Project : USDA ARS

ARS Home » Plains Area » Las Cruces, New Mexico » Cotton Ginning Research » Research » Research Project #428934

Research Project: Enhancing the Quality, Utility, Sustainability and Environmental Impact of Western and Long-Staple Cotton through Improvements in Harvesting, Processing, and Utilization

Location: Cotton Ginning Research

2016 Annual Report

Objectives
1: Determine the expected impact of new cultivars, agronomic practices, and harvesting/storage practices on profitability and risks in ginning of Western and long-staple cotton in collaboration with private-sector partners, ARS-SRRC-CSQ, and other ARS laboratories. 1A: Improve or enhance cotton fiber ginnability, textile utility, and cottonseed end use value of new germplasm releases of both Upland and Pima cottons. 1B: Reduce fiber damage during harvesting. 1C: Improve and reduce environmental risk of cotton harvest preparation. 2: Enable, from a technological standpoint, new commercial technologies, methods and processes to (1) improve process efficiencies, (2) reduce uncertainties and risk, and (3) increase end-product and co-product value in the ginning of Western and other long-staple cottons. 2A: Improve seed-cotton drying and foreign matter extraction. 2B: Develop improved saw ginning technologies to increase efficiency and productivity, and enhance fiber quality. 2C: Enhance high speed roller-ginning technologies to increase capacity and improve textile processing efficiency and yarn quality. 2D: Enhance understanding and knowledge of ginning techniques and processes for better decision making tools at the gin and textile mill. 2E: Improve foreign matter extraction and fiber quality of ginned lint. 2F: Develop methods and systems to reduce energy consumption during ginning. 2G: Assist the ginning industry in complying with regulatory standards. 3: Enable the commercial processing of cotton companion crops, such as chile peppers and tree nuts. 3A: Assist tree nut industries in improving process efficiency and reducing environmental risk. 3B: Optimize field machinery for chile harvest mechanization.

Approach
To address critical production, processing and regulatory compliance issues pertaining to Western irrigated cottons and companion crops, this project focuses on three main research areas. The first area advances knowledge of and improves cotton cultivars and production and harvesting practices by 1) collaborating with cotton breeders to determine the ginned fiber quality, textile processing characteristics, and cottonseed quality of newly developed cotton cultivars; 2) investigating cotton picker spindle designs to reduce quality degradation during harvesting; and 3) developing a technology to thermally treat cotton plant stalks for whole-plant desiccation and defoliation. The second improves processing, reduces risk, and increases value by 1) building on earlier work to advance the use of microwave energy to effectively dry seed cotton; 2) improving a device developed to accurately measure seed cotton moisture content for better system management; 3) developing an infrared based sensor to detect plastics contamination in seed cotton at the gin and an electrostatic based device to separate plastics from seed cotton by exploiting static charge affinity differences; 4) evaluating current and, then, developing improved gin saw designs that maintain capacity and reduce fiber damage; 5) cooperating with industry partners in further evaluating and refining a prototype seed cotton reclaimer and lint cleaner feed works capable of processing seed cotton carryover and ginned lint from high speed roller gin stands; 6) evaluating roller ginned upland cotton textile utilization without combing to reduce processing cost; 7) studying in depth the cost of roller ginning upland cottons; 8) exploring improvements in lint cleaner saw wire configuration and grid bar design, and developing new air knife and rotary brush technologies to reduce seed coat fragments in ginned lint; 9) developing continuous air system monitoring and control systems and performing cyclone flow sensitivity analyses to reduce gin energy consumption; and 10) updating particulate emission factors, evaluating regulatory dispersion models, documenting federal reference method particulate samplers for more equitable industry regulation. The third area enhances the viability of cotton companion crops by 1) modifying current walnut drying technologies to reduce energy usage and drying time; 2) building on previous testing and utilizing an experimental approach to improve a retrofit particulate abatement technology for mobile agricultural equipment; and 3) optimizing a prototype to mechanize succulent chili harvest.

