I know what you’re thinking right now; Potato chip bags? Well, I’m not going to explain to you why those bags are only half full but rather why the packaging itself is far more interesting than is apparent at first glance. You see, everybody knows that the packaging does have a significant impact on the taste of the food (amongst other things like the longevity and the marketability of the product) but not everyone knows how a potato chip bag is made/how much thought went into making them. Now, let’s talk some science.

The reason why those bags are rather complex is because they are supposed to keep contaminants and moisture outside while simultaneously preventing the leaching of it’s own components. So how exactly are they doing it? With multiple layers of polymer materials. The bag itself consists of various layers of polymers and a thin layer of aluminum foil which acts as an oxygen barrier. Here is a basic rundown of how the various polymers are arranged: oriented polypropylene is on the inside of the bag, on top of it is a layer of low-density polyethylene which is followed by a second layer of oriented polypropylene that is also coated by an ionomer resin which is commonly referred.

For good measure I’ll also divulge to you why those bags appear to be “filled with air”. Before potato chip bags are sealed they usually get filled with nitrogen in order to create an air cushion so that the chips won’t get damaged. Why nitrogen? Considering how nitrogen is for the most part an inert gas (doesn’t easily react with other chemicals) it doesn’t negatively affect the taste of the potato chips.
So the next time you open one of those bags, remember: a lot of science went into making them. Enjoy!