News Picks : Perishable food spawns development of innovative plastics
NPR: Plastic food packaging involves more science and innovation than one might think. Lighter than glass, more durable than paper, and relatively cheap to produce, the plastic used in the food industry is actually an amalgam of several different types. Take a bag of potato chips: The bag may have as many as three layers—an exterior layer of polypropylene, which serves as a moisture barrier; an inner layer of thin aluminum coating, which strengthens the bag; and a layer of another plastic called polyethylene sandwiched in between. Besides the potato chips, the bags may also get a shot of nitrogen gas before they are sealed, which helps prevent the chips from getting crushed. The type of packaging used depends on the type of food inside, since some materials can cause chemical reactions and affect the product's flavor. Because all the nifty packaging creates a lot of extra waste, however, researchers are now working to create new plastics that are also environmentally friendly.