Improving dough production


Accredited automation solutions provider, Control Freaks, has applied the latest Mitsubishi Electric PLC technology to solve production challenges and increase competitiveness for Bakkavor’s Lincolnshire based pizza production facility, as MEPCA discovered.

At its pizza factory in Holbeach St. Marks, fresh prepared food provider, Bakkavor, is enjoying the benefits of having successfully improved pizza dough base quality and consistency while at the same time reducing production costs through less maintenance and downtime.

Bakkavor’s pizza facility includes a fully automated manufacturing line extending over two floors, which turns raw materials into finished products. The basic process mixes mainly flour and water to make pizza dough which then continues to be rolled, stretched, heat treated and proved. Once the dough is ready, round pizza bases are produced.

Every single process builds on the steps before it; therefore, any issue upstream in the sequence not only influences the end result but is also difficult to correct downstream. In such a highly synchronised system, effective inter-process control becomes crucial. When the project to make improvements started, the incumbent control system on Bakkavor Pizza’s dough rolling section was over 20 years old. As a result of its age and relative obsolescence, any issues had become harder to fix over time, and production was not running at optimum efficiency.

To address these issues, the food manufacturer got in touch with its preferred system integrator, Control Freaks, which, in turn, contacted its first-line automation supplier Mitsubishi Electric.

Reverse engineering

When looking at migrating the existing control system to a new, modern set-up, Mitsubishi Electric and Control Freaks noted the presence of some programming code operating on a separate processor, or microcomputer, within the original PLC set-up. The 16-bit processor could not handle complex mathematical functions; therefore, between 30-50% of the entire dough rolling process was handled by this separate microcomputer.

To further complicate the upgrade project, there was no way to extract this code to include it in the new control system. Therefore, the automation and system integration specialists had to conduct extensive reverse engineering to figure out what functions the microcomputer controlled, how they played a role in governing the process and then re-write this code in the new infrastructure. David Hamilton, Site Engineering Manager for Bakkavor Pizza, explained: “Not only were there no diagrams to help engineers understand what the code was controlling but no member of the staff could help, as the engineers who worked on the initial set-up were all retired.”

Clint Johnson, Director at Control Freaks, added: “The absence of any documentation on the existing code within the control system made the reverse engineering operations particularly challenging. Mitsubishi Electric’s specialised teams provided extensive support, conducting crucial investigations.”

Flavoursome automation

Once the challenges associated with the microprocessor’s code were solved, Mitsubishi Electric and Control Freaks started the system migration.

All the old PLCs were replaced with new Mitsubishi Electric Q series controllers. These were equipped with Mitsubishi Electric’s QnUDV central processor unit to offer integrated Ethernet-based network communications. In this way, the PLCs could be easily connected to inverters and other pieces of equipment.

In addition, the two automation specialists replaced the existing third party stand-alone I/O components using the CC-Link IE Field Basic network system, which is integrated within the new PLC modules. This would allow Bakkavor to save panel space that could be used to host the new system’s inverters and servos in the near future, optimising the plant’s overall equipment footprint.

Paul Judge, Compact PLC & Visualisation Product Manager at Mitsubishi Electric, commented: “Our main goal was providing a solution that solved the immediate issues and met the main objectives for the project. This new, more reliable automation ‘backbone’ also provides Bakkavor Pizza with the right migration path for future developments. Partnering with skilled system integration specialists, such as Control Freaks, is vital to support our customers with implementing ideal, more future-proofed solutions.”

Once the new automation solution had been installed, the food manufacturer noticed substantial increases in the uptime, speed and responsiveness of the bakery line, plus higher product quality and consistency.


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