Location: Cotton Ginning Research
2017 Annual Report
Objectives
1. Enable, from a technological standpoint, new commercial methods and processes to reduce energy use, labor costs, and environmental impact, while preserving cotton fiber and seed quality, during the saw-ginning of picker-harvested cotton.
1.A. Develop a fan speed control system for conveying fans used at gins to reduce energy inputs.
1.B. Develop improved systems for drying seed cotton to optimum moisture levels with reduced energy inputs.
1.C. Determine effect of higher than recommended processing rates on fiber quality and losses.
1.D. Improve understanding of the fundamentals of pneumatic conveying of seed cotton and lint.
1.E. Determine the cause of fiber breakage prior to ginning, which results in fiber and seed losses during processing.
2. Enable new commercial methods and machinery to improve product quality in the saw-ginning of picker-harvested cotton.
2.A. Develop machinery and processes to remove plastic contamination at the gin.
2.B. Determine causes of increased bark content of picker-harvested saw- ginned cotton.
2.C. Improve foreign matter removal by seed cotton cleaners, thus reducing the need for lint cleaning and associated fiber damage.
2.D. Apply high-speed roller ginning equipment for use with picked cotton in the humid region of the United States.
2.E. Improve foreign matter removal by lint cleaners, thus reducing the need to use an additional stage of lint cleaning.
3. Identify material properties that have a significant impact on fiber and seed quality during saw-ginning, and enable new or improved, commercial methods for measuring product moisture content and process mass flow rates during ginning.
3.A. Develop a mass flow rate sensor for seed cotton.
3.B. Improve seed cotton moisture content measurement during the ginning process.
3.C. Identify cotton properties or measurable process parameters indicative of fiber damage occurring in the gin stand.
3.D. Develop a system to measure the fiber removed by gin cleaning machinery.
Approach
The work includes a variety of specific activities. A fan speed control system will be developed to reduce energy inputs. With this system fan electricity use will be reduced by using a control system with no negative effects on gin operation. An improved system for drying seed cotton will optimize moisture levels with reduced energy inputs using computational fluid dynamics models.
Acceptable leaf grades and extraneous matter levels will be achieved with higher processing rates through seed cotton and lint cleaners using the recommended sequence of ginning machinery. A new ginning system is under construction at the CGRU that will allow testing of processing rates comparable to commercial gins through the extractor-feeder and lint cleaner.
Machinery and processes will be developed to remove plastic contamination at the gin. Work will concentrate on developing a retrofit or change in operation of existing seed cotton cleaning equipment. ARS engineers will examine causes of increased bark content of picker-harvested saw-ginned cotton. ARS engineers will improve foreign matter removal by seed cotton cleaners, thus reducing the need for lint cleaning and associated fiber damage. ARS engineers will use high-speed roller ginning equipment with certain cultivars grown in the humid region of the U.S. which will result in longer fiber with less short fiber and fewer neps.
Seed cotton mass flow rate will be accurately predicted using a system based on air velocity, conveying system static pressure, and temperature measurements. The weight of seed cotton used for each test run will be recorded and linear regression will be used to identify model parameters in the improved model, which will include the static pressure measurement. More accurate prediction of seed cotton moisture will be made using the temperature drop that occurs during the drying process.
Power measurements of individual gin stand components and fiber properties determined from HVI or AFI will be used to predict short fiber and nep content occurring due to different processing conditions, such as moisture and ginning rate. Samples will be ginned and electricity use will be monitored. Predictive models for fiber quality parameters, particularly short fiber and nep content, will be developed for each genotype based on energy data and moisture content.
Measurement of fiber loss during cleaning is an important part of understanding the ginning process and control of that fiber loss may be related to other factors being studied. The proposed measurement system for the quantity of fiber lost from cleaning machinery includes a measurement of the proportion of material with cotton fiber color and a measurement of the total cleaner waste mass flow rate.
Progress Report
Commercial gin drying systems were monitored nationwide, data was analyzed, and a publication made in conference proceedings. Data from commercial gin conveying systems was collected to inform development of a fan speed control system. Tests were conducted to study the feasibility of using a static generator to charge plastic and separate from cotton in ginning equipment. Data was analyzed from an experiment conducted to determine the effect of higher seed cotton cleaner speeds on foreign matter removal and presented. Fiber and yarn quality data was analyzed comparing a conventional saw gin with the high-speed roller gin stand and multiple lint cleaners and the results presented at a conference. Data was analyzed from the improved mass flow measurement system, and an invention disclosure submitted, as system performance was suitable for process control needs. The second year of a study of five cotton genotypes was conducted to determine variations in energy use in the gin and textile mill and the relationship to quality parameters in cooperation with cotton breeders. Analysis of the first year’s data was published in conference proceedings. Images of the material removed by seed cotton cleaners were acquired to use in developing image analysis techniques for identifying individual components of the material.
Accomplishments
1. Reducing plastic contamination in cotton gins. Plastic contamination is a significant problem for the U.S. cotton industry, likely costing over $100 million per year and the loss of access to certain markets. The introduction of a new harvester that produces a seed cotton module wrapped in plastic, as well as greater use of contamination detection equipment in mills, has increased industry concerns regarding plastic contamination. No research had previously been conducted on plastic removal in the cotton gin. A study by ARS researchers in Stoneville, Mississippi was conducted that determined that conventional ginning equipment removed some plastic from cotton; however, nearly 20% remained in the ginned lint, primarily from larger and thicker sources of plastic in the raw seed cotton. Studies were conducted to increase plastic removal of conventional gin equipment, as this could avoid the cost of additional machinery at the gin. Increasing the air flow rate through the cylinder cleaner 67% above the manufacturer’s recommended rate increased plastic removal between 20 and 30 percentage points. For each 100 rpm decrease in cylinder speed, plastic removal increased by 4 percentage points and fiber loss decreased. This information has been communicated to ginners through presentations at research conferences, cotton ginners association meetings, and gin schools.
Review Publications
Hardin IV, R.G., Byler, R.K. 2016. Removal of sheet plastic materials from seed cotton using a cylinder cleaner. Journal of Cotton Science. 20(4):375-385.
Bechere, E., Fang, D.D., Kebede, H.A., Hardin Iv, R.G., Islam, M.S., Li, P., Scheffler, J.A. 2017. Quantitative trait loci analysis for net ginning energy requirements in upland cotton (Gossypium hirsutum L.). Euphytica. 213:160-171. https://doi.org/10.1007/s10681-017-1951-z.
