This Small Business Innovation Research (SBIR) Phase I project will investigate methods to efficiently spray staple polymeric nanofibers (NFs with avg. diameter ~400 nm) of short lengths (200-700 micro-m) in wet or dry form at high rates onto rolled good nonwoven substrate manufacturing lines. Existing nanofiber technologies simultaneously produce at low throughputs and apply NFs at very slow line speeds (~1-30 m/min) as a low basis weight surface coating onto nonwoven substrates. Due to the inefficient delivery and high costs of NFs, they are commercially only used in high-end applications in filtration, acoustics, medical, energy and textiles. By separately producing bulk NFs and developing methods to efficiently spray them at high rates (>150 m/min) inline, the significant value of NF?s can be more widely applied to the US nonwovens manufacturing sector. The key research objectives include developing methods to disperse NFs for wet or dry spraying, determining how to spray NFs using commercially available equipment, and testing the value that sprayed nanofibers add to air filtration and acoustic nonwoven products. It is anticipated that methods to spray and disperse NFs will be developed and pilot spraying equipment design requirements will be determined as a result of this research.
The broader impact / commercial potential of this project could unleash the high value that NFs can add to nonwoven products by spraying bulk, short-length polymeric nanofibers (NFs) inline at full line speeds (> 150 m/min) in nonwoven manufacturing processes using commercially-available spraying hardware. The NF spraying equipment would be a fraction of the hardware costs compared to existing electrospinning and melt blowing NF technologies. Recently a novel transformative NF closed-loop chemical production process has been scaled up and it addresses a fundamental limitation of current NF processes ? high throughput off-line production of short length NFs. Spraying nanofibers at full nonwoven line speeds would accelerate the growth rate (estimated at 34% per year) of the existing $176 million market for nanofibers. In the $6.6 billion air filtration market, this novel NF spraying technology will be a key to improving filter efficiency and lowering costs through new improved products worth hundreds of millions of dollars. The first target markets for spraying nanofibers in-line will be for air filtration and acoustics applications. The broader impact of developing nanofiber spraying capabilities will make the US nonwoven industry more competitive worldwide and improve North Carolina?s economy through job creation.
