Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2007
Publication Date: 7/10/2007
Citation: Holt, G.A., Laird, J.W. 2007. Screening for optimal operating parameters for the powered roll gin stand using Taguchi's robust design. Journal of Cotton Science. 11:79-90. Interpretive Summary: The powered roll gin stand is a new ginning technology developed at the USDA-ARS, Cotton Production and Processing Research Unit, in Lubbock, TX. Earlier studies demonstrated increased processing rates and lint turnout without adversely affecting fiber properties. In some instances, fiber properties where improved. The gin stand has three main components: the paddle roll, the saw, and the seed finger roll. The speed and loading rate of these components have a significant effect on the ginning rate, turnout, and fiber properties of the seed cotton being ginned. Determining the optimal speed and loading rate settings for these components is a critical element in moving this technology into the ginning industry. Based on the operating ranges and conditions evaluated, the optimal operating settings were: 1) paddle roll speed (rpm) = 200, 2) saw speed (rpm) = 900, 3) paddle roll loading = 100% of load (20 amps), and 4) seed finger roll speed (rpm) = 7.5. Based on the findings of this research, additional studies are needed to further define mathematical relationships between production and fiber quality properties of interest and the operational settings of the powered roll gin stands components. These mathematical relationships, in conjunction with the appropriate economic factors and/or Taguchi’s loss function, could potentially result in higher production rates, greater turnout, less fiber damage during ginning, and greater profits for the cotton gin and producer.
Technical Abstract: The powered roll gin stand (PRGS) is a new saw-type ginning technology that has shown increased production and turnout without adversely affecting fiber properties. In some cases, improvements in fiber properties over a conventional gin stand were demonstrated. The new gin stand has three primary components:paddle roll, saw, and seed finger roll. The operational settings of these components have been shown to affect both production rates and fiber characteristics of the seed cotton being ginned.This research focused on determining the optimal speeds and loading rates for the paddle roll, saw, and seed finger roll components of the PRGS based on turnout, processing rate, and fiber quality data. An experiment using stripper-harvested seed cotton, with and without field cleaners, from two different fields was evaluated with Taguchi’s Method. Nine different operational setting configurations were selected for the gin stand's components. Evaluation was based on eleven response variables involving processing rate, turnout, and fiber quality measurements. In addition to predicting the optimum operational settings based on individual response variables, six different combinations of response variables were evaluated. Results varied depending upon the response variable of interest. Overall, results indicated the most "robust" configuration included the 900 rpm saw speed. Other parameters of paddle roll speed, seed finger roll speed, and paddle roll loading rate varied based on the response variables. The results emphasized the potential application of this gin stand to a real-time dynamic control system that regulates operational parameters based on processing rate, turnout, and fiber quality.