Nonwovens Go Nuts for Nanofibers?

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by Karen Bitz McIntyre

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rnThey say good things come in small packages, and anyone who has worked with nanofibers in nonwovens is likely to agree. While these small denier fibers have been the recipient of some negative press in other industries, nonwovens technologies allow them to be produced via a continuous filament processes—eliminating the risk of airborne particles. The result is new and improved application areas for nonwovens.
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rnThe definition of nanofibers vary, but most industry experts define nanofibers as those below one micron in diameter, just how far below depends on the nonwovens process used, according to experts. Recent technologies have allowed professionals to spin nanofibers as low as 10 nanometers microns but more typical diameters are in the 75-100 nanometer range.
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rnSo far, the use of nanofibers technology within nonwovens has been limited largely to filtration and some biomedical, acoustical and energy storage applications, but researchers familiar with the technology say the possibilities for this technology are endless.
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rn“We are trying to get the industry to look at a new technology—like nanofibers—to existing applications,” said Anthony Fabbricante, president of Nonwovens Technologies, Inc. “This can be potential in any use for nonwovens, so many different areas. We are not the experts, but we want to provide the lumber. Once we get our technology out there, the possibilities are endless.”
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rnMr. Fabriccante has been studying the use of nanofibers in meltblown nonwovens for years and recently made a major breakthrough in producing massive amounts of meltblown nanofibers in polypropylene and polyester. Last year, NTI signed a licensing deal with Arthur G. Russell (AGR) for the use of its patented high speed meltblown nanofiber technology. According to Mr. Fabriccante,NTI’s breakthrough in high speed meltblown nanofiber technology and AGR’s 60-plus years of building automated equipment puts us in a unique position in the industry.
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rnThe new technology makes nonwovens with 20% more throughputs per commercial orifice size. The fabrics contain more orifices per linear inch than competing fabrics, and these orifices are as small as 0.002 inches. Executives expect to create a one- to three-meter, 500 m/min line to make this material, which will target insulation, geotextile and hotmelt applications. Other capabilities will include bicomponent fibers, binano fibers, spunbonding and hydro/air entanglement.
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rnAccording to Mr. Fabbricante, recent, meltblown nanofiber trials were successfully conducted at the University of Tennessee in Knoxville, andAGR is currently designing a four-spinneret assembly with each row being 15 inches wide.When completed, the total state-of-the-art fiber-making assembly will only be 24 inches long.
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rnThe NTI technology is just one of various process technologies used to produce microfiber nonwovens for applications requiring barrier properties and high surface areas, including specialty meltblowing, electrospinning, electroblowing and splittable fiber approaches. While microfibers are well established in meltblown and wetlaid microglass technologies, the next frontier is expected to involve fibers with even smaller diameters—or nanofibers.
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rnA long-time industry leader in nanotechnology is Czech Republic-based Elmarco, which offers industrial-scale equipment for effective, reliable and low-cost mass production of nanofibers from organic polymers, biopolymers and inorganic materials. “Nanofibers are the most developed and well-defined nanomaterials bringing clear added value to products,” said Ladislav Mares, executive director. “The most developed applications for them are in air filters and biomedical materials for wound care but many other applications are in the stage of final prototyping.”
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rnElmarco has already forged partnerships, both in private and with academia, to expand its technologies into new nonwovens areas. “Generally, the nonwovens industry plays a key role in our business plan,” said Stanislav Petrik, strategy and business development director for Elmarco.“The potential need for our equipment there is huge.”