Is it really that expensive or impractical to settle the contents of cereal boxes (and potato chip bags) on the assembly line so they aren’t 20-40% air? I assumed that the fill level was something that manufactures co-evolved to — based on what their major competitors are doing and what they can get away with.
Potato chip bags are deliberately inflated with nitrogen. This preserves them (oxygen causes chips to go stale) and it protects them in shipping. The air pressure acts as a shock absorber. If they tightly packed these bags with product then a lot of it would be crushed into tiny crumbs.
It costs them money to ship a bunch of air to the stores. They can’t fit nearly as much product on a truck this way. They do it because it improves product quality, not because they’re trying to rip people off.
There’s one thing to not have chips bags tightly packed and another to have them a tiny amount of chips and the rest nitrogen filler. I think manufacturers got a bit too greedy at this point…
Yes, it requires sustained mechanical agitation for a period of time that you can't really accelerate without severely damaging the product. Add to that that you really can't start settling the product until _after_ its in the container. Maybe you oversize the bag, leave it open while settling (keep in mind that the atmosphere in the container is frequently not room air), before finally sealing and trimming off the excess? Or you could skip all that and just ship the same amount of product, using the same amount of packaging, and save the energy input and cycle time needed to pre-settle the product.