Continuous mixing of elastomeric compounds
CA 2054181 C · Owner: Lansinger, Colleen Marie · Inventors: Handa, Pawan Kumar; Schorr, Gordon Richard; Lansinger, Colleen Marie
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A method of making an elastomer masterbatch or a compounded productive elastomer stock is provided. A twin screw extruder is used to mix elastomer components in multiple mixing zones at controlled temperatures. Elastomer and other ingredients are fed into the twin screw extruder continuously through precise loss-in-weight or volumetric feeders. The degradation temperature and/or cross linking temperature of the elastomer determines the rate at which the elastomer can be processed, since friction created during mixing heats the elastomer. Accordingly, the maximum rate of compounding is a function of the torque limit cooling, efficiency, and conveying capacity of the extruder. The conveying …
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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 24, 1991 and granted December 7, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended October 24, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by October 24, 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.