Evolution of Emergent Technologies for Producing Nonwoven Fabrics for Air Filtration

Nonwovens is a fast growing industry driven by technological research and development (R&D), and one of the major application areas for nonwovens is air filtration. Research on nonwovens technologies has mainly focused on the science and technology areas, but there is very little published research on technology management issues within the nonwovens industry. The purpose of the study is to utilize Tech mining to quantify and map out the technical developments and innovations in nonwovens technologies, with particular emphasis on nonwoven fabrics for use in the subsequent manufacture of air filters. In order to measure the R&D activities and evaluate the recent developments in nonwovens technologies and air filtration manufacturing, a systematic search strategy was employed to collect data from relevant sources, such as journal publications, patent literature, and trade journals. Initially, a bottom-up approach was used to retrieve relevant information regarding the target application area--air filtration. The results yielded information on developments in nanofibers, which is the newest technology trend in making air filter medium. Then, a top-down search focused on the technology and nonwoven processes was conducted. Using this approach, application areas for nanofibers, other than air filtration, were analyzed. The results from the analyses using text mining and visualization tools revealed the technological pathways and potential growth within the nonwovens air filtration industry. Moreover, the development of micro and nanofibers and their associated nonwoven technologies were illustrated. Applications for air filtration range from the filters for HVAC systems and respirators, to air sampling and filters for compressed air in industrial settings. With an increase in pollution and consumers' awareness, high efficiency filters, such as HEPA, are in higher demand. Nanofibers, along with microfibers, present the capability of improving filter performance, and the process can be achieved in multiple ways. The versatility of electrospinning has become the most mentioned method for making nanofibers in academia, while meltblown is more commonly used to produce fibers at micro and submicron scale in industry. Bicomponent process enables production of micro and nanofibers. Nanofibers have also been used in other application areas, including electronics, energy purposes, and medical applications.This study fills a research gap by providing fresh insights into the development of nonwovens technologies and a specific application area, air filtration, from a technology management perspective. It contributes to the overall understanding of nonwovens filtration medium manufacturing and innovations. Ultimately, this study should have implications for researchers and manufacturers looking to target selected technologies, such as nanofibers, for making nonwovens filtration products. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]