Pack tracking
Make sure the controller knows which pack produced the measurement and where that pack is when the reject device fires.
Guide
How should underweight or overweight packs be rejected and reworked?
Reject handling should be designed before the line is ordered, because the checkweigher decision is only useful if the wrong pack is removed reliably, identified clearly and handled under an agreed rework procedure.
Buyer guidance
The reject device must remove the correct pack.
A reject system has to match the pack type, line speed, conveyor spacing and product risk. The best checkweigher result is wasted if the wrong pouch, bag or container reaches the reject bin.
Reject confirmation
Where risk justifies it, use sensors or bin confirmation to prove the rejected pack actually left the good-product stream.
Safe rework path
Decide whether rejected product can be reworked, checked manually, quarantined or scrapped.
Line response
Agree whether repeated failures warn the operator, stop the line or trigger a controlled investigation.
Quality records
What information helps investigate rejects?
Rejects are useful process information. Recording only the number of rejects may not show whether the issue is overfill, underfill, unstable tare, sealer disturbance or a product-flow problem.
| Record | Why it matters |
|---|---|
| Pack weight and limit band | Shows whether rejects are just outside tolerance or far outside the expected process. |
| Recipe and target weight | Links the event to a specific product and setup. |
| Time and operator action | Helps separate start-up adjustment from sustained process drift. |
| Reject reason or zone | Supports investigation of underweight, overweight, metal-detected or missing-pack events. |
| Disposition | Shows whether product was rechecked, reworked, quarantined or discarded. |
Buyer guidance
Questions buyers ask about reject handling.
Reject handling is often specified too late. These questions should be answered while line layout and controls are still flexible.
Can a reject bin just be open beside the conveyor?
An open bin may be acceptable for some low-risk applications, but many production environments need controlled access, clear labelling and a defined rework or quarantine procedure. The correct approach depends on the product and site quality system.
Should overweight packs be rejected?
Overweight packs may represent giveaway, pack damage, wrong tare or product clumping. Whether they are reworked depends on the product, pack and quality policy. Even when saleable, overweight data should be used to improve the filler setting.
Can checkweigher feedback automatically change the filler?
Feedback can be useful when it is bounded and based on enough finished-pack data. It should not chase every individual pack because normal product variation can lead to unstable target adjustments.
Related support
Related weigh filling guides.
Use these pages to connect this decision with machine route, samples, accuracy and support.
Send product, pack and output details.
Include the product, target weight, pack format, available space, existing equipment and any samples or drawings. Lancing can then advise which weigh filling route is worth testing.