Investigating the efficiency of saw gin machine in the processing of seed cotton at different levels of moisture content, rotational speed and cotton variety

Separating the seeds from the cottonseed with a gin has an effect on seed quality and germination. Mechanical damage reduces the economic and biological value of the seeds. The effect of mechanical damage is considered a serious problem in seed production, and reducing this effect leads to an increase in the efficiency of seed utilization. This study was conducted with the aim of reducing the mechanical damage of cotton seed and increasing the efficiency of gin and rotating the saw and moisture content appropriately in two varieties of Hekmat and Golestan cotton seeds.

To increase gin efficiency, the effect of saw rotation in three levels, 300 (S1), 350 (S2) and 400 (S3) rpm, lint moisture content in three levels, 3-5% (M1), 6-8% (M2) and 8-10% (M3) and seed variety in two levels of Hekmat (V1) and Golestan (V2) varieties were studied in a factorial experiment in the form of a completely randomized design with three replicates. The parameters length, width, thickness, geometric mean, sphericity coefficient and bulk density of cotton seed were determined according to the relationship between the physical properties of the seed and the performance of the machine during processing. In addition, the parameters related to the gin, including the extent of mechanical damage to the seed, percentage of ginning and material capacity, were measured. The data were subjected to analysis of variance and the regression equation between the independent variables (experimental treatments) and the dependent variables (measurable parameters) was determined.

An increase in moisture content led to an increase in the geometric mean of the dimensions of the cotton varieties. The increase in mechanical damage to the seed also increased with the increase in moisture content from 6-8% to 8-10%. The main reason for this was the adhesion of the fibers to the cotton seeds and the increase in the time for separating the fibers from the seed. The results showed that increasing the moisture content from 3-5% to 6-8% increased the percentage of ginning operations and the material capacity of the gin in both Hekmat and Golestan varieties; however, as the moisture content increased to 8-10%, the extent of these parameters decreased.