A back-sealed pouch is a type of flexible packaging made from a single continuous sheet of film that is wrapped into a tube and sealed vertically down the center of the back. It is then heat-sealed at the top and bottom to create a “pillow” shape.
Unlike 3-side seal pouches, the main structural seal runs vertically down the rear of the package, leaving the front and side panels completely seamless for high-impact branding.
Key Structural Features
The Vertical Seal (Fin Seal vs. Lap Seal):
Fin Seal: The two inner sides of the film are sealed together (like a fish fin). This is the strongest seal.
Lap Seal: One side of the film overlaps the other. It uses less material but requires a specific “overlap” lacquer or compatible material layers.
Expansion (Pillow Effect): When filled with air or nitrogen (common for chips), the pouch puffs out, providing a natural cushion that protects fragile contents from being crushed during shipping.
The “V” or “U” Tear Notch: Usually placed at the top or bottom horizontal seal for easy opening.