Bearing down on contamination

For many years, the food and beverage industry has been a focus area for NSK, and to combat these increasingly important issues, the bearing manufacturer NSK continues to provide components with multiple highly-relevant design characteristics, such as corrosion-resistant materials, sealed construction and lifelong lubricants, that are all compatible with foodstuffs.

The challenges are endless

Bearing applications for food plants stretch far and wide, from raw material, to primary (cutting and mixing) and secondary (moulding), conveying, inspection, heating and packaging processes - while beverage applications focus on bottle moulding, filling, sealing and packaging.  But they all have one thing in common – the requirement for high-speed, uninterrupted, hygienic operation.

To put it bluntly, continuous high-speed operation, stringent hygiene standards and demanding operating conditions call for reliable, robust bearings that facilitate cost-effective production, while optimised performance and maintenance-free operations are also essential, despite having to withstand high temperatures, excessive water and intrusive chemicals. The bearings must also prevent any potential contamination safely and reliably.

The fact truth is, your bearings have an endless list of challenges to contend with.

A silver lining for food facilities

Among the core products from NSK specifically for hygiene-related applications, is the RHP Silver-Lube® range of corrosion-resistant bearing units.

Silver-Lube® units consist of bearing inserts with high-grade stainless steel rings and balls, cage, flingers and set screws, Silver-Lube® units are further enhanced with durable, heat-resistant silicone rubber seals. These inserts are located within a high-strength PBT thermoplastic housing, featuring a stainless steel grease nipple and bolt-hole liners, purposely moulded into the housing to achieve optimum hygiene.

Adding to the strong list of hygienic benefits, the PBT thermoplastic resin housings of the NSF-approved Sliver-Lube® bearings are paint-free, eliminating potential of chipping or flaking, while also offering an exceptional working temperature suitability from -20° to +90°C. And let’s not forget the long life capacity and low total cost of ownership.

These innovative bearing units also benefit from the sealed-for-life lubrication provided by NSK’s Molded-Oil technology. Molded-Oil is a solid lubricant, designed to not only prevent the ingress of contaminants such as water and particulates, but means that lubricant cannot exit the bearing and enter other areas of the machine, where it could potentially come into contact with foodstuffs.

As standard, the bearings are equipped with a proprietary oil-impregnated material that compromises oil and a polyolefin resin with an affinity for oil. The carrier material releases lubricant continuously over a long period, ensuring the operating environment remains clean, with the removal of any oil filling requirement.

Turning over a new leaf

Food facilities around the globe are turning to NSK’s innovative technology and reaping the benefits, in particular from Silver-Lube®. One as such example is a plant UK Company that harvests baby leaf produce supplied to leading supermarkets.

Milking the benefits

A UK-based milk processing plant was enduring repeated bearing failures on one of its principle conveyors, where inaccessible positioning resulted in the inability to provide re-lubrication.   As a result of this frustrating occurrence, the customer was required to change the bearings every 10 weeks, at the expense of three hours downtime each time.   As you can imagine this was proving rather costly, for from increased maintenance time and lost production.

Following an application review undertaken by a highly trained NSK engineer as part of the AIP Value-Added Programme, the milk processing plant decided to adopt Life-Lube® bearing units, utilising stainless steel bearing inserts charged with Molded-Oil lubrication, and fitted within corrosion-resistant polymer housings.

A new lease of life

Offering the combination of Silver-Lube ® corrosion-resistant housing and the sealing and lubricating properties of Molded-Oil inserts in one convenient package, more notably, Life-Lube® bearings are suitable for wet and damp conditions, including those that are exposed frequently to process fluids and harsh chemicals.

Following trials on the milk processing plant conveyor, the results were truly positive, displaying a life extension from 10 weeks to more than a full year, while also removing the need to replace the shaft after each bearing failure.  This cost, coupled with the labour costs associated with deploying two maintenance engineers, as well as lost production costs, achieved annual savings of over £10,000 – now that’s what you call a new lease of life!