Bag sizes, filling systems and options for the vertical form-fill-seal machines we build and install.
Key Takeaways
Film is formed into a tube, filled from above, then sealed and cut below in the same cycle.
A new bag width means changing the forming tube and collar; a new bag length is a setting.
An auger, weigher, cup filler or pump sits above the same forming and sealing section.
A VFFS machine works in one continuous vertical cycle: film comes off a roll, a forming collar wraps it around a forming tube, pull belts draw it down, a vertical jaw seals the back seam, the doser drops one portion down the tube, and horizontal jaws seal the top of that bag and the bottom of the next before a knife cuts it free. The VFFS machine diagram at the top of this page labels each part in the order the film meets it. For the machines we build and the products they pack, see the VFFS packaging machine page.
Every bag goes through the same six steps, and the machine repeats them without stopping:
The PLC times each step and holds the settings for each bag size and product, so a change of product is a change of settings rather than a rebuild.
A VFFS machine with a multihead weigher running the cycle above.
A VFFS machine has a film path, a forming set, sealing jaws, a doser and a control system. The table names each part as it appears on the diagram and says what it does.
| Part (diagram label) | What it does |
|---|---|
| Packaging roll (film unwind) | Holds the roll of film and feeds it into the machine |
| Forming collar (molding device) | Folds flat film into a tube around the forming tube |
| Forming tube | Carries product down into the bag; changed with the collar to change the bag width |
| Film pulling belts | Draw the film down one bag length per cycle |
| Vertical sealing jaw | Seals the back seam along the length of the bag |
| Receiving hopper and doser | Takes one portion from the auger, weigher, cup filler or pump and drops it down the tube |
| Horizontal sealing jaws and knife | Seal the top of one bag and the bottom of the next, then cut between them |
| PLC and touch screen | Times each step and stores the settings for each bag and product |
| Date coder (optional) | Prints the date or batch code on the film |
The doser sits above the forming tube and decides how accurately each bag is filled; the forming and sealing section below it stays the same. An auger filler doses powders such as flour, spices and milk powder by a set number of screw turns. A multihead weigher weighs snacks, nuts, frozen pieces and other irregular products. A volumetric cup filler measures free-flowing granules such as rice, sugar and salt. A pump or piston filler doses liquids and pastes into sachets.
Our guide to VFFS dosing systems compares them in more detail.
The forming set decides the bag width and the film pull decides the length. A new length is a setting on the PLC; a new width means changing the forming tube and collar. The same frame forms pillow bags, side-gusset bags and sachets from roll film, and options extend it: date coding, gas flushing, zippers and multi-lane heads for sachets and sticks.
A VFFS machine does not make stand-up, spout or flat-bottom pouches. For those, a horizontal machine forms the pouch from film or fills one made in advance, as compared in VFFS vs premade pouch machine.
A VFFS machine forms, fills and seals in one vertical cycle, and the doser and forming set are what change from one product to the next. See the VFFS packaging machine page for the machines we build and the products they pack, then send us your product and bag size for a trial or quotation.
Send us your product, the bag size you sell in and the output you need, and we will trial it on a VFFS machine and quote the configuration that suits it.