Giving Chocolate its Crunch

When sales of a popular product are constrained by production limitations, it’s time to take a good look at the manufacturing systems. Mars Austria found itself in that situation with the Mars Delight candy bar product family. In response, the company effectively doubled production by implementing a new production line that integrates advanced automation technology with intelligent proces...

06/01/2008


When sales of a popular product are constrained by production limitations, it’s time to take a good look at the manufacturing systems. Mars Austria found itself in that situation with the Mars Delight candy bar product family. In response, the company effectively doubled production by implementing a new production line that integrates advanced automation technology with intelligent process control.

A subsidiary of the global Mars group, Mars Austria is based in Breitenbrunn, southeast of Vienna, in the country’s eastern Burgenland region. Here it heads up production of well-known brands like Mars Delight, Amicelli, and Milky Way Crispy Rolls for European and Middle Eastern markets.

The manufacturing systems have an annual production volume of more than 20,000 tons, making Breitenbrunn the Mars group’s competency center for wafer products. Indeed, Mars Austria has been honored with several awards for its strength in innovation and for being the most family-friendly employer in the region.

Secret’s in the wafers

The secret of the Mars Delight chocolate bar lies in the composition of its wafer, which is not only unique, it also makes a decisive contribution to the product’s huge sales success. The details of the techniques used for its production, like preprocessing, precise ingredient measurement, heat treatment in special oven segments and further processing are, of course, carefully guarded trade secrets.

For the most part, Mars Austria has not adopted standardized process technologies — and that can make automation challenging. But finding itself needing to increase production to keep up with market demand, the company approached Rockwell Automation to help design and construct a new Mars Delight production line. As part of the contract, Rockwell was required to plan all the hardware and software details of the project from start to finish, and implement them in accordance with Mars’ stringent requirements.

Alongside Thomas Winkler, a technical consultant at Rockwell Automation Austria, the project partners included the Rockwell Automation Service Team and two locally based companies. The engineering side of the project was driven by a particularly ambitious timeframe, with a period of only six months between releasing the order and initial start-up of the production system.

The project partners needed to keep to this schedule while ensuring that Mars’ production could be run at maximum capacity with a minimum of maintenance effort. As a result, they used solutions based on Integrated Architecture, Rockwell Automation’s scalable control and information platform.

The goal of this high-performance, integrated control environment was to monitor the exact status of all system components — such as servo drives, I/O, and HMIs — at all times. To reach this goal, engineering specialists were involved in planning right from the start, and were able to tailor the system architecture to fit production tasks. In addition, all requirements relating to speed and quality were directly incorporated into the system design at an early stage.

Meeting tough process demands

In addition to fulfilling the requirements for managing sanitation, recipes, and traceability, the new system must also meet target production cycle times. The complete solution, designed for maximum productivity, comprises a fully integrated environment with high-performance control and servo technology, EtherNet/IP-based fiber optic communications (SERCOS) and DeviceNet to connect peripherals.

Mars Austria selected an Allen-Bradley ControlLogix control platform with three processors. This system combines sequential control, motion applications and process control in a single platform. Powerful and compact drive modules for the servo axes (decentralized Kinetix high-power servo drives connected via the SERCOS interface) were chosen for this multi-axis application.

“One of the many advantages of the implemented solution is its routing capability,” notes Robert Heidenbauer, key account manager at Rockwell Automation Austria. “This enables the customer to directly access technical data on parts of the machine, such as ac drives, from anywhere on the enterprise network.” As a result, time-consuming physical visits to the machine to set parameters are no longer necessary, and the staff has a clear overview of the whole system.

60 servo axes, 1,800 I/Os

The potential for engineering cost savings became clear once the planning phase had been completed. During engineering, the programming software RSLogix 5000 was used as the common development tool for PLC and motion applications. In the final implementation, the overall design allows 60 servo axes to operate as needed and deliver detailed information about their current status at any time. In addition, some 1,800 digital I/Os have been implemented in the production line.

The system also includes a six-axis robot to performs handling tasks. Although this adds complexity to the conveyor equipment, it is critical to ensuring that all parts of the system interact smoothly and product samples can be taken and checked at any time. In order to guarantee a consistently high level of product quality, intelligent process technology allows the system to comply with precise procedures that regulate commands like “stop” and “restart.”

Although interruptions are rare, they can occur unexpectedly in some areas of the production system due to the physical characteristics of the primary products, such as when sugar clumps together. To mitigate this issue, the production line is structured into different areas separated by buffers, so that this type of incident is easy to resolve.

More capacity, on time

The team was able to implement a massive expansion of production capacity — in every section of the system — right on schedule. As Heidenbauer observes, “Together, we were able to successfully implement a highly ambitious and innovative project. Great communication on both sides, as well as our solution expertise, produced swift results.” With its completion last autumn, the expansion of the system in Breitenbrunn helped Mars Austria chalk up an increase in output of more than 100%.

Hannes Huszar, from Mars Austria’s Breitenbrunn factory, is now also responsible for ongoing improvements. Thinking about the scope of the project, he says, “The production system’s mechatronic structure is designed for maximum productivity and security. As a result, it corresponds to the objectives that have made our company so successful around the world. The overall design of the system enables it to restart automatically after a production stop. In everyday practice this is really useful, because it significantly reduces the amount of maintenance necessary.”



Author Information

Mike Jamieson is global director, consumer packaged goods for Rockwell Automation. Reach him at mjamieson@ra.rockwell.com .