Though I imagine to get the fibers fine enough, you would need even higher molecular weight and a little more crosslinking. Possibly with a better plasticizer so you could get tighter loops (from the knitting process) without breaking the strands.
This is awesome. If you can get this to succeed as hosiery, gloves are the obvious next step, then the inner liners for multilayer outerwear garments.
Apparently you can't have crosslinking - the melt would be too viscous to be extruded from a tiny spinneret. You wouldn't use plasticizers in polyethylene, the "plasticizer" in LLDPE is a tiny amount of long-chain terminal alkenes that serve as domain breakers.
Fibers is truly where chemistry and engineering collide.
This problem is even worse with PCL, which is so viscous it's almost unusable for most purposes. Thinking about PCL fibers in https://news.ycombinator.com/item?id=16380491, it occurred to me that I had made some crude PCL fibers by hand — while the plastic wasn't molten. So it occurred to me that you could probably make PCL fibers by the process of die drawing, the same way you make copper fibers or steel fibers, maybe without even the annealing steps in the middle. Presumably this would work for a variety of plastics with high elongation at break.
There are definitely lots of interesting applications - it has been amazing to me that this fiber has been so under utilized in apparel to date. We started with hosiery because of the very obvious pain point, which I've experienced personally, but love hearing about people's experiences with other products we could take this to!
