Patent Application
20070232173
The invention generally relates to penetration-resistant materials, and, in particular, to non-plain-woven, laminated structures capable of use in antiballistic and other high-modulus, high-strength applications.
Throughout history, various types of materials have been used as body armors to protect humans from injury in combat and other hostile situations. From earliest times, protective vests were made from animal skins and hides. As time and technology progressed, wooden and metal vests were used as body protection. These armors were cumbersome, heavy and uncomfortable, which collectively suggested a desired need for soft, more effective, and lightweight body armors. Modern civilization has responded and continues to respond to this need through research and development of high-performance, laminated fibers (“laminates”) which have extinguished former and sole reliance on wood and animal hides to provide protective applications.
Today, body armor laminates are often constructed from one or more layers of ballistic resistant material(s), such as polyethylene, polyolefin and aramid fibers, sometimes in combination with resin, to produce a wearable, soft body armor laminate that protects a wearer against high-velocity bullets and fragments. In addition, these soft body armor laminates are occasionally amplified in strength by removably or permanently appending them to a ballistic panel or substrate, otherwise more generically known as a ballistic composite, such as metal or ceramic.
Despite advances in the antiballistic laminates, whether used in soft or hard body armor, problems remain in providing their underlying purpose, i.e., antiballistic protection against “hits,” whether viewed as “fair” or “unfair” according to known industry standard tests definitions. In the real world, criminals, terrorists, and antiballistic vest wearers are not concerned with whether a bullet is a “fair” or “unfair” hit if the bullet kills or mutilates the antiballistic laminate wearer. In addition, another problem stems from manufacturing impracticalities associated with some existing antiballistic laminates' inability to be produced in rolled goods format, which may limit manufacturing functionality, significantly impede ultimate production efficiency, and/or cause unwieldy transportation and storage issues. Still another problem is absorption of water by antiballistic materials, a problem known to lower ballistic performance by as much as 40% as compared to an anhydrous version of some antiballistic materials.
In light of the above-listed and known example problems, a need, therefore, exists for improved laminate structures that are capable of enhanced antiballistic applications while being rollable and/or water-repellant.
Embodiments of the invention generally provide laminate structures capable of antiballistic applications or other high-modulus, high-strength composite applications, such as the formation of intricately shaped or molded materials. In one embodiment, the laminate structure includes a first array having first, non-plain-woven fibers in a substantially A-B or 0/90 degree orientation. That is, the component fibers of the non-plain-woven fibers are substantially arranged in an A-B or 0/90 degree orientation with respect to each other. Further, the laminate structure includes a second array having second, non-plain-woven fibers also in a substantially A-B or 0/90 degree orientation. Further still, the laminate structure includes a securing material for adjoining the first array and the second array so that the laminate structure has a substantially A-B/A-B orientation, i.e., the first array having an A-B orientation cross-plied and adjoined to the second array, which also has an A-B orientation, so that the finished product has a substantially overall A-B/A-B orientation. Finally, the laminate structure optionally and externally includes a water-repellant coating, which may penetrate the unbonded fibers of the laminate structure.
The laminate structure may optionally include additional, non-plain woven arrays, such as a third, fourth, fifth, etc. array. Each such additional array has a substantially A-B or 0/90 degree orientation of its constituent fibers, and each is adjoined to the laminate structure's arrays with the security material, such as a film or resin.
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
The following is a detailed description of example embodiments of the invention depicted in the accompanying drawings. The embodiments are examples and are in such detail so as to clearly communicate the invention. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims. The detailed descriptions below are designed to make such embodiments obvious to a person of ordinary skill in the art.
Generally speaking, laminate structures for antiballistic applications or other high-modulus, high-strength composite applications are contemplated. Embodiments include a first array having first, non-plain-woven fibers in a substantially A-B or 0/90 degree orientation. That is, the component fibers of the non-plain-woven fibers are substantially arranged in an A-B or 0/90 degree orientation with respect to each other. Further, embodiments include a second array having second, non-plain-woven fibers also in a substantially A-B or 0/90 degree orientation. Although used interchangeably, herein, a 0/90 degree orientation is sometimes used to refer to a fiber bundle's directions in an array, and an A-B orientation is sometimes used to refer to the orientation of each array to each other in a multi-plied array system, i.e., a single array terminology versus a multi-plied array terminology, respectively. Further still, embodiments include a securing material for adjoining the first array and the second array so that the laminate structure has a substantially A-B/A-B orientation, i.e., the first array having an A-B orientation cross-plied and adjoined to the second array, which also has an A-B orientation, so that the finished product has a substantially overall A-B/A-B orientation. In some embodiments, the laminate structure may optionally include additional, non-plain woven arrays, such as a third, fourth, fifth, etc. array. Each such additional array has a substantially A-B or 0/90 degree orientation of its constituent fibers, and each is adjoined to the laminate structure's arrays with the security material, such as a film or resin. In some embodiments, the laminate structure may include a water-repellant coating on the structure's exterior, especially useful if the underlying laminate's array's materials are hygroscopic. Finally, in some embodiments, the laminate structure may also include at least one plain-weave filament along at least one of the two orientations, i.e., the A and/or B direction (the warp and/or weft) of the substantially A-B orientation.
