Three-dimensional net, and composite structural material using the same

A three-dimensional net formed by warp knitting and having a first mesh web, a second mesh web and connecting yarns connecting the first and second mesh webs, on front and back sides of the net, with a required spacing therebetween;

• each of said mesh webs being formed such that mesh openings are defined by ribbons continuous in a knitting direction, each of said ribbons being alternately junctioned together with a rightward adjacent ribbon and a leftward adjacent ribbon at a required interval in the knitting direction as to define respective polygonal mesh openings on each of said mesh webs;
• a number of said ribbons on the second mesh web being larger than that on the first mesh web and thereby, a size of the mesh openings on the first mesh web being smaller than that on the second mesh web, said connecting yarns being front-back-wise passed between the ribbons defining relatively small and large mesh openings, so as to form three-dimensional cords;
• said three-dimensional cords being formed such that the connecting yarns are front-back-wise passed from each of the ribbons defining relatively large mesh openings on the second mesh web, to a plurality of the ribbons defining relatively small mesh openings on the first mesh web, thereby forming a three-dimensional void within each of said three-dimensional cords shaped such that width thereof on the second mesh web encompasses the relatively small mesh openings and such that said connecting yarns are inclined as front-back-wise passed between the first and second webs, at least partly among portions for defining three-dimensional mesh spaces.