“With the new solution, we have significantly shorter changeover times – we now only need a quarter of the time compared to before.” Ralf Heckwolf, Project Manager, Unilever Ralf Heckwolf was the project lead for modernization of the ice cream line. The aim was to implement a machine solution in the new end-of-line area, i.e. the section of the line where the ice cream is packaged, that allows various product formats to be flexibly packaged, from normal 650 ml size to 1,000 ml XXL packs. In addition, the Königsrolle ice cream novelty is also packaged on the line, in a quantity of 1,000 ml. For this purpose, the ice cream products are first packageinto a film bag and then in the product carton before they are collated for shipping. Production times and quantities are planned as required. The machines must therefore be easy to adjust to different products. Especially for the first packaging step, this means that not only different products, but also different quantities of product must be fed into the machine synchronously – a task that Unilever entrusted to Schreyer Sondermaschinen GmbH. “We have already successfully implemented a number of projects with Schreyer here at the site, which is why the company was our partner of choice for this project as well,” continues Heckwolf.
Changeover in just a quarter of the time
For Julian Schreyer, the mechanical engineer who was in charge of the project at Schreyer, this meant translating an extensive list of requirements into a new machine solution: “On the one hand, there was the demand to drive different sizes at a much higher speed of up to 150 products per minute, and on the other hand, we’re in the food sector here, which means that the design must be hygienic. And then the machine should be as easy as possible to handle for operators and maintenance.” To meet these requirements, the Schreyer project team has come up with a number of ideas, including a completely contactless laser controlled infeed of products into the machine. This prevents the individual ice cream portions from jamming up and sticking together. The film for packaging the ice cream portions is fed in via a double magazine so that the material can be changed with minimum production interruption. The cross-sealing unit used to seal the film bags can also be removed from the machine for maintenance in just a few simple steps. The result is impressive, confirms Ralf Heckwolf: “With the new solution, changeover times are significantly shorter – we are now four times faster than before!”
Saving time with the digital twin
For testing purposes, Schreyer used the same data from the control program created in the TIA Portal. While the SIMIT simulation software stores the behavior model of the machine, the mechanical model of the plant was created with the NX MCD Mechatronics Concept Designer. With PLCSIM Advanced, the automation program is tested with a virtual controller. All models can be easily linked together thanks to the seamless integration of simulation tools, thus creating a digital image of the machine. “The simulation allowed us to identify many potential fault causes and fix problems in advance. What was particularly helpful was that we were able to test all variants of the product flow on the model – this is simply not possible manually on the machine. This not only allows us to deliver a much more sophisticated solution, we can also make commissioning significantly easier and more efficient. Overall, we had almost twice as much time to complete and tune the machine.”
Author Name: Grzonka, Holger
Division: Digital Industries Factory Automation Production Machines for FA
