produce up to 400% improvement in bearing service life at Georgia poultry plantAt the Seaboard Farms chicken-processing plant in Elberton, G.a., composite bearing units with double-protection seals are yielding up to four times greater service life than standard bearing units in conveyors, breading machines and other equipment.

   According to Seaboard Farms Schedule Planner Wayne Jones, about 150 of the new Marathon Series Composite Mounted Bearing Units, supplied by MRC Bearing Services, are now operational at the plant.

   “With standard bearing units, rust and lubricant washout were constant problems,” says Jones. “MRC Marathon Series units have a much longer life in the same applications, and require no regreasing.”

   The Seaboard Farms plant is primarily a “cook” operation that processes poultry that has already been skinned and deboned. A network of conveyors operates throughout the plant, delivering chicken parts to breading, battering and frying stations. Some of the conveyors are large units with multiple shafts and 12 or more bearing positions.

   Prior to mid-1998, most of the plant’s conveyors and other processing equipment used standard ball or roller bearings with cast-iron or nickel-plated housings. These bearing units were subjected not only to food contaminants but also to daily high-pressure washdowns with bleach, chemical sanitizers and other caustic cleaning agents. Many units showed signs of rust within a few weeks; others suffered significant lubricant loss due to washout. Plant maintenance technicians were required to manually regrease standard bearings at least once a day. The frequent relubrication often caused damage to bearing seals. Due to seal problems or contamination, the typical bearing unit failed within two or three months and had to be replaced.

   Especially difficult was the poultry breading application. Here, sifting conveyors holding flour are arranged above a belt conveyor carrying chicken parts. As the poultry passes by, the overhead conveyors release a stream of flour onto the chicken parts below. Flour in the air poses a continual contamination threat for the breading machine’s bearing units.

   “During operation, flour particles routinely settle on the machine’s bearing units,” says Jones. “If a bearing unit is not sealed effectively, these particles can enter the bearing housing. Once inside, the particles act like a lapping compound, causing wear and seriously damaging the insert bearing.”

Corrosion-resistant housing
When bearing problems persisted, company officials consulted with Will Campbell of the distributor Campbell Sales and Service in Athens, G.a. In mid-1998, at Campbell’s recommendation, Seaboard Farms installed a pair of Marathon Series pillow blocks, equipped with stainless steel insert bearings, on a conveyor line. Unlike conventional bearing units, Marathon Series units feature a light-colored thermoplastic housing that resists corrosion from water, food acids, cleaning agents and other food industry chemicals. The units’ two-part seal consists of an AISI 304 stainless steel flinger and an AISI 304 stainless steel insert seal. Together, these seal components form a barrier that prevents contaminant entry and protects against lubricant loss due to high-pressure washdowns. The unit’s stainless steel insert bearing is lubricated for life with a USDA-approved food grade grease.

   The initial set of Marathon Series bearing units proved highly successful in the Seaboard Farms conveyor application. Over the next few months, utilization of Marathon Series greatly increased. Maintenance technicians installed Marathon Series units featuring stainless steel insert bearings in a host of plant applications, including large conveyor lines and poultry breading equipment.

   According to Wayne Jones, even in the most difficult applications the Marathon Series units employed at Seaboard Farms have lasted an average of six to nine months – three to four times longer than the conventional bearing units used previously. The company has already reduced bearing replacement costs. In addition, because the units are lubed for life, technicians never have to regrease them. The changeover resulted in labor savings of more than 10 man-hours per month and allowed the plant to assign technicians to more important maintenance tasks.