Most of us go through our lives eating potato chips without ever stopping to think about the bag that they come in. Truthfully, the only time many people are aware of the packaging design of their favorite chips is when they are trying to sneakily open a bag in a silent room. But potato chip packaging is shockingly complex – would you have ever guessed that a typical bag of chips contains at least 4 different layers of 3 different materials? Read more…
What’s in a bag? The science of potato chip package design
When you take a moment to consider the many functions that chip packaging must provide, the complexity of the bag and its materials actually makes a lot of sense. The bag must be able to protect the contents from environmental moisture; otherwise, you’d have soggy chips every time you packed a bag in your lunchbox with an icepack or cold drink. On the other hand, you don’t want grease leaking through the bag and getting all over the place. And let’s not forget that fats are very vulnerable to absorbing unwanted odors and tastes.
The list goes on and on: potato chips packaging needs to be strong enough to withstand normal handling, but still be easy to open when you’re ready to dig in. All the materials used must be food-safe and approved by the government, so they have to be things that won’t leach chemicals into the chips. To top it all off, the package design has to be attractive and informative so that consumers will choose your brand of potato chips out of the dozens of options available.
It’s all about the layers (I’ll spare you the Lays potato chips pun)
As I mentioned, conventional packaging for potato chips typically is made up of at least 4 different layers, and each has a very specific purpose. The innermost layer is almost always a polymer called BOPP, which stands for bi-axially oriented polypropylene. It is the gold standard today in terms of food-safe materials that protect package contents. BOPP is a great barrier for moisture, oils, and gases that can contaminate the chips with bad odors and tastes. BOPP is also used in a middle layer, after a second layer of LDPE (low-density polyethylene). LDPE provides potato chip packaging with strength and additional grease resistance. Finally, the outermost layer is usually a thermoplastic resin whose trademark name is Surlyn. Manufacturers love Surlyn because it adds strength and puncture resistance to the chip bag and can be heat-sealed shut very quickly and at relatively low temperatures.
Some brands are trying to shake up these conventions in the interest of making a more environmentally friendly option, primarily PLA (polylactic acid). You may have experienced this firsthand when buying “healthy” chip alternatives or potato chips from brands that market themselves as organic. You would know something was different about that packaging almost immediately – although the material is biodegradable, it is much noisier than conventional chip packaging when being handled and opened!