NOVELTY - Producing a composite core panel involves forming elongated strips (52) of low density cellular material; arranging the strips in laterally adjacent relation with the strips; progressively advancing the adjacent strips between spaced platens to form the adjacent strips into a panel; feeding a flexible sheet of reinforcing material between the panel of strips and at least one of the platens; progressively folding spaced portions of the sheet to form elongated parallel spaced double wall pleats; and connecting the sheet to the strips with adhesive resin to form the core panel.    USE - For producing a composite core panel (claimed) used in applications which require engineered structural properties and light weight such as blades of wind turbines used to produce electrical energy.    ADVANTAGE - The method prepares composite core panels has improved strips or blocks of low density cellular material of relatively low structural properties and weight.    DETAILED DESCRIPTION - Producing a composite core panel involves forming elongated strips (52) of low density cellular material; arranging the strips in laterally adjacent relation with the strips having opposite first and second side surfaces; progressively advancing the adjacent strips between spaced platens to form the adjacent strips into a panel; feeding a flexible sheet of reinforcing material between the panel of strips and at least one of the platens with the flexible sheet continuously contacting the first side surfaces of the strips; progressively folding spaced portions of the sheet between adjacent strips to form elongated parallel spaced double wall pleats in the sheet between the adjacent strips, with the pleats projecting at least partially through the thickness of the strips as defined by the opposite first and second side surfaces; and connecting the sheet to the strips with adhesive resin to form the core panel. An INDEPENDENT CLAIM is included for a composite panel comprising elongated strips of low density cellular material arranged in laterally adjacent relation to form a core panel with the strips having opposite first and second side surfaces and with adjacent strips having opposing faces, a first flexible sheet of fibrous and porous reinforcing material continuously overlying the first side surfaces of the strips, where the first flexible sheet having parallel spaced portions projecting between the adjacent strips and forming double wall pleats between the opposing faces of the adjacent strips, where the pleat extends at least partially through the thickness of the core panel as defined by the opposite side surfaces of the strips, and adhesive resin attaching the first sheet to the strips.    DESCRIPTION OF DRAWING(S) - The figure shows view of another core panel.    Pleated end portion (42)    Flange (43)    Single-layer portion (48)    Strip (52)    Bi-directional core panel (125)