Method and apparatus for shaping of tubular film
CA 1099467 A · Owner: Idemitsu Petrochemical Company Limited · Inventors: Ushioda, Katsuyoshi; Imaizumi, Fumio
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Tubular films having superior mechanical proper-ties and extremely small deviation in thickness can be produced according to a method and an apparatus in which a means of downwardly tapered hollow inverted-truncated-conical shape is placed on the top of an annular die and used as a means for stabilizing bubbles of olefinic polymer synthetic resins which are extruded from the annular die in an air-cooling inflation process with a take-up speed of about 5 m to 50 m per minute.
Read the whole patent
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 April 21, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended April 21, 1998.
- 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.