Quality is the number 1 key to success

The Bavarian dairy products and fruit juice producer Gropper is committed to quality  
– not only of the products that they produce and bottle themselves.  
When selecting their partners and suppliers the company also sets high quality requirements. They rely on Leuze electronic for the secure monitoring of dangerous processes. The manufacturer of optical sensors offers an economical and space-saving safety solution here, which keeps with the stipulated machinery directive requirements. 

Quality without compromise
Gropper, Bissingen plant

Gropper is synonymous with top quality - and this is guaranteed by the company, as it makes no compromises with its products and processes in the cold chain. The result: Highest standards and continuous monitoring, which are based on one hand on the food industry's hygiene requirements - but on the other hand are imposed by Gropper itself, especially regarding the selection of its suppliers. In this instance Gropper relies on quality and years of experience. "In addition to the quality of the products and components used, the most important criteria when choosing a partner are a high level of system availability, a high degree of flexibility, and qualitative sound advice and problem-solving expertise, should a problem arise", states Stefan Malechowsky, manager for bottling and packaging system configuration, for Gropper in Bissingen, Bavaria. 

Individual solutions for versatile requirements 

Gropper produces milk and direct fruit juice products, which are distributed by a wide range of different European trading companies. Gropper also mixes milk, fruit juice products and smoothies according to different recipes and bottles them at plants in Bissingen and Stockach. "The greater the requirements and recipes vary in the mixing and bottling processes, the more they differ with regard to packaging, film wrapping and storage", says Stefan Malechowsky. Individual plies or even whole euro pallets of different products are left an average of 24 to 28 hours in high-bay warehouses, which are cooled to six degrees, before they can be loaded onto freight trucks.

From filling to palletizing
Guarding the palletizer

Numerous conveying belts guide the freshly filled yoghurts, puddings, shakes and smoothies in the direction of the palletizer system. The products have diverse shapes and sizes, are packaged individually in plastic or paper cups, smaller or larger bottles. The conveying belts are illuminated in red - Leuze electronic sensors monitor the position and the sequence of the approaching products. The situation becomes more critical at the palletizer, which groups the individual products and puts them into position. Due to the risk of crushing, each of the four palletizers, which are enclosed by safety fences, is protected by two Leuze MLC protective sensors to protect employees working in this area from the dangerous movement of the palletizer. "Personnel protection has to be guaranteed at all times. Nevertheless, safety technology has to be economical enough so that it does not slow down or even restrict the production processes – the workflow should only be interrupted and consequently the system brought to a standstill in case of emergency", says Stefan Dicker, project manager for IDH. He has a detailed knowledge of the system and recently put the new film wrapper from Tosa 124  into operation on site.

From palletizing to pallet safeguarding

Gropper had a positive experience in its second plant in Stockach with the pallet wrapping machine Tosa 126 from the Italian manufacturer of the same name, which only requires 30 seconds for the film wrapping procedure including transit time for in and outflow. As the freshly packed products are colder than the ambient temperature and would consequently "sweat" the euro pallet is not completely wrapped, either only the upper layer is partly wrapped in film or a banderole is laid over the entire pallet. In this way the unstable load can be stabilized and secured on the pallet, and at the same time, the products have enough air to breathe. The objective is also to achieve a high level of transport stability while keeping the costs for load securing as low as possible. A fully automated lacing device ensures that the pallet is highly stable by connecting the pallet with the products. The outer packaging is applied to the entire euro pallet in a second step, shortly before the products leave the high-bay warehouse and are loaded onto the truck.

Twofold problem for safety technology

The film wrapper and the subsequent outflow are secured using protective sensors from Leuze electronic. The special feature of this application is that the actual specified minimum in and outflow of 2.20 m before and after the wrapper is not existent, but only half of the stipulated space is available. In addition, immediately afterwards it is necessary to secure a turning movement in the conveying belt. Both these aspects place specific demands on the safety technology to be used at Gropper and IDH's safety concept. However, CE conformity is still attained using the Leuze photoelectric sensors with a resolution of 14 mm at simultaneous machine speed reduction and enclosure extension when crossing the conveying belt. Leuze electronic and IDH have tackled the common problem of nonexistent space for the actual specified minimum in and outflow flexibly and creatively: "With a space-saving muting solution, which results in the use of only two photoelectric sensors instead of four", explains Frank Wüster, technical sales manager for Leuze electronic. An efficient solution was also found for the scissor movement of the conveying belt: The turning movement is monitored by the binary switching sensors from the PRK 46B series, ensuring that the pallets can run smoothly directly into the refrigerated shelf warehouse or are transported directly to dispatch, where the truck is waiting to be loaded. 

On the way to the refrigerated warehouse or to direct dispatch
Height compensation before entering the refrigerated warehouse

Even before entering the high-bay warehouse (cooled to six degrees) or direct dispatch there is another challenge for Gropper: the filling area and the refrigerated warehouse are not on the same spatial level, that means: a height difference needs to be overcome. For each partially film-wrapped pallet a height difference of approximately one meter has to be compensated. Another film wrapper was recently installed directly in front of the entrance to the refrigerated warehouse or direct dispatch. This wrapper also provides Gropper with the highest level of availability and flexibility. Banderoles and partial wrapping of the storage products can be attached to the load at every height and selectable width, in addition to the products being wrapped as an entire pallet for dispatch. In addition to the quality and a long life expectancy of the Leuze sensors, Stefan Malechowsky specifically prioritized the flexibility and creativity in the solution of the concrete safety-related application requirements. "And if a problem should arise and the system comes to a standstill, Leuze electronic is only roughly a one-hour drive away and quick and flexible help is at hand." With its Smart Sensor Business 4.0, Leuze electronic promises its clients in-depth application expertise, in addition to simple use of its products and in particular: smart customer service, 24 hours a day, 7 days a week, worldwide. With a reliable Partner like IDH, who proficiently put the system into operation and maintain it on site, this is a safe solution for all involved in the project. 

About the companies 


The Gropper dairy was founded in 1929 in Berg near Donauwörth, Germany. The company headquarters has been in Bissingen since 1973. Today the company ranks as one of the leading German providers selling trademark products. Meanwhile, the company's clients include almost all major European trading companies. The company's core business, in addition to the production of trademark products, is co-packing for branded goods companies and the manufacture of products for the Gropper brand. The dairy specialist's product range spans from milk and milk drinks to yoghurt, puddings and other desserts through to coffee milk mixes, cooled direct juices and smoothies. Today, Gropper employs over 720 staff members at their sites in Bissingen and Stockach (Germany).  


IDH - Industrieautomation Dirk Hähner 

Founded in 2001, the company Industrieautomation Dirk Hähner (IDH) began its still quite short company history as a service provider for programming and service work on behalf of renowned production plants and machine manufacturers. Continuous project support from the planning stage to assembly and initial operation of complex industrial systems is one of IDH's core competences, in addition to control and switchgear construction. 



Leuze electronic is one of the world's innovation leaders in optical sensors and is internationally known as a leading manufacturer and solution provider in electrical automation. Its main focus is on the areas of intralogistics, packaging industry, tool manufacturing and automotive industry as well as medical technology. The product range includes switching and measuring sensors, identification systems, solutions for image processing and data transmission and also occupational safety components and systems. Founded in 1963, the company, based in Owen (Germany), possesses specific application know-how as well as comprehensive industry knowledge. More than 1000 employees at 22 locations are involved in development, production, sales and service – supported by more than 40 sales partners around the world. Innovative product developments, tailor-made complete solutions and an extensive range of services stand for the "Smart Sensor Business 4.0" at Leuze electronic.