Thurne-Middleby Ltd. offers a comprehensive range of slicing systems for fresh and precooked bacon, cooked and cured meats, natural products and cheese applications.
The original Thurne brand was launched in 1969 as an innovative, forward thinking manufacturer of food processing machinery, pioneering the then new vision and computer technologies in a range of high speed slicers which gave bacon, cheese and cooked meat processors huge savings and gains in production efficiency.
Forty-five years later, and now part of Middleby Corp, the company's commitment to innovation has led to the design of a market leading slicer dedicated to the pre-cooked bacon market – the IBS 4600 Vision Slicer.
Until now, the production of pre-cooked bacon as a major ingredient for burgers, sandwiches, ready meals and food service industry had been a somewhat low tech, inefficient affair.
Demand for the product has been increasing across many markets - especially Europe and the USA. Thurne's vast knowledge and experience of high-speed slicing has now been applied to the IBS4600 – the world's first slicer to have four independent blades and feeds. It needed a robust and accurate control solution and, as a result Thurne turned to Rockwell Automation.
Thurne is a Rockwell Automation OEM Program Participant, demonstrating that it has a commitment to offering high-quality, innovative machinery and equipment that uses Rockwell Automation solutions. As an OEM Program Participant, Thurne is dedicated to helping manufacturers increase business agility, optimize productivity and achieve sustainability objectives by delivering flexible and efficient equipment.
Bacon slicing accuracy is critical in order to help ensure more consistency and less wastage. The older style machines rely too much on an antiquated approach, so Thurne opted for a solution that tied in a precision vision solution.
Key to pre-cooked bacon slicing is consistency and accuracy. Other slicers for the pre-cooked bacon segment using gravity-fed slicing technology do not offer full product control and are unable to deliver consistently cooked individual slices every time.
They might produce overlapping slices and variations in thickness that would result in overcooking and undercooking, therefore wasting slices or increasing giveaway (giveaway is the extra weight above the weight indicated on the packaging). To deliver consistent weight slices with minimum giveaway, Thurne had to bring the lean and fat into the equation and opted for a solution that paired a precision vision solution with accurate control.
According to John Kelsey, Product Specialist for the IBS4600 slicer: “Our four-bladed cutting solution is very tightly controlled using signals from an advanced vision system.
For every single revolution of the blades the vision system takes two images of the bacon slice face and from that we can identify the lean and fat areas. Using this information, which is fed back to the primary controller, we are able to adjust the slice thickness and obtain slices of a set weight.”
For this vision approach to be effective, Thurne needed a control solution that could move the product feed very quickly and very accurately to help ensure the target weights were consistent.
At the heart of the control infrastructure is an Allen-Bradley® ControlLogix® L71 programmable automation controller (PAC). An in-house developed vision system sends data to the PAC which calculates the slice thickness for a particular weight. The PAC's eight Allen-Bradley Kinetix® 6000 servo drive/motor combinations, control the blades and the product feed drives. The feed drive rate is altered to obtain the desired thickness.
In addition to the motion solutions, Thurne has deployed Allen-Bradley PowerFlex® 40 variable speed drives with Ethernet cards to control the infeed and outfeed conveyors.
Allen-Bradley Flex™ I/O is also used for communication as sometimes there can be up to 30 m distance between the panel and the machine. This is due to the way the microwave cooking system works, where the microwave transmitters are upstairs with the oven downstairs.
Hard wired Allen-Bradley Guardmaster® 440R safety relays are also used and conform to EN13849 – the whole machine is performance level E. These relays are configurable without having to use a PC or proprietary programmer, instead it can all be done using DIP switches, making them easy to use and very flexible.
The final part of the control solution is an Allen-Bradley PanelView™ Plus 1250 human machine interface (HMI), which is used to provide a visual overview and for adjusting parameters, such as the blade speed, slice thickness and weight – all of which can be stored as preconfigured recipes.
“The beauty of the machine,” Kelsey explains, “is that it is consistent and dull. I mean that in the nicest possible way. What I am referring to is its ability to produce 500,000 slices per day, running at 16 hours a day, six days a week and 50 weeks per year.”
Thurne has calculated that the greater accuracy and reduced giveaway can result in a significantly lower cost of ownership, with a payback period of less than a year. It is also capable of more accurate out feed-belt placement, which removes the need to discard overlapping product prior to microwave cooking – saving yet more time and money for the customer.
“We are seeing multiple benefits of the Rockwell Automation based system,” Kelsey explains. “Our knowledge of the devices and our closeness to Rockwell Automation has allowed us to streamline our design time. In much the same way, our knowledge of the Logix programming environment and the integration of the motion solution has also reduced our programming efforts.
“The Ethernet backbone also helps a great deal, especially in combination with the Ethernet cards used within the PowerFlex drives,” he continues. “We get super quick diagnostics of the drives via a web page. I can look at an inverter's web page and open up a window that updates every three seconds, delivering all the important parameters. This really helps with training – you don't even have to open Logix. It is great using Ethernet to vary the speeds of the drives and to tie it into Logix is a joy.”
In addition to easier testing and validation Thurne is also looking to the future and is considering the addition of Web modules. The idea being that the machines can report how they are doing and if Thurne had service agreements with customers, the machines would flag up when they need a service.
By using Ethernet as the communication backbone, Thurne has the option to expand the machine even further into The Connected Enterprise.
This will Thurne to offer a broad range of additional value-add functions to their customers, including the collection of real-time performance data, historical data for performance assessments and maintenance schedules and connectivity beyond the shop floor into enterprise systems that can help manage the equipment even more precisely in line with other assets on site.
The use of standard Ethernet within EtherNet/IP means that there is very little that needs to be done for these connections to be established; and full security solutions are also available for user control and to prevent unwarranted access.
“Rockwell Automation has been our supplier for control equipment for quite some time,” Kelsey concludes. “We have used them for the past many projects. It has been a fruitful, ongoing relationship, which I am sure we will both enjoy for many years to come.”
Allen-Bradley, ControlLogix, Flex I/O, Guardmaster, Kinetix, PowerFlex, PanelView, and Rockwell Automation are trademarks of Rockwell Automation, Inc. EtherNet/IP is a trademark of the ODVA. Trademarks not belonging to Rockwell Automation are property of their respective companies.
The results mentioned above are specific to Thurne-Middleby Ltd.'s use of Rockwell Automation products and services in conjunction with other products. Specific results may vary for other customers.