LARGE, DIMENSIONALLY STABLE NYLON CASTINGS ARE KEY COMPONENTS OF NEW HIGH-CAPACITY WATER FILTRATION SYSTEM
18 February 2002 - Quadrant EPP

The Ultrazur 450 filtration unit, which is manufactured by Aquasource, Toulouse, France, a subsidiary of ONDEO Degremont, has multiple columns, each containing 5,000 hollow acetate fiber membranes (pore size is 0.01 mm). The base and cover for the module's main housing are made of a lightweight, corrosion-resistant, dimensionally stable nylon, Nylatron M AQS, produced by Quandrant Engineering Plastic Products.

The nylon components are made using a special casting process, which allows these complicated parts to be made to near-final dimensions, which require minimal machining. Casting the components reduces material cost and machining time (and cost). Similar to injection molding, casting allows several parts to be combined into one, thus reducing manufacturing, assembly and maintenance costs. Another benefit is that casting of these structural parts allows larger cross sections and minimizes flow-induced stress. Compared to injection molding, this results in improved dimensional stability during use, with parts less likely to distort or change shape.

Raw water arrives to the Ultrazur water purification plant through a connection in the structural base of the unit. The water is pumped up through the cartridges and the ultra-filtered water exits through the cap. The filtering process is a continuous operation and includes retro-rinsing phases.

The mechanical strength of cast nylon allows it to support higher bearing loads than are possible with many other thermoplastics. Cast-in ribs provide added structural strength. The resiliency of cast nylon allows it to return to its original shape without permanent deformation when deflected by the non-uniform, short-term pressures experienced by the Ultrazur equipment during normal operation.

Quadrant EPP Receives 2002 European Engineering Award for Components in Aquasource's New Ultrazur 450 Water Filtration System

At the 2002 European Sub-contracting and Engineering Fair, January 2002 in Utrecht, Quadrant EPP was presented the European Engineering Award 2002. The award encourages the development of industrial subcontracting, and recognizes "exemplary professionalism and know-how."

Low forming pressures are used in casting of the nylon parts thus tooling costs are low compared to injection molding. Minimal finish machining is required and only in those areas where critical dimensions must be held. Machining the cap's inner surface makes it perfectly watertight to the ends of the membrane columns.

Nylon has not been used a lot for drinking water applications: steel and aluminum are more commonly used. However, as Franck Zirilli, project manager at Quadrant EPP, points out, "If steel or aluminum had been used, the components would have needed a protective coating against corrosion. Further, the coating would have to be certified for contact with drinking water. The coating would have been an extra manufacturing step and the coating would have been subject to abrasion or other damage. And, there is also the weight issue: handling problems to install the cap."

Nylatron AQS is FDA compliant and also is certified for products that come in contact with drinking water.

Philippe Gaudet, director-general of Aquasource, says, "Ultrazur 450 plants are in use in Rouen and Lorient, France. Further, we are developing two water treatment plants for use in the United States and they are planned to be operational in 2002." In addition to the new Ultrazur 450, Aquasource produces modules diameters of 150 and 300 mm.

http://http://www.quadrantplastics.com

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