A High-Efficiency Method of Fiber Opening andCotton Trash Removal

ABSTRACT
Cotton trash plays an important role on determining yarn quality. The mechanism of fiber opening and cleaning is the key technique to remove trash from raw material. In this study, a multi-fiber opening, including pre-, coarse-, fine- and microfine-opening was designed and a high-voltage static-electricity equipment combined with air suction was applied to improve fiber opening and trash removal. The results show that the percentage of trash removal is increased by 40-50% and nep increase of the processed cotton is only 30-50%, which is advantageous in producing a good-quality yarn.

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Maintaining Quality of Stripper Harvested Cotton from Field to Textile Mill

ABSTRACT
Since fiber quality cannot be improved after it has been removed from the cotton plant, it is very important that fiber quality be maintained during harvesting and ginning. Recent developments in harvesting and ginning practices have made significant advances that will better preserve fiber quality during these critical steps. One recent development for stripper cotton production involves the use of earlier harvest dates to reduce exposure to inclement weather conditions and to allow for a more favourable harvest period. Although several factors have led to earlier harvest dates, the recent utilization of boll openers and the availability of new defoliants and desiccants that better prepare the cotton plant for stripper harvesting, are the biggest contributors. Additional factors such as modifications of the cotton stripper have reduced foreign matter, in particular stick content, which can have a significant effect on reducing bark content in lint. Modifications of the stripper include changing the combinations of brushes and bats, use of a wider spacing between stripper rolls and between combing pans, and improved adjustment of grid bars in field cleaners. Improved seed cotton drying systems along with new developments in seed cotton cleaning at the cotton gin have significantly enhanced seed cotton cleaning in the gin thus reducing lint-cleaning requirements. New lint cleaning equipment and procedures have minimized the amount of cleaning required while maintaining fiber cleanliness and quality. These improvements in harvesting and ginning technologies are critical elements in maintaining the quality of stripper cotton as it moves from the cotton field to the textile mill.

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How Genotype and Temperature Modify Yarn Properties and Dye Uptake

ABSTRACT
Genotype and weather are important factors in determining both cotton fiber quality and yield. Examinations of the effects of genotype on those fiber properties most important to textile manufacturers have led to development of cotton genotypes with potential for producing high yields of fiber with improved spinning properties. However, significant genotype-temperature interactions complicate maximization of yields of fiber with the properties demanded for modern textile processing. Temperature [cumulative heat units above 15.6C] during the growing season alters micronaire and the fiber maturity properties most closely linked to spinning and dye-uptake success. When four Upland cotton genotypes were grown in South Carolina, AFIS fiber-quality assessment showed that genotype was a powerful determinant of fiber length, short fiber content, diameter, circularity, immature fiber fraction, area, fine fiber fraction, micronAFIS, and perimeter. Temperature also modified all AFIS fiber properties, and genotype interacted with temperature to modify fiber length, short fiber content, circularity, immature fiber fraction, and micronaire. Tests of yarns spun from fibers of the four genotypes showed genotype to be a significant factor in yarn nep count, strength, elongation, and tenacity. Temperature was also a factor in yarn nep count, evenness, strength, elongation, and tenacity. Genotype and temperature were significant factors in dye-uptake. Regression analyses of temperature-modified fiber properties vs. yarn testing and dye-uptake data described and predicted spinning and dyeing success.

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Computerized Process Control for Gins

ABSTRACT
A computerized gin process control system (CGPCS) to “prescription process” cotton was developed and implemented in the United States. Properly controlling the cleaning and drying that cotton receives during processing at the gin with a CGPCS increases monetary returns to the farmer, increases fiber yield and improves fiber quality. The CGPCS can be simple or complex and can range from a single camera that measures the colour and trash of the cotton to a full CGPCS that has several camera systems to measure colour and trash, multiple moisture sensors and automated valves that allow continuous and immediate diversion of the cotton during processing. Positive results from field experiences over a 9-year period from 1989 to 1997 at commercial cotton gins indicated that the equipment and software are very beneficial to the farmer. Sufficient increased profits to the farmer and ginner should recover the entire cost of the CGPCS system during the first year of operation. In general, controlling the level of drying increased bale weights about 4.5 kg (10 lb.) per bale and bypassing one stage of lint cleaning on cotton selected by the computerized system increased the bale weight about 4.5 kg (10 lb.) per bale. Monetary returns can be increased by $7 to $21 per bale for 16-20 million bales produced annually in the U.S. Fiber yield is increased 6% and neps and short fiber content are decreased over 40%.

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Gin Machinery1 Influence on Cotton Quality and Value

ABSTRACT
Studies involving moisture levels, gin machines and types of cotton were conducted to assess their impact on cotton market value and fiber properties after processing with various gin machinery sequences. Bale values ranged from $357.13 for the standard machine sequence to $404.10 for the extractor-feeder/gin stand only sequence for cultivar DPL 50 cotton. The predominate optimum sequence for the hairy-leaf cottons was stick machine, extractor-feeder/gin stand and two lint cleaners. The smooth-leaf cottons required fewer cleaning machines to maximize monetary returns and also provided higher returns than hairy-leaf cottons. Short fiber content and neps were dramatically lower when fewer machines and less drying was used. Using fewer machines than the currently recommended machine sequence indicated more profits and resulted in other fiber quality factors that were more desirable than the standard machine sequence. Selecting the optimum machine sequences increased monetary values from $12.22 to $20.85 per bale and averaged $16.72 per bale.

