Based on a successful metal to composite replacement in another application, our paper mill customer presented another problematic application. The existing design – a bronze bushing would start releasing metal shavings into their production line as it experienced wear. Metal particles in a finished paper product presents a significant problem, to say the least.
Typically an application like this would result in a recommendation of CG material, a graphite impregnated material that is “self-lubricating” – meaning in bushing form, it can operate without lubrication for some time. In this case, though, the operating environment requires a self-lubricating material because the bushing operates in a very wet environment.
Also present is a constant water “flooding” – not a spray, not submerged, but constant heavy flow of water – so moisture absorption of a composite recommendation is also critical. And the customer asked us to maximize radial compressive strength and modulus. Finally, the new part would have to be designed as a like-for-like part since the journals and housings could not be changed or modified.
WS Hampshire recommended Ryertex ST which fit the requirements extremely well – lower moisture absorption, stronger, and self-lubricated. The pictures on the right show the like for like design of the parts.
BUT WAIT, THERE’S MORE! How about an incredible weight reduction from 21 pounds in brass to 3 pounds in Ryertex – an 86% reduction in weight!
Upon installation, which became much easier with the light weight composite, the production supervisor implemented a quarterly plan to pull the bushing and measure for wear to be sure the Ryertex ST performed as expected. As of this writing (September, 2016), the installation is approaching one year. The latest data shows wear of 5/32″ or .156″ total which is a significant improvement from the brass bushing. Our customer is very, very happy!
Understanding what problems needed to be solved and the application environment have resulted in another value added win for the customer. To learn more about this project or how our materials expertise, combined with precision CNC machining services can benefit your next project, contact us today.