How a Vertical Form Fill Seal Machine Works
A VFFS machine, also called a vertical packaging machine, makes the bag from a roll of flat film, fills it from above and seals it, in one continuous vertical path.
- 01
Film unwinds
Film is pulled off the roll and kept in register by a photo eye reading the print marks.
- 02
Forming
The forming shoulder wraps the flat film around a vertical tube.
- 03
Back seal
A vertical seal joins the film edges into a tube. Quad-seal bags get four corner seals instead.
- 04
Dosing
A weigher or filler above the tube drops one dose down into the bag.
- 05
Cross seal and cut
Horizontal jaws seal the top of this bag and the bottom of the next, then cut between them.
- 06
Discharge
The finished bag drops onto a conveyor for checkweighing and case packing.
In continuous motion the film never stops and the jaws travel down with it, which allows higher speeds. In intermittent motion the film stops for each cross seal, which suits many products and bag sizes at moderate speeds.