefinite article "a" or "an" is
used with respect to a statement or description of the presence of
a step in a process of this invention, it is to be understood,
unless the statement or description explicitly provides to the
contrary, that the use of such indefinite article does not limit
the presence of the step in the process to one in number.
[0025] As used herein, when an amount, concentration, or other
value or parameter is given as either a range, preferred range, or
a list of upper preferable values and lower preferable values, this
is to be understood as specifically disclosing all ranges formed
from any pair of any upper range limit or preferred value and any
lower range limit or preferred value, regardless of whether ranges
are separately disclosed. Where a range of numerical values is
recited herein, unless otherwise stated, the range is intended to
include the endpoints thereof, and all integers and fractions
within the range. It is not intended that the scope of the
invention be limited to the specific values recited when defining a
range.
[0026] The term "composite article", as used herein, refers to an
article that comprises at least two components (i.e. a fabric
section and an overlay section) with significantly different
physical or chemical properties and which remain separate and
distinct on a macroscopic level within the finished structure. By
"composite article" is meant any type of construction, such as a
panel, whether flat or otherwise, and formed or molded products,
such as a helmet. The term "composite article" also includes but is
not limited to laminates, multilayer structures, matrices, or
variants thereof.
[0027] The term "strike face" as used herein refers to the surface
of the armor that faces the ballistic threat or is otherwise
intended to be struck first by a projectile.
[0028] The term "back face" as used herein refers to the surface of
the armor that is worn toward the body or property to be
protected.
[0029] The term "back face deformation" as used herein refers to
the amount of rearward deformation the armor receives when struck
abruptly by a non-penetrating projectile. Back face deformation,
abbreviated herein as "BFD", is also known as "back face
signature". Although the projectile may not penetrate the armor,
the part of the body or property to be protected which is directly
behind the point of impact usually receives a "hammer-like" blow as
a result of the deformation of the armor from the impact of the
projectile. This blow can produce not only bruises and lacerations
to the surface of the skin, but can produce damage to internal
organs. Thus a reduction in the back face deformation of armor can
correspond to reduced trauma to the body directly behind the point
of projectile impact.
[0030] The terms "fibrous fabric" and "fabric", as used herein, are
synonymous and refer to a multilayer construction of fibers.
[0031] The term "fiber" as used herein refers to an elongate body
the length dimension of which is much greater than the transverse
dimensions of width and thickness. Accordingly, the term fiber
includes monofilament fiber, multifilament fiber, ribbon, strip, a
plurality of any one or combinations thereof and the like having
regular or irregular cross-section.
[0032] The term "thermoplastic" as used herein refers to polymers
that undergo a transition from solid state to fluid state when
heated and freeze to a glass or semi-crystalline state when cooled
sufficiently. Thermoplastic polymers can be re-melted and
re-molded.
[0033] The term "comparable" as used herein refers to numerical
values which are within about 20% or alternatively within about 10%
of each other.
[0034] Disclosed herein is an impact-resistant ballistic composite
article comprising a fabric section and an overlay section which,
when tested under the conditions specified herein, provides
ballistic performance comparable to or greater than that of a
comparison article consisting of only the fabric section and having
an equal areal density. The overlay section comprises a
thermoplastic resin comprising polycarbonate, polyester,
thermoplastic elastomeric polyester, polyamide, polyolefin,
polysulfone, polyimide, or combinations thereof. The overlay
section can comprise one or more layers. Optionally, an adhesive
layer is disposed between the fabric section and the overlay
section. In one embodiment, the overlay section is disposed on the
strikeface of the composite article. In one embodiment, the overlay
section encapsulates the fabric section.
[0035] The fabric section of the ballistic composite article
comprises two or more fibrous fabric layers. The fibrous layers may
comprise bundles of fibers that are assembled to form a fibrous
layer. The fiber type is determined by the ballistic properties
required of the composite article. The fabric section of the
ballistic composite comprises fiber that can be woven or nonwoven
and can further comprise an aramid, even poly(p-phenylene
terephthalamide), or ultra-high molecular weight polyethylene
(UHMWPE). By nonwoven it is meant that in some embodiments the
fabric layer can be a unidirectionally oriented structure, such as
a cross ply or tape structure, a multi-axial fabric, or a
three-dimensional fabric, each of these provided with or without
binder. The multi-axial fabric can have layers of yarn oriented at
an angle with respect to adjacent layer(s), and these layers can
comprise unidirectional arrays of yarns. The three-dimensional
fabrics can also comprise unidirectional arrays of yarns. In one
embodiment, one or more of the fibrous fabric layers comprises a
woven fabric. In one embodiment, one or more of the fibrous fabric
layers comprises a non-woven fabric. In one embodiment, the
non-woven fabric comprises a unidirectionally oriented tape
structure.
[0036] The composite ballistic articles can comprise a fabric
section comprising a fiber network, the fiber network comprising
highly oriented ultra-high molecular weight polyethylene fiber or
tape (UHMWPE), highly oriented ultra-high molecular weight
polypropylene fiber or tape (UHMWPP), aramid fiber, polyvinyl
alcohol fiber, polyazole fiber or combinations or blends, including
mixtures of fibers made of different materials or blends of
different polymers in one fiber. U.S. Pat. No. 4,457,985 generally
discusses oriented ultra-high molecular weight polyethylene and
polypropylene fibers, the disclosure of which is hereby
incorporated by reference to the extent not inconsistent herewith.
In the case of polyethylene, suitable fibers are those highly
oriented fibers of weight average molecular weight of at least
about 500,000, preferably at least about one million and more
preferably between about two million and about six million. Known
as extended chain polyethylene (ECPE) fibers, such fibers may be
produced from polyethylene solution spinning processes described,
for example, in U.S. Pat. No. 4,137,394 to Meihuzen et al. or U.S.
Pat. No. 4,356,138 to Kavesh et al., or spun from a solution to
form a gel structure as described in German Off. No. 3,004,699, GB
No. 2051667, and especially as described in application Ser. No.
259,266 of Kavesh et al. filed Apr. 30, 1981 and application Ser.
No. 359,019 (continuation-in-part of Ser. No. 259,266) (see EPA No.
64,167, published Nov. 10, 1982).
[0037] As used herein, the term "polyethylene" refers to a
predominantly linear polyethylene material that may contain minor
amounts of chain branching or comonomers not exceeding 5 modifying
units per 100 main chain carbon atoms, and that may also contain
admixed therewith not more than about 25 wt % of one or more
polymeric additives such as alkene-1-polymers, in particular low
density polyethylene, polypropylene or polybutylene, copolymers
containing mono-olefins as primary monomers, oxidized polyolefins,
graft polyolefin copolymers and polyoxymethylenes, or low molecular
weight additives such as anti-oxidants, lubricants, ultra-violet
screening agents, colorants and the like which are commonly
incorporated therewith.
[0038] Depending upon the fiber-forming technique, the draw ratio
and temperatures, and other conditions, a variety of properties can
be imparted to these fibers. The tenacity of the fibers is
ordinarily at least about 15 grams/denier, preferably at least
about 20 grams/denier, more preferably at least about 30
grams/denier and most preferably at least about 40 grams/denier.
Similarly, the tensile modulus of the fibers, as measured by an
Instron tensile testing machine, is ordinarily at least about 300
grams/denier, preferably at least about 500 grams/denier, more
preferably at least about 1,000 grams/denier and most preferably at
least about 1,500 grams/denier. These highest values for tensile
modulus and tenacity are generally obtainable only by employing
solution spun or gel fiber processes. In addition, many ECPE fibers
have melting points higher than the melting point of the polymer
from which they were formed. Thus, for example, whereas ultra-high
molecular weight polyethylenes of 500,000, one million and two
million generally have melting points in the bulk of 134.degree.
C., the ECPE fibers made of these materials have melting points of
145.degree. C. or higher. The increase in melting point reflects a
higher crystalline orientation of the fibers as compared to the
bulk polymer.
[0039] Improved ballistic resistant articles are formed when
polyethylene fibers having a weight average molecular weight of at
least about 500,000, a modulus of at least about 500 and a tenacity
of at least about 15 g/denier are employed. Cf. John V. E. Hansen
and Roy C. Laible in "Flexible Body Armor Materials," Fiber
Frontiers ACS Conference, Jun. 10-12, 1974 (ballistically resistant
high strength fibers must exhibit high melting point and high
resistance to cutting or shearing); Roy C. Laible, Ballistic
Materials and Penetration Mechanics, 1980 (noting that nylon and
polyester may be limited in their ballistic effectiveness due to
the lower melting point); and "The Application of High Modulus
Fibers to Ballistic Protection", R. C. Laible, et al., J. Macromel.
Sci. Chem., A7(1), pp. 295-322, 1973 (the importance of a high
degree of heat resistance is again discussed).
[0040] In the case of polypropylene, highly oriented polypropylene
fibers of weight average molecular weight at least about 750,000,
preferably at least about one million and more preferably at least
about two million may be used. Ultra high molecular weight
polypropylene may be formed into reasonably highly oriented fibers
by the techniques prescribed in the various references referred to
above, and especially by the technique of U.S. Ser. No. 259,266,
filed Apr. 30, 1981, and the continuations-in-part thereof, both to
Kavesh et al. Since polypropylene is a much less crystalline
material than polyethylene and contains pendant methyl groups,
tenacity values achievable with polypropylene are generally
substantially lower than the corresponding values for polyethylene.
Accordingly, a suitable tenacity is at least about 8 grams/denier,
with a preferred tenacity being at least about 11 grams/denier. The
tensile modulus for polypropylene is at least about 160
grams/denier, preferably at least about 200 grams/denier. The
melting point of the polypropylene is generally raised several
degrees by the orientation process, such that the polypropylene
fiber preferably has a main melting point of at least about
168.degree. C., more preferably at least about 170.degree. C.
Employing fibers having a weight average molecular weight of at
least about 750,000 coupled with the preferred ranges for the
above-described parameters (modulus and tenacity) can provide
advantageously improved performance in the final article especially
in ballistic resistant articles. C. f. Laible, Ballistic Materials
and Penetration Mechanics, supra, at p. 81 (no successful treatment
has been developed to bring the ballistic resistance of
polypropylene up to levels predicated from the yarn stress-strain
properties); and the relative effectiveness of NTIS publication
ADA018 958, "New Materials in Construction for Improved Helmets",
A. L. Alesi et al. [wherein a multilayer highly oriented
polypropylene film material (without matrix), referred to as "XP",
was evaluated against an aramid fiber (with a phenolic/polyvinyl
butyral resin matrix); the aramid system was judged to have the
most promising combination of superior performance and a minimum of
problems for combat helmet development].
[0041] Aramid fiber is formed principally from aromatic polyamide.
Aromatic polyamide fibers having a modulus of at least about 400
g/denier and tenacity of at least about 18 g/denier are
particularly useful for incorporation into composites of this
invention. For example, poly(phenylenediamine terephthalamide)
fibers produced commercially by E. I. du Pont de Nemours &
Company under the trade names of Kevlar.RTM. 29 and Kevlar.RTM. 49
and having moderately high moduli and tenacity values are
particularly useful in forming ballistic resistant composites.
(Kevlar.RTM. 29 has 500 g/denier and 22 g/denier and Kevlar.RTM. 49
has 1000 g/denier and 22 g/denier as values of modulus and
tenacity, respectively). Also useful in forming ballistic resistant
composites is Kevlar.RTM. KM2.
[0042] In the case of polyvinyl alcohol (PV-OH), PV-OH fibers
having a weight average molecular weight of at least about 500,000,
preferably at least about 750,000, more preferably between about
1,000,000 and about 4,000,000 and most preferably between about
1,500,000 and about 2,500,000 may be employed in the present
invention. Usable fibers should have a modulus of at least about
160 g/denier, preferably at least about 200 g/denier, more
preferably at least about 300 g/denier, and a tenacity of at least
about 7 g/denier, preferably at least about 10 g/denier and more
preferably at least about 14 g/denier and most preferably at least
about 17 g/denier. PV-OH fibers having a weight average molecular
weight of at least about 500,000, a tenacity of at least about 200
g/denier and a modulus of at least about 10 g/denier are
particularly useful in producing ballistic resistant composites.
