Flow wrap (pillow pack)

Flow wrap, or a pillow pack, is made by wrapping printed rollstock around a product, sealing it lengthwise along the back and then crosswise at both ends. It is one of the most common packs on supermarket shelves.

How it is produced

The packer buys rollstock rather than ready-made bags. A horizontal machine wraps individual items such as chocolate bars or biscuits, while a vertical machine forms bags for loose products like crisps or nuts.

Benefits

• Typically among the lowest cost-per-pack formats, because no pre-made pouch stage is needed.
• Very high line speeds on automated equipment.
• Pack length can be changed without changing film width.
• Compatible with modified atmosphere packing to extend shelf life.

What to watch

Flow packs are not reclosable, so they suit single-use or quickly consumed products. Machinability is critical: the film's coefficient of friction, sealing window and print repeat must match the machine, and the eye mark must be placed correctly so cuts stay in register. Decide early between a fin seal and a lap seal, as this affects the laminate structure.