Mike asks,
I have a question on what the % medium should be globally. I’m trying to get a handle on it algebraically so to speak.
Classic corrugated sheet, in my mind, is one 26# medium sheet and two 42# liner sheets. The medium has a wiggle factor of ~1.3 so,
Medium % = 26*1.3/(26*1.3+42*2) = ~ 29%.
Does this sound reasonable? As BWs tend downward, my gut tells me there is more % medium overall but I am thinking still less than a third.
Twenty five years ago, here, it was indeed 42/26/42 with C flute having a take up factor of 1.43. Then the sheet feeders began to request 23# medium and corrugating rolls started to have lower profiles which reduced the take-up factor. Then we moved to 35# and today that probably is 33/23/33. Globally the World Containerboard Organization http://www.wco-containerboard.org/ tracks total containerboard production. Additional information may be available through them.
— Ralph