Method and apparatus for producing closed cell foam
CA 2197891 C · Owner: Tark, John R. · Inventors: Hall, Charles A.; Tark, John R.; Schmitkons, James W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Methods and apparatus for producing high quality closed cell foams for use in applications such as coatings, sealant beads seam filling and gaskets. In a , first embodiment an in-line single pass static mixing device (10) containing a very large number of individual mixing elements (12) is used to homogeneously disperse a gas throughout a highly viscous liquid polymeric material such as a plastisol, silicone, butyl or urethane based material. In a second embodiment both a dynamic mixer (3a) and a single pass static mixer (3b) are used in series to form the closed cell foam.
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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 September 27, 1995 and granted July 31, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended September 27, 2015.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by September 27, 2017.
- 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.