An electrostatic filter (esf) or electrostatic air cleaner is a particulate collection device that removes particles from a flowing gas (such as air) using the force of an induced electrostatic charge. Electrostatic filters are highly efficient filtration devices that minimally impede the flow of gases through the device, and can easily remove fine particulate matter such as dust and smoke from the air stream. In contrast to wet scrubbers which apply energy directly to the flowing fluid medium, an esp applies energy only to the particulate matter being collected and therefore is very efficient in its consumption of energy (in the form of electricity).An electrostatic filter includes a fibrous component including a mixture of wool and synthetic fibers and a resinous component including a perfluoroalkyl acrylate copolymer resin and a p-tert-butylphenol formaldehyde resin, which resinous component is adhering to the fibrous component, both of the fibrous substrate component and the resinous component being in electrostatically charged conditions. An electrostatic filter is used to withstand effects caused by dop aerosol and to meet the niosh standard. By an electrostatic filter comprising an electrostatically charged fibrous component including a mixture of an animal wool fiber and a thermoplastic synthetic fiber, and an electrostatically charged resinous component adhering to the fibrous component and including a p-tert-butylphenol formaldehyde resin, wherein the resinous component includes further at least an electrostatically charged perfluoroalkyl acrylate copolymer resin. According to the electrostatic filter, the resinous component includes further at least any one of a polyalkyl acrylate resin, a polyalkyl methacrylate resin, and a polyalkyl styrene resin, each of which resins is in an electrostatically charged condition. Preferably, a polymethyl methacarylate resin is used as the polyalkyl methacrylate resin and a polystyrene resin is used as the polyalkyl styrene resin. More preferably, the resinous component includes a polymethyl methacarylate resin and a polystyrene resin, both of which resins are in electrostatically charged conditions.
According to the electrostatic filter, the fibrous component has been impregnated with the resinous component which has been solidified thereafter. According to still another embodiment of the electrostatic filter, the fibrous component includes the wool fiber having a diameter of 15 to 33 µm and the thermoplastic synthetic fiber having fineness not exceeding denier 1.5. The fibrous component preferably comprises a wool fiber of 20-70% by weight and a polyester fiber of 80-30% by weight. The fibrous component may have a weight range of 200-800 g/m 2 and may be any one of a nonwoven fabric and a felt.
