Guide

How should product flow be tested before choosing a weigh filler?

A weigh filler trial should prove how the product behaves through the feeder, weigh hopper, discharge path and pack opening before a production output is assumed.

Product-flow evidence

Test the material path before selecting the weighing route.

Free-flowing granules, dusty powders, fragile pieces and irregular hardware can all be filled by weight, but they do not behave the same way in a hopper or feeder.

What should a weigh filler flow test prove?

A product-flow test should prove that the product can feed consistently, settle on the load cell, discharge cleanly and enter the pack without bridging, dust loss, damage or unacceptable variation. The result should be judged using consecutive fills, not one successful sample.

The test should use the actual product grade, not a visually similar substitute. Particle size, moisture, oil content, fines, static, temperature and storage condition can all change feeder behaviour. If the product is supplied in bulk bags, drums or sacks, the refill method should also be represented because product consolidation and segregation can appear before the weigh filler itself.

Which product properties change the machine route?

The most important properties are flowability, bulk density, dust level, fragility, stickiness, particle-size variation and the risk of segregation. These factors decide whether a vibratory tray, linear head, multihead weigher, auger-assisted route or bag-clamp arrangement is practical.

A light powder can require dust control and careful refill, while a dense granular product may need attention to impact, cut-off and discharge height. Mixed products such as granola, pet treats or hardware kits should be checked for separation because a fill may be correct by weight but wrong by component mix.

Trial sequence

A practical flow test should follow the product through each stage.

The sequence below keeps the trial focused on information that helps Lancing select, configure and quote the right equipment.

Stage	What to observe	Why it matters
Refill into hopper	Dust plume, aeration, bridging, segregation, retained product and safe access.	Refill instability can make a suitable feeder appear inconsistent.
Coarse and fine feed	Cut-off behaviour, feeder overrun, product pulsing and response near target weight.	This determines whether the target can be approached repeatably.
Weigh settle	Vibration, airflow, product bounce and load-cell stabilisation time.	An unstable reading can create false accuracy expectations.
Discharge	Clean release, stringing, product impact, dust escape and pack-mouth capture.	A correct weight still fails if product is lost or damages the pack.
Finished pack	Accepted weights, rejects, pack appearance and sealing or closure readiness.	The finished pack is the evidence that matters in production.

How much product should be sent for a useful test?

Send enough product to run consecutive fills at the proposed target weight, including start-up, adjustment and repeated acceptance checks. A handful of product is normally useful for inspection only; it is not enough to prove production behaviour.

The best sample is packed as it will arrive in production, with the intended bag, pouch, jar, tub or carton also supplied.

What should be recorded during the flow test?

Record target weight, mean accepted fill weight, low and high readings, obvious outliers, refill points, feeder settings, pack format and any observed product damage or dust loss. Photographs or video of the product path can help later discussion.

What happens if the product does not flow consistently?

The test should identify the cause before the machine route is fixed. Possible responses include a different feeder style, hopper geometry change, agitator, dust-control provision, altered refill method, lower drop height or a different pack presentation.

Plan the full product trial and FAT Compare accuracy evidence Send product details

Send the product and pack details for a practical weigh filling route.

Include the product, target weight, pack format, target output, sample availability and any existing line equipment. Lancing can then advise which weighing route is worth testing.

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