New automation machines can speed food processing. It’s no wonder the industry is embracing the technology.

New packaging and inspection technologies have reached the supermarkets and food processing factories in the U.S. Intense competition among large scale food retailers has necessitated greater productivity in stocking and better data management capabilities. New machines are placed on site in food processing plants and also in the supermarkets to provide high speed weighing, wrapping, and labeling of meat, poultry, and other perishable food products.

The DACS WN weightchecker from Ishida Co. is fully automated and handles strict food handling requirements.

Unlike other industries, the food processing industry cannot afford products lying around waiting to be wrapped, weighed, and labeled. Successive generations of machines continue to shrink in size due to the availability of smaller more powerful electric motors and more intelligent drives using smaller semiconductor devices and microprocessors. These machines must be kept clean in order to provide safe, fresh and healthy food products for the consumer.

Automated Checkweighing Machine

Because food processing factories and supermarkets are as diverse as the products they produce and sell Ishida Co. has developed a family of automated machines to satisfy the strictest food handling requirements for the U.S., European, and Asian markets. The product line includes net weight fillers, checkweighers, labelers, and inspection devices. They are all focused on eliminating waste and improving productivity by having high speed weighing of mass produced products.

One of the automatic checkweigher uses technology that can handle a wide variety of package sizes and types, ranging from 0.1 oz to 110 lbs at speeds up to 300 weight measurements per minute. Measurement accuracy approaches 0.002 oz. Another company, Oriental Motor, supplies a high performance AXH type brushless permanent magnet (PM) motor that has the capability to achieve fast response and constant torque over a wide speed range needed to meet demanding machine requirements for fast accurate vibration free movement. A very low vibration response is needed to accurately move a conveyor system to support a range of tightly controlled speeds up to 300 weight measurements per minute.

Controlling Machine Operation

Using a digital signal processor (DSP), special software algorithms can control an anti-floor vibration mechanism. This allows for reliable and accurate measurements in vibration intensive storage and processing areas within food processing plants. The DSP provides a control platform for a 24 VDC board level driver for developing precision motion control. A control unit possesses a large display that helps eliminate reading errors. Preset parameter information and various performance data can be recorded and printed from a NEMA 4X control unit. A memory card stores operating parameters for up to 100 products to minimize operator errors and reduce production downtime during changeovers.

Cleanliness is Key

New checkweighers, such as the DACS-H Series, are built to withstand the harshest washdown procedures without sacrificing the machine’s weight measuring accuracy and fast throughput. Stainless construction and an open and accessible framework facilitate cleaning procedures, including rigorous high pressure hosedown with caustic solutions. The easy cleaning machine design is suitable for the stringent sanitation requirements of meat, poultry, and dairy products, as well as factories that manufacture products that can quickly rust or corrode standard machine frames.

Brushless PM Motor

A brushless PM motor is a truly different type of electric motor. It consists of a rotor (moving part) composed of a permanent magnet hub and shaft assembly and a stationary stator filled with copper windings. Brushless mechanical performance in the form of torque and speed are interconnected magnetically with voltage and current. Both torque and current exhibit a linear relationship when driven by an open loop voltage input.

An electronic circuit using Hall devices tracks rotor position and switches or commutates the stator windings at the proper time and location to achieve motor performance. The Hall devices also provide the signals for controlling motor speed accurately. The brushless PM motor develops the highest speed and torque (mechanical output power) performance for a given input voltage and current. This condition translates into higher motor power efficiencies. For example, the Oriental Motor 100-W AXH 5100 brushless PM motor provides a constant torque of 56 oz-in. from 100 to 2500 rpm. A peak starting torque of 71 oz-in. is available for accelerating the brushless PM and machine load to achieve fast changes in speed. The motor’s speed regulation varies no more than ۫ percent for each of the variations in load, voltage, or temperature conditions.

The smaller brushless PM motor achieves this performance in a package 50 percent smaller than equivalent powered ac induction motors. The brushless PM motor weighs about 3.1 lbs. Rated electrical current from the three-phase driver board reaches 6 A at 24 VDC input. Motor efficiency peaks at 76 percent. The low brushless PM motor vibration signature aids the machine control system in minimizing vibration through its AFV software control.

The smaller brushless PM motor furnishes a high performance motor that features high efficiency operation in a small physical package. The improved performance of brushless PM motor technology along with the latest speed control electronics equips the machine user with a cost effective motion control system for this generation and the next generation of food processing machines.

Dan Jones received a bachelor's of science in electrical engineering degree from Hofstra University and a master's of science degree in mathematics from Adelphi. He has more than 40 years experience in the design of precision servo and step motors and has held engineering design and management and marketing management positions at several companies. He has written more than 150 technical articles and papers and has held seminars in 10 countries. He is the past president of AIME and a past member of the Board of Directors of SMMA.