At the packaging trade fair Interpack 2017, the seed treatment engineers of Bayer’s SeedGrowth team saw the Schütz Impeller and were impressed. The single-use impeller, which is integrated in the IBC, makes handling the treatment agent much easier. “These formulations often separate, especially with large quantities. The seed dressing agent may settle if it is left to stand for prolonged periods. This means that the agent needs to be mixed and homogenised before processing, which is a complex process in an IBC with a volume of 1,000 liters”, says Norbert de Baey, seed treatment engineer at Bayer. Until now, special pumps were used for this purpose. The packaging always had to be opened and the pump inserted, which in many respects was a physically arduous task for the operators. In addition, it was almost impossible to avoid the exterior of the container becoming soiled, even if the greatest care was taken. This presented the risk of direct contact with the treatment fluid.
In contrast, IBCs with the integrated Impeller developed by Schütz can remain closed throughout the entire supply chain, from filling to discharge, and still allow the filling products to be stirred conveniently and effectively. The system is available for all 1,000 and 1,250 litre Ecobulk types with DN 150 and DN 225 filling openings. “This new development seemed to be perfect for our seed treatment agents – a simple, flexible and cost-effective design”, was de Baey’s initial assessment after the trade fair. In October 2017, Bayer, together with Schütz, subjected the Impeller to a stirring test on the premises of the seed treatment producer Klamroth-Börnecke in Saxony-Anhalt.
Stirring things up – for perfectly treated seeds
The single-use stirrer is connected to the screw cap of the IBC and is pre-inserted at the factory. While the IBC is being filled the Impeller is either briefly removed or remains in place, depending on the filling process and container configuration. To stir the contents a conventional stirrer drive can be used without the need for conversion or modification. The drive is placed above the cap and is fixed in place on the steel cage with the aid of a frame. The drive shaft locks into the bung of the screw cap which transmits the rotation to the Impeller inside the container. The Impeller has movable wings which change their position depending on the centrifugal force. The speed is individually adapted to the filling level. As the speed decreases, the wings sink, ensuring optimum stirring results even with smaller residual quantities.
Identical distribution – sedimentation is avoided
A visual test in the field showed that the dressing was homogeneously mixed, without any foam forming. The experts then examined the active ingredient content and its distribution by taking samples of the contents from the bottom, centre and top areas of the container. They compared these samples in the laboratory with samples taken before the stirring process. The results showed that the usual sedimentation of the heavy active substances could no longer be detected after stirring with the integrated Impeller. All substances were identically distributed at all levels in the dressing and the fluid was completely homogenised.
“We are extremely satisfied with this test. The Schütz Impeller ensures even mixing and uniform concentration of the active ingredients, allowing the seeds to be optimally coated with the dressing agent. Another benefit is that potential contact with the dressing agent is reduced for users, which is an important contribution to the safety of our customers in everyday use”, said de Baey, summing up the positive findings. Based on this test result, Bayer converted the packaging of its premium grain dressing agent products in Germany to Schütz’s IBC plus Impeller system in 2018.
Further advantages – from costs to environmental protection
The use of the Impeller as a disposable system also means that the risk of the dressing agent becoming contaminated by residues of the filling product is minimised. The immersion of the pumps used up until to now already represents a potential risk. The Impeller also eliminates costly cleaning processes and all similar costs. The entire component is made of HDPE; empty IBCs, including the Impellers, are collected by the Schütz Ticket Service; during reconditioning the inner bottle and the Impeller are processed to make HDPE recyclate. The recovered material is reused in an environmentally friendly way in Schütz products, for example to make plastic pallets.