Spreading the goodness: SCADA keeps watch over butter production

04Jan

Italian food producer, Parmareggio Unigrana chooses a SCADA system to automate one of the creameries that has helped it become a major butter producer, as well as world-famous for its cheese, which has special Protected Designation of Origin (PDO) status.

With demand for the Parmigiano Reggiano region’s butter soaring (up 22 percent in 2011 to Euro35m) a decision was made to automate Parmareggio Unigrana's Fiordalba creamery in Modena. This would enable the company to increase production sufficient to meet this increased demand, while guaranteeing consistent quality and full compliance with the PDO status requirements.

The creamery’s systems design and installation was entrusted to IT Technologies Srl, a Movicon integrator that works extensively throughout the region. The plant, which was already partially controlled by Movicon equipment, was to be fully automated, including installation of a new SCADA (supervisory control and data acquisition) system – an upgrade that would improve the system redundancy and add a quality certification capability. Many other new systems were also installed on the production floor, while some existing systems were upgraded to achieve additional functionality.

Fresh cream is the raw material used for making Parmareggio butter. This comes directly from regional PDO dairies - themselves also highly automated to guarantee product consistency and quality. Close relationships are maintained with suppliers, often built up over decades, to ensure product integrity.

The process
The cream is first put through a centrifuge where it is mixed with water and melted butter. It is then pumped into a storage tank from which it is collected and skimmed, before being transferred to the pasteurisation plant. This process cycle is constantly monitored by the Movicon SCADA system to ensure European food safety standards compliance. A near infrared reflectance spectroscope, also connected into the SCADA system is used to monitor and control product chemical parameters.

Once pasteurised, the cream is left to settle naturally in vats. During this phase the temperature is continually monitored and controlled in order to obtain a perfect end product with an easy spreading consistency. After this, it is pumped on to ripening tanks where it is cooled and re-mixed, then pumped to the butter making machines, where it is churned and transformed into butter. Separated buttermilk, a useful by-product, is sent to a separate pasteurising process then stored in silos to await collection for other processes.

The butter is automatically transferred to a packaging area and, as with the rest of the production, this phase uses completely enclosed and automated equipment to prevent risk of product contamination. The high speed lines include weight control systems and are able to package butter in all shapes and sizes according to market demands.

With all the production and packaging processes complete, the butter is placed in a refrigerated storeroom where temperatures are again monitored and recorded for batch traceability purposes.

The control system
The entire production plant is controlled by a Movicon 11 SCADA system implemented on three Siemens S7 PLCs built into stainless steel control panels in a central control room and connected via Ethernet. One PLC manages the production process system; the other two manage the CIP (cleaning in place) systems and the storage systems. In addition to overseeing the sequences of the different production stages, these systems monitor operational and chemical parameters - mainly temperatures and the product’s micro-organic profile as it passes through the process.

The control system also includes a number of Movicon HMIs which can display pages for every process within the plant, covering critical parameters for quality, hygiene, productivity and maintenance. The HMI screen pages are all divided into two frames, one displaying operational status, the other showing the operational command sequences.

The CIP system is fully integrated with the production processes and is scheduled automatically with all cleaning data being stored for traceability purposes in accordance with FDA standards. The plant is actually run in compliance to the FDA CFR21 part 11 regulations, normally associated with pharmaceuticals production, but also adopted for high quality food manufacture.

The main control room also accommodates two additional PC stations, which run Windows 7 with the Movicon 11 configured for redundant operation. Both PCs are constantly updated and each backs up the other, including the recording of all data for track and trace requirements. This guarantees maximum availability and enables the creamery to run a continuous 24 hour operation.

The redundant system also provides operators with independent access to the workstations – for example, enabling one to monitor a cream collection tank and start a cleaning process, while his colleague checks skimmer operations and prints out a product quality report.

Communication within the control system is based on Movicon S7-TCP communication drivers, which collect and aggregate data in a real time database residing on an MS SQL server. While the production process is managed via the plant HMIs, all instructions from these systems are added to the database, no matter from which HMI they come. Trending is used to identify any developing plant malfunctions and offer guidance on appropriate corrective/maintenance procedures.

Movicon features a user and command access management system explicitly designed to support the CFR21 Part 11 regulations. In addition to all the requirements defined by the user privileges (area and access level), the system manages ‘electronic signatures’ in reports and for historical data. This way, each significant action executed in the plant, such as commands or target parameter modifications can be traced back to an individual. Audits are recorded in the database with encrypted access and can be documented appropriately in reports.

The creamery production was not disrupted during the control system upgrade, which was completed quickly and efficiently thanks to a combination of excellent working practices on the part of IT Technologies and the rapid design and configuration ability of the Movicon platform.

Movicon SCADA and control products are supported in the UK by Products 4 Automation (P4A).