Industrial-Scale Solution Blowing of Soy Protein Nanofibers

Solution blowing is one of the most industrially viable processes for mass production of nanofibers without significant change of trade practices. In this work a novel industrially scalable approach to nanofiber production by solution blowing is demonstrated using Biax die. Blends of biopolymer soy protein isolate Clarisoy 100 and poly(ethylene oxide) (M_w = 600 kDa) were solution blown as aqueous solutions using a spinneret with 8 rows with 41 concentric annular nozzles. Nanofiber mats were collected on a drum, and samples with an area of the order of 0.1-1 m² were formed in about 10 s. Nanofibers were relatively uniform with the diameters of about 500-600 nm. Theoretical aspects of capillary instability, dripping, and fly formation in solution blowing relevant from the experimental point of view are discussed, as well as ways of their prevention are revealed.