Location: Cotton Ginning Research
2025 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
Objective 1: ARS researchers in Las Cruces, New Mexico, cooperated with Western cotton breeders providing ginning expertise and services for experimental cottons to produce pure seed for future planting and cotton lint samples for quality analyses. This collaboration helped Texas Agrilife to complete their El Paso County Cotton Variety Trials; New Mexico State University (NMSU) produced new cotton germplasm lines with drought and improved Fusarium Wilt (FOV-4) resistance and investigate new varieties with better seed size and quality; and a collaborating seed company improve a long-staple hybrid cotton with similar high-quality characteristics to Pima that grows where Pima cannot be grown.
There are questions about whether model-sized gin stands cotton breeders use to obtain lint from hand-picked cotton for quality analysis in their variety selection programs accurately predict properties of cotton that will be machine-harvested and processed in a commercial gin. A project to compare fiber properties and spinning performance of cotton from the breeder gin stands and conventional commercial gin stands showed similarities between the fiber quality from breeders and commercial gins, but it was dependent on well-trained personnel operating the gin stands, cleaning and opening of the seed cotton before ginning, and well-maintained ginning equipment.
OBJECTIVE 2: At times questions arise about the cotton quality from high-capacity rotary-knife gins used in the U.S. compared to the slower, reciprocating-knife stands used in countries. Tests showed the two ginning methods produced cotton with similar quality and in some cases the rotary knife produced superior quality cotton fiber, supporting U.S. Pima cotton as high quality on international markets.
An exploratory study found differences in fiber quality among conventional and experimental lint cleaners that use different feed methods of placing ginned fiber on the machine’s cleaning saw to remove foreign matter (most current lint cleaner feed mechanisms cause fiber damage). The results initiated further work that included installing and modifying lint cleaners for further testing that 1) use feed mechanisms that place ginned fiber directly onto the lint cleaning saw without changing direction and 2) connect directly to the gin stand, eliminating the feed mechanism altogether. The goal of the project is to improve fiber length uniformity of ginned cotton to help U.S. cotton compete with man-made fibers.
Previously tested experimental, high-capacity cotton roller gin reclaimer systems were modeled to understand the effect of process variables on cottonseed and lint losses. The experimental reclaimers had less cotton lint and seed losses for Upland cotton than conventional reclaimers used by industry. For Pima cotton, the conventional reclaimer minimizes seed loss, but the experimental reclaimers minimize lint loss. These results were used to plan the next steps for developing experimental, high-capacity cotton gin reclaimers for U.S. roller gins that have less losses.
A study with researchers at NMSU to determine ginning costs of saw ginning and conventional and high-speed roller ginning in the Far West was completed. The study included an NMSU economic survey sent to ginneries in the West with some facilities sharing their gin financial audit reports. Statistical models to measure the impact of economies of scale, time trends, and ginning technologies showed the cost of conventional and high-speed roller ginning was higher than saw ginning by 24 and 14% and 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.
Multiple studies were conducted to investigate methods to remove plastic contaminations from cotton at the cotton gin. The performance of a cotton plastic contamination cleaner manufactured by a Chinese gin machinery company was compared to that of typical cotton gin cleaning machinery to determine if it could serve as an off-the-shelf option for U.S. cotton gins. The machine removed pieces of plastic better than the typical cotton gin machinery, lightweight round module wrap (RMW) and shopping bag pieces were removed at rates within the range of the manufacturer’s claims, but thicker, heavier RMW was not effectively removed. Plastic capture rate was improved by increasing the airflow to the cleaner, but this increased the amount of seed cotton captured with the plastic to unacceptable levels. The usefulness of the machine as an off-the-shelf option would be limited. Tests were conducted to evaluate plastic contamination extraction performance of conventional cotton cleaners. Processing unginned seed cotton spiked with plastic through typical cotton gin seed cotton cleaners up to 5 times removed almost all plastic 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. This pointed to innovative modifications to existing cotton gin seed cotton cleaners to improve plastic extraction. Concepts that exploit differences in physical properties between cotton tufts and plastic pieces were explored to facilitate extracting the plastic at the cotton gin. There was a marked difference in terminal velocity in air between seed cotton tufts and plastic fragments and plastic fragment size and shape influenced behavior in an airstream. These measurements provide the basis for future models to predict air velocity ranges for separating plastic fragments from seed cotton and for further research on combining seed cotton cleaners with airflow techniques to effectively remove plastic fragments at the cotton gin. A novel approach to removing plastic contamination from cotton at the gin exploiting the relatively low melting point of plastics was explored. A prototype passive thermal plastic extraction apparatus was developed and preliminary results led to modifications to improve capacity and temperature maintenance. Full tests to optimize flow and performance using varied plastic fragment types and sizes were designed.
Studies with NMSU on preprocessing cotton gin by-products (CGB) produced from ginning Pima and Upland cotton were conducted. Lab-scale preprocessing systems and physical properties measurement capabilities were developed. Initial studies of segregated CGB streams showed a range of bulk densities (14 to 206 kg/m³) and ash contents (7.3 to 23.8%). Tests carried out on bulk CGB collected from three local gins in New Mexico revealed bulk density was about 100 kg/m3 and pelleting produced high-quality pellets, meeting ISO standards. Ash content was 8-17.5%. Results indicated that the long-term storage of CGB on the gin yard can increase the ash content, which can be detrimental to biofuels and other biobased applications from these materials. Further studies were planned to investigate the physical properties and compositional issues of the CGB for applications in biobased products.
