A bag palletizer can be either an in-line palletizer or a
robotic palletizer. There are advantages to either type of
system. An in-line palletizer might yield a higher
stacking rate, while a robotic system would be more flexible in
changing layer patterns, i.e., product types. A robotic
palletizer would also have the advantage of taking up less
space.
In
general a robotic bag palletizer will be able to achieve rates
up to 10 to 12 bags per minute on a single bag pickup. If
2 or 3 bags can be picked up simultaneously, stacking rates will
go up proportionately.
Depending
upon the type of bag to be picked up, various gripping
mechanisms can be used. The "finger" grip type
of end effector, shown above, is good for more rugged
bags. While more delicate bags might require a supported
bottom and a slightly slower rate, as show below.
A simple
bagging cell might look something like the figure
shown below. A conveyor system brings the bags
to be stacked into the cell, the robot control
distinguishes which pallet the bag is to be stacked
on, the robot then stacks the bag on the appropriate
pallet. In this particular case, the customer
had both 40 pound bags and 50 pound bags entering
the robot cell on the same conveyor. When the
robot completes a pallet, an indicator light comes
on and a forktruck driver picks up the completed
pallet and puts in an empty pallet.
Another
system might be a little more complex. Empty
pallets get fed into the cell on a conveyor and
completed pallets get taken away, and ultimately get
transported out of the robot cell and to the next
piece of process equipment, such as a stretch wrap
machine.
In
general a robotic bag palletizer will be able to achieve rates
up to 10 to 12 bags per minute on a single bag pickup. If
2 or 3 bags can be picked up simultaneously, stacking rates will
go up proportionately.
