Improving the Efficiency of Seed Cotton Cleaning Technology through Differentiated Technological Clearances in Peg-Spike and Saw Drum Sections

Purpose: This study aims to improve the efficiency of seed cotton cleaning technology by establishing rational, differentiated technological clearances between the peg-spike and saw-drum working elements and the underlying grid/mesh surfaces, accounting for the progressive structural transformation of cotton locks during processing. Methodology: The structural composition of seed cotton was quantified using a structural indicator K, defined as the ratio of the total count of individual cotton locks to the total count of seeds in 50 g samples taken before processing and after each cleaning section. The proportion of single-seed locks (P_single) was evaluated independently to distinguish structural loosening from lock dispersion. Two cleaning-line configurations were evaluated on a laboratory test bench at the Tashkent Institute of Textile and Light Industry: Variant 1, the standard configuration (32 drums: 4 peg-spike and 4 saw-drum sections) with a constant clearance of Δ = 15 mm, and Variant 2, a proposed combined redesigned line (24 peg-spike drums in 6 sections and 6 saw drums) with a differentiated clearance sequence of Δ = 18 → 15 → 12 mm. Trials were conducted under fixed operating parameters across five independent replications (n = 5). Findings: The share of single-seed cotton locks reached 70% - 96% after only two peg-spike/saw-drum passes, confirming that cotton-lock geometry diminishes rapidly during cleaning. Implementing the combined line redesign with differentiated clearances in Variant 2 raised the overall cleaning efficiency from 80.70% to 95.06%, with fine- and coarse-trash removal improving by 4.71 and 9.65 percentage points, respectively (p < 0.05), without inducing fiber damage or seed chipping. Originality/Value: This study provides the first quantitative link between an empirical structural indicator of lock disintegration and a stage-wise, differentiated clearance schedule, providing an industrial engineering basis for upgrading primary cotton-cleaning lines.