The Extreme Sausage Machine

01 April 2007

It produces sausages at one metre per second, smokes them, cooks them, packages them, and hands them over for delivery.

Rockwell Automation announced that the European winner of its ‘Extreme Machine’ contest was food
machine manufacturer Stork Townsend B.V. (, located in Oss, The Netherlands. Articles about the eight contestants (four from North America, and four from Europe) appeared in the October, 2006 issues of Control Engineering, Control Engineering Europe, and Design News and the winners were selected by magazine readers who cast their votes on the Internet.

Stork Townsend’s award winning machine is the QX family of co-extrusion sausage makers, which take raw meat as feedstock and produce finished smoked sausages ready for shipping, all in one continuous operation.

So, what is so ‘extreme’ about the QX sausage maker? For one thing, its size is massive: ten metres wide, six metres high, and up to thirty metres in length make it the largest machine in the contest, and a very large machine by anyone’s standards. It is powered by 60 variable speed motors, controlled by Rockwell’s PowerFlex variable speed drives, and 18 servomotors, which are controlled by ControlLogix controllers in
conjunction with Kinetix 6000 multi-axis servo drives. The entire control system is tied together with an EtherNet/IP network among the controllers. The main control cabinet for the machine is about ten metres long.

Another ‘extreme’ this machine boasts: a high degree of automation. A single operator can virtually run the
entire machine, from start to finish, greatly reducing labour costs. This also means no human contact with the meat product, which minimises the opportunity for contamination.

Stork Townsend in fact advertises its QX as producing sausages ‘untouched by human hands.’ The operator’s main decision is, in fact, to tell the machine what size sausages to make, and it does all the rest, synchronising all processes from smoking to packaging to the size of sausages that will be produced. The
company claims labour is reduced by 80%, resulting in a cost savings from 0.12€ to 0.40€ per kilogram of finished sausage.

Sausage making is one of the oldest and most widespread forms of food preservation. Homer mentions them in the Odyssey; they were probably the first convenience food in the days before refrigeration. Animal intestines were originally used as the casing material, but with the advent of artificial materials such as cellulose and collagen, new methods of making sausages were opened up.

Stork Townsend probably made the biggest advance in sausage making when it invented the co-extrusion
process in the 1960s. In manual sausage making, the operator loads a prefabricated sausage casing into the machine and then the machine proceeds to stuff meat dough into the casing. Once filled, the operator
removes the finished sausage and inserts a new casing. The stop-and-go process takes more time and inevitably wastes some of the meat product at the beginning and end of the cycle.

With the co-extrusion concept, the meat dough is continuously formed into the shape of a sausage through the extrusion process, and at the end liquid collagen (a natural protein derived from animal skin) is sprayed onto the meat. The collagen forms a gel on the surface which begins to harden as the newly made sausage ‘rope’ passes through a brine solution before it is wrapped around a wheel, called a ‘crimper,’ which cuts it into individual lengths.

With its process, Stork Townsend says it can make ‘designer’ casings to suit the taste of customers by varying the casing thickness and by adjusting the cooking cycle. The ‘bite’ can be adjusted to be softer, like a cellulose product, or with a ‘snap’ that imitates a natural casing.

From this point on, the rest of the process is a material handling operation. The sausages are dropped into baskets that carry them through the ‘pre-drying’ process, then ‘smoking’ followed by ‘post drying.’ The
‘smoke’ is in liquid form, sprayed onto the sausages.

The sausages then enter a packaging stage, where high-speed machinery loads and then vacuum packs them into clear plastic packages. Here a dedicated ControlLogix system with Kinetix 6000 servo drives manage the six-axis packaging system.

The sausages are then cooked inside the packages, cooled, and stored for shipment as ‘ready-to-eat’ (RTE) products. The whole operation takes one hour, from the start with raw meat, to the finish. During one hour it can process 2,200 kg. of meat.

Control system
When Jan Vissers, manager of electronic engineering, began working at Stork Townsend over 30 years ago, there was hardly anything electronic for him to manage. The control system consisted mostly of electromagnetic relays. The machine operators made most of the decisions.

Gradually the company adopted programmable controllers and other electronic equipment and over a period
of time accumulated a variety of different brands of controllers, SCADA, HMI, drives, and motor controllers. In
2003, Mr. Vissers was persuaded by Hans Zuur, Rockwell’s account manager for the food industry, to standardise on Rockwell’s Integrated Architecture.

Stork Townsend’s substantial presence in the U.S. market no doubt influenced the decision.

‘The contact began six years ago, where we supported the company when they requested us to do so,’ says
Mr. Zuur. ‘But this increased to a relationship where we began discussing the control needs of Stork Townsend.

‘I was very fortunate that Rockwell launched the Integrated Architecture solutions just at the right moment,
when Stork Townsend was in need of such a solution; a better integrated, complete solution.’ Mr. Vissers says that today nearly 90% of their machines ship with Rockwell Automation controls.

The start in 2003 began with only the controls: ControlLogix and HMI, in combination with RSLogix5000 and
RSView Studio Development software.

However, once Rockwell had its foot in the door, the control equipment was followed by low voltage switchgear, Intelligent Motor Control (which provides diagnostic data), PowerFlex drives, and Kinetix servo controllers. Networks used include SERCOS and well as Rockwell’s DeviceNet, ControlNet, and EtherNet/IP.

After two years working with the FactoryTalk Enabled Architecture, Mr. Zuur says the machine builder has
achieved ‘the highest possible transparency between controls, HMI, and motion control.’

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