Blown film process
CA 1098271 A · Owner: The Dow Chemical Company · Inventors: Havens, Carl B.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A blown film process wherein the temperature of the film is continually monitored in a select control or target area that is remote from the film frost line; a control or "target temperature" is determined based empirically ox otherwise on a given set of companion operating conditions; and a variable film cooling source or supply is regulated to establish the control temperature as an essentially constant or non-variable operating condition. The process is characterized by an essentially stable frost line position and to the extent movement of the frost line can be optically or otherwise observed or sensed, and an appropriate signal derived therefrom the process can be alternately practiced …
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 March 31, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended March 31, 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.