A critical process in the manufacture of plywood is drying the veneers. This is accomplished using massive multilevel ovens, containing thousands of bearings, which efficiently move the thin wood sheets along hundreds of feet to complete the task. Read on to learn how a specialized Rulon® material was developed that proved incredibly effective in this application.
The Problem was Brittle Bearings ─ Enter Rulon® 488
The material of choice for these bearings was traditionally copper graphite or carbon. The problem with these materials is they tend to be brittle at high temperature and, in the event of a flash fire, can weld themselves into the roller housings ─ hammer and chisel time!
The origin of Rulon® 488 goes back nearly 30 years, when Saint-Gobain was developing another grade to meet FDA and USPVI requirements for food and pharma industry bearings. During this process they discovered that the material they were working on just happened to be unusually effective at temperatures of 300°F and above. Realizing this bearing material (which was beginning to find its way into bakery ovens and rotisseries) would be ideal for high-temp industrial applications as well, they tweaked the formula to lean into that direction ─ and Rulon® 488 was born.
First year sales reached 30,000 bearings for the veneer oven market. Key selling points were thermal stability, long life in 24/7 service, ability to survive flash fires, and not be brittle. Bearings made with Rulon® 488 were so durable that, even in the unfortunate event of a fire, they could be removed, turned 90 degrees, and reinstalled to carry on!
Other Applications Ready-Made for Rulon 488
Over the years, TriStar has found many other applications where Rulon® 488’s unique combination of thermal, wear, friction and cost effectiveness make them ideal. These applications are primarily in dry service (various types of industrial ovens), but the material also excels as seals and rider rings, such as those found in hydrogen and natural gas compressors.
Other Uses Include:
- Applications where abrasives can find their way into service media, which causes many other filled PTFE materials to fail
- In clothes dryers as drum guides and spindle support bearings
- Auger bearings in ice machines and glass tempering line ovens
- Applications where the mating hardware is soft (e.g., 300 series stainless steel)
As we have hopefully demonstrated, Rulon 488 is unique in both service and broad application potential. When you need -400 to +550°F service, wet or dry, in corrosive environments, with chemical exposures, and/or need an alternative to glass, carbon, graphite, or moly-filled PTFE, Rulon® 488 might just be your solution! If you’d like to discuss this material or one of the many other Rulon formulations, our engineers are standing by to assist.
Common Causes of Bearing Failure
