Abstract: A multiple layer HEPA filter media includes, in an exemplary embodiment, a first layer that includes a nonwoven synthetic fabric formed from a plurality of bicomponent synthetic fibers with a spunbond process, and having a bond area pattern of a plurality of substantially parallel discontinuous lines of bond area. The filter media also includes a second layer laminated onto the first layer. The second layer is formed from a micro-porous membrane. Further, the filter media includes a third layer laminated onto the second layer, with the third layer including a synthetic nonwoven fabric formed from a plurality of synthetic fibers. The synthetic fibers include at least two different synthetic fibers having different melting points. The third layer has a cover factor of less than seven millimeters. In addition, the multiple layer filter media further includes a plurality of corrugations.

Abstract: A composite filter media structure and an associated method of making are provided. The structure includes a base substrate that includes a nonwoven fabric substrate formed from a plurality of bicomponent synthetic fibers using a spunbond process. The composite filter media structure includes a surface layer deposited on one side of the base substrate where a thermal lamination process can be used to combine the base substrate and the surface layer. The surface layer is formed from a microporous expanded polytetrafluoroethylene membrane. In one aspect, the base substrate and the surface layer are configured to provide greater than 95% and equal to or less than 99.5% filtration efficiency measured in accordance with an EN 1822 test method. In another aspect, the filter media includes an embossing pattern or a plurality of corrugations formed using opposing rollers at a temperature of about 90° C. to about 140° C.

Abstract: A multiple layer HEPA filter media includes, in an exemplary embodiment, a first layer that includes a nonwoven synthetic fabric formed from a plurality of bicomponent synthetic fibers with a spunbond process, and having a bond area pattern of a plurality of substantially parallel discontinuous lines of bond area. The filter media also includes a second layer laminated onto the first layer. The second layer is formed from a micro-porous membrane. Further, the filter media includes a third layer laminated onto the second layer, with the third layer including a synthetic nonwoven fabric formed from a plurality of synthetic fibers. The synthetic fibers include at least two different synthetic fibers having different melting points. The third layer has a cover factor of less than about seven. In addition, the multiple layer filter media further includes a plurality of corrugations.

Abstract: A waterproof, vapor-permeable and gas-permeable sheet material and a method of making are provided. The sheet material includes a waterproof microporous layer and a thermoplastic layer attached to the microporous layer. The thermoplastic layer is vapor-permeable and air-permeable. The microporous layer is at least partially integrated with the thermoplastic layer to form a zone that prevents passage of water droplets, while permitting passage of water vapor and air, when a chemical is present on the sheet material that would otherwise cause the microporous layer to permit passage of water droplets. The Zone can be considered to be resistant to chemical interference with at least the waterproof property of the microporous layer and inhibits detachment of the layers.

Abstract: A composite filter media structure and an associated method of making are provided. The structure includes a base substrate that includes a nonwoven fabric substrate formed from a plurality of bicomponent synthetic fibers using a spunbond process. The composite filter media structure includes a surface layer deposited on one side of the base substrate where a thermal lamination process can be used to combine the base substrate and the surface layer. The surface layer is formed from a microporous expanded polytetrafluoroethylene membrane. In one aspect, the base substrate and the surface layer are configured to provide greater than 95% and equal to or less than 99.5% filtration efficiency measured in accordance with an EN 1822 test method. In another aspect, the filter media includes an embossing pattern or a plurality of corrugations formed using opposing rollers at a temperature of about 90° C. to about 140° C.

Abstract: A waterproof, vapor-permeable and gas-permeable sheet material and a method of making are provided. The sheet material includes a waterproof microporous layer and a thermoplastic layer attached to the microporous layer. The thermoplastic layer is vapor-permeable and air-permeable. The microporous layer is at least partially integrated with the thermoplastic layer to form a zone that prevents passage of water droplets, while permitting passage of water vapor and air, when a chemical is present on the sheet material that would otherwise cause the microporous layer to permit passage of water droplets. The Zone can be considered to be resistant to chemical interference with at least the waterproof property of the microporous layer and inhibits detachment of the layers.

Abstract: A gas turbine air inlet filter element is described. The filter element includes a first end cap, a second end cap, and a filter media. The filter media includes a nonwoven synthetic fabric formed from a plurality of bicomponent synthetic fibers with a spunbond process, and having a bond area pattern that includes a plurality of substantially parallel discontinuous lines of bond area. The filter media has a minimum filtration efficiency of about 50%, measured in accordance with ASHRAE 52.2-1999 test procedure. The filter media also includes an embossing pattern or a plurality of corrugations. The embossing pattern or the corrugations are formed using opposing rollers at a temperature of about 90° C. to about 140° C.