A sensor for friction measurement on a moving web

This research introduces a new class of sensor, a sensor for in-process, on-line friction measurement. Friction is not an intrinsic material property but a system related phenomenon. Its measurement is straightforward. Two materials of interest are placed in contact in the desired environment and relative motion is induced. The motion inducing forces are measured and related to applied contact (normal) forces resulting in friction coefficients. These measurements are typically taken in a laboratory setting. A material's behavior in friction systems (tribological systems) is of interest to both academics and practitioners. While laboratory tests of material samples in tribological systems are used to predict this behavior, on-line or in-process friction measurements are non-existent. A new class of sensor, the tribosensor, is developed that accomplishes tribological system testing while the material (one of the two materials in the tribological system) is being processed or in motion such as paper, plastics and other web-like materials. In order to predict a material's behavior in a given tribological system, the target system is usually approximated in an experimental setup. Experimental results can then be related to actual behavior. Similarly, the tribosensor must approximate the target system and a relationship between tribosensor output and actual system behavior must be established. A device was successfully developed and tested using paper as the web material. It is anticipated that the new sensor will: (1) provide manufacturers a practical friction measurement tool for on-line process control of moving webs; and (2) provide a useful tool for further tribological and sensor development research.