Patent ID: 8383231

Claim:
A sandwich panel comprising: a hollow columnar core; a middle material layered on a first surface of the hollow columnar core and layered on a second surface of the hollow columnar core; a surface material layered on the middle material layered on the first surface of the hollow columnar core and layered on the middle material layered on the second surface of the hollow columnar core, wherein said middle material comprises: a first unidirectional fiber body, said first unidirectional fiber body having fibers that are aligned in a direction that is substantially parallel to an edge of the sandwich panel; a second unidirectional fiber body, said second unidirectional fiber body having fibers that are aligned in a direction that is substantially orthogonal to the edge of the sandwich panel; a first bonding layer having a resin content ratio of 50% or higher provided between the first unidirectional fiber body and the second unidirectional fiber body; and a second bonding layer having a resin content ratio of 50% or higher provided between said hollow columnar core and said second unidirectional fiber body, wherein the second bonding layer is composed of a woven fiber body in which fibers are used for a warp yarn and a woof yarn, and the yarns are woven, the warp yarn and the woof yarn being orthogonal to each other, wherein the woven fiber body is formed so that one of said warp yarn and said woof yarn is substantially parallel to said edge of the sandwich panel, and the other of the warp yarn and the woof yarn is substantially orthogonal to said edge of the sandwich panel, and wherein the resin content ratio is a ratio between a weight of resin in a bonding layer and a weight of the bonding layer containing the resin, wherein the sandwich panel has a weight per unit area of 1.59 kg/m 2 or less, a maximum bending load of 510 N or greater, a peel strength of 60·N in/3 in or greater, and an in-plane shear strength of 20 kN or greater.