A palletizer is a precision machine fed by a conveyor that is often designed as an afterthought. If the carton arrives rotated, too close or at the wrong height, the palletizer either stops or builds a pallet that leans.
Key takeaways
- Define the carton orientation before the conveyor layout.
- Accumulate before the palletizer to decouple it from the packaging line.
- Control the gap and the speed at the infeed.
- Match the conveyor height to the palletizer infeed, not the other way round.
Carton orientation
The palletizer expects the carton in a specific orientation. If the packaging line produces cartons in a different orientation, the conveyor needs a turning section. A turn table or a right-angle transfer can rotate the carton, but it adds a jam point and takes space.
It is usually better to orient the carton at the case packer and keep it in the same orientation to the palletizer. A straight conveyor with a guide rail is simpler and more reliable than a turning section.
Accumulation
The palletizer stops for pallet changes, wrap cycles and fault clearing. Without accumulation, those stops propagate back to the packaging line and reduce output. A buffer of 10–30 cartons is typical, depending on the palletizer cycle and the line rate.
The accumulation conveyor should be controlled by zones, not by back-pressure. Cartons that are pushed together can be damaged, and the palletizer may receive them with no gap.
| Interface element | Typical requirement | Why |
|---|---|---|
| Conveyor height | Match palletizer infeed | Avoid a step or a ramp |
| Carton gap | 50–150 mm | Palletizer pick timing |
| Accumulation | 10–30 cartons | Cover pallet changes |
| Orientation | Fixed, per pattern | Pattern accuracy |
| Guide rails | Adjustable | Carton size change |
Height and transfer
The conveyor should deliver the carton at the palletizer infeed height, with a level transition. A step of even 5 mm can cause the carton to catch and the palletizer to fault. Use a transfer plate or a nose bar, and check the height with a straight edge.
If the packaging line is lower than the palletizer, use an incline conveyor with a transition that does not tip the carton. The incline angle should be low enough that the carton does not slide back.
Pallet pattern and stacking
The pallet pattern determines the carton orientation and the number per layer. A pattern that is efficient on the pallet may be difficult for the palletizer to build, especially with a layer pick. Check the pattern with the palletizer supplier before the conveyor is designed.
For a manual palletizer, the operator should not have to lift above shoulder height. Provide a lift table or a pallet positioner so the working height stays constant as the pallet builds.
Safety and access
The palletizer infeed is a pinch point. Guard the conveyor and the transfer, and provide an emergency stop within reach of the operator. Leave access for clearing jams without climbing over the conveyor.
If the palletizer is robot-based, the robot cell needs a safety fence and an interlocked door. The conveyor should stop when the door is opened.
Frequently asked questions
Can I use a gravity conveyor before the palletizer?
Only if the palletizer can handle the variation in speed and gap. Most palletizers need a powered, controlled infeed.
How much accumulation is enough?
Enough to cover a pallet change and a wrap cycle, typically 10–30 cartons. More accumulation adds floor space without improving the palletizer.
What if the carton size changes?
Use adjustable guide rails and a palletizer recipe for each carton size. The conveyor should be designed for the largest carton and adjusted for the smallest.
Send your carton sizes and pallet pattern to our engineers through the contact page; we will design the interface conveyor with the palletizer.
