Three dimensional braid
A three-dimensional braid includes a plurality of first plaits adjacent one another oriented in a first direction and a plurality of second plaits adjacent one another oriented in a transverse second direction intertwined forming a braid with each first plait intersecting each of the plurality of second plaits in succession. Each first plait includes a first group of tows and a second group of tows, each of the tows in the first group of tows corresponding to one of the tows in the second group of tows in pairs of first plait tows. Each second plait includes a plurality of tows. For each first plait, one of the first plait pairs crosses over a subset of second plait tows at each intersection of the first plait and successive second plaits forming a series of braid points along the first plait.
1 . A braided fabric having a length along a braid direction and a cross-thickness direction substantially perpendicular to the braid direction, the braided fabric comprising;
a plurality of plaits including at least one set of plaits, each of the plurality of plaits including at least a plurality of tows configured to cross with each other in the cross-thickness direction, and wherein a first plait of the at least one set of plaits is configured to be oriented along its length at an angle with respect to at least one of a second plait of the at least one set of plaits or a third plait of the at least one set of plaits along the length of the first plait;
wherein the plurality of tows comprise at least two different materials selected from carbon fiber, glass fiber, aramid fiber, polyethylene fiber and metallic wire; and
wherein the braided fabric forms a three-dimensional tubular structure having a hollow interior configured to receive a core element.
2 . The braided fabric of claim 1 , further comprising the first plait configured to be at least partially layered over the second plait at a first location along the cross-thickness direction, wherein at least a first tow of the plurality of tows of the first plait crosses with a second tow of the plurality of tows adjacent to the first location; and the third plait configured to be at least partially layered over the second plait substantially at the first location.
3 . The braided fabric of claim 2 wherein each of the plurality of plaits having a cross-thickness width, and the first location of a partial layer of the first plait and the third plait over the second plait is at substantially half the cross-thickness width of at least one of the first plait and the third plait.
4 . The braided fabric of claim 3 wherein the first plait and third plait are configured to be oriented substantially parallel to one another.
5 . The braided fabric of claim 1 further comprising the first plait configured to be oriented above the third plait, such that the second plait is configured to be at least partially layered between the first plait and the third plait.
6 . The braided fabric of claim 1 , wherein each of the plurality of tows comprises a cluster or grouping of materials that extend together in a principal direction as a unit, wherein the plurality of tows include at least one of monofilaments, multiple filaments, or combinations of monofilament and multiple filament strands.
7 . The braided fabric of claim 1 , wherein at least one tow of the plurality of tows has a cross-sectional shape selected from the group consisting of generally circular, ellipsoidal, triangular, and flat tape shapes.
8 . The braided fabric of claim 1 , wherein at least some of the plurality of tows are coated with resin or other coating to facilitate braiding and/or subsequent processing.
9 . The braided fabric of claim 1 , wherein at least one tow includes a combination of carbon and thermoplastic materials, or a combination of aramid and glass materials.
10 . The braided fabric of claim 1 , wherein the first plait is oriented at a positive angle from the reference braid direction and a transverse plait is oriented at a negative angle from the reference braid direction.
11 . The braided fabric of claim 10 , wherein the positive angle is +45 degrees and the negative angle is −45 degrees.
12 . The braided fabric of claim 10 , wherein the positive angle is +60 degrees and the negative angle is −60 degrees.
13 . The braided fabric of claim 1 , further comprising axial tows laid-in along a longitudinal direction, wherein the axial tows intersect and/or intertwine with at least one of the plurality of plaits.
14 . The braided fabric of claim 1 , wherein the braided fabric forms a tubular sleeve having a central axis, and wherein the cross-thickness direction corresponds to a radial direction with respect to the central axis.
15 . The braided fabric of claim 1 , wherein each plait includes two groups of tows, each tow in one group corresponding to one tow in the other group to form pairs of tows, and wherein along each plait, a portion of the tows forms an outer subset and a remainder of the tows forms an inner subset.
16 . The braided fabric of claim 15 , wherein at each intersection between a plait in a first direction and a transverse plait, one of the plait pairs in the first direction crosses over a subset of tows in the transverse plait so that the tow of the crossing pair in the inner subset switches to the outer subset and the other tow of the pair switches to the inner subset.
17 . The braided fabric of claim 1 , wherein the braided fabric has a repeating braid pattern wherein like-crimps in adjacent plaits oriented in the same direction do not cross at the same transverse plait.
18 . The braided fabric of claim 1 , wherein the braided fabric is manufactured using a braiding machine having four concentric carrier rings that rotate to intertwine the plurality of tows.
19 . The braided fabric of claim 1 , wherein the plurality of plaits forms a multilayer structure including a third set of plaits in a second direction such that first plaits in a first direction are positioned between second plaits and third plaits in the second direction.