Maintain distribution without overloading heads.
The elevator and distribution system should keep enough product available while preventing compaction, breakage, blockage or an unstable head load.
Verified Lancing model reference
Lancing LU-GFKL420 multihead VFFS weigh filling line.
An automatic vertical form-fill-seal reference configuration combining ten electronic weighing heads with roll-film bag forming, filling and sealing for suitable dry products.
Integrated automatic bagging
Treat every headline figure as conditional on the complete line.
The LU-GFKL420 reference combines product distribution, ten electronic weighing heads, a timed discharge, a vertical bag maker and heat sealing. Performance therefore depends on more than the weigher: the product elevator, film, former, sealing dwell, drop distance, coding, outfeed and controls handshake all contribute.
The cited 500 g to 1 kg application sits inside the broader reference weight range, but the usable result for any new product must be demonstrated with representative product, production film and the intended finished bag.
| Reference weighing range | 10–2500 g; the cited application was 500 g to 1 kg. |
|---|---|
| Weigher configuration | Ten electronic weighing heads. |
| Reference hopper volume | Approximately 1.3 litres per weighing head. |
| Published output reference | 5–60 bags/minute, dependent on target weight, product behaviour, bag length, film and sealing conditions. |
| Published accuracy reference | Approximately ≤0.3–1 g under referenced conditions; a new product requires a representative trial and agreed test method. |
| Reference bag format | Approximately W100–200 × L230 mm for the cited configuration. |
| Reference maximum film width | 420 mm. |
| Film boundary | Compatible heat-sealable roll films that run correctly through the former and sealing system, subject to sample approval. |
Line sequence
Synchronise weighing, bag making and finished-pack inspection.
The fastest component does not define the accepted line output. The process is limited by the slowest stable stage and by the controls required to prevent product discharge without a correctly formed bag.
Select a combination near the target.
The controller evaluates available hopper weights and releases an appropriate combination. Product size and head fill consistency affect how many combinations are available.
Discharge only into a ready bag.
The bag maker must signal readiness before release. The dose travels through the timing hopper and forming tube before the transverse seal closes the pack.
Film and bag engineering
Approve the actual roll film and filled-bag geometry.
Film width alone does not prove compatibility. The web must track on the machine, form cleanly around the selected collar and achieve an acceptable seal through the intended product, temperature and production environment.
- Supply production-quality film with confirmed roll width, core, winding direction and registration details.
- Define flat bag width, finished length, seal style, gusset and tear features where required.
- Check the product drop for breakage, dust plume, bounce and contamination of the seal area.
- Test the longest bag and the highest target because both can extend the cycle.
- Confirm coding position, print registration and outfeed support using the final artwork layout.
Controls that protect the line.
A safe interface should distinguish ready, weigh request, discharge permission, busy, cycle complete, low product, film fault, seal fault, downstream unavailable and emergency-stop conditions. The final signal list belongs in the project controls specification.
FAT and output proof
Run the whole line with product, film and normal replenishment.
First verify the weigher using consecutive fills and an agreed reference scale. Then run the combined system with the production film, normal bag length, coding and outfeed. Record accepted bags, rejects, film stops, seal contamination, product spill, operator intervention and hopper replenishment.
Accuracy should be assessed on net finished-pack weights using a documented tare method. Report the mean, sample standard deviation, minimum, maximum and any pack outside the acceptance band. Where a checkweigher is included, verify pack tracking and reject confirmation separately from the filler control.
Output should be stated as sustained accepted finished bags per minute over a defined test period. A short peak speed without normal film changes, refill and fault handling is not the same as production capacity.
Information required for line selection.
- Representative product, bulk density, piece size and fragility.
- Smallest, routine and largest target weights.
- Production roll-film samples and bag drawings.
- Required accepted output and shift pattern.
- Seal-integrity, coding and inspection requirements.
- Product infeed method and available ceiling height.
- Outfeed conveyor, metal detector and checkweigher scope.
- Cleaning, allergen, dust and cross-contamination controls.
- Utilities, footprint, access and operator positions.
- Agreed FAT and site-acceptance criteria.
Confirm the LU-GFKL420 with your product, film and output target.
Lancing can review the complete product-feed, weighing, forming, sealing, coding and outfeed sequence before a final automatic line is specified.
Buyer questions
LU-GFKL420 line questions.
Is 60 bags per minute available on every product and bag?
No. The reference range is conditional. Target weight, product flow, number of usable combinations, bag length, film tracking, seal dwell, coding and outfeed can all limit the stable rate.
Is the published accuracy figure guaranteed?
No. It applies only to referenced conditions. The new application must be tested with representative product, a documented tare method and consecutive finished packs.
Can any heat-sealable film be used?
The film must be compatible with the forming collar, web handling and sealing process. Production-quality roll samples and seal trials are required before approval.
Why is a controls handshake necessary?
It prevents product release when no valid bag is ready and allows the line to stop in a controlled way when film, sealing, product feed or downstream equipment is unavailable.
Can a checkweigher adjust the filler automatically?
Potentially, but feedback must be bounded, delayed to the correct pack and validated so that it corrects a genuine mean shift rather than reacting to isolated variation.