“Moreish” with Schubert

Crailsheim . Wernli AG in Trimbach (Switzerland) currently produces no fewer than 45 different types of biscuit. Although the company already had a robot packaging plant in place, it was unable to keep pace with the ever more stringent demands, particularly in terms of flexibility. Technical manager Peter Wernli was convinced there must be a generally faster and more economical method of packaging the many different biscuit types. He found the ideal partner for the project in Gerhard Schubert GmbH.

Wernli is the biggest and best known of the Swiss biscuit manufacturers. The very sound of product names such as ‘Capucine’, ‘Truffet’, ‘Florentine‘ or ‘Gianduja‘ provides an accurate indication of the high quality products which are being manufactured here. It goes without saying that Wernli makes use of state-of-the-art machine technology to manufacture and package its baked goods. But painstaking attention to technical details is what makes that essential difference here: A machine is not just another machine - the details behind the dough machines and ovens used at Wernli are a closely guarded company secret. Just as decisive when it comes to the quality of the end product is the careful choice of the high-grade ingredients processed at Wernli. The successful outcome of a business strategy centred on quality is an annual output of 8,000 tons of baked goods in the form of four million mouth-watering biscuits which roll beautifully packaged off the production line every year at the Wernli plant in Trimbach.

And this is where the Schubert plant comes into its own: Nine robot stations with a total of 18 robot arms currently place up to 1,800 biscuits per minute in trays. In practice, the processed quantity achieved depends on the degree of production capacity utilization, meaning that on average between 80,000 and 160,000 products per hour are packaged. The machine plant achieves an overall efficiency of 98 to 99 per cent.

The machine constellation has been designed using the internationally patented counterflow system. One of its most striking features is the highly compact relative dimensions permitted by this technology of just 20 metres in length by 5.50 metres in width. This principle involves feeding the products into the machine in the opposite direction to the containers. Of the total of 18 robot arms, only two are responsible for placing the containers on the belt, while the remaining 16 arms pick the biscuits off the belt using vacuum grippers and place them precisely into the fed trays, which are located on the parallel belt.
Appreciation of fine details

The nine packaging stations operate as independent machines which are centrally coordinated by the Schubert machine control system – a concept which substantially enhances machine efficiency. Several scanners installed in the plant define the position of the biscuits on the belt. They benefit from a resolution of 0.5 mm per pixel, and prepare the relevant image data which permits the system to detect and evaluate around 4000 individual baked articles per minute. The last insertion station simultaneously fulfils a quality control function, testing whether all the biscuits are present in the tray and have been correct positioned.

The plant is operated at Wernli in two shifts, corresponding to 16 hours of operation per day. For certain periods, an employee takes care of feeding the trays, while during the rest of the time the Schubert machine robot operates without staff supervision or operation. Changing the format takes around ten minutes, although the format scope and flexibility of each tool and of the overall plant mean that a change of format is rarely required.

The Schubert TLM F44 picker line is ideally suited for operation in the food sector. As is the case at Wernli, all the components are ideally accessible, and the entire machine system provides a floor clearance of between 150 and 300 mm. Only rust-proof or plastic materials ever come into contact with the product. Filter systems for particles and fine dust ensure the functional capability of the suction cups which engage the individual biscuits. The closed switch cabinet system and the food-safe grease and lubricant types used in compliance with CE regulations all conform fully to the stringent demands of the food industry.
Sophisticated robot recipes

For the company’s technical manager Hans-Peter Wernli, one of the most defining arguments in favour of the Schubert plant was the wealth of experience and maturity behind Schubert technology. Continuously further developed over many years of hands-on practical application, this is a brand which has staked out the market leadership for itself time and time again over the years. Associated benefits include not just the high degree of operational reliability and minimal maintenance requirement of the machines, but also their modularity and flexibility. If requirements change due to shifting market conditions, setting up the plant to address these needs or upgrading it is simplicity itself. The staff at Wernli were also positive in their appraisal of the new machine plant, highlighting particularly the pick-and-place characteristics and the general operating and resetting convenience.

Wernli also underlined the positive cooperation with the Schubert project team, in particular the matter-of-fact, efficient communication between the planning, electrical and mechanical divisions, and the prompt, expert execution. The robot plant was ready within 20 weeks, with a further two weeks required for installation on site. Wernli’s response to the question of whether his expectations were realized with the Schubert plant: “They certainly were!” Hans-Peter Wernli himself refers to the “stringent demands” placed on Schubert in the execution of the project. “Despite the usual minor “teething troubles” at first, we are now really reaping the benefit of this wonderful packaging line.“

When something is pronounced “moreish” it is not only highly appetizing but leaves you wanting more – an attribute that applies in very different ways both to Wernli’s month-watering biscuits and Schubert products too.