Limiting PV, Wear Factor and Coefficient of Friction
Limiting PV is a description of the capability of a bearing material to resist the pressures and velocities of use. It is defined as the product of the unit load P (psi) based on the projected bearing surface area and the velocity of the shaft expressed in feet per minute.
A glass transition temperature (Tg) describes the point at which a thermoset polymer changes its physical structure to a crystalline state and is an average of the temperature range those changes occurred. The actual glass transition temperature range depends upon the molecular structure of the material, the testing method, sample preparation, the cure schedule, and the degree of cure.
Glass epoxy tubes and sheets have been used for many years in outdoor applications such as railroad track insulators and oil refinery insulators. They act as electrical insulation preventing electrolytic and galvanic corrosion and are constantly exposed to UV radiation. Convolute & filament wound glass epoxies have also been used for decades as antenna protection and are frequently the body of sonobuoys dropped into the ocean for sonar underwater research or submarine detection.