ENT DEVELO MENTS IN FILTER MEDIA Gore focuses on fibres for filtration W L Gore & Associates produces m Ebres which have been specially developed for wet El- tration applications, and Rastex filtration products.

The polytetrafluoroethylene (PTFE) monofilament thread is a special product for the manufacture of screens for wet filtration applications. PIYE fi- bres are usually weak, but Gore has been able to make this Ebre sufficiently strong for it to be precision woven into a high- strength filtration screen by Swiss-based Sefar (formerly ZBF)

The screens are temperature resistant up to 26O”C, and have excellent chemical resistance. The mesh size is below 15 pm, and they offer good cake release and high strength. They are suitable for all wet filtration

applications, but are expected to End greatest use in the chemical and pharmaceutical sectors.

Gore also produces the Ras- tex scrim product, for adding strength to needlefelts used in filtration applications.

W L Gore & Associates GmbH, Wernher-von-Braun-Strasse 18, D-85640 Putzbrunn/Mtinchen, Germany. Tel: +49 89 46120, fm: + 49 89 4612 300.

W L Gore & Associates (UK) Ltd, 5 Macintosh Road, Kirkton Campus, Livingston, West Lothian EH54 7BW, UK. Tel: +44 1506 460607, f&c: +44 1506 462270.

&far Inc, Moosstrasse 2, CH- 8803 Riischlikon, Switzerland. Tel: + 41 1 724 6511, fm: f41 1 724 1525.

Ultra-low-pressure membrane cuts operating costs in half

California-based Fluid Systems ler pumps and less expensive Corporation has announced its components. new ultra-low-pressure reverse The membrane comes in osmosis membrane, the TFC- both 4 and g-inch models. The ULP. This membrane, which model 4821-ULP, when operat- the company claims to be un- ing at 75 psi, provides 98% ique, is designed to operate in rejection and 1300 gallons per the pressure range from 75 to day (gpd) of output. At 150 psi - i.e. at approximately 150 psi, it provides twice the half the operating pressure of rejection at 99% and an output other low-pressure membranes. of 2650 gpd. As a result, it can cut energy On the other hand, the requirements in half, so redu- model P&21-ULP at 75 psi pro- cing overall system operating vides 98% rejection with an costs. output of 5300 gpd, while at

The TFC-ULP membrane can 150 psi the performance also also contribute to reduced sys- doubles to give 99% rejection tern component costs. Because with an output of 11,000 gpd. less pressure is required to achieve the same or better

Fluid Systems Corporation;

performance as with similar 10054 Old G-rove Road, San Lhkgo, CA 92131, USA. Tel: + 1

membranes, reverse osmosis 619 695 3840, fbx: fl 619 695 systems can instead use smal- 2176.

Synthetic media producer to open UK operation in 1996

Following the recent commis- web liquid filtration melt- sioning of meltblown lines in blowns, but also for a new China, US meltblown producer generation of air filtration syr- Web Dynamics is continuing its thetic media for ASHRAE and ambitious expansion pro- automotive applications. gramme with the announcement that it plans to open a UK

Since January 1995 the com- pany’s products have been

meltblown operation in 1996. available from its UK warehouse As the largest privately

owned meltbiown producer in along with sales, service and

the world, with more than technical support.

25 years’ experience, Web Dy- Web Dynamics Ltd, 20 Goldsmith namics has always been at the Road, London W3 SPX, UK. Tel: forefront of meltblown technol- + 44 181 992 8776, fax: +44

ogy in both air and liquid 181 992 8775. filtration.

Web sees excellent opportu- Web Dynamics Inc, 1 Forge Road, East Stroudsburg, PA 18301,

nities in Europe not only for its USA. Tel: + 1 717 420 1200, well established range of Dyna- fm: f 1 717 420 1203.

Filtration & Separation October 1995

Ceramic fibres for hot gas filtration

are constructed from continuous oxide fila- tion efficiency with advantages ments, which are polycrystalline over other ceramic monolithic and non-porous, offering excel- type filters such as low pressure lent strength, flexibility and drop, thermal shock resistance thermal and chemical resis- and chemical stability in both tance. The Ebre diameter is oxidising and reducing condi- controlled such that it is con- tions. sidered non-respirable. The Nextel Ebre has been

A Nextel fibre-reinforced incorporated into seamless wo- ceramic matrix composite filter ven filter bags for use in bag- has been developed for ad- house filtration. Conventional vanced coal-fired power genera- fabrics are said to be restricted tion. The filter consists of a to an operating temperature fibrous substrate which is che- below 260°C. Nextel filter bags mically vapour coated with have been demonstrated in silicon carbide to form a tough- operation up to 760°C. ened rigid composite structure, which can be used at tempera-

3M Deutschland GmbH, Postfach

tures up to 12OO’C. Known as 100422, Carl-Schurz-Strasse 1,

the Ceramic Composite Filter D-41453 Neuss, Germany. Tel: + 49 2131 140, fax: f49 2131

(CCF) , it offers excellent filtra- 142649.

Activated-carbon impregnation process for wide range of technical applications

The Technical Division of UK- based BFF Nonwovens has an- nounced the development of an activated-carbon, filter medium suitable for a wide range of technical applications.

Ebre blend or binder variant can be incorporated. The weight, density and surface fin- ish can therefore be tailored to meet a precise requirement.

The chemical composition of the pollutant to be filtered determines the selection of the activated carbon used, and its efficacy in use is dependent on retention time, pore size and pore distribution.

BFF chemists involved with the project say that, because of its unique chemistry, the pro- cess ‘locks’ the activated parti- cles into the nonwoven matrix, thus avoiding the problems normally associated with ‘loose’ activated carbon power or gran- ules.

Not only is dust contamina- tion reduced, but as the non- woven substrate can be custom- designed to a precise specifica- tion, the process provides the means to produce materials to meet end-use applications not previously attainable.

Activated carbon has been used for many years to purify and reduce odours in industrial, medical and domestic products. lXe material is characterised by the phenomenal surface area it provides. A substrat,e formed on the company’s chemical-bond Line is used as the base material. rhese dry-laid, chemically bonded fabrics are extremely versatile, in that almost any

Where necessary, and to meet the technical demands of some industrial, medical and military applications, the per- formance of the activated car- bon may be further enhanced by the inclusion of chemical im- pregnates.

BFF reports that numerous trials have already been suc- cessfully completed on a wide range of end-uses. With such powerful adsorbent properties, the new materials will have applications in both gas and liquid phase filtration, includ- ing gas removal filters, oil and water filters and use for odour prevention in medical dressings.

BFF Nonwovens, Bath Road, Bridgwater, Somerset TA6 4N2, UK Tel: + 44 1278 428500, fa: + 44 1278 429499.

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