There is an important group of media materials that are not fabrics in the normally accepted sense of the word, because they are mostly not flexible, but they are made in similar ways, and serve a similar purpose, so they are included here. These are the sheets and tubes made from bonded components: fibres and […]
Just as needlefelts took market shares from some woven fabrics as filter media, so now are the newer meltspun synthetics expanding quickly into most filtration applications. These are the class of media that start with a filament of molten thermopolymer being extruded from a fine nozzle. As it leaves the nozzle the filament is quenched […]
For some, undemanding, applications, a simple felt can provide suitable filtration performance, without any form of strengthening. However, their low tensile strengths, and the ease with which fibres can become detached, make simple felts unattractive for most filtration purposes, and some mechanical (or chemical) strengthening is required. Needle punching is the most common mechanical strengthening […]
It is a common feature of solid/gas filtration, and, to a lesser extent, solid/liquid filtration, that the particles in suspension may carry an electrostatic charge, and therefore that a filter medium carrying the opposite charge will be more effective in their removal. Many different media can be given a charge for this purpose, but one […]
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 […]
