Normal batch plus known extremes.
Provide enough product for tuning, consecutive fills, hopper refill and a sustained run. Include known variation in piece size, fines, density or moisture where it affects flow.
Technical buying guide
Weigh filler product trial and factory acceptance testing.
A practical method for proving product flow, weight distribution, pack handling and complete-line output before a weigh filling machine is approved for production.
Purpose of the trial
Turn a promising machine route into measurable acceptance evidence.
A catalogue range or a successful empty-cycle demonstration cannot prove how a real product will feed, settle, weigh, discharge and enter its final pack. A useful trial uses representative product and production-quality packs, records the operating conditions and measures consecutive results rather than selecting only favourable fills.
Factory acceptance testing should then confirm that the agreed machine and line configuration reproduces the required process under a documented test method. The scope can cover weight results, accepted output, controls, safety functions, changeover, cleaning access and pack quality.
Representative evidence
Supply samples that expose normal production variation.
The trial is only as useful as the material and packaging supplied. A clean, uniform sample can hide the fines, moisture, static, broken pieces or flow changes that appear in production.
Production-quality bags or containers.
Supply the smallest and largest pack formats, final film or pouch specification, closures and any liner, label or coding area that affects handling.
Real targets and acceptance rules.
State routine and extreme fill weights, accepted finished output, tolerance method, product refill method and the upstream or downstream equipment to be represented.
Trial matrix
Test the difficult combinations, not every possible permutation.
A focused matrix should cover the combinations most likely to expose a limitation. These commonly include the smallest target, the largest target, the highest-volume product, the slowest-flowing batch and the most restrictive pack opening.
| Product condition | Record product identity, batch, temperature where relevant, visible fines, moisture or static behaviour and bulk density when available. |
|---|---|
| Machine condition | Record hopper level, feed settings, recipe, change parts, outlet and any settling or timing delay. |
| Pack condition | Record pack size, tare method, support position, film or seal specification and whether the result is an open dose or a finished pack. |
| Weight sample | Use consecutive net results. Record every fill, intervention, spill, incomplete discharge and reject. |
| Output sample | Use a defined sustained period and count accepted finished packs, not theoretical cycles only. |
| Changeover sample | Repeat first-off verification after cleaning, reassembly, recipe selection or change-part replacement. |
Statistics to report.
- Number of consecutive accepted and rejected fills.
- Mean net weight and difference from target.
- Sample standard deviation.
- Minimum, maximum and total range.
- Count and identity of results outside the agreed band.
- Average giveaway where the mean is above target.
- Stops, adjustments, spill, retained product and operator intervention.
A single “accuracy” value without the sample size, product, target and conditions is not enough to compare two trials.
Factory acceptance test
Separate machine checks from production-process proof.
- Configuration review. Confirm machine identity, contact parts, guarding, controls, change parts, utilities and the agreed product and pack formats.
- Static and functional checks. Check zero stability, load-cell isolation, reference-weight response, alarms, interlocks, manual controls and recovery from defined faults.
- Product tests. Run the agreed target/product/pack matrix and record every consecutive result under the agreed method.
- Line-interface checks. Verify ready, request, busy, discharge, fault and downstream-availability signals where the filler is integrated.
- Pack-quality checks. Inspect product transfer, pack contamination, spill, seal area, coding position and reject handling.
- Sustained run. Include normal product refill, pack replenishment, operator activity and downstream equipment for the agreed period.
- Changeover and cleaning. Demonstrate safe access, retained-product inspection, correct reassembly and first-off verification.
- Exception record. List open points, agreed actions, retest requirements and the evidence required before release.
Define acceptance before the test starts.
- Reference scale and calibration or verification status.
- Gross, tare and net-weight calculation method.
- Sample size and consecutive-fill rule.
- Target, permitted band and packaged-goods rules where applicable.
- Accepted finished-pack output and test duration.
- Maximum manual interventions or defined stop conditions.
- Pack integrity, seal, code and reject requirements.
- Who witnesses, records and approves the result.
Send enough evidence to reproduce your production challenge.
Lancing can use representative samples, real packs and an agreed acceptance matrix to confirm the most suitable weighing route before final approval.
Trial questions
Questions to settle before FAT.
How much product is needed?
Enough for setup, the full test matrix, consecutive weight samples, at least one normal hopper refill and a sustained line run. The exact quantity depends on target weight and test duration.
Can substitute packs be used?
They may help with early feasibility, but final approval should use production-quality packs or film because mouth opening, stiffness, friction, static and seal behaviour can change the process.
Should rejected fills be removed from the statistics?
The acceptance method should state how rejects are treated, but every result and intervention should remain in the trial record. Excluding poor results without explanation creates a misleading distribution.
Is a short speed run enough?
No. A useful output test includes normal refill, pack replacement, downstream handling and a long enough period to expose interruptions and drift.
Does FAT replace site acceptance?
No. Site installation introduces the final utilities, environment, product supply, operators and connected machinery. Site checks should confirm the agreed interfaces and production conditions.