Patent ID: 7658810

Claim:
A method of producing a composite sandwich structure, comprising the steps: a) providing a core structure having a folded cell structure with fold valleys that form continuous open channels with open channel ends and/or open channel sides at edges of said core structure, and having opposite first and second major surfaces on opposite first and second sides thereof; b) closing and sealing said open channel ends and said open channel sides of said channels by forming respective edge seals having a limited spatial volume in respective edge regions on said edges of said core structure, by disposing first and second temporary covers on said first and second sides of said core structure so that said temporary covers leave said edge regions of said core structure open and exposed while covering at least a portion of said core structure situated inwardly displaced from said edges along said edge regions, and introducing a sealant material into said edge regions whereby said temporary covers limit said sealant material to said limited spatial volume and prevent said sealant material from penetrating beyond said limited spatial volume farther into said open channels, and wherein said sealant material forms said edge seals in said limited spatial volume, and then removing said temporary covers from said core structure after forming said edge seals, wherein said edge seals extend only a limited distance into said open channel ends and said open channel sides of said channels corresponding to said limited spatial volume thereby filling, closing and sealing said open channel ends and said open channel sides while leaving a remaining majority of a length of said channels hollow and devoid of said edge seals; and c) after said step b), applying first and second cover layers respectively on said first and second sides of said core structure having said edge seals formed thereon, thereby bounding said channels between said fold valleys and said first and second cover layers on said first and second sides.