Every application has certain requirements. One requirement that is crucial is from which materials do we make the Rotary Viscous dampers and friction hinges. After years of testing in environmental chambers and the real outside environment we have been successfully have found excellent materials : metallic and plastic that have more than satisfied our customers requirements.
For a friction hinge we look for materials with low wear, thermal expansion and the ability to keep a consistent coefficient of friction without stiction or noise when moving. There are also other considerations such as tolerance to heat. One special feature that our friction hinges have is the ability to perform many cycles without loss of torque without use of grease or external lubrication. Externally added lubrication adds a problem that everyone expected but never anticipated the impact. The problem was handling. If a friction hinge that uses grease that is un-shielded is handled by an auto worker and inadvertently touches another interior cabin component the results can be disastrous. I have seen actual production lines shut down because of wanton, unintentional spreading of friction grease on cloth by installers. We have revolutionized the industry with a greaseless friction hinge that out performs steel band hinges. The trick was to find materials that could achieve the cycle life, survive the abusive environments, get the same or higher torque and be reasonably priced. Rotary viscous dampers are extremely precise devices and the crucial parameters are the tolerances of the spaces where the sealed damping greases reside. So the critical mechanical characteristic of the material is the coefficient of linear expansion. So when you have your next slim-line application for a Rotary Viscous Damper or friction hinge application visit us at www.mmtech.us to discuss.