Patent ID: 8334042

Claim:
A sandwich panel comprising: a hollow columnar core having an upper surface and a lower surface; a pre-impregnated laminating material comprising at least four unidirectional fiber bodies, a resol-type phenolic resin material, and a stitching yarn for stitching the at least four unidirectional fiber bodies, the laminating material directly disposed on each of the upper surface and the lower surface of the hollow columnar core, respectively; and a surface material directly disposed on each of the laminating materials, so that each of the laminating materials is disposed between the surface material and the hollow columnar core, the surface material being a polyvinylidene fluoride film or an unwoven fabric containing glass fibers, wherein the at least four unidirectional fiber bodies each has fibers aligned in a uniform direction and is disposed so that each of the fiber directions thereof is at approximately 0°, +45°, −45°, and 90°, respectively, in relation to one edge of the sandwich panel.