Location: Cotton Ginning Research
2024 Annual Report
Objectives
Objective 1: Integrate new information and technologies for new cultivars, and production/handling practices to enhance quality and utility of Western and long-staple cotton for ginning.
Subobjective 1: Improve or enhance cotton fiber ginnability, textile utility, and cottonseed end-use value of new germplasm releases of both Upland and Pima cottons.
Objective 2: Develop and integrate new or improved ginning technologies, methods, and processes to enhance product quality and value, increase process efficiencies, and reduce environmental risk of Western and other long-staple cottons.
Subobjective 2A: Improve seed cotton conditioning and foreign matter and contamination extraction.
Subobjective 2B: Develop improved ginning technologies to increase efficiency and productivity and enhance fiber quality.
Subobjective 2C: Improve or enhance fiber quality and end use.
Objective 3: Enable commercial technologies that support processing of cotton companion crops.
Subobjective 3: Assist tree nut industries in improving process efficiency and reducing environmental risk.
Approach
The Southwestern Cotton Ginning Research Laboratory (SWCGRL) mission is to develop technologies that solve problems directly affecting, or being affected by, the cotton ginning industry to maximize the economic viability and competitiveness and minimize the environmental impact of the U.S. cotton production and processing system. To carry out this mission, our core problem is to address critical cotton and related companion crop production, ginning or processing, textile processing, and regulatory compliance issues - especially those pertaining to Western irrigated cottons. The cotton production and processing chain is an integrated system that starts with plant breeders selecting cultivars for yield and other factors. It includes cultural practices and harvesting, seed-cotton drying and cleaning, ginning, lint cleaning, bale packaging, shipping, storage, marketing, spinning, weaving, finishing, and garment making. U.S. agriculture, including cotton, has increasingly become more integrated where companion and rotation crop systems rely on and influence one another. Similarly, environmental impact and compliance plays a significant role in agricultural production and processing. In this 5-year research cycle, our group will use engineering, understanding of ginning systems and agricultural processing, and knowledge of the factors that affect cotton quality to assist cotton breeders in developing easier-ginning higher-quality cultivars; to develop ginning solutions for superior foreign matter removal, more efficient and lower cost operations, and less fiber and cottonseed damage; to assist agricultural industries in reducing environmental footprints and complying with regulations; and to develop information and technologies that increase process efficiencies and enhance economic viability of cotton companion crops.
Progress Report
To address the three main objectives, progress focused on cotton production, ginning, and companion crop processing.
Objective 1: ARS researchers in Las Cruces, New Mexico cooperated with New Mexico State University (NMSU) cotton breeding program working on disease resistant cotton lines and a collaborating seed company developing a long-staple hybrid cotton with similar quality characteristics to Pima cotton but that can be grown in areas, like West Texas, where Pima cannot. This lab provided gin expertise and ginned experimental cottons to produce cotton lint samples for quality analyses.
Textile tests were completed on ginned fiber samples produced by model-sized gin stands used by breeders to predict properties for cotton that will be machine-harvested and processed in a commercial ginning environment. Data analysis began to compare the textile spinning performance and yarn properties of cotton lint from these saw- and roller-breeder gins to that from conventional saw- and roller-gin stands used in modern cotton gins and from a reciprocating-knife roller gin stand that is used in countries other than the U.S.
Objective 2: A preliminary study was completed that compared fiber properties among conventional and experimental lint cleaners that use different methods of placing ginned fiber on the machine’s cleaning cylinder to remove foreign matter. Based on findings of the study, work began on installing and modifying lint cleaners that 1) use a feed mechanism that places ginned fiber directly onto the lint cleaning cylinder without changing direction (most feed mechanisms currently in use cause the fiber to reverse direction around a damaging bar edge), and 2) connect directly to the gin stand (coupled lint cleaner), therefore eliminating the feed mechanism altogether as fiber is transferred directly from the gin saw to the lint cleaning cylinder.
A collaborative study was completed with researchers at NMSU to determine ginning costs of saw and conventional and high-speed roller ginneries in the Far West. Results showed that the cost of ginning cotton using conventional and high-speed roller ginning was higher than saw ginning by 24.4 and 14.2%, respectively (ginning costs were 10.2 percentage points lower for high-speed than conventional roller ginning). Also, a 10% increase in electricity price increased the average ginning cost by 8.3%. Pima and Hybrid varieties must be roller ginned, but this information will help producers decide if roller ginning Upland cotton to obtain a high-quality fiber is also feasible in their situation.
Investigations continued to understand and exploit differences in physical properties of plastic pieces and cotton tufts to facilitate extracting the plastic at the cotton gin. Measurements of physical characteristics of plastic fragments were taken and a simple method to determine terminal velocity was conducted. Results showed a marked difference in terminal velocity between seed cotton and plastic fragments. To further understand the influence of plastic fragment size and shape on behavior in an airstream, 3D scans were taken to make area and volume measurements of cotton tuffs and plastic fragments. These measurements will provide the basis for models to predict air velocity ranges for separating plastic fragments from seed cotton. It is hypothesized that combining seed cotton cleaner techniques and air classification will greatly enhance the effectiveness of plastic fragment removal from seed cotton at the cotton gin.
