Step 1 : Introduction to the question "Commonly used for juice today, what were drink boxes originally made for?"
...The single-serving juice box was introduced to the U.S. in the 1980s and quickly became commonplace in school cafeterias throughout the country. The engineering of these tiny cartons goes back decades. In the 1940s, Dr. Ruben Rausing began looking for a more efficient and hygienic way to package milk, as the existing reusable glass bottles presented a lot of contamination issues. Rausing’s new cardboard carton, called the Tetra Brik, could be filled all the way to the top, leaving no room for air that would cause the milk to spoil. The benefits of the Swedish-made cartons made them an instant hit, and they were quickly picked up by major juice brands throughout the United States.