<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">The article deals with development of new grid profiles in the equipment for cleaning of seed cotton from major impurities, improvement of the cleaning efficiency of the machine, and calculation processes. Four types of grid profiles were considered for cleaning machines when cleaning seed cotton from small and large impurities. Two versions of the profiles were installed: a radius-shaped and a curved metal grill. Profile fences were developed at the "Pakhta Djin KB" practical plant and joint research was conducted on installing of an experimental full-profile bench. Experiments were carried out at different speeds to determine the performance and cleaning efficiency by studying different profiles of the column bars in the experimental equipment for cleaning cotton from large impurities. The results of the experiment showed that the iron sheet bent colosnik grid is preferable. The recommended iron columnar grating is recommended for industrial implementation.</span></span></p>