Macro fiber for composite articles

#The present disclosure relates generally to composites and, more particularly, to fiber-reinforced composite articles having improved ballistic and optical performance.

#Glass is widely used as a transparency in a variety of applications due to its superior optical qualities. For example, glass is commonly used as a glazing material or as an architectural material for buildings. Glass is also commonly used as a transparency in vehicular applications. Unfortunately, glass is a relatively dense material and is also relatively brittle such that relatively large thicknesses are required to provide sufficient strength for resisting shattering when the glass is impacted by an object such as a projectile.

#In attempts to avoid the weight penalty associated with glass, transparencies may be fabricated from polymeric materials. For example, transparencies may be formed of optically transparent monolithic polymers such as acrylic which is less dense than glass and which possesses suitable optical properties. Unfortunately, acrylic is a relatively low strength material making it generally unsuitable for many applications where high impact resistance is required.

#These and other features of the present disclosure will become more apparent upon reference to the drawings wherein like numerals refer to like parts throughout and wherein:

#FIG. 1 is a perspective view of an embodiment of a composite article in an embodiment comprising a plurality of layers containing inner fibers embedded in matrix material;

#FIG. 2 is an enlarged perspective view of a portion of the composite article of FIG. 1 and illustrating the inner fibers;

#Referring now to the drawings wherein the showings are for purposes of illustrating preferred and various embodiments of the disclosure, shown in FIG. 1 is an embodiment of a composite article 100. The composite article 100 is configured as a composite panel 104 having upper and lower sides 108, 110. The composite article 100 may be fabricated using a plurality of structural layers arranged in a stacked formation 230. For example, the composite article may be comprised of a plurality of structural layers such as the first and second structural layers 400, 420 illustrated in FIG. 1. Each one of the first and second structural layers 400, 420 may be formed using a plurality of macro fibers 200 as shown in FIG. 5. Each one of the macro fibers 200 may be comprised of a plurality of substantially unidirectional inner fibers 300 (FIG. 5) surrounded by matrix material 236 (FIG. 5) as described in greater detail below. The inner fibers 300 may have an inner fiber length 310 (FIG. 3) that may be aligned with the macro fiber length 222 (FIG. 3).

#Referring to FIG. 2, shown is a portion of the composite article 100 of FIG. 1 and illustrating the inner fibers 300 in first and second structural layers 400, 420. Each one of the first and second structural layers 400, 420 has a stretched direction 406, 426. The composite article 100 may be configured such that the stretched direction of the structural layers may be oriented in any direction relative to the stretched direction of any of the other structural layers in the composite article 100. For example, in FIG. 2, the stretched direction 406 of the first structural layer 400 in each couplet 228 is oriented generally perpendicular to the stretched direction 426 of the second structural layer 420 of the couplet 228. By orienting the stretched direction 406 of a first structural layer 400 in a couplet 228 generally perpendicular to the stretched direction 406 of a second structural layer 420 in a couplet 228, the ballistic performance of the composite article may be improved as described below.

#However, the stretched direction 406 of the first structural layer 400 may be oriented at any non-perpendicular angle (not shown) relative to the stretched direction 426 of the second structural layer 420 and which may also result in an improvement in the ballistic performance and/or strength properties of the composite article 100 relative to an embodiment wherein the stretched directions of the structural layers are oriented generally parallel to one another. In this regard, the composite article 100 may also be provided in an embodiment wherein the stretched direction one or more of the structural layers may be oriented generally parallel (not shown) to one another.