As part of recent INDA RISE Conference, we were asked to pull together a presentation on industrial scale manufacturing of nanofiber (“NF”) membranes. As part of that presentation I wound up covering some observations on why it is tough to measure the adoption of nanofibers in applications.
— INDA (@INDANonwovens) October 2, 2013
There are three primary reasons:
- They are used in a composite
- NF layers perform like a membrane
The definitions argument pops up a lot – almost every speaker that hits on NF at a conference begins with a definition or winds up getting asked the question early on. From an Elmarco standpoint, we define nanofibers as a polymer based, highly uniform (in pore size and in fiber diameter), nonwoven web with membrane-like filtration performance at higher flow rates. We explicitly do not include carbon nanotubes, inorganic nanofibers (although we have research being done on these using Elmarco lab equipment).
Nanofibers are always used as a composite. Like meltblowing, in an electrospun layer, the fibers and deposited and formed into a web at the same time. This is different from carding, where a fiber is made and then those fibers are formed into a web in a separate and distinct step. However, in addition to forming the fibers and the web at the same time, the fibers are also deposited onto something else – a substrate, which for us is usually a nonwoven, paper or membrane, so we are also forming a NF composite at the same time we are making the fibers and the web.
Lastly, a major challenge is that nanofibers perform like a membrane – to the point that we are increasingly referring to them as NF membranes internally and with our customers. This is a bit sneaky for the NF to do – because the NF layer is formed of synthetic fibers arrayed in a chaotic pattern, they’ve traditionally been the province of those in the nonwovens and filtration industries. However, their performance is really best benchmarked to that of porous membranes.
The membrane industry is very different from that of the nonwovens and paper industry. End applications, manufacturing methods, performance metrics, and industry dynamics are all very different. These three reasons combine in many ways to make measuring nanofiber end application adoption a difficult activity.