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Posted: July 12, 2010
Nano-Fibers Spun from Melt-Blown Polymers
(Nanowerk News) Nano-fibers less than 0.5 micron diameter have been made from low cost polypropylene (PP), polyethylene (PET), PBT and many other polymers using an innovative, nano-fiber melt-blown extrusion die designed, developed and manufactured by The Arthur G. Russell Company, Inc.
Where typical melt blown fibers average over 1 micron in size, the Arthur G. Russell nano-fiber die produces fibers averaging as small as 400 nanometers. This fiber size at a basis weight of approximately 0.10 gram per sq. meter (gsm) and a production rate of 1200 meters per minute has the capacity to block contaminants under 0.3 microns. A multi-row die configuration offers even greater production economies or speeds.
Unlike standard dies that are limited to 20 to 40 die orifices per inch operating at pressures below 500 psi, the patented laminated stainless steel Arthur G. Russell nano-fiber die is designed to operate at extrusion pressures as high as 1500 psi with 64 orifices per inch. Higher pressures can be designed, for if required. In addition, the patented die structure is more resistant to pressure related failures that cause other dies to split open along orifice rows (unzip) during high-pressure excursions due to any cause.
In laboratory tests conducted at the University of Tennessee, Chris Eash and Dr. Gajanan Bhat working with a 20 inch Arthur G. Russell die retrofitted to an existing melt-blown line produced nano-fibers at 8 gsm and 15 meters per minute from PP and other polymers. This output rate is more than 64 times more productive than electro-spinning.
A coat-hanger manifold designed by Arthur G. Russell assures consistent fiber quality by providing uniform resin distribution and constant residence time to manage resin degradation across the width of the die. For high-volume production, multiple lines of spinnerets produce nano-fibers that are then further processed.
Secondary electrostatic charging or chemical processing operations, if desired, can be added directly into the processing line to enhance specialty filtration, barrier, or dispensing properties.
Nano-fibers produced with the Arthur G. Russell die afford protection from airborne and liquid-borne contaminants. Applications may include surgical and medical devices, clean room HEPA filtration devices, face masks, hospital gowns, adult incontinence products and diapers; filters for furnace, home, office, factories and automobiles; water purification system filters; environmental spill protection products, battery and fuel cell separators, geo-textiles, and other non-woven filtration, absorption or dispensing products.
The Arthur G. Russell nano-fiber die can be retrofitted to existing extrusion equipment or the company can design, engineer and construct a complete nano-fiber production system.
The Arthur G. Russell Company, Inc., established in 1945, draws on 65 years of designing, building and installing custom, high-throughput assembly equipment solutions and engineered components. The Arthur G. Russell Company is ISO 9001: 2008 registered.