The first fibers!
Achieving fiber formation took a couple tries. The first hurdle was drawing fibers out thin and far enough so the solvent could evaporate completely from the thread by the time it landed. If solvent accumulated on the collector, it would redissolve the fibers into a film.
Trial and error took us from sample 1 which consisted of fiber and film islands to sample 2 which was all fiber.
You’ll notice the collectors are now somewhat standardized to promote reproducibility. Surface area is one of the many variables to manage in order to compare test results from one trial to the next.
Now that our samples pass visual inspection, it’s time to review them under a more powerful lens, an optical profilometer if I’m not mistaken.
In sample 1, we can take a look at the splatter zones and note the absence of fibers. The top left grayscale image is the best visual and just shows blotchy accumulations.
The data for sample 2 looks much more promising. The top left grayscale image has prominent fiber formation, albeit littered with defects.
Look at all those globules! We’re looking for clean uniform fibers without beads.
There are some more experiments to run and parameters to refine. But this was a fun first development cycle!
With the foundation laid, a round of production and testing can turn around in two weeks. That’s a respectable cadence for a side project, especially considering ~5 days of that is just shipping and logistics between production in San Francisco and testing in Baltimore.