How to Measure, Prevent, and Eliminate Stick-Slip and Noise Generation with Lubricants
Tribological contacts between plastic or polymer materials can exhibit stick-slip behavior that generates noise. Tribological properties can be influenced by lubricants such as bonded coatings, greases, and fluids. In this paper, well known theories about polymer friction from the literature will be shown to be useful in the development of new lubricants. Theoretical results have been validated with a Ziegler Stick-Slip Test Rig. The test methods presented in this paper are used in the development of lubricants for automotive applications (in the interior of the car including invisible lubricants developed for Class “A” surfaces).
Under certain conditions, a sliding motion between two surfaces does not generate a stationary friction force, but the motion alternates periodically between adhesion and sliding. This phenomenon of oscillating friction between two surfaces is referred to as stick-slip.
Since stick-slip is a recurring event, it may be perceived as harmonic vibration or noise. Stick-slip effects are a frequent phenomenon in everyday life: when a table is pushed along the floor, its legs may begin to vibrate, as will a wineglass when a wet finger is moved along its rim. Stick-slip events in the interior of a car can generate annoying noise.
Polymers in particular can have a high static friction coefficient and can exhibit stick-slip in tribological contacts. Tribological properties can be influenced by the use of lubricants.
In this paper it is shown, how theories about polymer friction can be used in the development of new lubricants. Analytical results will be validated with a stick-slip test rig. The introduced test methods are used in the development for lubricants like oils, greases, fluids and bonded coatings for all applications, where friction induced noise can be present.
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