Bearing units can pose a risk to food safety - why and what can be done to prevent?
The importance of ensuring food safety on production lines can’t be overstated, and it’s to help maintain
high standards that these new bearing units were developed. These two videos underline why it’s such a
How mounted bearing units risk food safety
Eva Otel, one of SKF’s food and beverage industry specialists, explains
how bearing units can get contaminated during processing and cleaning, allowing bacteria to grow
About listeria – one of the bacteria that can strive in bearing units
Birgitta Bergström, of the Research Institutes of Sweden’s Microbiology
and Hygiene Department, demonstrates how dangerous listeria forms, multiplies and escapes from
biofilms, and how you can avoid this happen.
Key questions and answers
Q: Is it important for hygiene reasons to eliminate the gap between the bearing inner ring
and shaft on an open unit? (e.g. with a sealant)
A: For ease of mounting, all the insert bearings are loose on the shaft when mounted, and
this does create a gap. That's why we understood we had to seal the complete unit when full hygiene is
required. So if you need a 100% hygienic unit, go for the fully sealed one.
Q: What is the reason that we are focused on hygiene in the food sector more now than in
A: More and more products have extended shelf life and are supposed to be stored at
ambient temperatures, and that gives a bigger risk.
Innovation in hygienic design and bearing performance. How this was tested.
SKF has put considerable development, expertise and technology into ensuring that the new bearing units are
suitable for even the most demanding food and beverage applications, as these two videos explain.
SKF F&B Blue Line - Innovation in hygienic design and bearing performance
Fabio Falaschi, the SKF product development manager behind the Food Line
bearing units, details how the new solution raises the bar for hygienic design, and for outstanding
reliability in washdown and various processing environments.
SKF F&B Blue Line - Testing the hygienic design
Alessio Nebbia Colomba, SKF product development engineer, recalls the rigorous performance testing conducted on the Food Line bearing units – both inside SKF and by third-party experts. For example, he highlights the cleanability and performance difference of conventional re-lubricable units, compared to hygienic SKF units equipped with relubrication-free bearing technology.
Key questions and answers
Q: Could you deliver the Blue Range bearings units with solid lubrication?
A: Solid lubrication has been widely adopted so far as a work-around solution, since the
relubrication-free solutions offered before were not nearly as effective. Development of a specific solid
lubrication can be done to create a special variant if required. Nevertheless, we think that the new
innovative SKF Food Line solution as it is delivers effective performance, most probably better than a
solid lubrication solution.
Q: Sometimes end caps fall off because of contact by high-pressure hoses or people hitting
them. Did you test the rigidity of the end cap with that in mind or did you only test with high-pressure
A: The end cap has been tested up to 80bar pressure from a 30cm distance (which is quite
harsh compared to standard applications we have seen) and we found no dislocation or movement. In addition,
the new patent pending anchorage system assures a much more reliable anchorage compared to the classic
snap-fit solution, especially protecting against hitting.
Q: Are the watertight capabilities of these hygienic bearings certified for thermal
A: We have performed some tests on thermal cycles and found that there weren't major
deviations on the main cover dimensions. Therefore, we do not expect performance difference in this area.
Q: What are the maximum and minimum temperature environments the housing and grease are
A: In continuous temperature, -20˚C to +80˚C, and in peak temperature, -30˚C to +100˚C. In
any case of extreme temperature conditions, our advice is to get in contact with SKF application engineers,
just to be on the safe side!
Q: Is there a tolerance diameter on the housing to align the ball bearing correctly?
A: In the case of the fully-sealed unit, for the back seal to be effective, the shaft
tolerance against the housing is +/-1˚. For the units without a back seal, it’s +/-5˚.
Why shift form food-grade to food-safe bearing units? The value.
As well as the technical benefits, there’s a clear business case for moving from food-grade towards a
food-safe approach within your operations.
The shift from food grade to food safe bearing units
David Oliver, one of SKF’s food and beverage industry drivers, brings
facts about food safety recalls and what the shift from food-grade to food-safe bearings means for
the sector. He highlights how SKF’s new units can reduce food safety risks, improve line
availability, and reduce maintenance, cleaning and environmental costs.
Key questions and answers
Q: It looks like you have conducted extensive testing to ensure the performance of this new
units. Could you tell us more around bearing life at customer facilities?
A: We performed some validation through selected customers to evaluate the effective
benefits in terms of bearing life in demanding conditions. In applications where we tested the new
bearings, we managed to almost double bearing life expectancy.
Q: When you speak with end-users, do you see a shift towards food-safe solutions? How is
this balanced with reliability targets?
A: There is definitely a shift towards proactive food-safe thinking: this is the priority.
End users also then enjoy the benefits of reduced maintenance needs/costs and improved reliability.
Contribution to environmental targets. About waste handling at end of life.
SKF Food Line bearing units are environmentally friendly – not only in the benefits they can bring to users,
but in their construction, too. These two videos take a closer look at the related environmental issues.
The unconsidered environmental gains
Eva Otel, one of SKF’s food and beverage industry specialists and
sustainability managers, discusses the environmental implications of a traditional washdown and
relubrication cycle. She also details how the new Food Line solution can help reduce such impacts
while fostering a prevention-oriented environmental culture.
A second life?
Taina Flink, recycling design specialist at Stena Recycling, shows the
recycling process for bearing units, and shares tips about waste management during the bearing unit
Key questions and answers
Q: These bearings reduce the carbon footprint of a plant when in use. But what about the
production phase? Are these bearings more environmentally friendly to produce compared to the 'old'
A: Yes. When we started this offer, all parties were involved, including design,
manufacturing and supply chain, so throughout the process we have considered how to minimize the
environmental impact from a full life cycle perspective.
Q: Should we expect a future increase in sustainability regulations and obligations? Can
you give some examples?
A: Packaging is in focus now, but product recyclability is likely to be regulated as well,
or at least be incentivized.
Q: It was mentioned that the units are FDA approved. Do they also fulfil EC 1935/2004 for
Food Contact Materials?
A: Yes for the cover, housing base seal rubber, back seal, and the bearing sealing system.
Q: Has there been any test of the plastic covering of the bearings with respect to the EU
A: The end cover to be mounted on the housing is made of TPU and it's both FDA and EC
Q: What stainless steel grade is used in the bearing insert of the stainless steel version?
A: It’s AISI 420 B.