From earliest times, woven fabrics formed the bulk of filter media. Beginning in the 1940s, with the production of a suitably bonded felt, nonwoven materials started to be used for filtration, and now they dominate the business. One reason for this is the continuing demand for finer filtration, of both liquids and gases, which […]
Monofilament fabrics are woven from extruded synthetic filaments produced in diameters from 30 um to 2–3 mm.These fabrics have become important as filter media in a broad range of industries and applications. Because of their corrosion resistance, ability to withstand vibration fatigue, uniformity and economy to use, they have replaced a number of other types of […]
Fabrics can be woven from yarns of many sorts. It is usually the case that warp yarns (those running lengthways on the loom) are the stronger, while the weft yarns (those running across the loom) may be bulkier and less tightly twisted – weft yarns are often called filler yarns. It is quite common for the […]
Fabrics make up the largest component of filter media materials. They are made from fibres or filaments of natural or synthetic materials, and are characterized by being relatively soft or floppy, lacking the rigidity of dry paper, such that they would normally need some kind of support before they can be used as a filter […]
Filter sheets are made in the same way as paper, i.e. by wet laying, but they are both thicker than paper and rougher in texture. They have traditionally been used in forms of filter presses and employed to clarify beverages such as beer and whisky or to sterilize pharmaceutical solutions. An array of filter sheets […]
Paper is made by the wet laying of a mass of cellulose fibres onto a woven wire band, which is effectively a filter through which the water drains and the fibres settle down to produce a continuous sheet. A slurry of cellulose fibres, or pulp, is formed by disintegrating and beating (or chemically treating) wood […]
The previous part of this Section covered processes that dealt with filtration in a minor way, but which were not primarily intended for the separation of particles from fluids. The majority of the Section is now concerned with those materials intended for filtration and will describe them in sufficient detail to explain how they are […]
First to be considered in this review of filter media are three types of material whose prime function is not the separation of solid particles from fluids, but in whose use such separation does occur. They operate by different physical processes from filtration (and from each other), and are used for different purposes. Absorbent media […]
The industrial context within which filter media are made and supplied to their endusers is of more than passing interest. The great variety in which media are made leads to a corresponding variety in the types of company involved with the supply of media. Some are devoted to its manufacture, while for others it may […]
A filter medium is any material that, under the operating conditions of the fi lter, is permeable to one or more components of a mixture, solution or suspension, and is impermeable to the remaining components. The retained components, the ones to which the medium is impermeable, may be particles of solid, droplets of liquid, colloidal […]
