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Expired Canadian patentCanada

Cellular fibers via soluble fluid injection

CA 1290118 C · Owner: Windley, William T. · Inventors: Windley, William T.

CIPO record

Overview

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Its claims, description and drawings are in the Canadian Patents Database.

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Abstract From the Canadian patent

A fiber having 1/2-50% substantially gas-filled and essentially all closed cells having a diameter of 0.2-25 microns and a length to diameter ratio of greater than 500 is disclosed. The fiber is made by mixing a fluorocarbon blowing agent into molten polymer, shearing the polymer at a high shear rate, extruding the polymer in a spinneret capillary at a low jet velocity and a low capillary entrance pressure and drawing down the polymer at a total extension greater than 1000.

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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.

Why it's free to use

  • Granted October 8, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended October 8, 2008.
  • We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledApril 30, 1987
GrantedOctober 8, 1991
Term endedOctober 8, 2008
Patent numberCA 1290118 C
Classification (IPC)D01D5/24 +2 more

Timeline

Timeline From CIPO dates

1988199119941997200020032006Application filedApril 30, 1987Patent grantedOct 8, 1991Term endedOct 8, 2008

Sources & verification

Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.