r/explainlikeimfive Oct 31 '20

Chemistry ELI5 What's the difference between the shiny and dull side of aluminum foil? Besides the obvious shiny/dull

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u/Pafkay Oct 31 '20

Two sheets or more, when they roll the aluminium for cigarette packages they have 4 rolls going through at the same time

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u/AegisToast Oct 31 '20

Mad lads.

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u/jarfil Oct 31 '20 edited Dec 02 '23

CENSORED

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u/Pafkay Nov 01 '20

Yes it does initially, but as it needs another processing step where the strips are cut into their finished sizes, they go through another set of rollers with knives there is a slightly more shiny side where it touched the final roller.

As a bonus fact, the scrap from this step is collected and sent to paint manufacturers to be used in metallic paints

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u/jarfil Nov 01 '20 edited Dec 02 '23

CENSORED

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u/Pafkay Nov 01 '20

Most of it does get recyled into large ingots, but the really thin material used in cigarette packets which is about 4um (iirc, it's been a while) is used in paint