Sandwich panel, method of forming core material for sandwich panel, and method of forming sandwich panel

Abstract

An object of the present invention is to provide a sandwich panel which is capable of securing its flexural or its shear rigidity as a whole and securing a compression rigidity of a core material itself, while at the same time of readily reducing the weight of the sandwich panel. According to an aspect of the invention, there is provided a sandwich panel comprising two resin skin sheets, and a resin core material sandwiched between the two resin skin sheets and planarly adhered to each of the two resin skin sheets, said core material consists of an foamed resin with a predetermined expanding ratio and has a plurality of recesses each of which forms an opening formed on at least one surface thereof and extends inwardly to define an inner space closed by the corresponding skin sheet, the number of said recesses and the total area of the openings are determined in such a manner that the planer adhesion of at least one surface of the resin core material to the corresponding skin sheet is maintained, while at the same time solid portions of the foamed resin of the resin core material excluding said inner space formed by the plurality of recesses function to support a compressive load in the thickness direction of the resin core material, under the predetermined void volume allocated to said plurality of recesses in relation with said predetermined expanding ratio.