Apparatus and method for making pressboard from poly-coated paper using relative movement of facing webs
CA 2014089 C · Owner: Lamb, Vernon L. · Inventors: Lamb, Vernon L.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A system and process for fabricating pressboard from shredded paper coated with a thermoplastic material and a pair of facing webs includes placing the shredded poly-coated paper between the two traveling webs to form a composite, the composite then being passed in a manner to differentially shift the traveling webs relative to each other for enhanced bonding of the shreds to themselves and to the facing webs, by pressing them through a series of heated rollers defining a serpentine path while heating the thermoplastic material above its softening point and, pressing the composite together.
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 April 6, 1990 and granted January 14, 1997. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended April 6, 2010.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by April 6, 2012.
- 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.