Methods and apparatus for extruding a tubular film
CA 2430810 A1 · Owner: Rasmussen, Ole-Bendt · Inventors: Rasmussen, Ole-Bendt
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Processes and apparatus for extruding a tubular film of polymer material. The apparatus comprises a circular coextrusion die having an inlet (10) for the or each component and having an exit channel (18) ending in a circular exit orifice (21) which is located radially outwardly from the die axis compared to the inlet (10). The die comprises several planar or conical die parts (5 6, 7, 28, 29) clamped together, with surfaces supplied with grooves (14) shaped to form channels (11, 12, 13) for the flow polymer material. The shape of the channels is adapted to equalize the flow over the circumference of the exit orifice (21), and the flow of material is divided between the inlet (10) and …
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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
- Filed October 15, 2001. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended October 15, 2021.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 15, 2023.
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.