Abstract: Microfibrous, polymeric filter sheets and filter elements prepared therefrom comprised of a normally hydrophobic, microfibrous, polymeric web, wherein the surfaces of the microfibers making up the web are coated with a cured, precipitated, cationic, thermosetting binder resin or polymer. The filter sheet is further characterized by being hydrophilic and having a positive zeta potential.

Abstract: A self-cleaning system and method for dispersing aggregates in a fluid medium is provided. The system is comprised of first and second members operatively associated to form an internal chamber and having an inlet to the chamber for admitting the fluid to be treated. At least one of the members is biased toward the other whereby the introduction of a fluid medium to be treated into the chamber under an operating pressure in the range of from about 50 to about 1,000 psid (3.5 to 70.3 kg/cm.sup.2) provides an elongated orifice between the first and second members having a transverse dimension or width of from about 1 to about 1,500 micrometers for egress of the fluid medium. As the fluid passes through the elongated orifice, aggregates contained therein are dispersed. The system is self-cleaning by virtue of the biased nature of at least one of the members toward the other, thereby providing longer onstream operation and requiring less servicing.

Abstract: Filter media comprised of charge modified, resin coated inorganic microfibers are prepared by mixing inorganic microfibers with an aqueous solution of a water soluble, noncolloidal cationic thermosetting binder resin to form a dispersion, following which a precipitating agent is added to precipitate the binder resin and coat the microfibers. The coated microfibers may be used in the dispersed or suspended form as a filter aid. Preferably they are formed into a filter sheet which is then dried and cured to form a filter sheet of narrowly distributed pore size, pore sizes as small as one-half micron, and having a positive zeta potential in alkaline media. Glass is the preferred microfiber and polyamine-epichlorohydrins the preferred resins. By providing the normally negative zeta potential microfibers with a positive zeta potential the binder resins used to coat the microfibers substantially enhance particulate removal capabilities of the microfiber filter sheet.

Abstract: A process for cleaning porous metal filters, particularly stainless steel filters, comprising the steps of:(1) electrolyzing the filter in an electrolyte bath using the filter as one of the electrodes, preferably as the cathode of the electrolytic system, and subjecting the system to an imposed or applied current, highly preferably a DC current; and(2) rinsing the filter to remove electrolytic solution from the filter and flush any residual contaminants from the filter.When organic material is to be removed, a baking step prior to the electrolysis step is used.

Abstract: An improved tracheal tube cuff which is resistant to gas permeation. The improved cuff has good compliance and has a nitrous oxide permeability of less than 10,000 cc/mil/100 sq. in/24 hrs/atms of 100% nitrous oxide. The preferred cuff material is a cross-linked, polyester-based polyurethane resin.