Location: Cotton Ginning Research
2023 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 the New Mexico State University (NMSU) cotton breeding program that was producing new cotton germplasm lines with improved Fusarium Wilt (FOV-4) resistance. ARS provided ginning expertise and ginned experimental cottons from field trials.
Ginning tests were completed for a project investigating cotton fiber properties 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 on ginned fiber properties. Additionally, textile testing began on ginned fiber samples to determine the spinning performance and yarn properties from these saw- and roller-breeder gins, 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: Data analysis was completed on a study 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. Textile testing continued on fiber samples taken during the ginning test that will be used to determine the spinning performance and yarn quality among the varying types of lint cleaners. The goal of the project is to improve fiber length uniformity of ginned cotton, which should help U.S. cotton compete with man-made fibers.
Collaborative work continued with researchers at NMSU to determine ginning costs of saw and roller ginneries in the Far West. A larger set of gin economic data was obtained from more ginneries and used to develop statistical models that measure the impact of economies of scale, time trends, and ginning technologies on total ginning costs. Work began on summarizing results of the study.
Preliminary testing of a prototype passive thermal plastic extraction apparatus was completed. Issues with throughput capacity and maintaining temperature and rotational speed of the heated cylinders were identified. Modifications were made and the apparatus readied for testing. However, testing was put on hold as the lead researcher for this project retired in early FY 2023. Plans were made to test the apparatus in FY2024.
Tests were conducted to answer the question, “Can cotton gins improve plastic contamination extraction by adding more seed cotton cleaners before ginning without reducing fiber quality?” It was found that processing unginned seed cotton spiked with plastic through typical cotton gin seed cotton cleaners up to 5 times removed almost all pieces smaller than 2 inches square but did not effectively remove larger pieces. No cotton quality characteristics were worsened and some, like foreign matter and color, were improved. Innovative modifications to existing cotton gin seed cotton cleaners to improve plastic extraction are being considered.
Investigations of the aerodynamic properties of plastic pieces and cotton continued. A cone-shaped air chamber was manufactured with cross-sectional area doubling over its length so that airflow rate decreases with the increasing area. Separation of small plastic pieces and cotton locks due to differences in aerodynamic properties was achieved, but it was erratic. Further development and testing are needed and planned.
Processing before and after images of gin stand saws to measure changes in tooth profile area due to wear in a three-year cooperative test at a commercial cotton gin to evaluate the effect of deep cryogenic treatment on gin saw wear was completed. This and other before and after physical properties measurements of more than 2,800 saws and process data are being analyzed. Due to catastrophic failures of machinery during testing, analysis became complicated, so an ARS statistician is assisting.
Data from previous tests on experimental, high-capacity cotton gin reclaimer systems were used to develop non-linear regression models to understand the interaction effect of the process variables on losses of cottonseed and lint. The models were optimized to identify process conditions that can result in a minimum of seed and lint loss during the roller-ginning process. The results indicated that high-capacity reclaimers had less cotton lint and seed losses for Upland cotton than conventional reclaimers used by the industry. For Pima cotton, the conventional reclaimer minimized seed loss, but the high-capacity reclaimers minimized lint loss. These results were used to plan future developments of the experimental, high-capacity cotton gin reclaimers.
A collaborative study investigated the suitability of cotton gin waste material (leaf, hulls, sticks, and motes) for various biobased applications such as fuels and biobased materials. ARS researchers in Las Cruces, New Mexico, established lab-scale grinding and pelleting systems to conduct the tests. Physical properties characteristics of the cotton ginning products were measured and showed that cotton gin precleaning byproducts have high amounts of ash (11% to 24%), but ash content of lint cleaning byproduct was lower (7%). Pellets made from three cotton gin byproducts fractions met the International Organization for Standardization standards in terms of durability. The ARS researchers are working on scaling tests for a lab-scale continuous pellet mill.
Studies evaluating the impact of lint moisture content, residence time, and line pressure using a pneumatic fractionator for lint cleaning were conducted on three varieties of cotton, two harvest methods (stripper and picker), and three ginning methods (saw, roller, and reciprocating). The initial data analysis indicated that lint moisture content significantly impacts the fiber length and trash removal from the lint. Models developed indicated that some of the fractionator process conditions resulted in better cotton quality than conventional cotton gin lint cleaners. Work continues to optimize the process to produce lint with the best properties and with minimum foreign matter.
A large collaborative effort was completed that resulted in an industry requested compilation of past and current research on how seed coat fragments are created, the damage that they do during processing of textile products, and methods to alleviate them in the ginnery. An ARS researcher in Las Cruces, New Mexico, led this effort that will help direct future research and funding to address the long-standing problem of seed coat fragments in ginned cotton.