Progress Report
Progress on the three objectives of this project focused on cotton harvesting, ginning, and textile utility, and agricultural regulatory and processing issues. Under Objective 1, progress was made in improving harvesting practices and reducing environmental risk of harvest preparation. The final year of cotton harvester field tests were conducted. Using previously established optimum spindle speed and size, the ground speed of the picker was varied to evaluate the impact on Upland and Pima cotton quality. Mechanical and thermal techniques to cause cotton plant desiccation and defoliation were investigated. Two apparatuses that utilized heat to desiccate cotton plants without chemicals (one used an open flame, one used forced hot air to thermally girdle cotton plants) were designed, built, and field tested. A mechanical method explored was based on a string trimmer, girdling the cotton plant by cutting. Another mechanical method involved physically uprooting the mature cotton plant, replacing it upright on the soil surface, and allowing it to desiccate in that position. Under Objective 2, progress was made to improve gin process efficiency, maintain fiber quality, and reduce waste and energy consumption. A previously improved small-scale microwave cotton dryer was tested to evaluate whether the majority of moisture was removed from the lint or the seed. Also, seed was collected and sent for germination trails to determine the effect of the microwave radiation of seed viability For better cotton gin dryer control, another year of sampling with a cotton moisture measurement system was conducted. Data from previous years showed poor correlation between model predicted and actual seed cotton moisture due to low drying temperatures and variability in measured seed cotton mass flow. Higher drying temperatures were achieved in the most recent test, but mass flow still varied considerably. Modeling data analyses showed that calculating a moving average of seed cotton mass flow improved the measurement. Still, further evaluations and analyses are needed to improve the model performance. To address concerns about plastics contamination in U.S. cotton, a bench top IR reflectance instrument based on previous hyperspectral analyses was constructed and tested with collaborators at New Mexico State University. Infrared response for cotton and plastic contamination samples were measured and a mathematical algorithm to distinguish contaminant samples from cotton was developed with 100% correct classification achieved with pure cotton and contaminant samples. Additional testing was done to determine the minimum size of contamination detectable with the instrument when the contaminant was placed against a cotton background. Also, a low-cost LED/photodiode based prototype system was tested, but results showed that resolution was lacking. Further testing, using UV fluorescence and visible/near-infrared reflectance with line-scan imaging techniques are planned. Cryogenically treated gin saws were installed in a cooperating commercial cotton gin and operated side-by-side with untreated standard gin saws to compare saw-life in terms of number of bales ginned before gin saw failure. Both the treated and the standard gin saws were still functioning properly at the end of the ginning season after about 13,000 bales processed. Thus, the saws were left in their respective gin stands for further evaluation during the upcoming 2016-17 cotton ginning season. An experimental reclaimer, previously developed in cooperation with Lummus Corporation, was tested during FY16. The reclaimer met the required increased capacity goal of handling ginned seed from high-speed roller-gin stands. However, the reclaimer allowed more ginned seed than was desired to be returned with the seed cotton, to then be lost with the cotton trash in a cleaning machine. These tests indicate that further work is needed to reduce seed loss. Plans were made to modify the reclaimer design and make adjustments to the existing components to improve seed extraction. To improve the efficiency and capacity of roller-gin lint cleaners, modifications including viewing ports were made to an experimental high-capacity lint cleaner feeding unit. Testing showed that there may be recirculation of lint within the feeding unit, indicating further modifications are needed. Plans were made to use high-speed videography to confirm the recirculation and reveal the path and velocity of fiber tufts within the unit. Working to better understand roller-ginned cotton textile utility, several selected Upland cotton varieties were ginned on the laboratory high-speed roller gin as part of a replicated test. The raw ginned fiber was sent to ARS collaborators at the Southern Regional Research Center for textile processing and quality evaluation. These textile processing evaluations were completed and data analysis and reporting are ongoing. Data from a three-year industry-wide roller-ginning industry costs, needs, and practices survey was compiled and studied. Analysis continues using GINMODEL, an economic-engineering simulation of cotton ginning costs. Efforts to improve removal of seed coat fragments (SCF) that cause spinning mill processing problems and yarn defects were continued. Specifications were developed for three experimental lint cleaner saws specifying different pitch angles and wrapping densities. It was hypothesized that a less aggressive saw may improve removal of SCF. Saw cylinder cores for manufacturing the experimental saws were specified and sourced. Also, work continued on developing an air knife that works in conjunction with experimental grid bars to blow SCF out of the lint stream and into the trash stream. Another prototype air knife without a deflection plate was built and installed. Testing showed a better distribution of high velocity air along the grid bar. Lastly, a device that utilizes a rotating knife to facilitate the extraction of foreign material, especially SCF, at the lint cleaner was designed. Solid modeling is ongoing to evaluate how best to integrate the device into existing lint cleaner configurations. Previous gin energy use audits indicated that a better understanding of dryer fuel consumption and fuel use efficiency was needed. Thus, as part of collaborative research to reduce energy consumption during ginning, ginning fuel use audits at four gins were conducted. Air flow and temperature measurements were made and seed and lint cotton were sampled for moisture content. These data were analyzed in an attempt to estimate fuel consumption. A more comprehensive fuel energy audit campaign was planned for the 2016-17 ginning season. To assist the ginning industry in complying with regulatory standards, this Lab collaborated with researchers from Oklahoma State University to answer questions, and provide information and support data requested by US EPA for 264 previously submitted cotton gin particulate matter emissions sampling reports. The reports are currently being reviewed by EPA reviewers for inclusion in and updating the current, but outdated, EPA cotton gin particulate matter emission factors dataset: AP-42 “Compilation of Air Pollutant Emission Factors”. At the request of the Western Ag Processors Association (WAPA, a sister organization of the California Cotton Ginners & Growers Association), this laboratory took on a short-term study concerning the combustibility of almond huller dust. Earlier, this lab had conducted OSHA accepted tests that revealed that particulate collected from the interiors of commercial cotton gins was not combustible and therefore was not subject to OSHA regulation. Combustibility of dusts generated by processing materials is important because combustible dusts may also be explosible and pose a significant safety hazard if not properly handled. WAPA was dealing with a possible combustible dust regulatory issue with the dust generated by processing almonds in almond huller plants. Interior dust was collected from commercial almond huller plants in the San Joaquin Valley of California and sent to this laboratory. Tests were run and it was determined that almond huller dust was not combustible and therefore not an explosible hazard. The results from both the cotton gin and almond huller plant interior particulate were reported at a technical meeting and submitted for documentation in a peer-reviewed journal. ARS scientists at this laboratory, with the Research Leader as coordinator, collaborated with other ARS scientists and industry leaders to completely revise and update the Cotton Ginners Handbook, an invaluable information source for the ginning industry and text for university courses teaching ginning technology. Currently, 35 proposed chapters are in the process of being revised or newly written, thirteen directly overseen by scientists from this lab as lead author. The new Cotton Ginners Handbook will be published in the Journal of Cotton Science; an industry supported, open-access, online peer-reviewed journal Under Objective 3, significant progress was made to aid processing and mechanization of cotton companion crops. At the request of WAPA, a project studying nut processing technologies was initiated with the goals of improving efficiency and reducing environmental impact. A search and review of prior art in walnut processing with emphasis on drying was conducted. A review publication was planned and this information will provide focus for project. In collaboration with researchers at New Mexico State University on a project to optimize chile harvest machinery, a commercially available chile harvester was modified to be more compatible with domestic cultivars. Scientists from this lab also designed a field experiment and aided the harvest and lab work for a cooperative project comparing the impact of cultivars and plant populations on machine harvest. Further tests were planned for Fall 2016.

