Maybe you mean juice pack? A pack of juice?

It is a small box that holds fruit juice. The package is rigid until opened because all the air has been removed. It can also be used for milk and other liquids. The contents are packaged "aseptic ally" which means they are sterile, so the product can safely be held for a time without refrigeration.

A juice pak, also called a juice pack or juice packet or juice box, is a small container of juice and is made of a soft material like heavy paper. It usually contains a small amount of juice (300 to 500 ml), and is referred to as a single serving. You can see images of juice boxes at this webpage: https://www.google.ca/search?hl=en&site=imghp&tbm=isch&source=hp&biw=1366&bih=655&q=juice+pack&oq=juice+pak&gs_l=img.1.8.0i5l8j0i10i24l2.1740.3710.0.14870.9.9.0.0.0.0.104.769.7j2.9.0.msedr...0...1ac.1.60.img..0.9.758.LHCIhwr5zQo#hl=en&tbm=isch&q=juice+pack+drink&revid=475731065

What ev, I've only ever heard juice box. Unless it's like Capri Sun, so it's a pouch...