Studies using a pneumatic fractionator for lint cleaning were conducted to determine its cleaning performance and effect on quality. Data analysis and modeling and optimization indicated that the pneumatic fractionation produced lint with superior quality properties, (longer and more uniform length, better color, and less foreign matter) than conventional cotton gin lint cleaners. Based on these results, a prototype laboratory-scale pneumatic lint cleaning system was designed and fabricated with the following features: a) changeable cleaning screen sizes, shapes, and surface areas; b) mounting for high-speed camera to visualize cleaning mechanism; c) controls to regulate airflow rate, and d) modular design to support the scale-up studies.
At the request of industry stakeholders, an investigation and documentation of how seed coat fragments are created, the damage they cause during textile processing, and methods to alleviate them in the ginnery were completed. An ARS researcher in Las Cruces, New Mexico, led the cross-disciplinary team of ARS, university researchers and industry professionals covering all facets of the cotton industry that will help direct future research and funding to address the long-standing problem of seed coat fragments in ginned cotton.
Objective 3: A study aimed at improving drying efficiency and reducing energy footprint of walnut hulling operations was conducted by ARS researchers from Las Cruces, New Mexico, and Albany, California, and an industry cooperator. Four years of field research at a commercial walnut huller facility resulted in 1) innovative in-bin walnut sampling equipment; 2) a new rapid method to measure walnut moisture that takes 1/6th the time of the conventional method; 3) an innovative drying technology that resulted in shorter drying time and less variability in walnut moisture content after drying; 4)a new computational fluid dynamics model of walnut drying; and 5) better understanding of the mechanisms of airflow in drying bins and moisture migration during drying. These studies led to drying bin design modifications and tests and could result in significant time, energy, and money savings for walnut producers.
Per stakeholders’ request, ARS researchers in Las Cruces, New Mexico, conducted tests to determine the combustibility of dust from walnut hulling and shelling facilities. Results showed that walnut dust was not combustible and therefore not an explosion hazard and should enable the industry to keep walnut huller and sheller dusts from being classed as combustible, 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.
Accomplishments
1. Optimizing roller gin reclaimers to reduce losses and increase revenue for U.S. cotton gins. Operation of high-speed roller-gin stands that were largely adopted by the U.S cotton industry in the mid-2000s to gin high quality Western cotton produce a much larger amount of carryover (a mixture of unginned seed cotton and ginned cottonseed that is expelled from the roller-gin stand during operation) than conventional roller-gin stands. Existing conventional seed-cotton reclaimers cannot adequately handle the increased carryover and either become a bottleneck for production or do not adequately separate the unginned seed cotton from the ginned seed, resulting in excessive lint and seed losses. ARS researchers in Las Cruces, New Mexico, modeled and optimized the performance of two, previously developed, experimental high-capacity reclaimers to minimize seed and lint loss. Under the optimized process conditions, one of the experimental reclaimers significantly reduced losses over the conventional reclaimer for Upland cotton. However, the conventional reclaimer performed better for Pima cotton by lowering seed loss. Estimated economic impact indicated that financial losses with Upland cotton were about 2.5 times greater for the conventional reclaimer. For Pima cotton, the conventional reclaimer resulted in a slightly lower economic loss than the experimental device. As more “fuzzy” seeded cottons, like Upland, are roller ginned, significant economic losses could be avoided by deploying the experimental reclaimer.
Review Publications
Armijo, C.B., Delhom, C.D., Abidi, N., Hand, L.C., Bechere, E., Dowd, M.K., Thomas, J.W., Holt, G.A., Blake, C.D., Donohoe, S.P. 2025. Past and current research activities on seed coat fragments. Journal of Cotton Science. 29(1):24-47. https://doi.org/10.56454/MFIH2900.
Amaly, N., Harrison, S., Tumuluru, J., Sun, G., Pandey, P.K. 2025. Development and application of a polycationic soybean protein-based flocculant for enhanced flocculation and dewatering of dairy manure. Water Research. 371. Article 144050. https://doi.org/10.1016/j.chemosphere.2024.144050.
Zhang, J., Mohammedi, M., Gong, H., Hodge, D., Tumuluru, J., Sousa, L.D., Dale, B., Balan, V. 2025. High throughput pretreatment of corn stover using compacted biomass with recycled ammonia (COBRA) process. Chemical Engineering Journal. 505. Article 159731. https://doi.org/10.1016/j.cej.2025.159731.
Tumuluru, J., Igathinathane, C., Archer, D.W., Mcculloch, R. 2024. Energy-based break-even distance transportation distance of biomass feedstocks. Frontiers in Energy Research. 12. https://doi.org/10.3389/fenrg.2024.1347581.
Sandberg, M., Frodeson, S., Brunzell, L., Tumuluru, J. 2024. Forest industrial waste materials upgraded to fertilizer pellets for forest soil. Sustainability. 16(7). https://doi.org/10.3390/su16072868.
He, X., Darsell, J., Tumuluru, J., Wang, W., Meyer, H.M., Keiser, J., Rohatgi, A., Howe, D.T., Qu, J. 2024. Mitigating municipal solid waste fouling in biofuel conversion via screw surface modifications. Biomass and Bioenergy. 188. Article 107337. https://doi.org/10.1016/j.biombioe.2024.107337.
Tumuluru, J., Gottula, J., Hidalto, M.A., King, J., Barnes, E., Ashley, H., Whitelock, D.P., Funk, P.A., Holt, G.A., Wanjura, J.D., Pelletier, M.G., Thomas, J., Delhom, C.D. 2025. Cotton ginning rate prediction model development for commercial gins: Impact of variety, quality, and moisture content. Journal of Cotton Science. 29(2):95-112. https://doi.org/10.56454/QOHS1717.