PV-OH fibers having such properties can be produced, for example,
by the process disclosed in U.S. patent application Ser. No.
569,818, filed Jan. 11, 1984, to Kwon et al. and commonly
assigned.
[0043] In the case of polyazoles, some preferred embodiments of
polyazoles are polyarenazoles such as polybenzazoles and
polypyridazoles. Suitable polyazoles include homopolymers and also
copolymers. Additives can be used with the polyazoles and up to as
much as 10 percent, by weight, of other polymeric material can be
blended with the polyazoles. Also copolymers can be used having as
much as 10 percent or more of other monomer substituted for a
monomer of the polyazoles. Suitable polyazole homopolymers and
copolymers can be made by known procedures.
[0044] Preferred polybenzazoles are polybenzimidazoles,
polybenzothiazoles, and polybenzoxazoles and more preferably such
polymers that can form fibers having yarn tenacities of 30 gpd or
greater. If the polybenzazole is a polybenzothioazole, preferably
it is poly(p-phenylene benzobisthiazole). If the polybenzazole is a
polybenzoxazole, preferably it is poly(p-phenylene benzobisoxazole)
and more preferably poly(p-phenylene-2,6-benzobisoxazole).
[0045] Preferred polypyridazoles are polypyridimidazoles,
polypyridothiazoles, and polypyridoxazoles and more preferably such
polymers that can form fibers having yarn tenacities of 30 gpd or
greater. In some embodiments, the preferred polypyridazole is a
polypyridobisazole. A preferred poly(pyridobisozazole) is
poly(1,4-(2,5-dihydroxy)phenylene-2,6-pyrido[2,3-d:5,6-d']bisimidazole
which is called PIPD. Suitable polypyridazoles, including
polypyridobisazoles, can be made by known procedures.
[0046] The aramid fabric or aramid fiber can optionally be finished
with a repellent material. As used herein, the term "repellent
material" refers to a hydrophobic material that resists wetting by
aqueous media, an agent comprising fluorine and carbon atoms being
preferred. In one embodiment, the fluorinated material comprises
fluorinated methacrylate polymers or copolymers, for example as in
Zonyl.RTM. D fabric fluoridizer, or Zonyl.RTM. 8300 fabric
protector, or OLEOPHOBOL SM.RTM. available from Ciba
Spezialitatenchemie Pfersee GmbH, Langweid, Germany. Optionally,
the water-repellent agent may in addition contain an antistatic
agent, such LEOMIN AN.RTM. from CLARIANT GmbH, Textile Leather
Products Division, Textile Chemicals BU, Frankfurt Main, Germany.
The aramid fabric or aramid fiber can be completely or partially
coated with the fluorinated repellant material. The treatment of
fabrics or fibers with such fluorinated polymers and oligomers is
common in the trade and is not limited to these chemicals. One
skilled in the art will be able to choose a suitable treatment.
[0047] The finish may be applied to the fiber in a variety of ways.
One method is to apply the neat resin of the coating material to
the stretched high modulus fibers either as a liquid, a sticky
solid or particles in suspension or as a fluidized bed.
Alternatively, the finish may be applied as a solution or emulsion
in a suitable solvent which does not adversely affect the
properties of the fiber at the temperature of application. While
any liquid capable of dissolving or dispersing the coating polymer
may be used, preferred groups of solvents include water, paraffin
oils, aromatic solvents or hydrocarbon solvents, with illustrative
specific solvents including paraffin oil, xylene, toluene and
octane. If the fiber achieves its final properties only after a
stretching operation or other manipulative process, e.g. solvent
exchanging, drying or the like, it is contemplated that the finish
may be applied to the precursor material. In this embodiment, the
desired and preferred tenacity, modulus and other properties of the
fiber should be judged by continuing the manipulative process on
the fiber precursor in a manner corresponding to that employed on
the finished fiber precursor. Thus, for example, if the coating is
applied to the xerogel fiber described in U.S. application Ser. No.
572,607 of Kavesh at al., and the coated xerogel fiber is then
stretched under defined temperature and stretch ratio conditions,
the applicable fiber tenacity and fiber modulus values would be the
measured values of an uncoated xerogel fiber which is similarly
stretched.
[0048] For application of the water-repellent finish to an aramid
fiber, any method is suitable in principle that allows the
water-repellent agent in the chosen formulation to be distributed
on the surface of the fiber. For example, the water-repellent agent
formulation can be applied as a thin film on a roller and the
aramid fiber passed through the film. Alternatively, the
water-repellent agent formulation can be sprayed on to the aramid
fiber. The water-repellent agent formulation can also be applied to
the fiber using a pump and a pin, slit or block applicator. In
another application method, the aramid fibers or aramid fabric can
be dipped into a bath of a solution containing the water-repellent
finish. Evaporation of the solvent produces a finished fiber or
fabric. The dipping procedure may be repeated as required to obtain
a desired amount of water-repellent coating on the aramid fibers or
aramid fabric.
[0049] The application of finish is effected preferably by passing
the aramid fiber over a roller immersed in a bath containing the
aqueous emulsion of the water-repellent agent, the emulsion
preferably having a temperature in the range 15-35.degree. C.
[0050] The drying of the aramid fiber after application of finish
is performed within ranges of temperature and of drying time that
suffice to ensure that the aramid fiber does not agglutinate in the
subsequent winding up. The parameter ranges for temperature and
drying time are also determined by the requirements of the selected
application method. If the water-repellent agent is applied on the
aramid fiber in the aramid fiber spinning process, for example,
after the fiber has left the wash bath, the ranges of temperature
and drying time will be determined by the spinning speed and the
structural features of the spinning facility. In one embodiment,
the finish-treated aramid fiber is dried at a temperature in the
range of 130-210.degree. C. and for a period in the range of 5-15
seconds.
[0051] The finished fabric layer is heat treated, preferably until
the water absorption of the fabric is reduced. The ranges of
duration and temperature required for the heat treatment are
determined essentially by the water-repellent agent applied in the
coating step. In many cases a temperature in the range of
120-200.degree. C. with a duration of 30-120 seconds is adequate
for heat treatment.
[0052] A proportion of water-repellent agent in the range of
0.001-0.02 g of water-repellent agent per g of fabric, for example
0.006-0.015 g of water-repellent agent per g of fabric, can result
in particularly high hydrophobic efficiency coupled with high
antiballistic efficiency in the dry and wet states.
[0053] The fabric section can further comprise a polymeric resin
disposed between at least two of the fibrous fabric layers. The
polymer of the polymeric resin can be any polymer that provides the
required level of adhesion with the fabric. Polymeric resins
suitable for use between at least two of the fibrous fabric layers
include polyvinyl butyral phenolic, polyesters, polyolefins
(polyethylene, polypropylene, polybutylene and copolymers and
blends of these), polyetheramides, fluoropolymers, polyethers,
celluloses, phenolics, polyesteramides, polyurethanes, epoxies,
aminoplastics, silicones, polysulfones, polyetherketones,
polyetheretherketones, polyesterimides, polyphenylene sulfides,
polyether acryl ketones, poly(amideimides), polyimides, polystyrene
copolymers, polyamides, vinylesters, and blends thereof. In one
embodiment, the polymeric resin comprises either a thermoplastic
resin or a blend thereof, or a thermosetting resin, or a blend
thereof, but not both a thermoplastic and a thermosetting resin
together as disclosed in published patent application US
2001/0113534, which is incorporated herein by reference. In one
embodiment, the polymeric resin can comprise an acid ethylene
copolymer disposed between at least two of the fibrous fabric
layers, wherein the ethylene copolymers are neutralized with an ion
as disclosed in published patent application US 2001/0113534. In
one embodiment, the polymeric resin comprises a pvb-phenolic
thermosetting matrix resin. In one embodiment, one portion of the
fabric section contains a thermoplastic resin and one portion of
the fabric section contains a thermosetting resin.
[0054] Useful ethylene copolymers are those that can be neutralized
with an ion selected from the group consisting of sodium,
potassium, lithium, silver, mercury, copper and the like and
mixtures thereof. Useful divalent metallic ions include, but are
not limited to, ions of beryllium, magnesium, calcium, strontium,
barium, copper, cadmium, mercury, tin, lead, iron, cobalt, nickel,
zinc and the like and mixtures therefrom. Useful trivalent metallic
ions include, but are not limited to, ions of aluminum, scandium,
iron, yttrium and the like and mixtures therefrom. Useful
multivalent metallic ions include, but are not limited to, ions of
titanium, zirconium, hafnium, vanadium, tantalum, tungsten,
chromium, cerium, iron and the like and mixtures therefrom. It is
noted that when the metallic ion is multivalent, complexing agents,
such as stearate, oleate, salicylate, and phenolate radicals may be
included, as disclosed within U.S. Pat. No. 3,404,134. The metallic
ions used herein are preferably monovalent or divalent metallic
ions. More preferably, the metallic ions used herein are selected
from the group consisting of ions of sodium, lithium, magnesium,
zinc and mixtures therefrom. Yet more preferably, the metallic ions
used herein are selected from the group consisting of ions of
sodium, zinc and mixtures therefrom. The parent acid copolymers of
the invention may be neutralized as disclosed in U.S. Pat. No.
3,404,134.
[0055] By "degree of neutralization" is meant the mole percentage
of acid groups on the ethylene copolymer that have a counterion.
The ethylene acid copolymer utilized in the present invention is
neutralized to a level of about 70% to slightly greater than 100%
with one or more metal ions selected from the group consisting of
potassium, sodium, lithium, magnesium, zinc, and mixtures of two or
more thereof, based on the total carboxylic acid content of the
acid copolymer.
[0056] The fabric section may also contain one or more layers of
high strength, polyolefin fiber composites such as the cross-plied
unidirectional polyethylene fiber composite Dyneema.RTM. HB26 from
DSM Co. (Netherlands) or tapes such as Tensylon.RTM. previously
available from BAE or Dyneema.RTM. BT10.
[0057] In one embodiment, the fabric section may comprise hybrid
yarns. As used herein, the term "hybrid yarns" refers to two or
more multifilament yarns, the filaments of which have been
intermixed with each other without adding twist or otherwise
disturbing the parallel relationship of the combined filaments.
Examples of suitable hybrid yarns include those containing aramid
and carbon; aramid and glass; aramid, carbon and glass; and carbon,
glass, and extended chain polyethylene. Other suitable hybrid
fibers may also be used. Hybridization of the fibers not only
reduces costs, but in many instances improves the performance in
armor structures. It is known that aramid fiber and carbon are
significantly lighter than glass fiber. The specific modulus of
elasticity of aramid is nearly twice that of glass, while a typical
high tensile strength-grade of carbon fiber is more than three
times as stiff as glass in a composite. However, aramid fiber has a
lower compressive strength than either carbon or glass, while
carbon is not as impact resistant as aramid. Therefore, a hybrid of
the two materials results in a composite that is (1) lighter than a
comparable glass fiber-reinforced plastic; (2) higher in modulus,
compressive strength and flexural strength than an all-aramid
composite; and (3) higher in impact resistance and fracture
toughness than an all-carbon composite.
[0058] The overlay section of the ballistic composite article
comprises a thermoplastic resin. Thermoplastic resins suitable for
use in the overlay section can include polycarbonate, polyester,
thermoplastic elastomeric polyester, polyacetal, polyamide,
polyolefin, polysulfone, polyimide, a blend of polyamide and an
ethylene/.alpha.,.beta.-unsaturated C3-C8 carboxylic acid copolymer
partially neutralized with metal ions, or combinations thereof. In
one embodiment, the thermoplastic resin comprises polycarbonate, a
thermoplastic elastomeric polyester having poly(1,4-butylene
terephthalate) and poly(alkylene ether)glycol blocks, polybutylene
terephthalate, a polyacetal, a blend of polyamide and an
ethylene/.alpha.,.beta.-unsaturated C3-C8 carboxylic acid copolymer
partially neutralized with metal ions, or combinations thereof. The
thermoplastic resins can be unfilled or filled, for example by
inclusion of glass or mineral particles or fibers. Optionally, the
thermoplastic resins can be toughened as well. Generally, suitable
thermoplastic resins have sufficient molecular weight to provide
optimized strength and toughness, and exhibit flow at temperatures
greater than 75.degree. C. In one embodiment, the polymeric resin
of the overlay section and the polymeric resin disposed between at
least two of the fibrous fabric layers of the fabric section
comprise the same thermoplastic resin. In one embodiment, the
polymeric resin of the overlay section is continuous.
