Method for expansion injection molding
CA 2477149 C · Owner: Okamoto, Akio · Inventors: Yamamoto, Naoto; Shimizu, Fumihiko; Takatori, Hiroyuki
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An injection-foaming molding process for manufacturing a formed article by injecting a molten resin containing a foaming agent into a cavity of a mold being retained in an openable state and then expanding the cavity by opening the mold to allow the resin to foam includes: i) a step of discontinuing a cavity of a mold from a resin-reserving section located at front end of a screw immediately after the completion of injection of a molten resin containing an expandable resin into the mold cavity; and, ii) a step of keeping the resin-reserving section under pressure at least equal to back pressure for charging during a period from the completion of injection to start of charging the …
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 February 28, 2003 and granted October 2, 2012. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended February 28, 2023.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by February 28, 2025.
- 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.