How is a juice box made waterproof?

Juice boxes are not waterproof, but they are liquid-tight. This is achieved through a combination of materials and construction methods.

The main material used in juice boxes is paperboard, which is made from wood pulp. Paperboard is naturally porous, so it would not be able to hold liquid on its own. However, juice boxes are coated with a thin layer of plastic, which makes them liquid-tight.

The plastic coating is applied to the paperboard using a process called extrusion. Extrusion is a process in which molten plastic is forced through a die to create a thin film. The plastic film is then laminated to the paperboard, creating a watertight barrier.

In addition to the plastic coating, juice boxes also have a number of other features that help to keep them liquid-tight. These features include:

* Heat seals: The edges of the juice box are sealed together using a heat seal. Heat sealing creates a strong bond between the two layers of paperboard, preventing liquid from leaking out.

* Gusseted corners: Juice boxes have gusseted corners, which help to reduce stress on the seams and prevent leaks.

* Pour spouts: Juice boxes have pour spouts that are designed to be leak-proof. The pour spouts are typically made from a flexible plastic material that can be easily opened and closed.

These features all work together to create a liquid-tight juice box that can keep your juice fresh and delicious.