Accomplishments
1. Burning issue resolved. In 2009, the U.S. Occupational Safety and Health Administration (OSHA) began developing a comprehensive mandatory combustible dust standard for general industry. The National Fire Protection Association defines combustible dust as “a finely divided combustible particulate solid that presents a flash fire or explosion hazard when suspended in air or the process-specific oxidizing medium over a range of concentrations”. While some agricultural industries like sugar and grain handling facilities could constitute combustible dust hazards and have been subject to rules on dusts for many years, other agricultural processors like cotton gins or almond huller plants have had no issues with dust fires or explosions. Agricultural processors that do not handle combustible dusts could request exemption from the general industry rule. At the request of the National Cotton Council (NCC), ARS researchers in Mesilla Park, New Mexico collaborated on a study to determine the combustibility of cotton gin dust. Later, the Western Ag Processors Association (WAPA) requested that the ARS researchers again conduct tests to determine the combustibility of almond huller dust. These tests showed that cotton gin dust and almond huller dust collected in facility interiors were not combustible and therefore not an explosion hazard, and have scientific grounds to request exemption from the general rule. These results were submitted to a peer-reviewed journal and should enable the NCC and WAPA to keep cotton gin and almond huller dusts from being classed as combustible. In turn, allowing cotton gins to keep their normal housekeeping practices, clearing the way for construction of new almond huller plants to serve this growing sector of agriculture, and all the while saving many thousands of dollars for explosion suppression hardware and practices.

U.S. DEPARTMENT OF AGRICULTURE

Cotton Ginning Research: Las Cruces, NM