Wear Prediction
Numerical surface simulations analyze the friction, lubrication and wear behavior of materials in relative motion. In the development of new synthetic yarns, tribological modeling predicts how spin finishes affect the friction of fibers passing through metal guides. This simulation helps engineers optimize lubricant formulations before conducting expensive trial runs in the mill.
Fiber Contact
The simulation calculates the contact forces at the microscopic level, taking into account the surface roughness of both the yarn and the metal guide. By modeling the behavior of individual polymer chains and the lubricant layer, the simulation predicts the transition from dry friction to boundary and hydrodynamic lubrication. This allows designers to predict yarn tension across a wide range of production speeds.
It also estimates the heat generated by friction at the guide surface.
Lubricant Simulation
Predicting the wear rate of machine parts like travelers and ceramic guides is another key use of these models. High friction leads to groove formation in yarn guides, which then damages the yarn and causes breaks. Modifying the guide material or surface finish based on modeling results extends the lifetime of these components.
Validation Method
Validating the model requires comparing the simulated tension and wear results with data collected from laboratory test rigs. If the model predictions match the test results, it can be used to evaluate new guide geometries and yarn finishes. This validation ensures that the modeling tool remains reliable for process design.