Turning now to
Now, with respect to the specific figures,
The materials for use in the disclosed invention use a twill-based weave pattern, such as the twill weave 110 pattern depicted in
Satin weaves 120 are fundamentally twill weaves 110 modified to produce fewer intersections of warp and weft. The ‘harness’ (“H”) number used in the designation of a satin weave 120 is the total number of fibers crossed and passed under, before the fiber repeats the pattern. Examples of such harnessed-numbered satin weaves 120 are 4H, 8H, and 20H, and
Generally, satin weaves 120 are very flat, have good wet out and a high degree of drape, which means a high degree ability to conform to a complex surface. The low crimp gives good mechanical properties. Satin weaves 120 allow fibers to be woven in the closest proximity and can produce materials having fibers with a close ‘tight’ weave.
With the foregoing enabling discussion of weave patterns depicted in
All embodiments of the invention, whether or not the laminate structure is composed of two, three, four, five, or more cross-plied arrays of non-plain woven, unspread fibered, high-modulus, high-strength materials have the repeated A-B orientation. Thus, for example, a three-array, cross-plied version of the laminate structure would have an overall A-B/A-B/A-B orientation, and additional cross-plied arrays follow the generalized overall orientation formula of [(A-B) times (number of arrays)]. Important to note is that the A-B orientation, especially when repeated by cross-plying with one or more additional arrays in the same A-B orientation, dissipates energy, such as from oncoming bullets, better than other orientations, such as A-B/B-A or A-B/B-A/A-B.
In some embodiments, the laminate structure may also include at least one plain-woven filament along at least one of the two orientations, i.e., the A and/or B direction (warp and/or weft) of the substantially A-B orientation. Such optional, plain-woven filament(s) is part of each array(s) in the laminate structure. Since the plain-woven filament(s) is woven in either the A or B orientation with respect to a specific array, its inclusion does not vitiate the overall, repeated A-B orientation of the laminate structure regardless of the number of cross-plied arrays. Instead, for example, the ballistic or non-ballistic plain-woven filament(s) may add strength to the laminate structure. Examples of plain-woven filaments include 70 denier nylon or cotton.
This disclosure now turns to even more specific embodiments of the invention. In one embodiment, a 1000 denier 4H satin weave aramid array and a 1000 denier 10H satin weave aramid array are cross-plied to form an A-B/A-B overall orientation, and uses a polymeric film or resin to secure the laminate structure into place. Typically, with two-array, non-plain-woven, cross-plied A-B/A-B systems, the laminate structure uses 30 g/m2 or less of polymeric film or resin as the securing material. However, for systems having greater than such two arrays, the film or resin weight ratio to fiber weight may be at 15% or slightly greater in total weight. Additionally, for systems having greater than such two arrays, it may be desirable for interior arrays to be higher denier materials as compared to the arrays immediately flanking such an interior array, e.g., a 1140 or 1500 denier interior array flanked by 185 to 800 denier arrays for a three-ply laminate structure. In such embodiments, the higher denier interior array is wetted more easily with the securing material from the arrays immediately flanking such an interior array. Furthermore, the lower denier flanking arrays provide further support for the higher denier interior array, and, thereby, translate into added integrity for such laminate structures, especially when compared to the existing link points and securing material alone.
If the antiballistic material is hygroscopic, such as an aramid, then coating the laminate structure is advised. As shown in
Manufacturing of the disclosed invention has revealed that the invention is pliable and formable into either sheet and rolled formats, wherein the latter especially provides for more time-efficient and ease in production of ultimate antiballistic applications or other high-modulus, high-strength, composite (i.e., draping) applications for the laminate structures. As depicted in
While the foregoing is directed to example embodiments of the disclosed invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims, which may be read in light of the foregoing disclosure, that follow.
