Fluid power makes the grade for food applications

23 November 2020

Christopher Buxton explains the benefits of modern fluid power technology in the food factory.

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While it may be stating the obvious for many, a key driver of the selection of all process technology in the food production industry is a need for extremely high standards of cleanliness and the need for resilience to rigorous CIP regulations. Because of this many specifiers may be nervous about selecting fluid power driven technology. It needs to be highlighted that today such concerns are misplaced, as new fluid power technology not only provides significant benefits over alternative power sources but has evolved to adapt to the more stringent requirements of the food industry.

Selecting materials such as stainless steel, combined with the careful selection of hose and seal materials now ensures that it is much easier to keep fluid power systems clean. Stainless steel can also handle high-temperature sanitation, high-pressure washing, and even steam cleaning without any major issues, as can certain polymer materials that are commonly used in high-performance seals.

In the past it may have been difficult to find industrial fluids that were compatible with the high standards involved in food preparation and processing, but technologies have advanced, and today food-grade lubricants and fluids are readily available.

It is always important to define whether or not the technology being specified is supporting the core manufacturing process and so a good understanding of the core process is required by the specifier. For example, hydraulic-dependent forklifts are used to transport both raw ingredients and finished products, whilst conveyance systems that not only move products but can also sort and distribute them to different destinations, often use fluid power technology.

Benefits for food applications

The benefits of fluid power over other electromechanical systems include:??

• Safety in hazardous environments: Fluid power systems are inherently spark-free and can tolerate high temperatures.

• High horsepower-to-weight ratio: You could probably hold a 4 KW hydraulic motor in the palm of your hand, but a 4 KW electric motor might weight 18 Kg or more.

• Force or torque can be held constant: This is unique to fluid power transmission.

• High torque at low speed: Unlike electric motors, pneumatic and hydraulic motors can produce high torque while operating at low rotational speeds. Some fluid power motors can even maintain torque at zero speed without overheating.

• Pressurised fluids can be transmitted over long distances: They achieve this through complex machine configurations with only a small loss in power.

• Multi-functional control: A single hydraulic pump or air compressor can provide power to many cylinders, motors, or other actuators.

• Simplified motion: Elimination of complicated mechanical trains of gears, chains, belts, cams, and linkages means that motion can be almost instantly reversed.

Fluid power systems are often specified to serve as actuators along food production lines to aid in any number of tasks, including opening and closing oven doors, aligning packaging with dispensers, redirecting certain types of products along the production line, and assisting with cleaning and sanitation processes.

Hydraulic motors can generate tremendous torque for blenders and mixers and air compressors can generate high-pressure, fast-moving blasts of air for everything from sorting to cutting.

One of the most well recognised uses of fluid power in food factories is in the use of pneumatics driven delta robots used in ‘pick & place’ and packaging applications.

The added speed and flexibility of pneumatic based systems, makes them ideally suited to such applications and the use of vacuum pressure to lift, manipulate, and place food products is extremely effective, especially when the food items are delicate or a non-symmetric shape. Pneumatic systems are also often used in connection with forming, filling, and sealing food packaging tasks.

Conclusion

In short, as in most walks of life, the appropriate selection of a diverse mix of technologies, including Fluid Power, makes for the most effective and efficient food manufacturing facility.

Christopher Buxton is CEO at The British Fluid Power Association (Incorporating the British Fluid Power Distributors Association).