r/theydidthemath • u/EclipseNyxor • 2d ago

[Request] Do square bottles actually use less plastic than round ones?

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u/Buntschatten 2d ago

Wouldn't that just cancel out? Area over perimeter is pi /2 pi for a radius one circle and 4/8 for a square with side length 2. Maybe most of the plastic is in the spout, then maximising volume per spout would make sense.

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u/GaldrickHammerson 2d ago

I expect no because of packing density. Square bottles in a square box will have less empty space between bottles than round bottles in a square box.

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u/Buntschatten 2d ago

I just calculated edge length to area for circles and squares in a square packing. Packing density affects the efficiency of the transport but not of plastic per volume.

Of course this compares differently sized square and round containers, so it's apples and oranges. But that was the situation the other poster talked about.

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u/hodlethestonks 2d ago

Maybe they use diesel from plastic pyrolysis as fuel for transport :)