Short answer
Key takeaways
- The forming collar sets the web width.
- Bag length and repeat must match the cutoff and eye mark.
- Sealant choice affects seal range and line speed.
- Run a trial on the actual bagger.
How a VFFS bagger uses roll stock
A vertical form fill seal machine pulls film from a roll over a forming collar into a tube, makes a back seal, fills the product, and seals and cuts each bag. Every step depends on the film: its width, its slip, its stiffness, and how it seals.
Web width and the forming collar
The forming collar is built for a bag width, and the web width follows from it. Give the supplier the collar size or the current web width, the back seal style (lap or fin), and the bag length.
Repeat, cutoff, and eye mark
Printed film has to register to the cutoff, so the print repeat and the eye mark must match the machine. Specify eye mark size, color, location, and the clear space around it so the sensor can read it reliably.
Sealant and seal range
Ask what sealant layer the structure uses and the seal temperature range. A wider range can help on fast lines. Share the product, the fill temperature, and any seal contamination from powder or oil.
Rolls, cores, and splices
Specify core inside diameter, maximum roll diameter or weight, unwind direction, and how splices are allowed and marked. These details prevent stops.
How to compare your shortlist
Ask every supplier the same questions on the first call. Which plant will run the job, and does its certificate cover that site? Which print method and how many colors in one pass? How is color approved and by what standard? What starts the lead time clock, purchase order or approved artwork? What documents come with the first order? Who is your day to day contact when something goes wrong? Write the answers in one table. The supplier that answers clearly and in writing is usually the one that will run your job the same way every time.
Where PCI fits
Where PCI fits: Matt Louie, who writes this site, sells for Poly Craft Industries (PCI). PCI prints by flexographic printing only, runs new 10 color presses, is SQF and GMI certified, quotes a standard lead time of 3 to 4 weeks after artwork approval, and supplies brands sold at major retailers. That makes PCI one supplier to put on a short list, not an automatic answer. Use the checks on this page to compare PCI with every other supplier you are considering.
Next step
If you want PCI to quote your spec, send it to Matt directly through the quote form at /quote/, use Ask Matt at /send-your-package/, email Matt@PolyCraftInd.com, or call Matt at (516) 849 6237.
Questions buyers ask
What is the difference between VFFS and HFFS?
VFFS forms bags vertically and suits loose products dropped from above. HFFS forms packages horizontally and suits items that are placed into the package.
Why does my roll stock track badly?
Common causes include uneven roll tension, web width out of tolerance, a worn collar, or slip that does not suit the machine. Share roll labels and photos with your supplier.
What is an eye mark?
A printed mark the bagger's sensor reads to cut each bag in register with the print.
Do I need a trial?
Yes, if you can. A trial on your bagger confirms tracking, seals, and speed before volume is ordered.
See something that needs correcting? Tell Matt.