Rod for spinal brace
A fixture rod includes a plurality of layers of a reinforcing fiber layer and a plurality of layers of any one of a resin layer, a reinforcing fiber layer having fibers different from those of the reinforcing fiber layer, and a reinforcing fiber layer having fibers obliquely oriented with respect to a fiber direction of the reinforcing fiber layer, in which the plurality of layers are each alternately formed as viewed in a cross-section. The fixture rod reduces damage at the time of fixing with a screw, has high rigidity and high durability against a deformation load, and has greatly improved safety even at the time of breaking.
1 . A fixture rod comprising:
a first plurality of layers including reinforcing fiber layers and a second plurality of layers including resin layers, the reinforcing fiber layers being thicker than the resin layers; and
a cover layer acting as an outer surface of the fixture rod and covering at least a portion of the first plurality of layers and the second plurality of layers, wherein
each of the first plurality of layers is alternately formed with each of the second plurality of layers so as to be stacked in a direction substantially perpendicular to an axial direction of the fixture rod as viewed in a cross-section taken along a plane perpendicular to a central axis of the fixture rod.
2 . The fixture rod according to claim 1 , wherein each of the reinforcing fiber layers is a fiber-reinforced resin, in which carbon, glass, boron, SiC, or aramid is used as fibers, and epoxy, phenol, unsaturated polyester, PA, PC, PPSU, POM, PP, PE, ABS, PS, PAEK, or PEEK is used as a resin.
3 . The fixture rod according to claim 1 , wherein a resin of each of the resin layers is epoxy, phenol, unsaturated polyester, PA, PC, PPSU, POM, PP, PE, ABS, PS, PAEK, or PEEK.
4 . The fixture rod according to claim 1 , wherein the second plurality of layers further includes a reinforcing fiber layer having fibers different from those of the reinforcing fiber layers, and comprise a fiber-reinforced resin, in which carbon, glass, boron, SiC, or aramid is used as fibers, and epoxy, phenol, unsaturated polyester, PA, PC, PPSU, POM, PP, PE, ABS, PS, PAEK, or PEEK is used as a resin.
5 . The fixture rod according to claim 1 , wherein in the reinforcing fiber layers, fibers are aligned in one direction, formed in a woven fabric form, or randomly oriented.
6 . The fixture rod according to claim 1 , wherein the second plurality of layers further includes a reinforcing fiber layer having fibers obliquely oriented with respect to the fiber direction of the reinforcing fiber layers at an angle in a range of 10° to 90°.
7 . The fixture rod according to claim 1 , wherein fibers of the reinforcing fiber layers are long fibers.
8 . The fixture rod according to claim 1 , wherein a fiber content of the reinforcing fiber layers is 60 weight % or more.
9 . The fixture rod according to claim 1 , wherein fiber directions of the reinforcing fiber layers are aligned, and thicknesses of the reinforcing fiber layers are in a range of 0.02 mm to 0.25 mm.
10 . The fixture rod according to claim 1 , wherein each of the first plurality of layers and each of the second plurality of layers has a thickness dimension that extends in the direction substantially perpendicular to the axial direction of the fixture rod.
11 . The fixture rod according to claim 10 , wherein each of the first plurality of layers and each of the second plurality of layers has a width dimension that extends in another direction that is also substantially perpendicular to an axial direction of the fixture rod.
12 . The fixture rod according to claim 1 , wherein the fixture rod is rigid.
13 . The fixture rod according to claim 1 , wherein the cover layer forms an outer surface of the fixture rod and surrounds the first plurality of layers and the second plurality of layers as viewed in the cross-section of the fixture rod.
14 . The fixture rod according to claim 1 , wherein the cover layer includes a resin.
15 . The fixture rod according to claim 1 , wherein the reinforcing fiber layers each have fibers that are either randomly oriented or all aligned in substantially the same direction.