Automatically derinding cheese wheels
Even in the most modern cheese dairies, the derinding of naturally-ripened cheese is often done by hand. The Dutch company, DERO GROEP, has now automated this process. Two Stäubli six-axis robots work hand in hand to remove the rind in less than thirty seconds; a real milestone in industrial cheese production.
It takes a strong employee about two minutes to derind a cheese wheel. Manual derinding is difficult work. Because of this, cheese dairies are having a hard time finding the right personnel for this task. Manual derinding should also be viewed critically in terms of hygiene, since bacteria is responsible for the ripening process. Consequently, contamination has to be prevented at all costs. It is for this reason the ground rule in cheese dairies is “Hands off the cheese!“ Beyond the increase in efficiency, this is an important driver for the automation of cheese production.
But there was another reason why this process has not been automated to any great extent: Cheese is a natural product. The wheels differ in size and consistency. Therefore, the automation has to be flexible. In addition, the rind is the hardest part of the cheese, which means a lot of force is required for derinding.
Two robots work hand in hand
DERO has developed a system that carries out derinding in a simple and impressive procedure. A conveyor belt deposits a cheese wheel on a transfer station. An HE variant of a Stäubli TX200 six-axis robot then picks up the wheel with a suction cup that almost completely covers the top of the wheel. Because the tool to remove the rind is similar to a cutter and is fixed-mounted, the robot performs a multi-axis movement that includes turning the cheese wheel. This derinds half of the cheese wheel in only fifteen seconds.
The robot arm then moves to a transfer position far above the tool. A second identical robot arm reaches into the air and grabs the half-derinded wheel, allowing the process to repeat with the other half of the wheel at a second station. Because both robots can work simultaneously, the cycle time for derinding a cheese wheel is about thirty seconds. The processes are designed to be fully visible and hygienic. The rind waste falls directly into plastic containers that are then easily replaced.
Recipes for various cheese types and age groups
Not only is the system impressive for its processing speed, but also in its flexibility and ease of use. DERO stored recipes in the control unit for the shape, type and age of the cheese wheel. Whether it‘s a six-week-old Gouda or a hundred-week-old Edam, the robots know what they have to do. The benefits for cheese dairies are clear: They save time and money while minimizing the amount of waste, all with improved hygienic conditions in production.
The DERO designers chose to use the TX200 HE, the flagship of the six-axis range, because the robots require both an extended reach and a very rigid construction in order to apply the necessary contact force against the tool. In addition, the massive stainless steel motor which is mounted on the robot arm and generates the rotary motion of the vacuum gripper, plus the cheese wheel itself, increases the total payload which a smaller robot would struggle to handle.