Reduction of sag in a flattened web of tubular film
CA 2043655 C · Owner: VOß, KLAUS-PETER · Inventors: Feistkorn, Werner; VOß, KLAUS-PETER
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention refers to a method for the reduction of the sag and/or of the different stress profile of a flattened tubular film web produced by blow molding and made of thermoplastic synthetic resin, transversely to its longitudinal direction. For the solution of the problem to provide a method of said kind according to which the sag and/or the different states of tension transversely to the tubular film web can be easily reduced or eliminated to a maximum degree the tubular, film web is heated along its width and then cooled and/or stretched. Furthermore, the invention refers to an apparatus for carrying out said method.
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
- Filed May 31, 1991 and granted November 21, 2000. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 31, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 31, 2013.
- 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.