When a large commercial bakery needed bearings that could operate in a 500°F-oven environment, the company turned to Graphalloy for a solution.
The bakery producing bagels, pita breads, and flat breads needed bushings that could operate without the need for lubricant in a 500°F-oven environment. They were refurbishing their pita bread oven line, which is part of their pita chip production line. The oven is a three-tiered conveyorized oven which bakes the pita bread quickly, directly on a metal mesh conveyor belt.
Due to the belt speeds required for the quick bake of the pita bread, belt tracking was an issue, so they installed a series of guide rollers to help keep the belt running straight. In this setup, the bushings are pressed into the rollers which run on a vertical stationary shaft.
In the past, they had tried greased bronze bearings as well as plastic bearings but they proved to be a maintenance headache as the high temperatures degraded the lubrication and the bearings would fail. The customer purchased 24 Graphalloy copper grade bushings and installed them in the oven. Since installation in 2011, the bushings ran well and proved to need no maintenance over time.
In 2018, the time came for them to replace the oven belts. Although the Graphalloy bushings had not failed, the bakery maintenance manager assumed that they would need to replace the bushings while they had the oven disassembled.
When the maintenance team inspected the bushings, they found almost no wear even after more than seven years of use. The rollers were reinstalled without changing the bushings and the maintenance manager said he fully expected them to last another seven years. He estimated the cost savings in lubrication and shut-down time to be more than $20,000 per year.
Due to this success, they are also trialing Graphalloy pillow blocks (type 845) inserts on a bagel boiler and reviewing other possible applications.
Graphalloy has a wide temperature range, -400°F to 1,000°F, works submerged in low viscosity and corrosive liquids, and comes in FDA acceptable grades.
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