Wednesday, November 18, 2009

US Patent 7618579 - Electro-blown spinning of nanowires

This patent from du Pont teaches an electrospinning method for generating webs of polymeric nanowires which avoids the necessity of heating used in earlier methods. Claim 1 reads:

1. A method for preparing nanofiber webs comprising:

feeding a polymer solution comprising between 15 to 25 wt % polymer to a spinning nozzle;

compressively discharging the polymer solution through the spinning nozzle at a discharge rate between about 0.1 to 5 cc/min┬Ěhole, which is charged with a high voltage, while injecting compressed air through an air nozzle positioned adjacent the lower end of the spinning nozzle to form nanofibers; and

collecting the nanofibers on a grounded collector under the spinning nozzle in the form of a nanofiber web.