Thanks to the very low values of PTFE, the coefficient of friction of a PTFE-lined bearing is usually very good during the beginning of the bearing's service life. However, the very thin PTFE layer will be worn away over time, creating a rapid increase in the COF as metal-on-metal contact occurs. On the other hand, iglide® plastic bearing materials are a homogenous blend of base polymers, strengthening fibers, and solid lubricants. With particles of lubricant throughout the entire bearing thickness, the bearings have a brief start-up phase while they mate with the shaft surface, after which the COF remains constant throughout the entirety of the bearing's service life. See a comparison of iglide® bearings compared to PTFE-lined in terms of rotation vs COF in the above graph.

In-house testing was also carried out to investigate how friction between the plain bearings and their shafts changed through the service life/wear of the bearing. The COF of iglide® plastic bearings and metallic PTFE-lined bearing options were tested as brand new parts, then after 100 hours of rotation. This test was performed at 0.33 ft/s (0.1 m/s) under a load of 145 psi (1 MPa). Results showed that while both bearings exhibited the same COF as new parts, as wear occurred, the COF of the PTFE-lined bearings increased exponentially, as opposed to only a nominal increase in COF by the iglide® bearings.

5. RoHS compliance

Since 2006, RoHS (Restriction of the use of Hazardous Substances) has steadily tightened guidelines set to limit the values of industrially-necessary, yet potentially harmful substances, including lead, hexavelent chromium, mercury, polybrominated biophenyls, polybrominated diphenyl ethers, and cadmium in the manufacture of electronics and electrical equipment.

With newer RoHS II Standards, a maximum value of 0.1% of the total product weight is allowed for most of these substances, with the exception being cadmium, which is limited to 0.01%. These standards are similar to regulations that are also in effect in countries such as Germany, Japan, and China, so meeting these material standards is becoming of global importance for manufacturers. Though widely used in a vast array of applications, PTFE-lined metal bearings contain alloys that are not compatible to these new standards.

Customers that need to adhere to RoHS Compliance Standards can turn to iglide® plastic bearings in place of metal alloys. All substances covered by the new RoHS standards are absent from each iglide® composite plastic material.