An experiment was conducted to determine how a seed coat fragment (SCF) reacts after colliding with each of 10 different experimental grid bars mounted on a saw-type lint cleaner simulator. A high-speed video camera recorded the action that took place. The included angle of the sharp toe of the grid bars (or the clockwise angle from vertical) ranged from 30º to 105º in 15º increments. A rounded grid bar with a 0.76-mm (0.030-in) radius was also included in the experiment. Results showed that grid bars that had an included angle of the toe of the grid bar larger than the included angle found on conventional grid bars appeared to adequately remove a SCF. Also, grid bars that had a second corner a short distance from the toe of the grid bar appeared to remove the SCF more quickly and completely from the fiber bundle, and after separation from the fiber bundle, the SCF retained more energy and its momentum continued for a longer time period. Considering the position of the SCF a short time (700 µs) after impact with the grid bar, grid bars that had a 105º, 60º, and 45º included angle from the toe of the grid bar, and the rounded grid bar, performed best in removing SCFs from fiber bundles. These grid bars warrant further testing on a full-size conventional lint cleaner.
