Automated packaging line eases transition from bulk to bag

Gandl Natursteine is one of the most notable suppliers and processors of natural stones in Bavaria. To offer colored pebble stones in bags and not as bulk material, the company installed a new automated packaging and palletizing system.

“Until now, the colored stones were offered merely as bulk material,” says company founder Rainer Gandl. “However, the intention was to package them, and therefore we needed a completely new packaging line.”

After they are cleaned and sorted, a conveying system leads stones to the packaging system (Beumer, beumergroup.com) where they are filled in plastic bags that are then welded. An articulated robot stacks the bags quickly and gently. “The system palletizes bags very reliably and efficiently and does so in a very small footprint,” Gandl says.

The system palletizes 200 to 400 bags per hour, depending on package size and packing pattern, and several packages can be gripped and moved at the same time. The system is also flexible, managing processes with varying basic parameters. The robot is also freely movable on a guide rail. “The four-axis path computer is user-friendly and can be adapted flexibly to various conditions of use,” Gandl says. “The user does not need any robot-specific knowledge and can easily switch the robot to handle other sizes or materials with the push of a button or automatically by bar code identification.”

The robot’s gripper uses a special combined tool consisting of a fork gripper for bags and a pallet-gripping device. The approach saves space and does not require a pallet separator. It is possible to deposit up to 10 pallets in the empty pallet depot. The robot moves over the stack, opens the pallet gripping devices, takes the pallet, drives with the pallets over a roller conveyor and deposits the pallet. A take-away roller conveyor then transports the bags to the palletizer.

An ultrasonic system provides accurate measure of the stacking height, making it possible to calculate the exact placing position of the packaged goods, ensuring stability during shipping and storage as well as effective integration into the automatic stretch wrapper. “Approximately 36 pallets per day are completed, enabling a more rapid delivery to customers,” Gandl says.