It’s not hard to understand why applications in the food and beverage industry are especially challenging for linear motion systems. Food processing and packaging equipment must simultaneously meet high throughput requirements and withstand harsh environments, while safely handling and processing products which are at constant risk for spoilage or dangerous contamination caused by environmental factors or improper handling. Add to this the recent increase in concern regarding allergens—peanuts, gluten, dairy—and it’s clear that equipment manufacturers have to be ever more insistent on using components that help ensure that food is not only processed safely, but that also minimize the risk of cross-contamination.
Some aspects of machine design are addressed by government agencies and industry groups such as the US Food and Drug Administration (FDA) and the European Hygienic Engineering and Design Group (EHEDG), which provide both regulations and standards to promote safe and hygienic processing, handling, and packaging of food products. But many factors of machine design are still left up to the individual equipment manufacturers. To help ensure your machine meets the applicable safety requirements without compromising performance, here are four things to consider when designing equipment for food and beverage applications.
In many cases, the first thing a designer should consider are the materials that will be suitable for the application. Some food and beverage products—especially those with a high sugar or acid content, such as juices and sodas—will quickly degrade most metals. For these applications, special coatings can help avoid corrosion. Generally, surfaces should be electroplated, since anodizing can chip and flake, introducing a contamination hazard to the item being processed, as well as to the equipment itself.
Most food and beverage processing equipment will undergo cleaning (wash down) at least once a day, and in many applications, several times per day. Cleaning is usually done via an automated process known as Clean In Place (CIP) or Steam In Place (SIP). And while some wash down processes use only water, most use chemicals and detergents, which present an additional challenge to linear motion components. Be sure to check the compatibility of the component’s various materials—housings, seals, covers, and ancillary parts—with the cleaning agents that will be used.
In food and beverage applications, machine components should have smooth surfaces, as free as possible from grooves, indentions, or other areas where particles can be trapped. This helps prevent the growth of bacteria, and makes cleaning easier and more effective. Keeping welds smooth and designing corners with a radius rather than sharp angles are both important aspects of design, since these are often-overlooked areas where particles can be trapped and bacteria can grow. When components are enclosed in a housing, such as with linear actuators, strategically placed drainage holes or channels will allow liquids to drain from the system and help prevent the growth of bacteria and minimize damage to the equipment.
It’s obvious that consumers don’t want industrial lubrication in our food and beverages. Plastic sliding and self-lubricating bearings are suitable in some applications, but if the equipment is moving heavy loads or running at high duty cycles, the bearings will probably need some sort of lubrication. The best choice for designers is to use components that can operate with minimum lubrication and that use grease rather than oil, since oil is more likely to drip from surfaces or be ejected from rotating components. For equipment that is in direct or very close contact with the process, the use of food-grade lubricants will often be required.
With most food and beverage applications involving potential liquid contamination, and many undergoing wash down processes, attention should be given to these hazards when choosing electrical components such as motors, sensors, and encoders. The most common way to ensure protection for electrical equipment is to choose components with the appropriate Ingress Protection (IP) rating. A part’s IP rating specifies the amount of protection against intrusion (fingers, hands, etc.), dust, and water. IP categories consist of two digits, with the first digit indicating the level of protection against solid particles (dust, dirt, wires, etc.) and the second digit indicating the level of protection against liquids, which ranges from dripping water to close-range, powerful water jets.
In order to improve both machine throughput and food safety, the food and beverage industry is becoming increasingly more automated. And over the last several years, manufacturers of linear motion and automation components have broadened their product offerings to include variations that meet the unique needs of food processing and packaging equipment. From motors and switches that meet the highest IP ratings, to linear actuators specially designed with smooth outer surfaces and drain holes, it’s becoming easier to find standard automation products that fit the needs of this important industry.
Feature image credit: Kollmorgen