The old bag gripper no longer provided the necessary performance. A visit to another company brought a new gripper solution to the company's attention. The solution was characterized by the fact that no one had to be directly present and employees were therefore available for other tasks.

In order to be sufficiently equipped for the upcoming winter season, Sapho decided to invest in a new gripper. "The impetus was that we wanted to get more performance out of the machine and pack the pallets cleaner and more dimensionally stable. Piab's technology, expertise and service convinced us after we had looked at several manufacturers. With the current combination of robot and gripper, we are more efficient," says Uwe Grundstein, Technical Manager at Sapho.

As part of the acquisition of SAS-Automation, Piab has had robust hybrid bag grippers in its range since November 2017, which are designed precisely for payloads of up to 50 kg. They are therefore suitable for handling road salt bags weighing 10, 25 and 50 kg. The hybrid gripper, which is attached to a robot arm, removes the sacks and bags from a roller conveyor on which they have been placed after filling. It reaches over the bags from above, moves the forks on both sides between the rollers of the belt and picks up the bag from the underside. As a result, the bag rests on the solid gripper fingers during the movement. To ensure that the hybrid bag gripper fits the system exactly and, in particular, the roller conveyor used, the distance between the forks was customized.

"In this way, we were able to use a standard product and adapt it to the customer's needs with just a few changes. This has advantages for the customer in terms of delivery time and costs compared to a completely customized solution," says Roland Singer, Team Leader Vacuum Automation & Robotic Gripping Division at Piab. When the bags are deposited, the gripper fingers open first and only then do the integrated cover plates open. This keeps the bags in shape during depositing and stacks them firmly and dimensionally stable on the pallets. Grundstein explains: "We fill big bags, PE sacks, bags and buckets from our loose warehouse fully automatically on more than ten systems. That corresponds to 800 to 1000 pallets a day.

The palletizing of the bags in particular had to run at significantly lower cycle times than before in order to increase the productivity of the overall process. With the new hybrid bag gripper and a slight process optimization, we can now palletize 9 bags per minute compared to 6 bags with the old system. This corresponds to up to 16 more pallets per day and therefore more than half a truck load. What's more, the process now runs smoothly and without damaging the bags."

"Our employees are also relieved even more. This is because the automatic layer pad handling integrated into the gripper eliminates the need to bend down and manually place a cardboard layer pad on each pallet when palletizing the 10 kg bags. This is easy on the back and has the advantage for us that the employee can focus on other tasks. It also eliminates the need to intervene in the automated process," adds Manuel Bender, Deputy Head of the Filling Solids Department.

"We used the summer break to convert the system so that it is now ready for winter business. The installation was very easy and smooth - basically like plug & play. Thanks to the support during the installation and additional advice from Piab employees, we were able to further optimize the use of the gripper and thus fully exploit all its possibilities," Grundstein continues.

The Piab range of robust bag grippers is ideal for palletizing plastic, woven or paper bags containing grains, chemicals, dog food, minerals and many other products. In addition to the adjustable hybrid bag grippers, Piab also offers static bag grippers. Both types are designed for payloads of 25 and 50 kg. They eliminate the need for expensive customized tools and can usually be adjusted in under five minutes. They consist of secure, solid stainless steel gripper fingers. The cover plates are used for precise and tight positioning of the bags on the pallet. Both gripper types can be optionally equipped with suction cups for placing intermediate layers or pallet hooks.

Andrea Bodenhagen, Marketing Director Europe , Piab