An antibacterial mask that includes a filter portion having a first principal surface and a second principal surface opposite the first principal surface, the filter portion including a plurality of first piezoelectric yarns that generate at least a first charge by stretching.

Filter media, such as electret-containing filtration media for filtering gas streams (e.g., air), are described herein. In some embodiments, the filter media may be designed to have desirable properties such as stable filtration efficiency over the lifetime of the filter media, increased normalized gamma, relatively low pressure drop (i.e. resistance), and/or relatively low basis weight. In certain embodiments, the filter media may be a composite of two or more types of fiber layers where each layer may be designed to enhance its function without substantially negatively impacting the performance of another layer of the media. For example, one layer of the media may be designed to have a relatively low basis weight and/or a relatively high air permeability, and another layer of the media may be designed to have stable filtration efficiency and/or a relatively high efficiency throughout the filter media's lifetime. The filter media described herein may be particularly well-suited for applications that involve filtering gas streams (e.g., face masks, cabin air filtration, vacuum filtration, room filtration, furnace filtration, respirator equipment, residential or industrial HVAC filtration, high-efficiency particulate arrestance (HEPA) filters, ultra-low particular air (ULPA) filters, medical equipment), though the media may also be used in other applications.

Filter media, such as electret-containing filtration media for filtering gas streams (e.g., air), are described herein. In some embodiments, the filter media may be designed to have desirable properties such as stable filtration efficiency over the lifetime of the filter media, increased normalized gamma, relatively low pressure drop (i.e. resistance), and/or relatively low basis weight. In certain embodiments, the filter media may be a composite of two or more types of fiber layers where each layer may be designed to enhance its function without substantially negatively impacting the performance of another layer of the media. For example, one layer of the media may be designed to have a relatively low basis weight and/or a relatively high air permeability, and another layer of the media may be designed to have stable filtration efficiency and/or a relatively high efficiency throughout the filter media's lifetime. The filter media described herein may be particularly well-suited for applications that involve filtering gas streams (e.g., face masks, cabin air filtration, vacuum filtration, room filtration, furnace filtration, respirator equipment, residential or industrial HVAC filtration, high-efficiency particulate arrestance (HEPA) filters, ultra-low particular air (ULPA) filters, medical equipment), though the media may also be used in other applications.

A unit for electrostatic filter includes: a repeated structure of patterns that are respectively formed of one selected from at least two different substances having different work functions. The patterns formed of the different substances are put in contact with each other. The work functions differ by 1 eV or greater between the different substances put in contact with each other in the patterns.

A unit for electrostatic filter includes: a repeated structure of patterns that are respectively formed of one selected from at least two different substances having different work functions. The patterns formed of the different substances are put in contact with each other. The work functions differ by 1 eV or greater between the different substances put in contact with each other in the patterns.

Filter media, such as electret-containing filtration media for filtering gas streams (e.g., air), are described herein. In some embodiments, the filter media may be designed to have desirable properties such as stable filtration efficiency over the lifetime of the filter media, increased normalized gamma, relatively low pressure drop (i.e. resistance), and/or relatively low basis weight. In certain embodiments, the filter media may be a composite of two or more types of fiber layers where each layer may be designed to enhance its function without substantially negatively impacting the performance of another layer of the media. For example, one layer of the media may be designed to have a relatively low basis weight and/or a relatively high air permeability, and another layer of the media may be designed to have stable filtration efficiency and/or a relatively high efficiency throughout the filter media's lifetime. The filter media described herein may be particularly well-suited for applications that involve filtering gas streams (e.g., face masks, cabin air filtration, vacuum filtration, room filtration, furnace filtration, respirator equipment, residential or industrial HVAC filtration, high-efficiency particulate arrestance (HEPA) filters, ultra-low particular air (ULPA) filters, medical equipment), though the media may also be used in other applications.

Filter media, such as electret-containing filtration media for filtering gas streams (e.g., air), are described herein. In some embodiments, the filter media may be designed to have desirable properties such as stable filtration efficiency over the lifetime of the filter media, increased normalized gamma, relatively low pressure drop (i.e. resistance), and/or relatively low basis weight. In certain embodiments, the filter media may be a composite of two or more types of fiber layers where each layer may be designed to enhance its function without substantially negatively impacting the performance of another layer of the media. For example, one layer of the media may be designed to have a relatively low basis weight and/or a relatively high air permeability, and another layer of the media may be designed to have stable filtration efficiency and/or a relatively high efficiency throughout the filter media's lifetime. The filter media described herein may be particularly well-suited for applications that involve filtering gas streams (e.g., face masks, cabin air filtration, vacuum filtration, room filtration, furnace filtration, respirator equipment, residential or industrial HVAC filtration, high-efficiency particulate arrestance (HEPA) filters, ultra-low particular air (ULPA) filters, medical equipment), though the media may also be used in other applications.

An imaging system includes: a housing; an ionizer including a first electrode and a second electrode and to charge airborne particles contained in the housing; a particle filter collecting charged particles; and a controller changing an amount of a current flowing between the first electrode and the second electrode by electric discharge during a printing operation, in which the controller controls the amount of current based on a print state indicator associated with the printing operation.

Apparatus for reducing the translucence or opacity caused by smoke within a closed environment includes a fibrous substrate comprising non-conductive fibers. The apparatus further includes elongated, substantially parallel electrodes disposed on the substrate arranged as one or more pairs of adjacent electrodes, wherein a discharge gap is defined between each pair. The apparatus additionally includes a component configured for applying a voltage between each pair to generate a non-thermal microplasma in a corresponding discharge gap to collect or bind one or more airborne particulate combustion byproducts.

An electret is disclosed including: a carrier, and polytetrafluoroethylene having a melting point of 35 C. or higher and 320 C. or lower deposited on the carrier, wherein the electret imparts an electrostatic charge to at least one of the carrier and the polytetrafluoroethylene, and has two or more melting point peaks in simultaneous thermogravimetry and differential thermal analysis. An electret filter is disclosed which preferably is used for a filter which requires durability to tobacco smoke. An electret filter is also disclosed having a fluorine-containing component deposited on a fiber surface, wherein an initial QF value is 0.5 mmAq.sup.1 or more in collection efficiency of particles having a particle diameter of 0.3 to 0.5 m at a wind speed of 5 cm/s, and a filter deterioration rate by tobacco smoke loading is 8/(g/m.sup.2) or more.