[0059] In one embodiment, the thermoplastic resin comprises
polycarbonate. Polycarbonate refers to any polymer in which the
structural units are linked by carbonate ester groups, including
2,2-bis(4-hydroxyphenol)propane (also known as bisphenol A) and
diphenyl carbonate. Polycarbonates are characterized by high-impact
strength, light weight, and flexibility and can be prepared by the
reaction of an aromatic difunctional phenol with either phosgene or
an aromatic or aliphatic carbonate, as is well known in the art.
Suitable polycarbonates are also commercially available.
[0060] In one embodiment, the thermoplastic resin comprises
polyester. In one embodiment, the thermoplastic resin comprises
polybutylene terephthalate, for example as Crastin.RTM. polymer
commercially available from E.I. du Pont de Nemours and Company
(DuPont). In one embodiment, the thermoplastic resin comprises
polytrimethylene terephthalate, for example as SORONA.RTM. polymer
commercially available from DuPont. In one embodiment, the
thermoplastic resin comprises polyethylene terephthalate.
[0061] In one embodiment, the thermoplastic resin comprises a
thermoplastic elastomeric polyester. In one embodiment, the
thermoplastic resin comprises a thermoplastic elastomeric polyester
having poly(1,4-butylene terephthalate) and poly(alkylene
ether)glycol blocks. In one embodiment, the thermoplastic resin
comprises a thermoplastic elastomeric polyester having
poly(1,4-butylene terephthalate) and poly(tetramethylene
ether)glycol blocks, for example as Hytrel.RTM. polymer,
commercially available from DuPont.
[0062] As used herein, the term "polyester" means a polymer in
which more than 50% of the linking groups are ester groups. Other
linking groups, such as amide or/or imide may also be present. The
polyester is selected from the group consisting of: at least one
polyester homopolymer; at least one polyester copolymer; a
polymeric blend comprising at least one polyester homopolymer or
copolymer; and mixtures of these.
[0063] Polyesters which have mostly or all ester linking groups are
normally derived from one or more dicarboxylic acids and one or
more diols; they can also be produced from polymerizable polyester
monomers or from macrocyclic polyester oligomers as disclosed in
U.S. Pat. No. 8,071,677, which is incorporated by reference
herein.
[0064] Suitable polyesters can comprise isotropic thermoplastic
polyester homopolymers and copolymers (both block and random).
Examples include without limitation: poly(ethylene terephthalate),
poly(1,3-propylene terephthalate), poly(1,4-butylene
terephthalate), a thermoplastic elastomeric polyester having
poly(1,4-butylene terephthalate) and poly(tetramethylene
ether)glycol blocks, poly(1,4-cylohexyldimethylene terephthalate),
and polylactic acid.
[0065] The dicarboxylic acid component is selected from
unsubstituted and substituted aromatic, aliphatic, unsaturated, and
alicyclic dicarboxylic acids and the lower alkyl esters of
dicarboxylic acids preferably having from 2 carbons to 36 carbons.
Specific examples of suitable dicarboxylic acid components include
without limitation terephthalic acid, dimethyl terephthalate,
isophthalic acid, dimethyl isophthalate, 2,6-napthalene
dicarboxylic acid, dimethyl-2,6-naphthalate,
2,7-naphthalenedicarboxylic acid, dimethyl-2,7-naphthalate,
3,4'-diphenyl ether dicarboxylic acid, dimethyl-3,4'diphenyl ether
dicarboxylate, 4,4'-diphenyl ether dicarboxylic acid,
dimethyl-4,4'-diphenyl ether dicarboxylate, 3,4'-diphenyl sulfide
dicarboxylic acid, dimethyl-3,4'-diphenyl sulfide dicarboxylate,
4,4'-diphenyl sulfide dicarboxylic acid, dimethyl-4,4'-diphenyl
sulfide dicarboxylate, 3,4'-diphenyl sulfone dicarboxylic acid,
dimethyl-3,4'-diphenyl sulfone dicarboxylate, 4,4'-diphenyl sulfone
dicarboxylic acid, dimethyl-4,4'-diphenyl sulfone dicarboxylate,
3,4'-benzophenonedicarboxylic acid,
dimethyl-3,4'-benzophenonedicarboxylate,
4,4'-benzophenonedicarboxylic acid,
dimethyl-4,4'-benzophenonedicarboxylate, 1,4-naphthalene
dicarboxylic acid, dimethyl-1,4-naphthalate, 4,4'-methylene
bis(benzoic acid), dimethyl-4,4'-methylenebis(benzoate), oxalic
acid, dimethyl oxalate, malonic acid, dimethyl malonate, succinic
acid, dimethyl succinate, methylsuccinic acid, glutaric acid,
dimethyl glutarate, 2-methylglutaric acid, 3-methylglutaric acid,
adipic acid, dimethyl adipate, 3-methyladipic acid,
2,2,5,5-tetramethylhexanedioic acid, pimelic acid, suberic acid,
azelaic acid, dimethyl azelate, sebacic acid,
1,11-undecanedicarboxylic acid, 1,10-decanedicarboxylic acid,
undecanedioic acid, 1,12-dodecanedicarboxylic acid, hexadecanedioic
acid, docosanedioic acid, tetracosanedioic acid, dimer acid,
1,4-cyclohexanedicarboxylic acid,
dimethyl-1,4-cyclohexanedicarboxylate, 1,3-cyclohexanedicarboxylic
acid, dimethyl-1,3-cyclohexanedicarboxylate,
1,1-cyclohexanediacetic acid, metal salts of
5-sulfo-dimethylisophalate, fumaric acid, maleic anhydride, maleic
acid, hexahydrophthalic acid phthalic acid and the like and
mixtures derived there from. Other dicarboxylic acids suitable for
use in forming the monofilaments will be apparent to those skilled
in the art. Preferred dicarboxylic acids include terephthalic acid,
dimethyl terephthalate, isophthalic acid, and dimethyl
isophthalate.
[0066] The diol component is selected from unsubstituted,
substituted, straight chain, branched, cyclic aliphatic,
aliphatic-aromatic or aromatic diols having from 2 carbon atoms to
36 carbon atoms and poly(alkylene ether)glycols with molecular
weights between about 250 to 4,000. Specific examples of the
desirable diol component include ethylene glycol, 1,3-propanediol,
1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol,
1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, dimer
diol, 4,8-bis(hydroxymethyl)-tricyclo[5.2.1.0/2.6]decane,
1,4-cyclohexanedimethanol (both cis and trans structures),
di(ethylene glycol), tri(ethylene glycol), polyethylene
ether)glycols with molecular weights between 250 and 4000,
poly(1,2-propylene ether)glycols with molecular weights between 250
and 4000, block poly(ethylene-co-propylene-co-ethylene
ether)glycols with molecular weights between 250 and 4000,
poly(1,3-propylene ether)glycols with molecular weights between 250
and 4000, polybutylene ether)glycols with molecular weights between
250 and 4000 and the like and mixtures derived there from.
[0067] A polyfunctional branching agent may be present as well,
i.e., any material with three or more carboxylic acid functional
groups, hydroxyl functional groups or a mixture thereof.
Essentially any polyfunctional material that includes three or more
carboxylic acid or hydroxyl functions can be used, and such
materials will be apparent to those skilled in the art. Examples of
polyfunctional branching agent components include without
limitation: 1,2,4-benzenetricarboxylic acid, (trimellitic acid),
trimethyl-1,2,4-benzenetricarboxylate,
tris(2-hydroxyethyl)-1,2,4-benzenetricarboxylate,
trimethyl-1,2,4-benzenetricarboxylate, 1,2,4-benzenetricarboxylic
anhydride, (trimellitic anhydride), and mixtures thereof.
[0068] In one embodiment, the thermoplastic resin comprises a
polyacetal. Polyacetal, also known as polyoxymethylene and
polyformaldehyde, is an engineering thermoplastic useful in
applications requiring high stiffness, low friction, and excellent
dimensional stability. Polyacetals are characterized by high
strength, hardness and rigidity to about 40.degree. C. Polyacetals
can be prepared, for example, by reaction of aqueous formaldehyde
with an alcohol to generate a hemiformal, followed by dehydration
of the hemiformal/water mixture via extraction or distillation and
heating to generate formaldehyde, which is then polymerized by
anionic catalysis. The resulting polymer is stabilized by reaction
with acetic anhydride. Suitable polyacetals are commercially
available.
[0069] In one embodiment, the thermoplastic resin comprises a blend
of polyamide and an ethylene/.alpha.,.beta.-unsaturated C3-C8
carboxylic acid copolymer partially neutralized with metal ions,
which is commonly referred to as "ionomer". See, for example, US
201210264342 and U.S. Pat. No. 5,700,890. The total percent
neutralization can be from 5 to 90 percent, and the metal ions can
be any metal on of group I or group II or the periodic table, for
example sodium, zinc, lithium, magnesium, calcium, or a mixture of
any of these. The partially neutralized
ethylene/.alpha.,.alpha.-unsaturated C3-C8 carboxylic acid
copolymers can be prepared by standard neutralization techniques,
as disclosed in U.S. Pat. No. 3,264,272. The ionomers can be
prepared by free-radical copolymerization methods, using high
pressure, operating in a continuous manner known in the art, as
described in U.S. Pat. No. 4,351,931, U.S. Pat. No. 5,028,674, U.S.
Pat. No. 5,057,593, U.S. Pat. No. 5,859,137. The polyamide can be
aliphatic and/or semi-aromatic, crystalline, semi-crystalline,
amorphous, and/or combinations thereof, and can be prepared by
methods known in the art or obtained commercially.
[0070] The weight percent of the overlay section relative to the
composite article is generally between about 1% and about 50%, for
example between about 1% and about 45%, or between about 1% and
about 40%, or between about 1% and about 35%, or between about 1%
and about 30%, or between about 1% and about 25%, or between about
1% and about 20%, or between about 1% and about 15%, or between
about 1% and about 10%, or between about 20% and about 30%, or
between about 20% and about 40%, or between about 20% and about
45%, or between about 20% and about 50%. Within these disclosed
ranges, a higher weight percent of overlay is generally desired as,
for a given areal density of a composite article comprising a
fabric section and an overlay section, a higher weight percentage
of overlay can provide a composite article having comparable or
greater ballistic protection at lower cost than a comparison
ballistic article of equal areal density but consisting of only the
fabric section. However, composite articles in which the weight
percent overlay section is greater than about 50% can also be
prepared and may provide adequate ballistic performance under some
conditions. The maximum useful weight percent of the overlay
section depends on the thermoplastic resin selected and the type of
ballistic threat faced.
[0071] In one embodiment, the weight percent of the overlay section
is between about 1% and about 40%, and the thermoplastic resin
comprises polycarbonate, a thermoplastic elastomeric polyester
having poly(1,4-butylene terephthalate) and poly(alkylene
ether)glycol blocks, polybutylene terephthalate, a polyacetal, a
blend of polyamide and an ethylene/.alpha.,.beta.-unsaturated C3-C8
carboxylic acid copolymer partially neutralized with metal ions, or
combinations thereof.
[0072] The overlay section of the ballistic composite article can
comprise one or more layers of thermoplastic resin. In one
embodiment, the overlay section comprises one layer of
thermoplastic resin. In one embodiment, the overlay section
comprises two or more layers. The layers can comprise the same or
different thermoplastic resins. The layers can have the same or
different thicknesses. Optionally, one or more adhesive layers can
be disposed between the layers of thermoplastic resin, and the
adhesive layers can comprise the same or different adhesives. The
thickness of the overlay section will generally depend on the
weight percent of the overlay section relative to the composite
article and to the areal density of the composite article.
