E.i. Dupont De Nemours and Company

Johns Hopkins University

Dupont Safety & Construction, Inc.

Gregory T Dee

William Howard Tuminello

Robert Clayton Wheland

Jose Manuel Rodriguez-Parada

Mark Weinberg

Jan Van Meerveld

Thomas William Harding

Joseph Brian Hovanec

Mark A McHugh

Mark Gary Weinberg

Methods and apparatuses are provided for producing fibers via electroblowing. In an embodiment of the present invention, a polymer stream, formed from a spinning nozzle, passes through a first temperature zone for a first residence time, and subsequently passes through a second temperature zone for a second residence time, where the second zone has a higher average temperature than the first zone. In an embodiment of an apparatus of the present invention, the apparatus has a region between the spinning nozzle outlet and collector that includes at least two zones through which a polymer stream passes, where the second zone has a higher average temperature than the first zone.

Multizone electroblowing process

A fiber spinning process comprising the steps of providing a polymer solution, which comprises at least one weakly interacting polymer dissolved in at least one weakly interacting solvent to a spinneret; issuing the polymer solution in combination with a blowing gas in a direction from at least one spinning nozzle in the spinneret and in the presence of an electric field; forming fibers and collecting the fibers on a collector.

Fiber spinning process using a weakly interacting polymer

The present invention is concerned with flash-spinning a surface-modified structure such as a plexifilimentary yarn or a microcellular foam.

Surface-modified plexifilamentary structures, and compositions therefor

Fluoropolymers containing a specified ratio of hydrogen to fluorine atoms attached to polymer backbone atoms dissolve in carbon dioxide under relatively mild conditions of temperature and pressure. The resulting solutions may be used for coatings or encapsulation.

Solutions of fluoropolymers in carbon dioxide

High melting point perfluorinated tetrafluoroethylene polymers dissolved in supercritical carbon dioxide at elevated temperatures and high pressures. The solutions are useful for making foams, spun-bonded or paper-like webs, or for purification of polymers.

Solutions of perfluorinated polymers in CO.sub.2

Disclosed herein is a process for dissolving high melting polymers containing tetrafluoroethylene units at pressures greater than autogenous pressure, using selected halogenated solvents that are often not solvents at autogenous pressure. Also disclosed are the solutions resulting from this process. The solutions are useful for preparing fibers and paper-like webs from these polymers.

Growing community of inventors

Wilmington, DE, United States of America

Gregory T Dee