Rightly or wrongly, plastic is currently getting a bad name among consumers. UFA AG, a Swiss manufacturer of compound animal feed stock, mineral salts, and milk powder, had long ago investigated how to avoid plastic when palletizing their feed sacks. Back in 2008, the company opted for the AntiSlip Gluing solution ysubng Robatech hot melt glue applicators, a system that would glue feed sack stacks on top of one another on a pallet for transport, rather than require stretch wrap for stabilization.
But in 2018, when a new bagging system was purchased for a specialty plant in Sursee, Switzerland, the glue-based palletizing process was put to the test. Upstream updates increased throughput in such a way that raised the possible pallet stack height.
New challenges
“With the new bagging system, we have been able to increase from eight to ten layers. That is a logistical advantage,” says Urs Steiner Head of Production, UFA Sursee. “However, not only did the gravity-controlled pallet rack have to be modified, but the existing adhesive application process had to be adapted as well. In the past, we just glued on one side. That worked well. But with the increase to ten layers per pallet, we had to increase the stability.”
Watch a brief video about the application by clicking here.
Steiner had an open mind with the new system and explored all his options. But when he inquired within the company for feedback, he found the decision was clear in favor of remaining hot melt adhesive application.
Robatech equipped the existing Concept melter with two of its next-generation AX spray heads.
“Shrink-wrapping would require more effort, space, and, assuming a throughput of 25,000 pallets per year, higher material costs. Our customers must already dispose of the feed bags. They would then still have piles of film,” Steiner says. And he knows what he is talking about. Raw material inputs of palletized ingredients that enter his plant for animal feed processing result in more than two tons of plastic film that the Sursee facility has to dispose of annually.
To achieve the taller stack and while maintaining stability, Robatech equipped the existing Concept melter with two of its next-generation AX spray heads.
“Thanks to the high backward compatibility and the modular design of the Robatech products, that was no problem at all,” Steiner says. “Beyond that, with the CoolTouch insulation on the Diamond application heads, you no longer have to burn your fingers. The energy efficiency is much better because the insulated application heads guarantee consistent adhesive temperature.”
The full packaging line
UFA AG produces feed stock in a two-step process. In the mixing plant, powdery raw materials are weighed in batch mode, mixed homogeneously, and stored in a silo. In the next step, the powdery mixture is continuously blown from above into a spray tower and free-fall enriched with hot fat, which is sprayed laterally. The cold air introduced from below creates a crystalline, flowable product.
Now, in the new bagging plant, 500 bags per hour are filled, sewn, and labeled. For subsequent palletizing, the two next gen AX-Diamond spray heads apply four hot melt spirals to the surface of the passing feed sack without contact. After that, a robot stacks layers of three sacks each on the pallet. Once two layers are stacked, a lift moves the pallet upwards and briefly presses the sacks against a press plate. This increases the adhesion between the layers, and the finished palletized stack can then be transported safely. Each layer is pressed, with the product counter of the Robatech application system ensuring that the last three sacks remain without adhesive application.
Reliable gluing quality is crucial for safe palletization and straightforward depalletization. After all, the bags should arrive at the customer undamaged and be easily removed without tearing. Finally, Urs Steiner sums up his experience with the pallet stabilization solution from Robatech: “We are very pleased with the AntiSlip Gluing solution. The process is an excellent solution for us, for our customers, and for avoiding plastic waste.”
“We aim for a high degree of automation,” says Steiner. “Malfunctions cause extra work. We have many systems, and they all have to run without interruption. Our philosophy is not to look for the cheapest, but the most reliable solution. There is no unscheduled downtime with Robatech devices. If there is a problem, it is not relevant, or the service technician is available immediately. We are very pleased.”
