Robotic case packers for Aussie bakery products

André Spoor, Project Engineer for Arnott's, explains that the requirement was to move from manual case packing to automated case packing as well as to change the type of secondary packaging, while guaranteeing a quick start-up in production on four lines simultaneously. He also adds that the solution needed to protect the integrity of the products and offer flexibility to accommodate frequent format changeovers and exponential increases in speed. Cermex, a specialist in secondary packaging and the provider of the Arnott’s solution, consequently worked on two main areas to meet this challenge: innovative project management and original technical solutions.

Two package types were involved: rectangular or pyramid-shaped cartons and flow-packed plastic trays of round biscuits. The project's first challenge involved controlling product conveying and collation while preventing the flowpacks from rotating. The second challenge resided in protecting the product integrity with the capacity to implement gripping systems adapted to 58 different SKU's packed into 32 different case sizes and formats. The third challenge stemmed from Arnott's choice to change secondary packaging (from RSC to wrap around blanks) at the same time as the lines were automated. Speed was the fourth challenge, with a requirement for 12.5 cases per minute and a maximum pack speed of 175 packets per minute. Quick and easy format changeovers were also stipulated in the requirements. The two most crucial aspects, says Spoor, were "The large number of SKUs and the fact that we previously packed our product in RSCs, and these all had to be changed to wrap around cases as part of the project."

Quick integration of the four machines at Arnott's production site and immediate reliability were also essential. "The project required that we install four machines back to back concurrently on our four main production lines,” says Spoor. “Three of the lines have no buffer system prior to the case packer, so once installed any downtime on the case packers would have a significant impact on the site's efficiency."

Cermex installed three identical multi-function WB45 wrap around case packers and one traditional wrap around case packer for a slower line. An early key idea was to integrate two robots per machine in order to guarantee operation at the required speed and optimum machine life span. Each robot runs at a reduced nominal speed so that the products aren’t subject to frequent accelerations and decelerations. Cermex chose robots manufactured by Fanuc , well known in Australia, particularly due to its strong presence in the car industry.

The second key idea consisted of transferring the products 90° onto a collation table by a small Pick & Place module, in order to prevent the flow-packs from rotating. The table is made up of front and rear servo-driven brackets to support the batch.

Robotic gripping and loading encompassed the third key idea. Loading is started by robot 1 and finished by robot 2, with smooth movements so that loading can be carried out without using a funnel.

Product integrity is ensured by the gripping tooling. The heads are composed of 30 to 50 mini suction cups, so as to constantly maintain the vacuum gripping even if one of the suction cups loses its adherence with the product. This is very important for flow-packs, as gripping film is tricky.

Robotics contributed to simplifying the solution and reducing the number of parts and adjustments so that the Cermex WB45 could fully meet Arnott's requirements. Specifying robot tooling common to several formats, for example, helps to significantly reduce the changeover time to 25 minutes maximum.

The absence of multi-lane guides on the product infeed also reduces setting requirements. Furthermore, the robot heads all weigh less than a kilo; a reduced mass which considerably facilitates changeover.

For Arnott’s, there is no doubt that flexibility is a key factor of success. Spoor puts it this way: "Our company is continually looking to develop new products. The ease of setting up new products ourselves with minimal requirements for new change parts and the flexibility in the machine to pack different case formats is important. It was for this reason that we chose a robotic solution for three of the four case packers."

In addition to the existing Cermex installed base in Australia, the permanent presence of a team of engineers from Cermex Sales & Services in Bangkok, the Cermex local representative in Sydney and the support given directly from Cermex France created the intimacy that was necessary to successfully complete this project that was ambitious both in terms of technical solution and lead time. Cermex contract management was perfectly adapted to the context:

• in its capacity to smoothly integrate the changes in technical data which intervened throughout the project

• thanks to mutual collaboration: joint design and optimisation

• by routine vigilance in meeting lead times and production constraints.

An important factor was that Cermex chose to push the machine trial phases to their maximum by testing all the formats at the factory in Corcelles-lès-Citeaux (France). Fine-tuning could consequently be carried out in order to eliminate hitches during start-up in production at the customer's site. This was evident to Spoor: "Cermex was willing to listen and to respond to the needs on our site and to adapt the machine solution to changes within our business throughout the design, build, install, and commissioning of the machines," says Spoor. "This project was a significant challenge for the site that required much cooperation and patience from our operators and a high level of flexibility from the Cermex commissioning engineers. We are proud that the team found a way to deliver on that challenge and work together through a significant period of increased activity and stress that was placed on the site".

In accordance with the requirement formulated by Arnott's from the beginning, Cermex delivered, installed, and commissioned four machines. Together, Arnott’s and Cermex devised an install and commissioning methodology that allowed hand packing production to continue throughout the integration of the case packers on Arnott’s site.

Spoor sums up the ambitious project this way: "All projects have a finite life, whereas maintaining and operating a machine is an ongoing event that continues for the complete life of the machine. During the project we were well supported by Cermex. As we look to maintain and further develop the machine capabilities for new products in the future, it has been pleasing to see that this support has not diminished after the commissioning and sign off of the machines."