A method and apparatus of producing a filter medium of a relatively strong substrate and a fibrous felt layer bonded to the substrate by needle punching the felt through the substrate and fusing the fibers protruding through the perforations to the substrate and each other.
Filtering material and filtration apparatus employing the filtering material. The filtering material includes a perforated laminate of a plastic sheeting and a metalized coating adhesively attached to a fabric backing. A filter bag formed from this filtering material is mounted within a support structure so that the metalized coating is electrically connected to the support structure.
A high efficiency and high capacity filter medium including a top layer of fibrous felt material, an intermediate layer of melt-blown material, and a substrate layer needled together into an integrated layer of filter material. The substrate layer is formed of a layer of composite fiber including a group of melt-blown fibers interspersed between groups of spun-bonded fibers. Alternatively, the substrate layer is formed of spun-bonded material.
A self-supporting tubular fibrous filter element consists of elongated fibers compacted in a direction parallel to the central axis of said tubular element to have a substantially constant density throughout the length and thickness of the tube with a majority of the fibers in parallel to one another in a circumferential direction about the said axis. When required, a perforated cylindrical support sheet is molded into at least one cylindrical face of the element.
Nonwoven fiber bed mist eliminators in which at least one filter element is comprised of a fiber bed of syntheic polymer nonwoven material or fabric containing coalescing or collection sites wherein the ratio of the wet bed pressure drop to the dry bed pressure drop is essentially constant.
Disclosed is a filtration process for the removal of undesired substances from dry cleaning fluids. Illustratively, a cylindrically-shaped batt of a long-fiber synthetic washable fabric filter is attached to a spoke-like rigid frame and the fabric-frame assembly is placed into a filter housing having a fluid collecting center rod. Contaminated dry cleaning fluid is introduced to the housing, passed inwardly through the fabric, and a contaminant free permeate is collected by the fluid collecting center rod.