[0073] The ballistic composite article can have an areal density
between about 2.5 lbs/ft.sup.2 (12.2 kg/m.sup.2) and about 1.0
lbs/ft.sup.2 (4.88 kg/m.sup.2), or between about 2.5 lbs/ft.sup.2
and about 1.5 lbs/ft.sup.2 (7.32 kg/m.sup.2), or between about 2.0
lbs/ft.sup.2 (9.76 kg/m.sup.2) and about 1.0 lbs/ft.sup.2 (4.88
kg/m.sup.2). The areal density of the composite article refers to
the sum of the areal densities of the fabric section and the
overlay section, and includes that of any adhesive layers
present.
[0074] Optionally, an adhesive layer is disposed between the fabric
section and the overlay section to join the sections together.
Adhesives suitable for use between the fabric section and the
overlay section, and/or between two or more layers of the overlay
section, can comprise a plant-based glue, a solvent-type glue, a
synthetic monomer glue, a synthetic polymer glue, or combinations
thereof. Examples of plant-based glues include methyl cellulose,
mucilage, resorcinol resin, and starch. Examples of solvent-type
glues include polystyrene with butanone (methylethylketone), and
dichloromethane. Examples of synthetic monomer glues include
acrylonitrile, cyanoacrylate (e.g. "Superglue" and "Krazy Glue"),
and acrylic. Synthetic polymer glues include urea-formaldehyde
resins, epoxy resins, epoxy putty, ethylene-vinyl acetate (a
hot-melt glue), phenol formaldehyde resin, polyamide, polyester
resins, polyethylene (a hot-melt glue), polypropylene,
polysulfides, polyurethane (e.g. Gorilla Glue), polyvinyl acetate
including white glue (e.g., Elmer's Glue) and yellow carpenter's
glue (e.g. Titebond.RTM. and Lepage.RTM. aliphatic resin glues),
polyvinyl alcohol, polyvinyl chloride, polyvinyl chloride emulsion,
polyvinylpyrrolidone, rubber cement, silicones, and styrene acrylic
copolymer. In one embodiment, an adhesive layer is disposed between
the fabric section and the overlay section, and the adhesive layer
comprises a plant-based glue, a solvent-type glue, a synthetic
monomer glue, a synthetic polymer glue, an epoxy resin, a
polyurethane, or combinations thereof. In one embodiment, an
adhesive layer is disposed between the fabric section and the
overlay section, and the adhesive layer comprises an epoxy resin, a
polyurethane, or combinations thereof. In one embodiment, an
adhesive layer is disposed between the fabric section and the
overlay section, the fabric section further comprises a polymeric
resin disposed between at least two of the fibrous fabric layers,
and the adhesive layer and the polymeric resin comprise the same
polymer,
[0075] When an optional adhesive layer is to be used, the adhesive
layer is preferably spread uniformly onto the entire surface of the
fabric section to be bonded to the overlay section, the overlay
section placed on top of the adhesive layer, and then minimal force
applied to keep the fabric section and overlay sections in contact
with the adhesive layer while the adhesive layer dries or cures. In
the case of a flat panel, force can be applied by weights placed on
top of the composite article. In the case of a helmet, force can be
applied by maintaining the components in a mold and keeping the
mold closed. The fabric section and overlay section should be kept
in close contact overnight, or for a sufficient time under
conditions recommended by the supplier to produce a durable
bond.
[0076] The overlay section is disposed on the strikeface of the
ballistic composite article. As used herein, the term "disposed on
the strikeface" means that the overlay section completely and
uniformly covers the strikeface of the ballistic composite. In one
embodiment, the overlay section is additionally disposed on the
backface of the ballistic composite article, and optionally on at
least a portion of at least one edge of the composite article, with
the proviso that the majority of the overlay section is disposed on
the strikeface. In one embodiment, the overlay section encapsulates
the fabric section, and the majority of the overlay section is
disposed on the strikeface of the composite article. By
"encapsulates" is meant that the overlay section is disposed on the
strikeface, on all the edges, and on all of the backface of the
composite article such that the fabric section is completely
covered by the overlay section. In the case where the overlay
section encapsulates the fabric section, the ballistic composite
article may optionally further comprise at least one adhesive layer
disposed between at least a portion of the fabric section and the
overlay section, for example on the face of the fabric section
which is oriented toward the strikeface of the composite article,
on the face of the fabric section which is oriented toward the
backface of the composite article, or on both faces of the fabric
section. By "majority" is meant at least 51%, or at least 55%, or
at least 60%, or at least 65%, or at least 70%, or at least 75%, or
at least 80%, or at least 85%, or at least 90%, or at least 95%, or
at least 97% of the overlay section by weight.
[0077] Referring to the figures, FIG. 1 shows a ballistic composite
article 1 comprising a fabric section 10 and an overlay section 20
with an adhesive layer 25 disposed between the fabric section and
the overlay section. The cut-away portion of the figure shows the
fibrous fabric layers 15 of which the fabric section is comprised.
The arrow 3 indicates the strikeface of the composite article; the
arrow 5 indicates the backface of the composite article.
[0078] FIG. 2 shows another ballistic composite article 1
comprising a fabric section 10 and an overlay section 20. A first
adhesive layer 25 is disposed between fabric section 10 and overlay
section 20. In this embodiment, overlay section 20 comprises a
first layer 30 and a second layer 35, with a second adhesive layer
40 disposed between them. The cut-away portion of the figure shows
the fibrous fabric layers 15 of which the fabric section is
comprised. The arrow 3 indicates the strikeface of the composite
article; the arrow 5 indicates the backface of the composite
article.
[0079] FIG. 3 shows a ballistic composite article 1 comprising a
fabric section 10 comprising fibrous fabric layers 15. Overlay
section 20' completely encapsulates fabric section 10, with a
majority of the overlay section being disposed on the strikeface 3
of the composite article. A first adhesive layer 25 is disposed
between the fabric section and the majority of the overlay. In this
embodiment, a second adhesive layer 45 is disposed between the
fabric section and the overlay on the backface 5 of the composite
article.
[0080] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising polyp-phenylene terephthalamide); b) an overlay section
comprising one or more layers, the overlay section being disposed
on the strikeface of the composite article and comprising
polybutylene terephthalate, wherein the weight percent of the
overlay section relative to the composite article is between about
1% and about 50%; and c) an optional adhesive layer disposed
between the fabric section and the overlay section.
[0081] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising polyp-phenylene terephthalamide); b) an overlay section
comprising one or more layers, the overlay section being disposed
on the strikeface of the composite article and comprising
polycarbonate, wherein the weight percent of the overlay section
relative to the composite article is between about 1% and about
40%; and c) an optional adhesive layer disposed between the fabric
section and the overlay section.
[0082] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising poly(p-phenylene terephthalamide); b) an overlay section
comprising one or more layers, the overlay section being disposed
on the strikeface of the composite article and comprising a
thermoplastic elastomeric polyester having poly(1,4-butylene
terephthalate) and poly(tetramethylene ether)glycol blocks, wherein
the weight percent of the overlay section relative to the composite
article is between about 1% and about 30%; and c) an optional
adhesive layer disposed between the fabric section and the overlay
section.
[0083] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising polyp-phenylene terephthalamide); b) an overlay section
comprising one or more layers, the overlay section encapsulating
the fabric section and comprising polybutylene terephthalate,
wherein the weight percent of the overlay section relative to the
composite article is between about 1% and about 50% and a majority
of the overlay section is disposed on the strikeface of the
composite article; and c) an optional adhesive layer disposed
between the fabric section and the overlay section.
[0084] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising poly(p-phenylene terephthalamide); b) an overlay section
comprising one or more layers, the overlay section encapsulating
the fabric section and comprising polycarbonate wherein the weight
percent of the overlay section relative to the composite article is
between about 1% and about 40% and a majority of the overlay
section is disposed on the strikeface of the composite article; and
c) an optional adhesive layer disposed between the fabric section
and the overlay section.
[0085] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising polyp-phenylene terephthalamide); b) an overlay section
comprising one or more layers, the overlay section encapsulating
the fabric section and comprising a thermoplastic elastomeric
polyester having poly(1,4-butylene terephthalate) and
poly(tetramethylene ether)glycol blocks wherein the weight percent
of the overlay section relative to the composite article is between
about 1% and about 30% and a majority of the overlay section is
disposed on the strikeface of the composite article; and c) an
optional adhesive layer disposed between the fabric section and the
overlay section.
[0086] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising unidirectionally oriented ultra high molecular weight
polyethylene tape; b) an overlay section comprising one or more
layers, the overlay section being disposed on the strikeface of the
composite article and comprising a thermoplastic elastomeric
polyester having poly(1,4-butylene terephthalate) and
poly(tetramethylene ether)glycol blocks, wherein the weight percent
of the overlay section relative to the composite article is between
about 1% and about 30% and c) an optional adhesive layer disposed
between the fabric section and the overlay section.
[0087] In one embodiment, the ballistic composite article comprises
a) a fabric section comprising two or more fibrous fabric layers
comprising unidirectionally oriented ultra high molecular weight
polyethylene tape; b) an overlay section comprising one or more
layers, the overlay section being disposed on the strikeface of the
composite article and comprising polycarbonate, wherein the weight
percent of the overlay section relative to the composite article is
between about 1% and about 30% and c) an optional adhesive layer
disposed between the fabric section and the overlay section.
[0088] A ballistic composite article as disclosed herein in which
the overlay is disposed on the strikeface of the composite article
can be made by preparing a consolidated fabric section, applying
adhesive to one face of the fabric section, placing the overlay
section in contact with the adhesive layer, and allowing the
overlay and fabric sections to be bonded together through the
adhesive layer. In some embodiments the overlay section can be
placed directly in contact with the fabric layer and sufficient
heat provided to bond the overlay section to the fabric
section.
[0089] A ballistic composite article as disclosed herein in which
the overlay section completely encapsulates the fabric section can
be made by a process in which a consolidated fabric section is
placed in an injection mold. The fabric section is then overmolded
with the desired thermoplastic resin using the process of injection
molding, which is well known in the art. The distribution of the
overlay can be controlled in the injection molding process so that
a majority of the overlay section is disposed on the strikeface of
the composite article. Helmets and flat ballistic panels in which
the overlay section fully encapsulates the fabric section can be
made this way. Optionally, additional functional features can be
added to the ballistic composite via the injection molding process,
as is known in the art.
[0090] The ballistic composite articles disclosed herein can
provide comparable or improved protection against projectile
threats relative to conventional ballistic composites consisting
only of a same-type fabric section having an equal area density.
"Same-type" as used herein refers to the fabric section of a
comparable composite, as described above, wherein the fabric
section is the same as the fibrous fabric layers used in the
inventive composite. The comparable or improved protection is
evidenced by comparable V50 values and/or lower BFD values for the
ballistic composite articles disclosed herein, when compared to
those values for corresponding conventional ballistic composites
without an overlay section disposed on the strikeface and tested
under the same conditions. Advantageously, the ballistic composite
articles disclosed herein can be made at reduced cost since a
portion of the higher cost ballistic fabric section is replaced by
the lower cost thermoplastic overlay. The composite articles
disclosed herein are rigid and can be used to provide comparable or
superior protection to the body or to property. Panels comprising
the disclosed composite articles can be used in rigid armor
applications such as helmets, tactical plates, structural members
of helicopters, vehicles, walls, shelters, and other military
equipment.
EXAMPLES
[0091] The ballistic composite articles described herein are
illustrated in the following examples. From the above discussion
and these examples, one skilled in the art can ascertain the
essential characteristics of this invention, and without departing
from the spirit and scope thereof, can make various changes and
modifications of the invention to adapt it to various uses and
conditions.
[0092] All commercial materials were used as received unless
otherwise indicated.
[0093] The following abbreviations are used: ".degree. C." is
degrees Celsius, ".degree. F." is degrees Fahrenheit, "gn" is
grain, "m" is meter, "s" is second, "psf" is pounds per square
foot, "lbs/ft.sup.2" is also pounds per square foot, "fps" is feet
per second", "ft/s" is also feet per second, "cm" is centimeter,
"mm" is millimeter, "g" is gram, "kg" is kilogram, "gpd" is grams
per denier, "AD" is area density, "wt" is weight, "wt %" means
weight percent, "Comp. Ex." is Comparative Example, "PVB" means
polyvinyl butyral.
