Abstract: A resin charged media can be a single or layered construction needled together to provide a graded-density structure of fine fibers intermixed with finer fibers. This resulting media possesses a higher particulate loading retention capability, particularly early in the filtration cycle, relative to other cellulose, spun-bonds, or other similar materials commonly applied to filtration applications where filtration is predominantly a surface-loading phenomenon. The filtration media provides for depth filtration with the multi-layered needled layers, thereby enhancing the overall particulate-holding capacity of the charged media. This results in more resistance to fine particulates and improvements in efficiency due to increased sub-micron particle loading. With the filter media consisting of a graded structure, surface loading phenomenon can be reduced and filter life improved. Since the layers in the media are physically combined using needling technology, they will not separate.

Abstract: The present invention relates to the treatment of particular filteraids to reduce the beverage soluble iron. In the method of the invention, a particulate filteraid, such as diatomite, is contacted with an aqueous solution of particular chelating agents. The process is applicable to treatment of loose filter media and is also applicable to the treatment of filter media in filter sheets. Lowering the pH during the time that the filter media is being contacted by the chelating agent produces an optimum affect.