Vacuum bagging is a technique employed to create mechanical pressure on a laminate. Pressurizing a composite lamination serves several functions.

First, it removes trapped air between layers. Second, it compacts the layers. Third, it reduces humidity. Finally, and most importantly, the vacuum bagging technique optimizes the glass-polycarbonate ratio in the composite part.

These advantages have for years enabled glass lamination industries to maximize the physical properties of bulletproof glass.