Abstract: An acoustic panel is provided that includes a perforated first skin, a second skin and a core. The core is between and connected to the perforated first skin and the second skin. The core includes a plurality of chambers, a first corrugated structure and a second corrugated structure. The chambers includes a first chamber. The first chamber extends from the perforated first skin, through the first corrugated structure and the second corrugated structure, to the second skin.

Abstract: An acoustic panel is provided that includes a perforated first skin, a second skin and a core. The core is connected to the perforated first skin and the second skin. The core includes a plurality of chambers and a plurality of septums respectively arranged with the chambers. The chambers include a first chamber that extends vertically between the perforated first skin and the second skin. The septums include a first septum that extends laterally across the first chamber. The first septum includes a first septum orifice. The first septum tapers laterally inward towards the first septum orifice as the first septum extends vertically towards the second skin.

Abstract: An acoustic panel is provided that includes a perforated first skin, a second skin and a corrugated structure. The corrugated structure is between and is connected to the perforated first skin and the second skin. The corrugated structure includes a first baffle, a first septum, first material and second material that is configured with the first material. The first baffle is formed by an uninterrupted portion of the first material. The first septum is formed by a portion of the second material that is exposed through an interruption in the first material.

Abstract: An acoustic panel is provided that includes a perforated first skin, a second skin and a core. The core is connected to the perforated first skin and the second skin. The core includes a plurality of chambers and a plurality of septums respectively arranged with the chambers. The chambers include a first chamber that extends vertically between the perforated first skin and the second skin. The septums include a first septum that extends laterally across the first chamber. The first septum includes a first septum orifice. The first septum tapers laterally inward towards the first septum orifice as the first septum extends vertically towards the second skin.

Abstract: An acoustic panel is provided that includes a perforated first skin, a second skin and a core. The core is between and connected to the perforated first skin and the second skin. The core includes a plurality of chambers, a first corrugated structure and a second corrugated structure. The chambers includes a first chamber. The first chamber extends from the perforated first skin, through the first corrugated structure and the second corrugated structure, to the second skin.

Abstract: An acoustic panel is provided that includes a perforated first skin, a second skin and a corrugated structure. The corrugated structure is between and is connected to the perforated first skin and the second skin. The corrugated structure includes a first baffle, a first septum, first material and second material that is configured with the first material. The first baffle is formed by an uninterrupted portion of the first material. The first septum is formed by a portion of the second material that is exposed through an interruption in the first material.

Abstract: This invention is directed to a honeycomb core structure having a high compression modulus. The core structure comprises (a) a plurality of interconnected walls having surfaces which define a plurality of honeycomb cells, wherein the cell walls are formed from a nonwoven sheet and (b) a cured resin in an amount such that the weight of cured resin as a percentage of combined weight of cured resin and nonwoven sheet is at least 62 percent.

Abstract: This invention is directed to a folded tessellated core structure having a high compression modulus. The core structure comprises a nonwoven sheet and a cured resin in an amount such that the weight of cured resin as a percentage of combined weight of cured resin and nonwoven sheet is at least 50 percent, The nonwoven sheet further comprises fibers having a modulus of at least 200 grams per denier (180 grams per dtex) and a tenacity of at least 10 grams per denier (9 grams per dtex) wherein, prior to impregnating with the resin, the nonwoven sheet has an apparent density calculated from the equation Dp=K×((dr×(100?% r)/% r)/(1+dr/ds×(100?% r)% r), where Dp is the apparent density of the sheet before impregnation, dr is the density of cured resin, ds is the density of solid material in the sheet before impregnation, % r is the cured resin content in the final core structure in weight %, K is a number with a value from 1.0 to 1.

Abstract: This invention is directed to a folded tessellated core structure having a high compression modulus. The core structure comprises a nonwoven sheet and a cured resin in an amount such that the weight of cured resin as a percentage of combined weight of cured resin and nonwoven sheet is at least 50 percent, The nonwoven sheet further comprises fibers having a modulus of at least 200 grams per denier (180 grams per dtex) and a tenacity of at least 10 grams per denier (9 grams per dtex) wherein, prior to impregnating with the resin, the nonwoven sheet has an apparent density calculated from the equation Dp=K×((dr×(100?% r)% r)/(1+dr/ds×(100?% r)% r), where Dp is the apparent density of the sheet before impregnation, dr is the density of cured resin, ds is the density of solid material in the sheet before impregnation, % r is the cured resin content in the final core structure in weight %, K is a number with a value from 1.0 to 1.

Abstract: This invention is directed to a honeycomb core structure having a high compression modulus. The core structure comprises (a) a plurality of interconnected walls having surfaces which define a plurality of honeycomb cells, wherein the cell walls are formed from a nonwoven sheet and (b) a cured resin in an amount such that the weight of cured resin as a percentage of combined weight of cured resin and nonwoven sheet is at least 62 percent.

Abstract: A filter element (1) with a tubular folded bag (2) of folded filter material, which has a plurality of fold blades (3) adjacent each other in the longitudinal direction (10) of the folded bag (2) a closure cover (4) is attached at at least one axial end (7) of the folded bag (2). In order to provide a filter element which can be bent to any desired curved form while maintaining a high degree of filtration performance, and can be produced in a cost effective manner, the fold blades (3) of a folded bag (2) are provided with a combination of diagonal folds extending at an angle relative to each other such that the fold blades (3) in the longitudinal direction (10) of the folded bag extend back and forth and thereby form a three-dimensional crown structure (18). At least the outer margin of the closure cover (4) has a form corresponding to the crown structure (18) of the fold blades (3).

Abstract: A filter element (1) with a tubular folded bag (2) of folded filter material, which has a plurality of fold blades (3) adjacent each other in the longitudinal direction (10) of the folded bag (2) a closure cover (4) is attached at at least one axial end (7) of the folded bag (2). In order to provide a filter element which can be bent to any desired curved form while maintaining a high degree of filtration performance, and can be produced in a cost effective manner, the fold blades (3) of a folded bag (2) are provided with a combination of diagonal folds extending at an angle relative to each other such that the fold blades (3) in the longitudinal direction (10) of the folded bag extend back and forth and thereby form a three-dimensional crown structure (18). At least the outer margin of the closure cover (4) has a form corresponding to the crown structure (18) of the fold blades (3).