Silver lining for food industry applications

Continuous high speeds, demanding hygiene standards and challenging operating conditions call for robust, reliable bearings that deliver cost-effective production at food and beverage plants. Any bearings deployed in these applications must prevent the onset of corrosion, which is a common threat on production lines subject to harsh wash-down regimes.

Central to NSK’s product offer for the food and beverage industry is its RHP Silver-Lube range of bearing units. These bearings comprise a host of corrosion-resistant components, including inserts with high-grade stainless steel rings and balls, cage, flingers, and set screws. “Furthermore, the inserts sit within a high-strength PBT thermoplastic housing, featuring a stainless steel grease nipple,” says NSK.

Recurring production downtime

“Excellent protection against corrosion, chemicals and detergents ensures Silver-Lube can endure challenging operating conditions at food plants around the world,” adds the company. “A case in point is a facility that processes baby leaf products for sale to leading supermarkets. Here, the leaf harvester machine previously featured numerous low-cost mounted-unit bearings to support shafts of various diameters. Unfortunately, the machine was prone to ongoing failures, due to the ingress of dirt and water into its bearings. The upshot was recurring production downtime and, on occasions, ruined crops.”

NSK experts accepted an invitation to review the application and operating conditions. This appraisal process ultimately led to the replacement of the existing mounted units with Silver-Lube, featuring “an innovative flinger seal arrangement and stainless steel bearings. During the subsequent harvesting season, just two bearing failures occurred, improving productivity and generating savings of €63,300, thanks to significantly lower production losses”.

Continues NSK: “As this success story illustrates, Silver-Lube bearing units are ideal for applications requiring frequent wash-downs, optimum hygiene standards and good chemical resistance over a broad temperature range.”

Sealing off the damage

As well as optimal protection against corrosion, Silver-Lube is said to offer durable and heat-resistant silicon rubber seals that protect against penetration by water or dirt, which is important to prevent the onset of defects and avoid washout of the bearing’s wide-temperature USDA H1 food-grade grease. Complementing the seal is the stainless steel flinger, which prevents the ingress of bacteria and helps the seal to resist impact damage.

Further Silver-Lube advantages outlined by NSK include: a paint-free resin housing to eliminate any risk of chipping or flaking; a smooth finish to prevent dirt adhesion; a cavity-free design to avoid ‘bug traps’ that might harbour bacteria or mould; suitability for working temperatures from -20 to +90°C; long service life; and low cost of ownership. Silver-Lube is also NSF-approved, meeting strict standards for public health protection.

“Another noteworthy attribute is the ability of Silver-Lube bearings units to accommodate any initial misalignment from mounting errors, making them ideal for use in food and beverage plant machinery such as shakers, fillers, centrifugal separators, bottling machines and conveyors.”

Silver-Lube bearings units are available in pillow block, two-bolt flange, four-bolt flange and take-up unit configurations.