How Ultrasonic Food Cutting Works
Date:Dec 08, 2020
How Ultrasonic Food Cutting Works
Ultrasonic food cutting is a process utilizing knives that vibrate at high frequency. Applying ultrasonic vibration to a cutting tool creates a nearly frictionless cutting surface which provides many benefits. This low friction cutting surface can slice a multitude of food products cleanly and without smearing. Very thin slices are also possible due to the reduced resistance. Foods containing items such as vegetables, meats, nuts, berries and fruits can be cut without deformation or displacement of the internal product. The low friction condition also reduces the tendency of products like nougat and other soft candies from sticking to the cutting tools, resulting in more consistent cuts and less down time for cleaning. And because of the advanced process control that is available in ultrasonic generators, cutting performance can be easily manipulated by simply adjusting the equipment parameters.
Ultrasonic food cutting systems are often used to cut the following types of foods:
• Hard and soft cheeses, including products containing pieces of nuts and fruit
• Sandwiches, wraps, and pizzas for catering industries
• Nougat, candy bars, granola bars and healthy snack bars
• Semi-frozen meats and fish
• Breads or cake products
Every ultrasonic food cutting system is comprised of the following components:
• An ultrasonic generator (power supply)
o The ultrasonic generator converts the 110VAC or 220VAC electrical supply current into a high frequency, high voltage electrical signal.
• An ultrasonic converter (transducer)
o The ultrasonic converter utilizes the high frequency electrical signal from the generator and converts it into linear, mechanical movement. This conversion occurs through the use of piezo-electric ceramic disks that expand when a voltage is applied. The converters used for food cutting systems are specifically designed to be completely sealed for operation in wash-down environments and incorporate air in and out ports for cooling.
• An ultrasonic booster
o The ultrasonic booster is a tuned component that mechanically adjusts the amount of linear vibratory movement from the converter to the required level for the specific application to produce optimal cutting performance. The booster also provides a safe, non-vibrating location to clamp onto the cutting tools. Boosters used in food cutting systems should be a one-piece, solid titanium design for maximum cutting accuracy and repeatability. In addition, the single piece design allows for a thorough wash-down, unlike multi-piece ultrasonic boosters that can harbour bacteria.
• An ultrasonic cutting tool (horn/sonotrode)
o The ultrasonic cutting horn is a custom made tool that is engineered to vibrate at a specific frequency. These tools are painstakingly designed using computer modelling technology for optimum performance and longevity. Ultrasonic tools must be tuned to match the frequency of the system. This tuning procedure requires consideration of the horn’s mass, length and geometry. Titanium is the material of choice for ultrasonic tools because of its resonance and fatigue resistance properties. Titanium is also compatible with the sanitary requirements of the food processing industry. Due to the high stresses inherent in the thin blade geometries required of ultrasonic cutting horns, manufacturing should be done using a wire EDM technique and subsequent stress relieving process in order to maximize the life of the tools.
• A material handling system
o Automated machinery is required for the proper positioning and movement of the food products and ultrasonic tools. Automation is critical in achieving the correct location, direction and rate of cut. Typically, these handling systems utilize servo drive mechanisms for precise control of speeds and positions of the food products and/or cutting tools.