Wear resistance depends on a number of factors, of which the coefficient of friction is one, but the magnitude of the coefficient of friction itself depends on a number of different environmental factors. Most importantly, the physical properties of most plastic polymers are pretty much the same on the inside and the outside, so it’s hard to see any differences in key properties (such as density, thermal expansion, and flow resistance during injection molding) between composites with the same base material.
The use of additives, such as reinforced fiber, PTFE fabric, PEEK and so on, has a very small impact on the value in the physical property table, but it may greatly affect the wear and sliding performance of bearings. Even if the composition of the mixture is very small, it may also have a significant change on the service life of bearings.
In our material development projects, even a small portion of the pigment used to change the color of the material may determine the success or failure of bearing durability. Therefore, the physical property table has a certain role, but it is far from enough for us to evaluate the performance of bearings.