Molded Oil bearings cut cost of ownership on packaging machine

NSK's Molded Oil bearings are being used to cut maintenance intervals and deliver extended periods of bearing reliability on a new packaging machine for beef burgers, which has been custom-designed by Autowrappers for Unilever - Birds Eye Foods. The Molded Oil bearings are also expected to reduce the total cost of ownership of the new machine by removing the downtime associated with relubrication intervals and by cost savings achieved through reduced requirements for replacement bearings and bearing lubricants.

The new Unilever machine is the latest in a long line designed and manufactured by Autowrappers for food packaging applications; the company regularly supplies equipment ranging from standalone machines for low-speed, hand-fed applications to fully automatic integrated systems that match the exacting demands of high-volume, fast-moving consumer goods (fmcg) and food processing and packaging lines.

The problems of supplying machines for food processing applications are well known, one of the most prevalent being the frequent washdowns that machines are subjected to in order to maintain high levels of hygiene. To protect against this procedure, most machines used for food processing are fabricated from stainless steel. However, components such as bearings are not so easy to protect; a fact that made Autowrappers and Birds Eye look for an alternative on the beef burger packaging machine.

Lubricant loss

In particular, the problem they were looking to solve concerned the tendency of lubricant to be flushed out of conventional bearings under repeated washdowns. The loss of lubricant is usually progressive rather than immediate, but the result is inevitably the same: premature failure of the bearing or bearings concerned. In the food processing industry, any downtime – planned or not – is costly, so any new design innovations that can overcome the problem are particularly welcome.

NSK's Molded Oil is one such innovation. A plastic composite material containing abundant lubricating oil (or grease), Molded Oil is a replacement for conventional lubricated bearings. Differing from other marketed oil-impregnated plastics, where the oil content is merely a few per cent by weight, Molded Oil permits a lubricating oil content of more than 50 per cent by weight.

NSK Bearings equipped with Molded-Oil are environmentally friendly, 'fit and forget' units that are designed to enhance the performance of machinery and equipment in all types of environments, especially those exposed to contaminants such as water or dust. Importantly, they address the problem of loss of lubricant due to water ingress, a feature of particular importance on machines used in food processing, as it provides the benefits of increased reliability and longer maintenance-free intervals.

Sealed deep-groove ball bearings

NSK introduced Molded Oil to Unilever - Birds Eye during a visit with its local distributor. The response from Unilever's new product and improvement engineers was extremely positive, resulting in the specification of the bearings - sealed deep-groove ball bearings and sealed inserts mounted in Silver Lube corrosion-resistant housings – on the new machine. To facilitate this process, NSK arranged for a senior application engineer to visit Autowrappers and provide advice and technical support on all aspects of Molded Oil technology.

"The solution that we have provided to Unilver/Autowrappers clearly demonstrates the benefits of working with recognised bearing suppliers and authorised distributors," says Simon Grant, NSK's Aftermarket Business Development Manager. "The engineering support provided by NSK, together with access to the latest technological bearing products, is a package that is simply not available from smaller bearing manufacturers and independent distributors. In addition, by supplying an innovative bearing solution, NSK has provided a value-added service to the customer, solving his problem and helping to reduce the cost of ownership on a what is considerable machine investment."