On a collaborative study investigating the suitability of cotton gin byproduct materials (leaf, hulls, sticks, and motes) for various biobased applications, lab-scale grinding and pelleting studies were conducted using byproducts from three commercial gins. The byproducts were from ginning Upland and Pima cottons and included fresh and stored for one year. The studies indicated that storage impacts the ground material physical properties, such as particle size and bulk density, and pellet quality. The cotton gin byproduct pellets were good quality, meeting the international standards (ISO). Work to understand the chemical composition and energy properties and biofuel and animal feed potential of these pellets continues.
Data from evaluations of a novel pneumatic technique for cleaning roller- and saw-ginned cotton lint were modeled and the process variables were optimized using a hybrid genetic algorithm. The optimized conditions for best cotton quality indicated higher lint moisture content was more desirable, but optimal pneumatic pressure and residence time differed for saw- and roller-ginned lint. The results led to design and fabrication of a prototype pneumatic lint cleaner that will allow precise control of more process variables for further evaluation and optimization of the technique.
Objective 3: The third year of testing for a study aimed at reducing the energy footprint of walnut hulling operations was completed by ARS researchers from Las Cruces, New Mexico and Albany, California. Walnut moisture and temperature data and airflow measurements were used by ARS researchers in Dawson, Georgia to further refine and validate a computational fluid dynamics (CFD) model that was originally developed for airflow through and drying in-shell peanuts. The CFD model was successfully applied to in-shell walnuts in drying bins and provides a valuable tool for researchers to visualize and quantify airflow passing up through walnuts in modified drying bin designs. Study results indicated that current experimental drying bin modifications did not appreciably increase the overall airflow rate or provide more even air distribution. Further modifications based on the current test results and CFD model to improve the airflow in the walnut drying bins are planned.
Data analysis was completed for an industry stakeholder requested test to determine the combustibility of walnut postharvest processing facility dust. The results showed that none of the material samples burned as described in the National Fire Protection Agency guidelines.
Accomplishments
1. Cost of high-speed roller ginning. Despite it being a slower and more expensive process than saw ginning, roller ginning is used to gin the superior quality Pima and Hybrid cottons grown in the Western U.S. because it damages the fiber less. With the improved quality of many Upland cotton varieties through selective breeding and wide-spread availability of new high-speed roller ginning technology, roller ginning to retain better quality may be a feasible option for Upland cotton producers. The capacity of high-speed roller ginning now approaches that of saw ginning, but questions remain about the cost of roller ginning versus saw ginning. In a collaborative study, ARS researchers at Las Cruces, New Mexico, and researchers from New Mexico State University we compared the cost of the new high-speed roller ginning, conventional roller ginning, and saw ginning in the Western U.S. They found that high-speed roller ginning costs were 14% higher than saw ginning, but 10 percentage points lower than conventional roller ginning. They also found that ginning costs were highly sensitive to electricity cost, a 10% increase in the price of electricity increased ginning costs by 8.3%. Producers will receive a higher price for their roller-ginned Upland cotton, which may offset the slightly higher roller-ginning cost. This information provides producers with a valuable tool to aid in deciding if roller ginning their Upland cotton for high-quality fiber and overall higher price is the right choice for them.
Review Publications
Tumuluru, J., Frodeson, S., Mohammadi, A., Venkatesh, G. 2023. Thermal pretreatment technologies for moisture removal and upgrading the biomass quality. In: Bisaria, V., Hess, J.R., Tumuluru, J.S. editors. Handbook of Biorefinery Research and Technology. Dordrecht: Springer Nature Applied Sciences. https://doi.org/10.1007/978-94-007-6724-9_49-1.
Armijo, C.B., Delhom, C.D., Whitelock, D.P., Tumuluru, J., Yeater, K.M., Rowe, C., Wanjura, J.D., Sui, R., Holt, G.A., Martin, V.B., Kothari, N. 2023. Evaluation of alternative-design cotton gin lint cleaning machines on fiber length uniformity index. AgriEngineering. 5(4):2123-2138. https://doi.org/10.3390/agriengineering5040130.
Smith, Z., Issac, B., Tumuluru, J., Yancey, N. 2023. Grinding and pelleting characteristics of municipal solid waste fractions. Energies. 17(1). Article 29. https://doi.org/10.3390/en17010029.
Tumuluru, J., Armijo, C.B., Whitelock, D.P., Funk, P.A. 2023. Modeling and optimization of high-capacity experimental reclaimers to minimize the seed and lint loss during roller ginning of Upland and Pima cotton. Processes. 11(10). Article 2868. https://doi.org/10.3390/pr11102868.
Acharya, R.N., Sapkota, S., Bhandari, P., Armijo, C.B., Whitelock, D.P. 2024. Relative cost of ginning cotton using saw, conventional roller, and high-speed roller gins in the U.S. Journal of Agribusiness. https://doi.org/10.1002/agr.21946.
Hess, R., Tumuluru, J. 2024. Biomass supply chain logistics: Challenges and technological advancements. In: Bisaria, V. editor, Handbook of Biorefinery Research and Technology. Germany: Springer, Dordrecht. p. 1-22. https://doi.org/10.1007/978-94-007-6724-9_46-1.