To slice delicate foods on a production line brings many challenges: to achieve this on the fly brings even more. Working with Mitsubishi Electric, a mechanical handling company in the based in the west country developed an automated inline cell for slicing delicate foods using twin production robots.
A Mitsubishi Electric MELSEC Q series high-performance PLC controls the MELFA RV-F six axis articulated robots via an HMI operator interface. The PLC then acts as an intermediary between the robots and a GOT2000 HMI, allowing the operators to set the type of cutting needed and check the process. Mitsubishi inverter drives also provide speed control the conveyor speed. The machine provides the performance, flexibility for food industry customers to slice any size and shape on the fly.
Competition in the food industry is fierce and advantages from productivity improvements have a considerable impact on sales and profitability. This innovative inline cutting unit offers significant advantages by reducing slicing time and wastage with its high accuracy and consistency.
Replacing manual task
Based on their 40 years of expertise in this sector, the company noticed a growing market need for better industrial food cutting solutions, which until now has often been a manual task. Even when automated, most solutions do not allow continuous processing because the robots needed the food to be stationary. As a result, cutting operations often slow down the entire production line, increasing lead times.
The new inline slicer marks a turning point by having a conveyor connecting the production line to the slicing process. As food trays move forwards, their robot slices the contents without stopping the conveyor belt. A big factor in the machine’s versatility are two robotic arms that tune themselves to the line speed, making all the cuts on the move. The robots can perform quality slicing using state-of-the-art ultrasonic blades from a leading producer.
Slice delicate foods
The machine can slice a range of foodstuffs with different consistencies and packed in various food tray shapes and sizes without requiring any hardware modifications. For example, chilled goods would need a slower cutting speed compared to softer foods.
Chopping orientations and angles for round products, such as pizza, differ from rectangular tray bake products like flapjacks. Furthermore, when faced with variable ingredients and toppings, such as cherries in a cake, slicing rather than squeezing is important to avoid damaging the whole product and ensuring a pleasing appearance.
Ultrasonic blades cut different materials fast and accurately by applying low pressures. Compared to conventional blades, the crumbs and waste are much lower, especially when cutting near the edges of the material. The 760mm blades used in this application are the largest available, giving faster cycle times, and higher quality cuts. Their ability to self-clean and maintain a sharp blade, further streamline the process.”
The process relies on accurate track positioning to ensure the robots cut the food and not the trays or conveyer. Importantly, this meant minimising any upward or downward movement of the conveyor belt. To achieve this the conveyor belt uses Mitsubishi’s variable speed drives to regulate its horizontal motion whilst eliminating height variations. The solution positions itself with an accuracy of 20 microns.
Selection of Mitsubishi Electric’s RV-F series of six-axis robots was due to their class-leading speed, precision. Moreover, their IP65 ingress protection makes them suitable for food grade wash-down working environments.
The twin robot inline ultrasonic cutting unit is already in use with a leading food producer, who recently installed a machine to slice delicate foods on a cheesecake production line.
