Abstract: The present invention provides methods and apparatus for the formation of heterogeneous ion-exchange membranes by prescribed in-line compounding and extrusion of a polymeric binder and heat sensitive ion-exchange resin. The ion-exchange resin is incorporated, at a late process stage, into the melted matrix polymer at relatively low temperature and residence time prior to transfer to a die head for extrusion. In the presently preferred embodiment, the in-line compounding apparatus comprises a twin-screw compounding extruder, for effecting late stage kneading and mixing of ion-exchange resin and optional additives to the polymer melt, prior to compression to transfer the blended polymer melt to a die head for extrusion. Accordingly, the final properties of the resultant heterogeneous ion-exchange membrane are enhanced as the blended polymer melt material is not exposed to excessive heat and shear history.
Type:
Grant
Filed:
January 3, 2003
Date of Patent:
April 6, 2004
Assignee:
Electropure, Inc.
Inventors:
Joseph M. Bernatowicz, Michael J. Snow, Ronald J. O'Hare
Abstract: The present invention provides methods and apparatus for the formation of heterogeneous ion-exchange membranes by prescribed in-line compounding and extrusion of a polymeric binder and heat sensitive ion-exchange resin. The ion-exchange resin is incorporated, at a late process stage, into the melted matrix polymer at relatively low temperature and residence time prior to transfer to a die head for extrusion. In the presently preferred embodiment, the in-line compounding apparatus comprises a twin-screw compounding extruder, for effecting late stage kneading and mixing of ion-exchange resin and optional additives to the polymer melt, prior to compression to transfer the blended polymer melt to a die head for extrusion. Accordingly, the final properties of the resultant heterogeneous ion-exchange membrane are enhanced as the blended polymer melt material is not exposed to excessive heat and shear history.
Type:
Grant
Filed:
November 19, 1999
Date of Patent:
January 7, 2003
Assignee:
Electropure, Inc.
Inventors:
Joseph M. Bernatowicz, Michael J. Snow, Ronald J. O'Hare
Abstract: Unique methods and apparatus are provided for rapidly identifying microscopic particles, such as protozoa and other microbes suspended in a fluid or gas.