Abstract: A spiral core comprises successive convolutions of a rigidifying layer which are spaced with respect to each other and maintained in a spiral spaced relationship. Preferably, a spiral insulation layer, having convolutions intermediate the convolutions of the rigidifying layer and forming a laminate with the rigidifying layer, is also present in the spiral core. The insulation layer and the rigidifying layer are bonded together to maintain the laminate spirally wound. The rigidifying layer can be a sheet material that is bonded to the insulation layer or a bonding material that hardens to both form the rigidifying layer and bond the rigidifying layer to the insulation layer. The insulation layer is a flexible insulation material such as, fiber glass blanket, a mineral wool fiber blanket, a ceramic fiber blanket, a polyimide fiber blanket or a foam sheet.

Abstract: An acoustic tile that provides soundproofing in a modular wall, such as is used in a modular panel office system, comprises a rigid rectangular metallic frame, a septum formed of a calcium carbonate-filled molded synthetic rubber polymer, a layer of low-density fiberglass and a layer of high-density fiberglass. The front of the frame is covered by fabric, and the back of the frame has fittings to attach the acoustic tile to a wall panel.