Analytical Methods:
[0094] Ballistic Penetration Performance:
[0095] Ballistic tests of the composite articles of Comparative
Examples A and B, and Examples 1-20 were conducted in accordance
with standard procedure MIL-STD-662-F (V50 Ballistic Test for
Armor) with the exception that 16 Grain Right Circular Cylinder
(RCC) fragment-simulating projectiles were used. For each Example,
one composite article was used as the target with up to seven shots
fired at it, at zero degree obliquity. The composite articles of
Examples 1-20 were oriented with the overlay section facing the
projectile, that is, with the overlay section on the strikeface of
the composite article.
[0096] Ballistic tests of the composite articles of Comparative
Examples E, F, and G and Examples 21-25 were conducted in
accordance with standard procedure MIL-STD-662-F (V50 Ballistic
Test for Armor) with the exception that 9 mm Full Metal Jacketed
bullet rounds with a nominal mass of 8.0 g (124 gn) were used as
the projectile. For each Example, one composite article was used as
the target with up to seven shots fired at it, at zero degree
obliquity. The composite articles of Examples 21-25 were oriented
with the overlay section facing the projectile, that is, with the
overlay section on the strikeface of the composite article.
[0097] The reported V50 values are average values for the number of
pairs of partial and complete penetrations achieved for each
example. V50 is a statistical measure that identifies the average
velocity at which a bullet or a fragment penetrates the target or
armor equipment in 50% of the shots, versus non-penetration of the
other 50%. The parameter measured is V50 at zero degrees where the
degree angle refers to the obliquity of the projectile to the
target. For a given set of test conditions and projectile, higher
V50 values indicate better resistance to ballistic penetration.
[0098] Back Face Deformation (BFD) Performance:
[0099] Ballistic tests of the composite articles of Comparative
Examples E, F, and G and Examples 21-25 were conducted using a
modified version of the HP White HPW-TP-0401.01B standard test
procedure for bullet resistant helmet deformation. The same
conditioning, testing, and measurement protocols were used, with
the modification being only that these example panels were flat and
not helmet shaped. The threat used was the 9 mm Full Metal Jacket
round, as described above weighing nominally 8.0 g (124 gn), and
the velocity used was within the 1400-1450 (427-442 m/s) range,
both as described in the document for NIJ Level IIIA protection.
For each Example, one composite article was used as the target with
up to two shots fired at it, at zero degree obliquity. The
composite articles of Examples 21-25 were oriented with the overlay
section facing the projectile, that is, with the overlay section on
the strikeface of the composite article. The reported BFD values
are the individual values for either the one or the two fair shots
achieved for each example. BFD values were taken using standard
clay measurement techniques developed in the industry, where a
lower back face deformation value for a given set of test
conditions and projectile corresponds to better panel performance.
After one or two fair shots were obtained and BFD values were
recorded, the remaining unshot area of the panels of Comparative
Examples E, F, and G and Examples 21-25 were then tested for V50
type ballistic testing using the same 9 mm projectile described
above.
[0100] Area density is reported as weight per unit area and was
determined by weighing 12 inch.times.12 inch panels (30.5
cm.times.30.5 cm) of material. In some cases, 15 inch.times.15 inch
(38.1 cm.times.38.1 cm) fabric sections were manually cut down to
12 inch.times.12 inch panels, then weighed.
[0101] Materials and Processing:
[0102] Kevlar.RTM. XP.TM. H170:
[0103] Comparative Examples A and B and Examples 1-17 used plies of
Kevlar.RTM. XP.TM. H170 prepreg, commercially available from E.I.
DuPont de Nemours and Company (Wilmington, Del.) (DuPont). This
material has a nominal areal weight of 170 g/m.sup.2 and comprises
(a) a plain weave woven fabric of 600 denier (660 dtex)
poly(p-phenylene terephthalamide) yarn having a nominal yarn
tenacity of 27.5 grams per denier (gpd) and a nominal yarn modulus
of 630 gpd (which is also available from DuPont under the trade
name of Kevlar.RTM. para-aramid brand KM2 yarn) which was woven at
11.4.times.11.4 ends per centimeter (29.times.29 ends per inch) and
(b) a thermoplastic matrix resin consisting of a highly neutralized
ionomer that had essentially no melt flow which was coated at
nominally 10-13 weight percent based on the total weight of the
fabric plus the matrix resin as an aqueous colloid of the ionomer
on one side of the Kevlar.RTM. fabric and dried, as described in
detail in published patent application US 2011/0117351(M), which is
incorporated herein by reference.
[0104] General Procedure for Consolidation of Kevlar.RTM. XP.TM.
H170 Plies:
[0105] In Comparative Examples A and B and Examples 1-17, the
Kevlar.RTM. XP.TM. H170 plies were processed identically to produce
fabric sections using the following procedure. The desired number
of plies were cut to a size of either nominally 12 inches.times.12
inches (30.5 cm.times.30.5 cm) or 15 inches.times.15 inches (38.1
cm.times.38.1 cm). Cut plies were laid up such that the one-sided
resin matrix coating was always facing the same direction, thus the
coated side of one ply was always in direct contact with the dry or
un-coated side of an adjacent ply, and vice versa. The layup was
placed in a compression molding press to undergo a consolidation
procedure in which the plies were consolidated into a fabric
section. Consolidation took place at a temperature of 160.degree.
C. (320.degree. F.), under a pressure of 31 MPa (4500 psi), for a
time of 15 minutes under heat, prior to cooling down to a
temperature below 38.degree. C. (100.degree. F.). The 31 MPa (4500
psi) pressure was maintained on the layup during the entire process
including the cooling phase. The fabric section was then removed
from the mold and analyzed. In the cases where the fabric section
was nominally 15 inches.times.15 inches (38.1 cm.times.38.1 cm), it
was cut down to a size of nominally 12 inches.times.12 inches (30.5
cm.times.30.5 cm) with a secondary operation using a band saw.
[0106] Tensylon.TM. HSBD-30A:
[0107] Comparative Examples C and D and Examples 18-20 used plies
of Tensylon.TM. HSBD-30A bi-directional polyethylene laminate
coated with resin, commercially available from DuPont. This
material has a nominal areal weight of 110 g/m.sup.2 and comprises
(a) a cross-plied set of orthogonal unidirectionally oriented ultra
high molecular weight polyethylene (UHMWPE) tape layers and (b) a
linear low density polyethylene (LLDPE) thermoplastic matrix resin
which was inserted at nominally 10 weight percent based on the
total weight of the fabric plus the matrix resin as a film layer
both in between the cross-plied unidirectionally oriented tape
layers and on the outside of one of the layers as well.
[0108] General Procedure for Consolidation of Tensylon.TM. HSBD-30A
Plies:
[0109] In Comparative Examples C and D and Examples 18-20, the
Tensylon.TM. HSBD-30A plies were processed identically to produce
fabric sections using the following procedure. The desired number
of plies were cut to a size of either nominally 12 inches.times.12
inches (30.5 cm.times.30.5 cm) or 15 inches.times.15 inches (38.1
cm.times.38.1 cm). Cut plies were laid up such that the one-sided
resin matrix coating was always facing the same direction, thus the
coated side of one ply was always in direct contact with the dry or
un-coated side of an adjacent ply, and vice versa. Cut plies were
also laid up such that the directionality of one layer of tape was
always perpendicular to any adjacent tape layer(s) in direct
contact with it, and vice versa. The layup was placed in a
compression molding press to undergo a consolidation procedure in
which the plies were consolidated into a fabric section.
Consolidation took place at a temperature of 132.degree. C.
(270.degree. F.), under a pressure of 31 MPa (4500 psi), for a time
of 30 minutes under heat, prior to cooling down to a temperature
below 38.degree. C. (100.degree. F.). The 31 MPa (4500 psi)
pressure was maintained on the layup during the entire process
including the cooling phase. The fabric section was then removed
from the mold and analyzed. In the cases where the fabric section
was nominally 15 inches.times.15 inches (38.1 cm.times.38.1 cm), it
was cut down to a size of nominally 12 inches.times.12 inches (30.5
cm.times.30.5 cm) with a secondary operation using a band saw. In
Comparative Examples C and D, where the fabric section was
nominally 15 inches.times.15 inches (38.1 cm.times.38.1 cm) and no
overlay section was used, the panels were left as 15
inches.times.15 inches (38.1.times.38.1 cm) for ballistic
testing.
[0110] Kevlar.RTM. S705, PVB-Phenolic:
[0111] Comparative Examples E, F, and G and Examples 21-25 used
plies of Kevlar.RTM. S705 fabric impregnated with resin,
commercially available from Sioux Manufacturing Corporation (Fort
Totten, N. Dak.). This material has a nominal areal weight of 270
g/m.sup.2 and comprises (a) a plain weave woven fabric of 850
denier (944 dtex) poly(p-phenylene terephthalamide) yarn having a
nominal yarn tenacity of 27.5 gpd and a nominal yarn modulus of 630
gpd (which is available from DuPont under the trade name of
Kevlar.RTM. para-aramid brand KM2 yarn) which was woven at
12.2.times.12.2 ends per centimeter (31.times.31 ends per inch) and
(b) a PVB/phenolic thermosetting matrix resin which was impregnated
at nominally 10-13 weight percent based on the total weight of the
fabric plus matrix resin into and throughout both sides of the
Kevlar.RTM. fabric.
[0112] General Procedure for Consolidation of Kevlar.RTM. S705,
PVB-Phenolic Plies:
[0113] In Comparative Examples E, F, and G and Examples 21-25, the
Kevlar.RTM. S705, PVB-Phenolic plies were processed identically to
produce fabric sections using the following procedure. The desired
number of plies were cut to a size of nominally 12 inches.times.12
inches (30.5 cm.times.30.5 cm). The layup was placed in a
compression molding press to undergo a consolidation procedure in
which the plies were consolidated into a fabric section.
Consolidation took place at a temperature of 160.degree. C.
(320.degree. F.), under a pressure of 14 MPa (2000 psi), for a time
of 15 minutes under heat, after four one-minute bump cycles at the
beginning of the cycle. No cooling cycle was used for processing
these materials. The 14 MPa (2000 psi) pressure was maintained on
the layup during the entire process. The fabric section was then
removed from the mold "hot", allowed to cool to ambient conditions,
and then analyzed,
Comparative Example A
[0114] Sixty-three plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 10.722 kg/m.sup.2 (2.196 psf). No overlay
material was used on the strike face of this fabric section, and no
adhesive layer. The final ballistic composite had an area density
of 10.722 kg/m.sup.2 (2.196 psf) and contained only a fabric
section. Ballistic testing was performed as described above and
gave a 2-pair V50 versus the 16 grain RCC threat of 896 m/s (2940
fps). Results are summarized in Table I.
[0115] Comparative Example A was used as the control for
Comparative Example B and Examples 1-17.
Comparative Example B
[0116] Forty-six plies of Kevlar.RTM. XP.TM. H170 were consolidated
as described above to provide a fabric section having an areal
density of 7.783 kg/m.sup.2 (1.594 psf). No overlay material was
used on the strike face of this fabric section, and no adhesive
layer. The final ballistic composite had an area density of 7.783
kg/m.sup.2 (1.594 psf) and contained only a fabric section.
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 722 m/s (2369 fps).
Thus a ballistic article was made having about 81% of the V50
performance of the control panel while using only about 72% of the
ballistic composite material in the fabric section and with no
overlay section. Results are summarized in Table I.
Example 1
[0117] Fifty-seven plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 9.755 kg/m.sup.2 (1.998 psf). An overlay
section of 0.820 kg/m.sup.2 (0.168 psf) of Hytrel.RTM. polymer
grade 4069, which is a low modulus grade thermoplastic polyester
elastomer available from DuPont, was adhered to the fabric section.
Hytrel.RTM. 4069 has nominal hardness of 40D and contains
non-discoloring stabilizer; it can be processed by many
conventional thermoplastic processing techniques such as injection
molding and extrusion. The overlay section was of the same size
length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was a 2-part epoxy
available from West System, Inc. (Bay City, Mich.), where part one
is their part number 105 Epoxy Resin and part two is their part
number 206 Slow Hardener. The final ballistic composite had an
areal density of 10.663 kg/m.sup.2 (2.184 psf). Ballistic testing
was performed as described above and gave a 2-pair V50 versus the
16 grain RCC threat of 927 m/s (3041 fps). Thus a ballistic article
was made having about 103% of the V50 performance of the control
panel while using about 91% of the ballistic composite material in
the fabric section, and also using an overlay section. Results are
summarized in Table I.