Objective 3: The second 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. The test included evaluating an experimental drying technology, investigating using near-infrared (NIR) spectrometers to rapidly measure nut moisture content, and developing a robust dataset for modeling in-bin walnut drying. Walnut moisture data indicated that the experimental technology had significantly better localized drying than drying without it. Results suggested that a portable, handheld NIR spectrometer may feasibly replace the time-consuming oven-drying moisture analysis method for future field experiments. Preliminary computational fluid dynamics models were developed with the current dataset by ARS researchers in Dawson, Georgia. A third year of testing was planned and is needed to further evaluate the experimental drying technology, verify the NIR moisture measurements, and further develop the dataset for modeling drying.
At the request of industry stakeholders in California, testing was conducted to determine the combustibility of walnut postharvest processing facility dust. Dust samples were collected from several walnut hulling and shelling facilities in California. These dusts were tested for combustibility following National Fire Protection Agency guidelines. None of the material samples burned as described in the guidelines and thus should not be considered flammable or combustible. These results will help the walnut industry avoid the necessity of installing expensive, and unnecessary, systems for fire and explosion mitigation at their walnut hulling facilities.
Accomplishments
1. Walnut dust combustibility. Fires and/or explosions at agricultural facilities have been an issue across the world. While some agricultural industries like sugar and grain handling facilities have had issues with fires or explosions and have been subject to regulations on dusts for many years, many other agricultural processors have had no issues with dust fires or explosions. It may be surprising to hear that walnut dust is designated as combustible by the U.S. Occupational Safety and Health Administration and some local governments, and insurance companies have attempted to apply that designation to dust at walnut huller and sheller facilities. Facilities that generate potentially combustible dusts must abide by National Fire Protection Association standards that require expensive sprinkler systems and approved dust control systems (costing $100,000 to over $1 million dollars in some cases) and may have difficulties obtaining approval for building permits and insurance coverage. At the request of the Western Agricultural Processors Association, ARS researchers in Las Cruces, New Mexico, conducted tests to determine the combustibility of dust from walnut hulling and shelling facilities. These tests showed that walnut dusts were not combustible and therefore not an explosion hazard. These results should enable the industry to keep walnut huller and sheller dusts from being classed as combustible and help clear the way for construction of new walnut processing plants and save the industry many thousands of dollars for needless fire and explosion suppression hardware and practices.
Review Publications
Whitelock, D.P., Armijo, C.B., Funk, P.A., Kothari, N., Martin, V. 2022. Performance of a cotton gin machine that removes plastic contamination from seed cotton. Journal of Cotton Science. 26(2):76-84. https://doi.org/10.56454/VKNF3731.
Zhu, Y., Elkins-Arce, H., Wheeler, T., Dever, J., Whitelock, D.P., Hake, K., Wadegaertner, T., Zhang, J. 2023. Effect of growth stage, cultivar, and root wounding on disease development in cotton caused by Fusarium wilt race 4 (Fusarium oxysporum f. sp. vasinfectum). Crop Science. 63:101-114. https://doi.org/10.1002/csc2.20839.
Funk, P.A., Thomas, J.W., Yeater, K.M., Kothari, N., Armijo, C.B., Whitelock, D.P., Wanjura, J.D., Delhom, C.D. 2022. Gin saw thickness impact on lint turnout, lint value, and seed damage. Applied Engineering in Agriculture. 38(4):645-650. https://doi.org/10.13031/aea.15171.
Zhu, Y., Willey, K., Wheeler, T., Dever, J., Whitelock, D.P., Wedergaertner, T., Hake, K., Bissonnette, K., Zhang, J. 2023. A rapid and reliable method for evaluating cotton resistance to Fusarium wilt race 4 based on taproot rot at the seed germination stage. Phytopathology. 113(5):904-916. https://doi.org/10.1094/PHYTO-08-22-0286-FI.
Tumuluru, J. 2023. High moisture pelleting of corn stover at pilot and commercial scale: Impact of moisture content, L/D ratio, and hammer mill screen size on pellet quality and energy consumption. Biofuels, Bioproducts, & Biorefining (Biofpr). https://doi.org/10.1002/bbb.2519.
Zhang, J., Abdelraheem, A., Zhu, Y., Elkins-Arce, H., Dever, J., Whitelock, D.P., Hake, K., Wedegaertner, T., Wheeler, T. 2022. Studies of evaluation methods for resistance to Fusarium Wilt Race 4 (Fusarium oxysporum f. sp. vasinfectum) in cotton: Effects of cultivar, planting date, and inoculum density on disease progression. Frontiers in Plant Science. 13. Article 900131. https://doi.org/10.3389/fpls.2022.900131.
Zhang, J., Zhu, Y., Elkins-Arce, H., Wheeler, T., Dever, J., Whitelock, D.P., Wedergaertner, T., Hake, K., Bissonnette, K. 2022. Efficiency of selection for resistance to Fusarium wilt race 4 in cotton when conducted in the field versus greenhouse. Euphytica. 218. Article 165. https://doi.org/10.1007/s10681-022-03117-6.