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Ginning: A New Frontier

ABSTRACT
The quality of baled cotton fiber is not solely dependent on ginning, but reflects the entire history of the bale including variety, soil type, geographical location, cultural practices, storage, ginning, etc. Controlling the appropriate factors before ginning and prescribing the appropriate gin cleaning and drying needs of cotton can substantially improve fiber quality and increase monetary returns to the farmer and textile mill. The current process control system known as “IntelliGin1” utilizes the cotton market price and the performance characteristics of gin machinery to determine the optimum drying level and machinery sequence. Cotton moisture, colour, and foreign matter measurements are made with electronic devices at three stations in the gin system and are used to feed forward and feed backward to control the gin process. Special routing valves are used to bypass or select any combination of seed cotton cleaners, dryers, and lint cleaners as directed by a computer. When gin machinery is bypassed, the quantity of marketable lint is increased and the amount of fiber damage is decreased. The gin process control system minimizes fiber damage and machinery usage while optimizing profits. Control of fiber moisture and gin machinery increases bale value, fiber length, fiber yield, reduces short fibers, neps, improves removability of seed-coat fragments at the textile mill, and decreases the number of seed-coat fragments.

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Effects of Meteorological Parameters and Irrigation on Micronaire Index of Cotton in Greece

ABSTRACT
The influence of temperature, rainfall, relative humidity and irrigation on the micronaire value of cotton grown in Greece during the period 1986-1994 was studied. Micronaire was positively affected by temperature, mainly by daily maximum and mean temperature. Within the temperature range encountered, depending on developmental stage, an increase of 1.5 – 2.0oC increased micronaire by 0.5. The micronaire value was most influenced during stages that include the period of boll maturation and boll opening, with R2 values over 0.5 in many cases, reaching 0.9 for the boll opening and harvesting phases. The effects of rainfall and relative humidity were negative and significantly stronger during the stages from boll opening to harvesting with R2 ranging up to 0.8 for rainfall and R2 up to 0.6 for relative humidity. Addition of irrigation water to rain weakened regressions and restricted the number of stages with significant water effects. Use of multiple regression analysis, taking account of all parameters studied, resulted in higher R2 values. Micronaire values could be predicted using the models developed. The applicability of management techniques to decrease adverse or increase favourable effects of weather is discussed.

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Nep Content in Relation to Cotton Fiber Quality Characteristics

ABSTRACT
Textile Technology Research Centre conducted a two-year research programme to determine the nep content in baled cotton and the actual processes that contribute to their evolution and increase. Cotton samples were collected from every ginning industry participating before the gin stand, before the lint cleaners and from the final ginned product for testing for their nep and trash content with the Zellweger Uster AFIS instrument and for their fiber quality characteristics with an HVI . Measurements revealed that a considerable nep content in seed cotton is increased during the ginning process and the following cleaning stages. Quality measurements revealed that the higher the nep content in the final product, the lower the uniformity ratio and the higher the short fiber content.

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Degree of Verticillium Wilt Infection and the Relative Damage in Fiber Quality Parameters

ABSTRACT
Verticillium wilt is a major problem in many cotton producing countries. In addition to causing big losses in yield, deterioration in fiber quality affects the commercial value of cotton. This study was undertaken to determine the damage caused in fiber quality characters by various degrees of Verticillium wilt infection. Four commercial cotton cultivars (G. hirsutum), varying in earliness and vulnerability to the pathogen, were used. Based on visual symptoms the degree (level) of infection ranged from 0 to 4. Eleven representative plants from each infection level and from each cultivar under study, were labelled and their product was bulked, ginned and evaluated for most fiber properties. Fiber length parameters were the least affected, except for the short fiber content (SFC) which was nearly doubled in the highest level. Micronaire deterioration was highly depended on the cultivar, while maturity was significantly decreased from 0 to 4 degree in all cultivars. Immature fiber content (IFC) increased and fineness decreased mainly in the highest two degrees. Fiber neps were dramatically increased in the highest degree but nevertheless cultivar plays an important role too. The same applies for trash and seed coat neps. The general conclusion is that fiber damage in the wilted plants was analogous to the severity of infection. Thus fibers from the higher degree are unsuitable as spinning raw material because they are below spinnable limits in all cultivars. In the lower degrees, fiber damage depends on the cultivar.

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Fiber Property Variability from Bale to Bale

ABSTRACT
Cotton (Gossypium hirsutum) fiber variability at the bale level is a composite of fiber properties contributed by individual bolls. Environmental conditions, crop management and genotype have an impact on fiber property variability at the boll and seed level. Cotton plants (DPL 51, 1995; NuCOTN 33B, 1996) were grown under rainfed (RF) and centre-pivot irrigated (IR) conditions at Perthshire Farms, Gunnison, MS. Plants were mapped prior to harvest. Fields were spindle picked and grab samples were taken pre and post ginning. Fiber samples from individual bolls and representative samples were analyzed using the Advanced Fiber Information System (AFIS). In 1995 cotton plants (RF, I) showed similar boll distribution patterns with 50% of the bolls located at the first position on fruiting branches. Fiber length and micronaire (micronafis) varied with mainstem node location. Composite fiber properties were similar for rainfed and irrigated cotton (1995). Boll distribution patterns were different for rainfed and irrigated plants in 1996. Composite fiber length properties were similar but micronaire (micronafis) was lower for irrigated cotton (1996). Lint cleaning (one lint cleaner) did not increase short fiber (<12.7 mm) percentages. A main contributor to fiber property variability at the bale level was variability at the boll level rather than ginning procedures.

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