Key points
The global demand for food continues to increase, requiring complex supply chains and a continuous drive for higher efficiency.
Food processors seek to increase speed and reduce mechanical failure while also increasing their facilities’ resistance to microbiological threats.
Hygienic Bearings are critical to keeping equipment turning and they must incorporate innovative features to meet hygiene and washdown requirements.
Manufacturers have produced cutting-edge designs to meet the needs of food processors and support the growing food and beverage markets.
Meeting the demands of regulations
Regulations across the world are influencing the composition of components used in food and beverage processing more than ever. Bearing manufacturers now are designing product lines to specifically comply with the long list of regulations, which grows in complexity when considering international markets.
For example, the Code of Federal Regulations (CFR) Title 21 provides lists of compliant substances for use as “indirect food additives.” Bearing manufacturers must abide by the accepted substances cited in this regulation when making products safe for food contact.
This regulation is enforced by the Food and Drug Administration (FDA) in the United States but other countries do not necessarily accept it. European nations often follow their own regulations, making bearing manufacturers pay close attention to how their total bearing package complies with these different rules.
Lubricants within bearings must abide by another set of regulations. Today, food-and-beverage-specific product lines often include a National Sanitation Foundation (NSF) category H1 registered lubricant. Under the H1 registration, a lubricant is deemed “food grade” and acceptable for limited incidental contact.
To meet the requirement, lubricants must abide by applicable sections of CFR Title 21. To take lubricant compliance a step further, food and beverage processors may have additional demands to meet, such as religious ingredient restrictions or ISO 21469 certification.
Sub-market specific regulations often influence bearing manufacturers’ design details as well. The NSF/ANSI/3A 14159-1-2019 standard outlines hygiene requirements specifically for the design of meat and poultry processing equipment.
Following the guidelines within this standard helps bearing manufacturers incorporate hygienic design features that are accepted in markets requiring high levels of cleanliness.
The United States Department of Agriculture (USDA) also publishes guidelines for the evaluation and certification of sanitary design and fabrication of meat and poultry processing equipment. After complying with these guidelines and completing a review from the Agricultural Marketing Service (AMS), bearing manufacturers can claim USDA acceptance under the Meat and Poultry Equipment Review Program.
A smart base: bearing housings for food and beverage equipment
While nearly all types of bearings are utilised in food and beverage machines, we will primarily focus on those used on core processing equipment. Mounted bearing products offer an easy way to incorporate hygienic bearings on processing equipment but often require bearing manufacturers to consider design aspects beyond the bearing itself.
In particular, the bearing housings need to be designed with features to increase hygiene and protect the internal bearing.
Starting with material selection, most food and beverage product lines now include the option for either food-grade polymer or stainless steel. Both materials protect from corrosion and a wide range of chemicals commonly used in washdown operations. Keeping housings free of corrosion is the first step in ensuring higher food safety and reliability.
Housings also are designed to enhance cleanability. Encouraging the shed of liquids and food particles, while minimising areas that are difficult to clean is of utmost importance. Utilising larger corner radii and ultra-smooth surface finishes are two design features to address this need. Gaining USDA acceptance through the AMS review program provides evidence of incorporated hygienic features.
Process equipment manufacturers often incorporate equipment designs to minimise cracks and crevasses around the bearing mountings. Regarding hygienic bearings, the most popular option is the “stand-off” design, which places spacers between the flat mounting surface of the housing and the equipment – increasing cleanability.
Many bearing manufacturers now offer this feature built into the housing, providing quicker installation and less fabrication for original equipment makers (OEMs) and end-users.
Food safety is not only about minimising microbial threats and corrosion but also ensuring detectability in cases where foreign particles may enter the food stream. Detectability comes in several forms and often changes depending on the processors and products.
Using high-visibility objects helps to minimise the risk of foreign objects reaching a consumer. Bearing manufacturers often use blue – one of the least naturally occurring colours – on housings and accessories for quick visual detectability.
Full stainless steel housings also are beneficial to food and beverage processors, allowing metal and X-ray detectability should a housing piece enter the food stream. Some manufacturers offer blue polymer products embedded with stainless steel particles to provide optical, metal and x-ray detectability in one unit.
Hygienic Bearings built for washdown increase reliability and food safety
Washdowns within food processing facilities are essential, but also one of the primary reasons for equipment damage. Bearings are not exempt from potential damage, so they must be able to withstand washdowns while ensuring food safety. From full stainless steel construction to washdown-rated seals, bearing manufacturers now offer some of the most food-focused components for these conditions.
Stainless steel bearing construction offers corrosion protection from washdown and harsh chemicals. While designs differ slightly between manufacturers, most food and beverage bearings are made from high-carbon stainless steel. These materials balance toughness and corrosion resistance, increasing longevity in these difficult environments.
Keeping contaminants out of the bearing and lubricant in the bearing is important for increasing reliability and maintain food safety. The ingress of contaminants can damage internal components and degrade the lubricant.
To combat this, some food and beverage producers may pump excessive amounts of grease into bearings, purging contaminants. This practice is wasteful and can compromise food safety by increasing the chances of contact with purged grease.
Bearing manufacturers now offer enhanced sealing technologies and maintenance-free features to address these issues. The IP69K rating is now offered on many ball-bearing products. Hygienic Bearings with this rating meet the highest levels of ingress protection as defined by ISO 20653. This standard outlines testing enclosures under high-pressure, high-temperature water at various angles – like the conditions found in washdown operations.
With the IP69K rating, hygienic bearings are often sealed for life, decreasing maintenance costs and increasing food safety. Additionally, lubricant technologies, such as solid lubricants, allow for greater survivability and improved food safety. Instead of using semi-solid grease, solid lubricant is a hard, polymer-based substance solidified within the bearing.
Some of the benefits of solid lubricants include increased resistance to wash out and minimised purge from the bearing. Solid lubrication formulas are available with NSF H1 registration and can sometimes comply with popular religious ingredient restrictions. Some food and beverage processors have claimed several times life increases simply by switching to this lubricant technology.
Other bearing technologies also are available to eliminate the issues of washdown and lubricants altogether. Plain bearings are a popular choice for OEMs and food producers due to their reduced complexity and ability to operate without lubricant. Manufacturers offer engineered polymers that provide high chemical resistance, food-contact compliance and favorable mechanical properties.
These polymers provide a versatile way to deliver custom bearing solutions for challenging environments. The lack of lubricant minimises maintenance and the risk of food contamination. However, these products typically cannot handle higher loads or speeds, limiting their utility to certain applications.
Various polymer plain-bearing styles
Conclusion
The food and beverage markets are rapidly evolving, demanding higher performance and safety standards than ever from equipment. To keep equipment running reliably and safely, bearing manufacturers have developed specific product lines to meet these demands.
Balancing regulations from various geographies around the world poses a challenge and requires careful consideration of each component. Food-grade materials set the industry standard in food-specific bearings.
Food processors seek to increase food safety with components that offer high detectability of contaminants and corrosion prevention. Hygienic Bearings now incorporate features that are designed to help withstand harsh washdown conditions and minimise relubrication. By combining these features, bearing manufacturers are helping to set a new standard of increased reliability and food safety for processors.
