Method of producing polypropylene yarns and apparatus for carrying out the method
CA 1284567 C · Owner: Bert, Paolo · Inventors: Bert, Paolo
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Continuous polypropylene multifilament yarns are made by melt spinning and stretching in an integral process; a sufficient number of filaments for forming at least 8 continuous filament yarns each consisting of at least 10 filaments are melt spun through a spinneret (11) at a speed of at least 400 m/ min into a vertical air quenching zone or shaft (12) for solidification; the filaments are arranged to form a substantially planar array of parallel and mutually distanced yarn strands; then, the filaments are stretched to achieve substantial orientation by passing the yarn strands while main-, taining them in the array over peripheral surface portions, of a sequence of rotating cylinders (141 …
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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 June 4, 1991. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended June 4, 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.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.