Example 2
[0118] Fifty-six plies of Kevlar.RTM. XP.TM. H170 were consolidated
as described above to provide a fabric section having an areal
density of 9.745 kg/m.sup.2 (1.996 psf). An overlay section of
1.008 kg/m.sup.2 (0.206 psf) of Delrin.RTM. polymer grade 100ST,
which is a super tough, high viscosity acetal homopolymer grade
thermoplastic polyacetal resin available from DuPont, was adhered
to the fabric section. Delrin.RTM. 100ST has superior impact
resistance and is designed for highly stressed parts where
outstanding toughness is essential. The overlay section was of the
same size (length and width) as the fabric section. The adhesive
used to adhere the overlay section to the fabric section was
Gorilla Glue from Gorilla Glue, Inc. (Cincinnati, Ohio), and
available at most hardware stores. For this and subsequent examples
where Gorilla Glue was used as the adhesive, the adhesive was
spread uniformly over one face of the fabric section and the
overlay section was placed on top of it, and the composite article
was placed under approximately 20 lbs (44 kg) of uniformly
distributed weight for a number of hours, usually overnight, while
the adhesive dried. The final ballistic composite had an areal
density of 10.663 kg/m.sup.2 (2.184 psf). Ballistic testing was
performed as described above and gave a 2-pair V50 versus the 16
grain RCC threat of 885 m/s (2903 fps). Thus a ballistic article
was made having about 99% of the V50 performance of the control
panel while using about 91% of the ballistic composite material in
the fabric section, and also using an overlay section. Results are
summarized in Table I.
Example 3
[0119] Fifty-seven plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 9.692 kg/m.sup.2 (1.985 psf). An overlay
section of 0.928 kg/m.sup.2 (0.190 psf) of Hytrel.RTM. polymer
grade 8238, a thermoplastic polyester elastomer available from
DuPont, was adhered to the fabric section. Hytrel.RTM. grade 8238
has high modulus, with nominal hardness of 82D and containing
non-discoloring stabilizer. The overlay section was of the same
size (length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the Gorilla
Glue described in Example 2. The final ballistic composite had an
areal density of 10.826 kg/m.sup.2 (2.217 psf). Ballistic testing
was performed as described above and gave a 2-pair V50 versus the
16 grain RCC threat of 875 m/s (2870 fps). Thus a ballistic article
was made having about 98% of the V50 performance of the control
panel while using about 90% of the ballistic composite material in
the fabric section, and also using an overlay section. Results are
summarized in Table I.
Example 4
[0120] Fifty-six plies of Kevlar.RTM. XP.TM. H170 were consolidated
as described above to provide a fabric section having an areal
density of 9.516 kg/m.sup.2 (1.949 psf). An overlay section of
1.191 kg/m.sup.2 (0.244 psf) of Crastin.RTM. polymer grade ST820,
which is a thermoplastic polyester available from DuPont, was
adhered to the fabric section. Crastin.RTM. grade ST820 is an
unreinforced, super tough, polybutylene terephthalate resin useful
for injection molding. The overlay section was of the same size
(length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the Gorilla
Glue described in Example 2. The final ballistic composite had an
areal density of 10.590 kg/m.sup.2 (2.169 psf). Ballistic testing
was performed as described above and gave a 2-pair V50 versus the
16 grain RCC threat of 889 m/s (2918 fps). Thus a ballistic article
was made having about 99% of the V50 performance of the control
panel while using about 90% of the ballistic composite material in
the fabric section, and also using an overlay section. Results are
summarized in Table I.
Example 5
[0121] Fifty-six plies of Kevlar.RTM. XP.TM. H170 were consolidated
as described above to provide a fabric section having an areal
density of 9.628 kg/m.sup.2 (1.972 psf). An overlay section of
1.113 kg/m.sup.2 (0.228 psf) of Hytrel.RTM. polymer grade G3548L, a
low modulus material with nominal durometer hardness of 35D
available from DuPont, was adhered to the fabric section. This
material contains nondiscoloring stabilizer and can be processed by
many conventional thermoplastic processing techniques like
injection molding and extrusion. The overlay section was of the
same size (length and width) as the fabric section. The adhesive
used to adhere the overlay section to the fabric section was the
West System 2-part epoxy described in Example 1. The final
ballistic composite had an areal density of 10.878 kg/m.sup.2
(2.228 psf). Ballistic testing was performed as described above and
gave a 2-pair V50 versus the 16 grain ROC threat of 914 m/s (2998
fps). Thus a ballistic article was made having about 102% of the
V50 performance of the control panel while using about 89% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 6
[0122] Fifty-seven plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 9.589 kg/m.sup.2 (1.964 psf). An overlay
section of 0.928 kg/m.sup.2 (0.190 psf) of Hytrel.RTM. polymer
grade 8238 was adhered to the fabric section. This grade of
Hytrel.RTM. is described in Example 3. The overlay section was of
the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the West System 2-part epoxy described in Example 1. The final
ballistic composite had an areal density of 10.780 kg/m.sup.2
(2.208 psf). Ballistic testing was performed as described above and
gave a 2-pair V50 versus the 16 grain ROC threat of 926 m/s (3038
fps). Thus a ballistic article was made having about 103% of the
V50 performance of the control panel while using about 89% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 7
[0123] Fifty-six plies of Kevlar.RTM. XP.TM. H170 were consolidated
as described above to provide a fabric section having an areal
density of 9.516 kg/m.sup.2 (1.949 psf). An overlay section of
1.123 kg/m.sup.2 (0.230 psf) of Hytrel.RTM. polymer grade G3548L,
was adhered to the fabric section. This grade of Hytrel.RTM. is
described in Example 5. The overlay section was of the same size
(length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the West
System 2-part epoxy described in Example 1. The final ballistic
composite had an areal density of 10.683 kg/m.sup.2 (2.188 psf).
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 872 m/s (2861 fps).
Thus a ballistic article was made having about 97% of the V50
performance of the control panel while using about 89% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 8
[0124] Fifty-three plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 9.018 kg/m.sup.2 (1.847 psf). An overlay
section of 1.699 kg/m.sup.2 (0.348 psf) of Hytrel.RTM. polymer
grade 4069 was adhered to the fabric section. This grade of
Hytrel.RTM. is described in Example 1. The overlay section was of
the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the Gorilla Glue described in Example 2. The final ballistic
composite had an areal density of 10.946 kg/m.sup.2 (2.242 psf).
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 871 m/s (2856 fps).
Thus a ballistic article was made having about 97% of the V50
performance of the control panel while using about 82% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 9
[0125] Fifty plies of Kevlar.RTM. XP.TM. H170 were consolidated as
described above to provide a fabric section having an areal density
of 8.700 kg/m.sup.2 (1.782 psf). An overlay section of 1.943
kg/m.sup.2 (0.398 psf) of polycarbonate sheet, available as part
number 8574K24 from McMaster-Carr (Princeton, N.J.), was adhered to
the fabric section. The polycarbonate is an unfilled,
impact-resistant material comparable to Lexan.RTM., Hyzod.RTM.,
Tuffak.RTM., and Makrolon.RTM.. The overlay section was of the same
size (length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the West
System 2-part epoxy described in Example 1. The final ballistic
composite had an areal density of 10.702 kg/m.sup.2 (2.192 psf).
Ballistic testing was performed as described above and gave a
1-pair V50 versus the 16 grain RCC threat of 920 m/s (3018 fps).
Thus a ballistic article was made having about 103% of the V50
performance of the control panel while using about 81% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 10
[0126] Forty-five plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.783 kg/m.sup.2 (1.594 psf). An overlay
section of 2.941 kg/m.sup.2 (0.602 psf) of Crastin.RTM. polymer
grade SO653, a thermoplastic polyester available from DuPont, was
adhered to the fabric section. Crastin.RTM. grade SO653 is a 20%
glass bead filled polybutylene terephthalate resin for injection
molding. It has isotropic properties and low warpage
characteristics. The overlay section was of the same size (length
and width) as the fabric section. The adhesive used to adhere the
overlay section to the fabric section was the Gorilla Glue
described in Example 2. The final ballistic composite had an areal
density of 10.380 kg/m.sup.2 (2.126 psf). Ballistic testing was
performed as described above and gave a 3-pair V50 versus the 16
grain RCC threat of 855 m/s (2805 fps). Thus a ballistic article
was made having about 95% of the V50 performance of the control
panel while using about 75% of the ballistic composite material in
the fabric section, and also using an overlay section. Results are
summarized in Table I.
Example 11
[0127] Forty-five plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.812 kg/m.sup.2 (1.600 psf). An overlay
section of 2.883 kg/m.sup.2 (0.590 psf) of Delrin.RTM. polymer
grade 100ST was adhered to the fabric section. This grade of
Delrin.RTM. is described in Example 2. The overlay section was of
the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the Gorilla Glue described in Example 2. The final ballistic
composite had an areal density of 10.351 kg/m.sup.2 (2.120 psi).
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 841 m/s (2759 fps).
Thus a ballistic article was made having about 94% of the V50
performance of the control panel while using about 75% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 12
[0128] Forty-five plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.792 kg/m.sup.2 (1.596 psf). An overlay
section of 2.927 kg/m.sup.2 (0.599 psf) of a thermoplastic blend of
Nylon 12 and a zinc ionomer of an ethylene/methacrylic acid
copolymer was adhered to the fabric section. The blend consisted of
55% Nylon 12 by weight having a melting point of 180.degree. C.,
commercially available from Arkema under the trademark Rilsan
AESNO, and of 45% by weight of zinc ionomer having a melting point
of 95.degree. C., having a neutralization percentage of 60% and
composed of ethylene (83% by weight), methacrylic acid (11% by
weight) and maleic acid monoethyl ester (6% by weight), based on
the weight of the ionomer. The overlay section was of the same size
(length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the Gorilla
Glue described in Example 2. The final ballistic composite had an
areal density of 10.790 kg/m.sup.2 (2.210 psf). Ballistic testing
was performed as described above and gave a 2-pair V50 versus the
16 grain ROC threat of 803 m/s (2634 fps). Thus a ballistic article
was made having about 90% of the V50 performance of the control
panel while using about 72% of the ballistic composite material in
the fabric section, and also using an overlay section. It should be
noted that testing of this panel resulted in an unusually high Zone
of Mixed Results (ZMR) of 73 m/s (240 fps). Results are summarized
in Table I.
Example 13
[0129] Forty-five plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.783 kg/m.sup.2 (1.594 psf). An overlay
section of 2.920 kg/m.sup.2 (0.598 psf) of polycarbonate sheet,
available as part number 8574K25 from McMaster-Carr (Princeton,
N.J.), was adhered to the fabric section. This polycarbonate is
described in Example 9. The overlay section was of the same size
(length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the West
System 2-part epoxy described in Example 1. The final ballistic
composite had an areal density of 10.741 kg/m.sup.2 (2.200 psf).
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 877 m/s (2878 fps).
Thus a ballistic article was made having about 98% of the V50
performance of the control panel while using about 72% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 14
[0130] Forty-five plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.626 kg/m.sup.2 (1.562 psf). An overlay
section of 2.959 kg/m.sup.2 (0.606 psf) of Crastin.RTM. polymer
grade ST820, was adhered to the fabric section. This grade of
Crastin.RTM. is described in Example 4. The overlay section was of
the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the Gorilla Glue described in Example 2. The final ballistic
composite had an areal density of 10.580 kg/m.sup.2 (2.167 psf).
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 829 m/s (2719 fps).
Thus a ballistic article was made having about 92% of the V50
performance of the control panel while using about 72% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 15
[0131] Forty-five plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.753 kg/m.sup.2 (1.588 psf). An overlay
section of 2.998 kg/m.sup.2 (0.614 psf) of Zytel.RTM. polymer grade
HTN51G35, available from DuPont, was adhered to the fabric section.
