Abstract: A composite structure comprising a rigid closed-cell foam core element to which is bonded an initially resilient open-cell foam material and a layer of high strength reinforcing material which are compressed against the core element so as to cause a thermosetting resinous material to form a resin matrix extending throughout the open-cell material and reinforcing layer to bond the composite layers together.

Abstract: The subject matter of the invention is a composite sheet structure having at least two layers of initially liquid-permeable material at least one of which layers is an initially resilient material with open and connected cells, and a thermosetting resinous material which impregnates the layers and which has been cured while the layers are maintained under compression, there being fibrils having a length not in excess of about 1/16 inch in the resinous material, the fibrils preferably being more numerous adjacent the interface of the two layers than in the portions thereof spaced from the interface.

Abstract: The invention relates to the fabrication of composite rigid tubular structures which include a rigidified tubular core member, an initially open-cell resilient foam material helically wrapped about the core member, a layer of reinforcing elements helically wrapped about and radially compressing said foam material, and a thermoset resinous matrix filling the compressed open-cells of said foam material and encapsulating said reinforcing elements.

Abstract: The invention relates to the fabrication of composite rigid tubular structures which include a rigidified tubular core member, an initially open-cell resilient foam material helically wrapped about the core member, a layer of reinforcing elements helically wrapped about and radially compressing said foam material, and a thermoset resinous matrix filling the compressed open-cells of said foam material and encapsulating said reinforcing elements.

Abstract: A method for molding a reinforced composite plastic structure to provide a roughened bondable surface over a portion thereof during the forming operation and which method includes molding a resin-filled, fiberglass-reinforced composite against a mold member having an elastomeric insert in the face thereof such that a portion of the fiberglass fibers are imbedded in the elastomeric member during molding so as to prevent encapsulation of the imbedded fibers by the resin and thereby leaving a roughened or three-dimensional surface over that area of the composite covered by the elastomeric mold inset.

Abstract: The invention relates to a composite structure comprising plural open-cell foam phases impregnated with a hardenable resin such that the cells of one phase are filled with the cured resin while the cells of another phase are coated but unfilled with the resin.