Search

The objective of this study was to determine whether the Shirley Trash Separator (STS) could be used to measure fine trash not captured by the standard Shirley Analyzer (SSA) and if the STS could be used to predict waste content expected using the SSA. Three experiments were conducted to compare waste quantities from the two machines. Visible waste contents were significantly lower with the STS in the first and second tests, but invisible and total waste contents were higher in the second test. All waste contents were significantly lower with the STS in the third test. This is more in line with what was expected because the STS was designed to catch what previously went out as invisible waste in the SSA. These tests have shown that the STS can be used to measure fine trash not collected by the SSA and that the STS can predict visible waste from the SSA satisfactorily.

Cottonseed merchants are concerned about damage to cottonseed that occurs at the cotton gin. Because of these concerns a two-year study was conducted to determine the effect of cottonseed moisture levels and seed cotton feedrates during ginning on cottonseed damage and the occurrence of seed coat fragments (SCF) in the lint. Five cottonseed moisture levels were tested the first year whereas four were used the second year. Two feedrate levels were considered each year. During the first-year experiment, the higher feedrate gave significantly higher seed damage while the SCF count only showed a higher trend. However, neither seed damage nor SCF numbers were significantly affected by the feedrates in the second-year experiment although both parameters tended to be higher for the higher feedrate. Seed damage increased with moisture content with the largest increase occurring at seed moisture levels above 12%. Seed coat fragment numbers and weights in ginned lint tended to be larger for the higher moisture contents. The study indicated cottonseed was more susceptible to damage at higher moisture contents and that high feedrates seem to accelerate the damage process.

Saw-cylinder lint cleaners at cotton gins improve the grade and market value of cotton but can reduce some of the quality factors desired at the textile mill. A four-year study was conducted to update lint cleaner recommendations for spindle-harvested cotton in response to new quality demands of spinners and new cotton varieties. The effects of none, one, two, and three stages of saw-cylinder lint cleaning on foreign matter content, length and short fiber content, strength, nep count, and seed-coat fragment level of ginned lint were developed. Smooth- and hairy-leaf variety cottons of various trash levels were used in the experiments. One or two stages of lint cleaning produced the highest monetary returns depending on the initial trash level and type of cotton. The information and guidelines should aid ginners in selecting levels of lint cleaning that preserve fiber quality while producing acceptable market returns for the grower.

The effect of saw-cylinder lint cleaning at gins on the number, weight, and size of seed-coat fragments in cotton was studied in a three-year investigation. The experimental treatments included zero, one, two, and three stages of lint cleaning. Fragments were sized in ten categories ranging from those with a maximum physical length shorter than 0.4 mm (1/64 in.) to those greater than 6.4 mm (1/4 in.). The study showed that lint cleaning has little effect on the number of fragments in the lint, although it shifts their size distribution toward the smaller fragments. The first and second lint cleaner stages both significantly reduce the weight of fragments present, but more than two lint cleaners are not recommended because of fiber breakage and lint loss attributed to the additional cleaning.

Neps and seed-coat fragments in lint cotton cause reduced efficiency in the textile mill and detract from appearance in yam and fabric. Ginning can influence and control to some degree the level of these imperfections. Experiments were conducted to determine if these imperfections can be further reduced by production methodology. Specifically the relationships of micronaire, maturity, and fiber strength on the occurrence of neps and seed-coat fragments were investigated. The study involved 15 commercially available and experimental varieties and strains, each harvested as many as seven times to give maturity differences. The varieties were selected to give a range of fiber properties. Information obtained will aid breeders in developing varieties with a low potential for the creation of imperfections during processing

Imperfections in lint cotton, particularly neps and seed-coat fragments, reduce processing efficiency in the textile mill and detract from appearance in yam and fabric. This study identified fiber properties and varieties which are consistently associated with low nep and seed-coat fragment levels in ginned lint, yam, and fabric. Growth conditions and maturity of the cottons were considered; the level of imperfections were measured in both dyed and undyed fabric. Correlations were determined and definite trends established between many of the variables. The information obtained will aid breeders in selecting for further development those cottons which have a low potential for imperfection formation during processing.

Weather, varietal, harvesting, and ginning effects on seed-coat fragment count and weight in ginned lint cotton were evaluated in a 2-year study in the Mississippi Delta. In this study, harvest and lint cleaner treatments had almost no effect on fragment count, while year and variety had strong influences. Based on 3 grams of lint, the fragment count averaged 51 and the total fragment weight averaged 46 mg. Weight was reduced from 83 to 24 mg as lint cleaning stages increased from 0 to 3, but the number of fragments was reduced only slightly. In this study, which included varieties of moderate seed-coat fragment producing potential, weather (year) influences were more important than harvest or varietal factors.

NEPS and seed-coat fragments in cotton are a source of trouble in textile manufacturing and finishing, and detract from appearance in yarn and fabric. At the cotton gin, the gin stand is a significant contributor to neps in ginned lint. Experiments were conducted to determine the effect of gin stand feed rate and seed-roll density on the occurrence of neps and other imperfections in ginned lint. Gin stand treatment effects were also evaluated for other related cotton quality factors and for spinning performance. Increasing the ginning rate 40% above the rated capacity decreased the classer's grade and fiber length, and increased the level of neps and other imperfections in the yarn..

The interactions between picking dates, locations, and varieties were studied to evaluate the effect of growth period on neps in ginned lint, yarn, and fabric. Five harvest intervals were selected, and the cotton yield increments between intervals were used to provide five levels of maturity. Neps in raw cotton were measured by the USDA-AMS web nep test and microscopic examination of card web, imperfections in the yarn ascertained by the Uster instrument, and neps in woven fabric counted by dyeing procedures. Results showed that growth period has a significant impact on the number of neps and other imperfections found in lint and manufactured yarns and fabrics. As a general rule, cotton grown early in the season will produce yarns and fabrics with a lower number of imperfections than cotton grown late in the season from the same field.