This Zytel.RTM. is a 35% glass reinforced, heat stabilized,
lubricated high performance thermoplastic polyamide resin. The
overlay section was of the same size (length and width) as the
fabric section. The adhesive used to adhere the overlay section to
the fabric section was the Gorilla Glue described in Example 2. The
final ballistic composite had an areal density of 10,898 kg/m
(2.232 psf). Ballistic testing was performed as described above and
gave a 2-pair V50 versus the 16 grain RCC threat of 888 m/s (2914
fps). Thus a ballistic article was made having about 99% of the V50
performance of the control panel while using about 71% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 16
[0132] Forty-five plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.636 kg/m.sup.2 (1.564 psf). An overlay
section comprised of 2.978 kg/m.sup.2 (0.610 psf) of Crastin.RTM.
polymer grade ST820 was adhered to the fabric section. This grade
of Crastin.RTM. is described in Example 14. The overlay section was
of the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the West System 2-part epoxy described in Example 1. The final
ballistic composite had an areal density of 10.693 kg/m.sup.2
(2.190 psf). Ballistic testing was performed as described above and
gave a 2-pair V50 versus the 16 grain RCC threat of 835 m/s (2741
fps). Thus a ballistic article was made having about 93% of the V50
performance of the control panel while using about 71% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Example 17
[0133] Forty-four plies of Kevlar.RTM. XP.TM. H170 were
consolidated as described above to provide a fabric section having
an areal density of 7.665 kg/m.sup.2 (1.570 psf). An overlay
section of 3.095 kg/m.sup.2 (0.634 psi) of Minlon.RTM. polymer
grade 10B40, available from DuPont, was adhered to the fabric
section. Minlon.RTM. grade 10B40 is a 40% mineral reinforced
polyamide 66 resin for injection molding. The overlay section was
of the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the Gorilla Glue described in Example 2. The final ballistic
composite had an areal density of 10.995 kg/m.sup.2 (2.252 psf).
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 851 m/s (2792 fps).
Thus a ballistic article was made having about 95% of the V50
performance of the control panel while using about 70% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table I.
Comparative Example C
[0134] Eighty-nine plies of Tensylon.TM. HSBD-30A were consolidated
as described above to provide a fabric section having an areal
density of 9.805 kg/m.sup.2 (2.008 psf). No overlay material was
used on the strike face of this fabric section and no adhesive
layer. The final ballistic composite had an areal density of 9.805
kg/m.sup.2 (2.008 psf) and contained only a fabric section.
Ballistic testing was performed as described above and gave a
2-pair V50 versus the 16 grain RCC threat of 909 m/s (2981 fps).
Results are summarized in Table II.
[0135] Comparative Example C was used as the control for
Comparative Example D and Examples 18-20.
Comparative Example D
[0136] Sixty-six plies of Tensylon.TM. HSBD-30A were consolidated
as described above to provide a fabric section having an areal
density of 7.318 kg/m.sup.2 (1.499 psf). No overlay material was
used on the strike face of this fabric section and no adhesive
layer. The final ballistic composite had an areal density of 7.318
kg/m.sup.2 (1.499 psf). Ballistic testing was performed as
described above and gave a 3-pair V50 versus the 16 grain RCC
threat of 735 m/s (2412 fps). Thus a ballistic article was made
having about 81% of the V50 performance of the control panel while
using about 75% of the ballistic composite material in the fabric
section, using only a fabric section. Results are summarized in
Table II.
Example 18
[0137] Sixty-nine plies of Tensylon.TM. HSBD-30A were consolidated
as described above to provide a fabric section having an areal
density of 7.919 kg/m.sup.2 (1.622 psf). An overlay section of
2.002 kg/m.sup.2 (0.410 psf) of Hytrel.RTM. polymer grade 4069 was
adhered to the fabric section. This grade of Hytrel.RTM. is
described in Example 1. The overlay section was of the same size
(length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the Gorilla
Glue described in Example 2. The final ballistic composite had an
areal density of 10.009 kg/m.sup.2 (2.050 psf). Ballistic testing
was performed as described above and gave a 2-pair V50 versus the
16 grain RCC threat of 835 m/s (2741 fps). Thus a ballistic article
was made having about 92% of the V50 performance of the control
panel while using about 79% of the ballistic composite material in
the fabric section, and also using an overlay section. Results are
summarized in Table II.
Example 19
[0138] Sixty-nine plies of Tensylon.TM. HSBD-30A were consolidated
as described above to provide a fabric section having an areal
density of 7.870 kg/m.sup.2 (1.612 psf). An overlay section of
1.953 kg/m.sup.2 (0.400 psf) of polycarbonate sheet, available from
McMaster-Carr (Princeton, N.J.), machined down to the desired
weight/areal density, was adhered to the fabric section.
Polycarbonate is described in Example 9. The overlay section was of
the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the Gorilla Glue described in Example 2. The final ballistic
composite had an areal density of 9.911 kg/m.sup.2 (2.030 psf).
Ballistic testing was performed as described above and gave a
1-pair V50 versus the 16 grain RCC threat of 828 m/s (2715 fps).
Thus a ballistic article was made having about 91% of the V50
performance of the control panel while using about 79% of the
ballistic composite material in the fabric section, and also using
an overlay section. Results are summarized in Table II.
Example 20
[0139] Seventy-seven plies of Tensylon.TM. HSBD-30A were
consolidated as described above to provide a fabric section having
an areal density of 8.964 kg/m.sup.2 (1.836 psf). An overlay
section of 0.898 kg/m.sup.2 (0.184 psf) of polycarbonate sheet,
available from McMaster-Carr (Princeton, N.J.), machined down to
the desired weight/areal density, was adhered to the fabric
section. Polycarbonate is described in Example 9. The overlay
section was of the same size (length and width) as the fabric
section. The adhesive used to adhere the overlay section to the
fabric section was the Gorilla Glue described in Example 2. The
final ballistic composite had an areal density of 9.999 kg/m.sup.2
(2.048 psf). Ballistic testing was performed as described above and
gave a 2-pair V50 versus the 16 grain RCC threat of 810 m/s (2658
fps). Thus a ballistic article was made having about 89% of the V50
performance of the control panel while using about 90% of the
ballistic composite material in the fabric section, and also using
an overlay section. It should be noted that the ballistic test
reports indicate that there was some de-lamination that occurred
between the fabric section and the overlay section as the testing
progressed, which is believed to have caused a lower than otherwise
anticipated V50 value for this panel. Results are summarized in
Table II.
Comparative Example E
[0140] Thirty-five plies of Kevlar.RTM. S705, PVB-Phenolic prepreg
were consolidated as described above to provide a fabric section
having an areal density of 9.394 kg/m.sup.2 (1.924 psf). No overlay
material was used on the strike face of this fabric section and no
adhesive layer. The final ballistic composite had an areal density
of 9.394 kg/m.sup.2 (1.924 psf) and contained only a fabric
section. BFD Testing was first performed as described above and
gave BFD values of 33 mm and 33 mm on two fair shots on the panel.
Ballistic testing was then performed as described above and gave a
2-pair V50 versus the 9 mm FMJ threat of 591 m/s (1940 fps).
Results are summarized in Table III.
[0141] Comparative Example E was used as the control for
Comparative Examples F and G and Examples 21-25.
Comparative Example F
[0142] Twenty-eight plies of Kevlar.RTM. S705, PVB-Phenolic prepreg
were consolidated as described above to provide a fabric section
having an areal density of 7.285 kg/m.sup.2 (1.492 psf). No overlay
material was used on the strike face of this fabric section and no
adhesive layer. The final ballistic composite had an areal density
of 7.285 kg/m.sup.2 (1.492 psf). BFD Testing was first performed as
described above and gave a BFD value of 30 mm on one fair shot on
the panel. Ballistic testing was then performed as described above
and gave a 3-pair V50 versus the 9 mm FMJ threat of 518 m/s (1700
fps). Thus a ballistic article was made having about 88% of the V50
performance of the control panel while using about 75% of the
ballistic composite material in the fabric section, using only a
fabric section. Results are summarized in Table III.
Comparative Example G
[0143] Twenty-one plies of Kevlar.RTM. S705, PVB-Phenolic prepreg
were consolidated as described above to provide a fabric section
having an areal density of 5.459 kg/m.sup.2 (1.118 psf). No overlay
material was used on the strike face of this fabric section and no
adhesive layer. The final ballistic composite had an areal density
of 5.459 kg/m.sup.2 (1.118 psf). BFD Testing was first performed as
described above and gave a BFD value of 34 mm on one fair shot on
the panel. Ballistic testing was then performed as described above
and gave a 2-pair V50 versus the 9 mm FMJ threat of 477 m/s (1566
fps). Thus a ballistic article was made having about 81% of the V50
performance of the control panel while using about 56% of the
ballistic composite material in the fabric section, using only a
fabric section. Results are summarized in Table III.
Example 21
[0144] Twenty plies of Kevlar.RTM. S705, PVB-Phenolic prepreg were
consolidated as described above to provide a fabric section having
an area density of 5.498 kg/m (1.126 psf). An overlay section of
4.121 kg/m.sup.2 (0.844 psf) of Zytel.RTM. polymer grade HTN51G35
was adhered to the fabric section. This grade of Zytel.RTM. is
described in Example 15. The overlay section was of the same size
(length and width) as the fabric section. No adhesive was used to
adhere the overlay section to the fabric section. Instead, the
overlay section was co-molded with the fabric section, and resulted
in a direct bond to the Kevlar.RTM. S705, PVB-Phenolic fabric
section. The final ballistic composite had an areal density of
9.570 kg/m.sup.2 (1.960 psf). BFD Testing was first performed as
described above and gave a BFD value of 27 mm on one fair shot on
the panel. Ballistic testing was then performed as described above
and gave a 1-pair V50 versus the 9 mm FMJ threat of 479 m/s (1572
fps). Thus a ballistic article was made having about 81% of the V50
performance of the control panel while using about 57% of the
ballistic composite material in the fabric section, and also using
an overlay section. In addition, this panel resulted in a BFD
reduction of 7 mm relative to a comparative panel made at
approximately the same fabric section content and using only a
fabric section. Results are summarized in Table III.
Example 22
[0145] Twenty-six plies of Kevlar.RTM. S705, PVB-Phenolic prepreg
were consolidated as described above to provide a fabric section
having an areal density of 7.167 kg/m.sup.2 (1.468 psf). An overlay
section of 2.490 kg/m.sup.2 (0.510 psf) of Zytel.RTM. polymer grade
HTN51G35 was adhered to the fabric section. This grade of
Zytel.RTM. is described in Example 15. The overlay section was of
the same size (length and width) as the fabric section. No adhesive
was used to adhere the overlay section to the fabric section.
Instead, the overlay section was co-molded with the fabric section,
and resulted in a direct bond to the Kevlar.RTM. S705, PVB-Phenolic
fabric section. The final ballistic composite had an areal density
of 9.550 kg/m.sup.2 (1.956 psf). BFD Testing was first performed as
described above and gave a BFD value of 26 mm on one fair shot on
the panel. Ballistic testing was then performed as described above
and gave a 2-pair V50 versus the 9 mm FMJ threat of 532 m/s (1745
fps). Thus a ballistic article was made having about 90% of the V50
performance of the control panel while using about 75% of the
ballistic composite material in the fabric section, and also using
an overlay section. In addition, this panel resulted in a BFD
reduction of 4 mm relative to a comparative panel made at
approximately the same fabric section content and using only a
fabric section. Results are summarized in Table III.
Example 23
[0146] Twenty-seven plies of Kevlar.RTM. S705, PVB-Phenolic prepreg
were consolidated as described above to provide a fabric section
having an areal density of T353 kg/m.sup.2 (1.506 psf). An overlay
section of 2.265 kg/m.sup.2 (0.464 psf) of Rynite.RTM. polymer
grade 415HP, available from DuPont, was adhered to the fabric
section. Rynite.RTM. grade 415HP is a 15% glass reinforced modified
polyethylene terephthalate with improved processing over a broad
molding range and excellent balance of strength, stiffness, and
temperature resistance. The overlay section was of the same size
(length and width) as the fabric section. No adhesive was used to
adhere the overlay section to the fabric section. Instead, the
overlay section was co-molded with the fabric section, and resulted
in a direct bond to the Kevlar.RTM. S705, PVB-Phenolic fabric
section. The final ballistic composite had an areal density of
9.501 kg/m.sup.2 (1.946 psf). BFD Testing was first performed as
described above and gave BFD values of 21 mm and 25 mm on two fair
shots on the panel. Ballistic testing was then performed as
described above and gave a 1-pair V50 versus the 9 mm FMJ threat of
528 m/s (1732 fps). Thus a ballistic article was made having about
89% of the V50 performance of the control panel while using about
77% of the ballistic composite material in the fabric section, and
also using an overlay section. In addition, this panel resulted in
a BFD reduction of 9 mm and 5 mm on different shots relative to a
comparative panel made at approximately the same fabric section
content and using only a fabric section. Results are summarized in
Table III.
