Sonoco announced it is implementing a $50 per ton price increase for all grades of uncoated recycled paperboard (URB) in the US and Canada, effective with shipments beginning April 26, 2021.   Sonoco said the price increase was in response to strong demand across its U.S. and Canada mill network which is driving significantly longer backlogs as well as stepped-up inflation of input costs, especially freight, papermaking chemicals and packaging supplies....