A horizontal form-fill-seal (HFFS) machine — also called a flow wrapper or pillow-pack machine — carries the product sideways through the machine, wrapping film around it and sealing in one continuous pass. Where a VFFS machine drops product down a vertical tube, an HFFS machine moves it horizontally; that difference makes HFFS the natural fit for fragile, flat or irregularly shaped products, and for premium flow-wrap and MAP packs.
The film path
Film unwinds from a flat reel and travels horizontally. The product is placed on top of (or between) the film, and the film is folded around it as it advances. Because the film travels with the product, HFFS suits products that cannot free-fall.
Product infeed
Products enter on an infeed conveyor or chain, spaced to set the pack length. The spacing and the film speed together determine the cut length of each pack.
Forming the pack
The film folds around the product to form a tube, then the longitudinal seal closes the bottom or the back of the pack. This gives the characteristic pillow shape of a flow-wrapped product.
The longitudinal seal
The longitudinal seal is usually a fin seal (the film edges folded together) or a lap seal (one edge overlapping the other). Fin seals are common on high-speed lines; lap seals present a flatter profile and are preferred where the pack must sit flat on shelf.
Cross-sealing: rotary vs long-dwell vs box-motion
The cross-seal is the part that separates one HFFS builder from another, and it comes in three architectures:
- Rotary jaw — rotating jaws seal continuously and suit high speed on standard heat-seal films. Omori’s NSW-7000 runs 10–330 packs/min with rotary sealing.
- Long-dwell — the jaws stay closed longer, which suits thick, high-barrier or laminated films and MAP packs. PFM’s Tornado LD runs up to 100 packs/min with long-dwell sealing.
- Box-motion — the sealing head follows the product’s forward motion while it seals, which suits fragile or irregularly shaped products. Fuji’s FW3400/box-motion variants run 10–300 packages/min.
Speed and seal dwell
Speed and seal dwell pull against each other: a faster line shortens the time the jaws stay closed, which can push the seal out of its range on the film. Multi-jaw machines get around this by running several jaw sets in parallel — Hayssen’s X850 reaches 300 ppm and the Minerva 500 ppm — so each seal keeps its dwell even as output rises.
Where it goes wrong
The usual failures are seal wander on splices, film tracking drift and print-registration misalignment. Because the film is the only thing holding the pack together, these show up as leakers or mis-cut packs at speed.
Last verified: August 25, 2026.