Example 24
[0147] Twenty-eight plies of Kevlar.RTM. S705, PVB-Phenolic prepreg
were consolidated as described above to provide a fabric section
having an areal density of 7.275 kg/m.sup.2 (1.490 psf). An overlay
section of 2.441 kg/m.sup.2 (0.500 psf) of polycarbonate sheet,
available from McMaster-Carr (Princeton, N.J.), machined down to
the desired weight/area density, was adhered to the fabric section.
This polycarbonate is described in Example 9. The overlay section
was of the same size (length and width) as the fabric section. The
adhesive used to adhere the overlay section to the fabric section
was the Gorilla Glue described in Example 2. The final ballistic
composite had an area density of 9.814 kg/m.sup.2 (2.010 psf). BFD
Testing was first performed as described above and gave a BFD value
of 29 mm on one fair shot on the panel. Ballistic testing was then
performed as described above and gave only a High Partial (HP)
penetration velocity versus the 9 mm FMJ threat of 553 m/s (1815
fps). No complete penetration was obtained on this sample, and so
therefore, no V50 value was obtained either, but the V50 is
typically anticipated to be equal to or greater than the High
Partial velocity. Thus a ballistic article was made having about at
least 94% of the V50 performance of the control panel while using
about 74% of the ballistic composite material in the fabric
section, and also using an overlay section. In addition, this panel
resulted in a BFD reduction of 1 mm relative to a comparative panel
made at approximately the same fabric section content and using
only a fabric section. Results are summarized in Table III.
Example 25
[0148] Twenty-eight plies of Kevlar.RTM. S705, PVB-Phenolic prepreg
were consolidated as described above to provide a fabric section
having an area density of 7.304 kg/m.sup.2 (1.496 psf). An overlay
section of 2.521 kg/m.sup.2 (0.516 psf) of thermoplastic blend of
Nylon 12 and a zinc ionomer of an ethylene/methacrylic acid
copolymer, was adhered to the fabric section. The blend consisted
of 55% Nylon 12 by weight having a melting point of 180.degree. C.,
commercially available from Arkema under the trademark Rilsan
AESNO, and of 45% by weight of zinc ionomer having a melting point
of 95.degree. C., having a neutralization percentage of 60% and
composed of ethylene (83% by weight), methacrylic acid (11% by
weight) and maleic acid monoethyl ester (6% by weight), based on
the weight of the ionomer. The overlay section was of the same size
(length and width) as the fabric section. The adhesive used to
adhere the overlay section to the fabric section was the Gorilla
Glue described in Example 2. The final ballistic composite had an
areal density of 9.814 kg/m.sup.2 (2.010 psf). BFD testing was
first performed as described above and gave a BFD value of 27 mm on
one fair shot on the panel. Ballistic testing was then performed as
described above and gave a 1-pair V50 versus the 9 mm FMJ threat of
541 m/s (1776 fps). Thus a ballistic article was made having about
92% of the V50 performance of the control panel while using about
74% of the ballistic composite material in the fabric section, and
also using an overlay section. In addition, this panel resulted in
a BFD reduction of 3 mm relative to a comparative panel made at
approximately the same fabric section content and using only a
fabric section. Results are summarized in Table III.
TABLE-US-00001 TABLE I Description and Test Results for Comparative
Examples A and B, and for Examples 1-17. Adhesive Overlay Section
Layer Fabric Section Panel & Ballistic Data Material Areal
Density Material Material Areal Density Areal Density 16 gn V50
Example -- (lb/ft.sup.2) (kg/m.sup.2) -- -- (lb/ft.sup.2)
(kg/m.sup.2) (lb/ft.sup.2) (kg/m.sup.2) (fts) (m/s) Comp No Overlay
No Kevlar .RTM. 2 .196 10.722 2.196 10.722 2940 896 Ex A Adhesive
XP .TM. H170 Comp No Overlay No Kevlar .RTM. 1.594 7.783 1.594
7.783 2369 722 Ex B Adhesive XP .TM. H170 1 4069 0.168 0.820 West
Kevlar .RTM. 1.998 9.755 2.184 10.663 3041 927 Hytrel .RTM. System
XP .TM. Epoxy H170 2 100ST 0.206 1.008 Gorilla Kevlar .RTM. 1.996
9.745 2.184 10.663 2903 885 Delrin .RTM. Glue XP .TM. H170 3 8238
0.190 0.928 Gorilla Kevlar .RTM. 1.985 9.692 2.217 10.826 2870 875
Hytrel .RTM. Glue XP .TM. H170 4 ST820 0.244 1.191 Gorilla Kevlar
.RTM. 1.949 9.516 2.169 10.590 2918 889 Crastin .RTM. Glue XP .TM.
H170 5 G3548L 0..28 1.113 West Kevlar .RTM. 1.972 9.628 2.228
10.878 2998 914 Hytrel .RTM. System XP .TM. Epoxy H170 6 8238 0.190
0.928 West Kevlar .RTM. 1.964 9.589 2.208 10.780 3038 926 Hytrel
.RTM. System XP .TM. Epoxy H170 7 G3548L 0.230 1.123 West Kevlar
.RTM. 1.949 9.516 2.188 10.683 2861 872 Hytrel .RTM. System XP .TM.
Epoxy H170 8 4069 0.348 1.699 Gorilla Kevlar .RTM. 1.847 9.018
2.242 10.946 2856 871 Hytrel .RTM. Glue XP .TM. H170 9
Polycarbonate 0.398 1.943 West Kevlar .RTM. 1.782 8.700 2.192
10.702 3018 920 System XP .TM. Epoxy H170 10 SO653 0.602 2.941
Gorilla Kevlar 1.594 7.783 2.126 10.380 2805 855 Crastin .RTM. Glue
XP .TM. H170 11 100ST 0.590 2.883 Gorilla Kevlar .RTM. 1.600 7.812
2.120 10.351 2759 841 Delrin .RTM. Glue XP .TM. H170 12 Nylon 0.599
2.927 Gorilla Kevlar .RTM. 1.596 7.792 2.210 10.790 2634 803
12/zinc Glue XP .TM. ionomer H170 13 Polycarbonate 0.598 2.920 West
Kevlar .RTM. 1.594 7.783 2.200 10.741 2878 877 System XP .TM. Epoxy
H170 14 ST820 0.606 2.959 Gorilla Kevlar .RTM. 1.562 7.626 2.167
10.580 2719 829 Crastin .RTM. Glue XP .TM. H170 15 HTN51G 0.614
2.998 Gorilla Kevlar .RTM. 1.588 7.753 2.232 10.898 2914 888 35
Zytel .RTM. Glue XP .TM. H170 16 ST820 0.610 2.978 West Kevlar
.RTM. 1.564 7.636 2.190 10.693 2741 835 Crastin .RTM. System XP
.TM. Epoxy H170 17 10B40 0.634 3.095 Gorilla Kevlar .RTM. 1.570
7.665 2.252 10.995 2792 851 Minlon .RTM. Glue XP .TM. H170
TABLE-US-00002 TABLE II Description and Test Results for
Comparative Examples C and D, and for Examples 18-20. Adhesive
Overlay Section Layer Fabric Section Panel & Ballistic Da
Material Areal Density Material Material Areal Density Areal
Density 16 gn V5 Example -- (lb/ft.sup.2) (kg/m.sup.2) -- --
(lb/ft.sup.2) (kg/m.sup.2) (lb/ft.sup.2) (kg/m.sup.2) (ft/s) ( Comp
No Overlay No Tensylon .TM. 2.008 9.805 2.008 9.805 2981 9 Ex C
Adhesive HSBD-30A Comp No Overlay No Tensylon .TM. 1.499 7.318
1.499 7.318 2412 7 Ex D Adhesive HSBD-30A 18 4069 0.410 2.002
Gorilla Tensylon .TM. 1.622 7.919 2.050 10.009 2741 8 Hytrel .RTM.
Glue HSBD-30A 19 Poly- 0.400 1.953 Gorilla Tensylon .TM. 1.612
7.870 2.030 9.911 2715 8 Carbonate Glue HSBD-30A 20 Poly- 0.184
0.898 Gorilla Tensylon .TM. 1.836 8.964 2.048 9.999 2658 8
Carbonate Glue HSBD-30A indicates data missing or illegible when
filed
TABLE-US-00003 TABLE III Description and Test Results for
Comparative Examples E, F, and C, and for Examples 21- Adhesive
Overlay Section Layer Fabric Section Panel & Ballistic Material
Areal Density Material Material Areal Density Areal Density 16 gn
V50 Example -- (lb/ft.sup.2) (kg/m.sup.2) -- -- (lb/ft.sup.2)
(kg/m.sup.2) (lb/ft.sup.2) (kg/m.sup.2) (ft/s) (m/ Comp No Overlay
No Kevlar .RTM. 1.924 9.394 1.924 9.394 1940 59 Ex E Adhesive S705,
12% PVB- Phenolic Comp No Overlay No Kevlar .RTM. 1.492 7.285 1.492
7.285 1700 51 Ex F Adhesive S705, 12% PVB- Phenolic Comp No Overlay
No Kevlar .RTM. 1.118 5.459 1.118 5.459 1566 47 Ex G Adhesive S705,
12% PVB- Phenolic 21 HTN51G35 0.844 4.121 No Kevlar .RTM. 1.126
5.498 1.960 9.570 1572 47 Zytel .RTM. Adhesive S705, 12% PVB-
Phenolic 22 HTN51G35 0.510 2.490 No Kevlar .RTM. 1.468 7.167 1.956
9.550 1745 53 Zytel .RTM. Adhesive S705, 12% PVB- Phenolic 23 415HP
0.464 2.265 No Kevlar .RTM. 1.506 7.353 1.946 9.501 1732 52 Rynite
.RTM. Adhesive S705, 12% PVB- Phenolic 24 Poly- 0.500 2.441 Gorilla
Kevlar .RTM. 1.490 7.275 2.010 9.814 1815 55 Carbonate Glue S705,
HP H 12% PVB- Phenolic 25 Nylon 0.516 2.521 Gorilla Kevlar .RTM.
1.496 7.304 2.010 9.814 1776 54 12/zinc Glue S705, ionomer 12% PVB-
Phenolic indicates data missing or illegible when filed
[0149] It can be seen from the data in Tables I, II, and III that
the composites containing an overlay section and a fabric section
typically had V50 and/or BFD values comparable to or better than
those for the composites having about the same final areal density
and containing only a fabric section. In Table I, panels with a
fabric section of between about 70 and about 92 percent by weight
of the composite article and an overlay section between about 8 and
about 30 percent by weight of the composite article (Examples 1-17)
demonstrated V50 values equal to or in excess of about 90% of that
of the comparable panel having the full areal density and
containing only a fabric section (Comparative Example A). In Table
II, panels with a fabric section of between 79 and 90 percent by
weight of the composite article and an overlay section between
about 10 and 21 percent by weight of the composite article
(Examples 18-20) demonstrated V50 values equal to or in excess of
about 89% of that of the comparable panel having the full areal
density and containing only a fabric section (Comparative Example
C). In Table III, panels with a fabric section of between about 57
and about 77 percent by weight of the composite article and an
overlay section between about 23 and about 43 percent by weight of
the composite article (Examples 21-25) demonstrated ballistic
performance with a combination of V50 values equal to or in excess
of about 90% of and/or a BFD reduction of from about 1 mm to about
9 mm lower than that of the comparable panel having the full areal
density and containing only a fabric section (Comparative Example E
for the V50 and BFD values, respectively).
* * * * *