A machine that forms a pouch from a roll of film, fills it, and seals it — all in one continuous cycle.
01 / Definition
What a VFFS Form-Fill-Seal Machine is
A VFFS machine does three jobs in one cycle: it forms a pouch out of flat film, fills it, and seals it. Film comes off a reel, wraps around a forming collar into a tube, gets its back seam sealed, has its bottom sealed, receives the product, and is then sealed and cut at the top — which is simultaneously the bottom of the next pouch.
Everything depends on timing. The jaws, the film pull and the product drop must stay synchronised to within milliseconds, and on printed film the photocell watching the registration mark has to correct drift before it accumulates. When a VFFS line is making bad bags, the fault is almost always somewhere in that timing chain rather than in any single component.
Also called
02 / Anatomy
The parts that matter
The components a technician reaches for when this machine stops working.
Forming collar
Folds flat film into a tube around the filling pipe. Collar geometry is specific to the bag width — the wrong collar never gives a clean back seam.
Vertical sealing jaw
Closes the back seam running down the tube, as a lap seal or a fin seal depending on the film structure.
Horizontal jaws
Seal the top of the finished pouch and the bottom of the next in one stroke, with a knife between them to separate the two.
Film pull belts
Draw a measured length of film down each cycle. Slipping belts are a common cause of drifting bag length.
Registration photocell
Reads the printed eye mark so artwork stays in position on every pouch. Dirt on this sensor shows up as creeping print.
Filling system
An auger for powders, a multi-head weigher for granules, or volumetric cups — matched to the product, not to the bagger.
03 / Applications
Where it is used
Snacks, spices, pulses, detergent powder, milk powder and sachet packing — the workhorse of Indian FMCG lines.
04 / Failure modes
How it fails
What actually goes wrong on Indian shop floors, and what each fault looks like to the operator.
FM_01
Leaking horizontal seals
Product dust trapped in the seal line. Most often the fill is dropping while the jaws are closing, so the timing needs correcting, not the jaws.
FM_02
Bag length drifting
Film pull belts slipping or worn, film tension wrong, or the registration mark being missed on printed film.
FM_03
Burnt or stringy seals
Jaw temperature above what the film needs, or a failed thermocouple reading low and driving the heaters harder than the display suggests.
FM_04
Film wandering off the collar
Reel not aligned on the shaft, a sticking dancer arm, or uneven tension between the two edges of the web.
FM_05
Knife not cutting cleanly
Blunt blade or hardened product residue on it, leaving pouches joined and jamming the discharge.
05 / Onsite
What our technician checks
A methodical path to root cause, not a scattergun of part swaps.
- 01Watch a full cycle in slow jog and confirm the product has finished dropping before the jaws start to close
- 02Measure jaw temperature with an independent probe and compare it against the controller display
- 03Check film pull belt condition and the tension of both web edges across the collar
- 04Clean the registration photocell and verify it triggers reliably on every eye mark
- 05Inspect both jaw faces for product build-up and for wear on the knurling that forms the seal pattern
- 06Confirm the film specification matches the seal temperature recipe in use — films change between suppliers
06 / Get it fixed
Related services
The MachineryFix services that cover this equipment.
07 / Questions
Frequently asked questions
Why are my pouches leaking at the horizontal seal?+
Almost always product caught in the seal line. If the fill drops while the jaws are closing, a dusting of powder lands exactly where the seal must form. Adjust the fill timing so the drop completes before jaw closure, and clean the jaw faces.
What causes bag length to drift during a run?+
The film is not being pulled the same distance each cycle. Check the pull belts for wear and slip, check web tension, and on printed film check that the registration photocell reads every eye mark. Dirt on that sensor produces a slow creep rather than a sudden jump.
Can one VFFS machine run both powders and granules?+
The bagger can, but the filling system usually cannot. Powders need an auger filler; free-flowing granules suit a multi-head weigher. Changing product family generally means changing the filler, not the machine.
Why do seals look good but fail a drop test?+
The seal has fused on the surface without full penetration — typical when jaw pressure is adequate but dwell time is too short, or when the film has changed to a different sealant layer. Try a fresh temperature and dwell combination before blaming the film.
Written & reviewed by MachineryFix — last reviewed — questions? Call +91 70133 33007