Abstract: A composite fabric formed by depositing a web of nanofibers electroblown from a first polymer onto a first support web comprising fibers of larger average diameter than the nanofibers spun from a compatible material, in the absence of an adhesive between the webs, and solvent-bonding the webs together.

Abstract: A filtration medium is disclosed for use in air filters used in heating, ventilating and air conditioning systems. The medium contains at least one nanofiber layer of fibers having diameters less than 1 ?m and at least one carrier layer, each nanofiber layer having a basis weight of at least about 2.5 g/m2, and up to about 25 g/m2. The medium has sufficient stiffness to be formed into a pleated configuration.

Abstract: Filtration media are disclosed for use in high efficiency air filters for filtering particulate matter in air. The media make use of at least one layer of fibers having a diameter less than 1000 nanometers sandwiched between two scrim layers to achieve high efficiency particulate air (HEPA) filtration performance at relatively low pressure drops.