Choose a reject system from the product first: its weight, dimensions, stability, fragility and surface. Then check maximum rate, belt speed, minimum pitch, reject direction, available space, inspection output, hygiene level and the required fail-safe response. Product trials are the safest way to confirm the final mechanism.
Application engineering
Which conveyor reject method should you choose?
Air blast is typically considered for light products that can be moved cleanly by a timed jet. Pneumatic pushers suit many rigid, stable packs with adequate spacing. Drop flaps provide a compact downward route, and retracting belts can give gentle, controlled removal for unstable or delicate products.
Swing arms and lane diverters are useful where larger packs, cases or classified products need a longer routing movement. None of these descriptions replaces product testing: pack friction, centre of gravity, guide-rail contact and the behaviour of adjacent products can change the result.
The reject mechanism is only one part of the system. Product tracking, independent confirmation, guarded access, lockable containment, bin-present and full-bin monitoring, low-air detection and the agreed fault response determine how much assurance the complete station provides.
Key application considerations
- Air blast: light, fast-moving packs
- Pusher: stable rigid products
- Drop flap: compact downward removal
- Retracting belt: gentle controlled rejection
- Swing arm: larger packs and cases
- Lane divert: reject, rework or classification