Most stoppages on a form fill seal machine do not come out of nowhere. A seal starts to leak, a bag length starts to drift, a jaw starts to knock. A preventive maintenance checklist turns those early signs into planned jobs instead of breakdowns in the middle of a shift. This guide gives a practical daily, weekly and monthly checklist for vertical (VFFS) and horizontal (HFFS) form fill seal machines, and explains how to adapt it to your own line.
Use it alongside your machine’s manual, which sets the manufacturer’s own intervals and procedures. Always isolate power and compressed air before working inside the machine.
Why preventive maintenance pays
- Fewer unplanned stops. Worn parts are replaced at a planned time, not when they fail.
- Better packs. Clean jaws, sharp knives and good belts give consistent seals and bag lengths, and fewer rejects.
- Longer machine life. A worn part left running damages the parts around it.
- Useful records. A log of what was checked and replaced tells you which spare parts to keep in stock.
The daily checklist (every shift or production day)
Short checks the operator can do at start-up and at the end of the run:
- Clean the sealing jaws of film residue and product, with the tools and method in the manual.
- Clean the film path: forming collar and tube, rollers and guides. Product dust on the film path causes slipping and poor seals.
- Check seal quality on the first packs: pull a seal apart, check for leaks, wrinkles and burnt edges.
- Check the cut: bags should separate cleanly with no chains or frayed edges.
- Check bag length and print registration against the specification.
- Check sealing temperatures on the display against the product’s settings.
- Listen for new noises: knocking at the jaws, air leaks, belts squealing.
- Check the air supply pressure and drain water from the air filter if needed.
- Check safety guards and emergency stops work.
The weekly checklist
A deeper look, usually by the maintenance technician:
- Pull belts: check for wear, glazing, cracks and correct tension. Worn belts cause film slip and bag length drift.
- Knife: check the edge for dullness and chips, and that it is secure in its holder.
- Jaw faces: check for damage, wear and even contact across the width.
- Sensors: clean the registration (print mark) sensor and product sensors; check their alignment.
- Pneumatics: check hoses and fittings for leaks and cylinders for smooth movement.
- Film unwind: check the brake or dancer and the splicing area.
- Dosing system: for a weigher or filler above the machine, clean and check according to its own manual.
The monthly checklist
- Jaw mechanism: check linkages, pins and bearings for play. Play in the drive links shows up later as uneven seals.
- Heaters and temperature probes: check wiring and connections; compare the actual jaw temperature with the reading.
- Feed rollers: check surfaces for wear and flat spots.
- Lubrication: lubricate the points listed in the manual with the specified lubricant, food-grade where there is any chance of product contact.
- Electrical cabinet: check for dust, loose connections and working cooling fans.
- Review the log: which parts were replaced this month, and are the spare parts restocked?
Periodic service by a technician
Some work needs specialist skills or tools: overhauling the jaw assembly, checking and setting timing, calibrating temperature control, and updating or backing up the control program. Plan it at a fixed interval that suits your running hours, or during a planned shutdown, rather than waiting for a fault. Welpack’s technicians carry out scheduled maintenance and calibration; see our after-sales services.
Adapting the preventive maintenance checklist to your line
The checklist above is a starting point. Adjust it to how your machine actually works:
- Running hours matter more than calendar days. A machine running three shifts needs its weekly checks more often than one running one shift.
- Your product matters. Powders and sugary or oily products dirty jaws and film paths faster; thick laminates work the jaws and knife harder.
- Your records matter most. If a part keeps failing before its check comes round, shorten that interval. If checks never find anything, you may be able to lengthen it.
Keep a simple log
A checklist only works if it is recorded. For each check, write down the date, the machine, who did it, what was found and what was replaced. After a few months the log shows the real wear pattern of your machine and tells you which parts to hold on site. Our guide to Hayssen spare parts to keep in stock shows how to turn that into a stock plan.
Common problems and what to check first
| What you see | Check first |
|---|---|
| Leaking or weak seals | Jaw temperature, heater and probe, dirty or damaged jaw faces |
| Burnt or shrunk seals | Temperature setting and probe reading, dwell time |
| Bag length varying | Pull belt wear and tension, registration sensor, film unwind |
| Bags not separating | Knife edge and holder, jaw timing |
| Knocking at the jaws | Linkages and pins, shock cylinder, air pressure |
| Film tracking off the tube | Forming collar, film roll position, unwind brake |
Frequently asked questions
Does this apply to both VFFS and HFFS machines?
Yes. Both have sealing jaws, a cutting system, film feed and sensors. On a horizontal form fill seal machine, add the infeed conveyor and product timing to the weekly checks; on a vertical form fill seal machine, the forming tube and the weigher or filler above it.
Who should do the checks?
Operators handle the daily cleaning and checks. A trained technician handles the weekly and monthly work and anything that involves adjustment or opening guarded areas.
What should be in a basic maintenance kit?
The cleaning tools and approved cleaning agents for the jaws and film path, the lubricant the manual specifies, a spare knife, a set of pull belts, a heater and a temperature probe for your model, and the machine’s manual and parts list kept at the line.
Keep your line running with Welpack
Welpack supports form fill seal machines across Malaysia from Puchong, Selangor: scheduled maintenance, calibration, troubleshooting and genuine Hayssen spare parts in stock. Ask us to set up a maintenance plan.