Papers by David McAlister
Twenty-nine bales of cotton with short fiber content ranging from approximately 5% to 25% were se... more Twenty-nine bales of cotton with short fiber content ranging from approximately 5% to 25% were selected for the purpose of comparing the effectiveness and relationships among the current testing methods for fiber length. The instruments and/or methods used to measure short fiber include HVI, AFIS, and Suter-Webb array. Comparisons between the three methods indicate that they correlate well with each
Journal of Cotton Science
The ultra-narrow-row (UNR) cotton system is defined as planting a cotton field with closely space... more The ultra-narrow-row (UNR) cotton system is defined as planting a cotton field with closely spaced rows (typically less than 38.1 centimeters). Because this narrow-row spacing provides the potential for increased yield, it has caught the attention of U.S. cotton producers, ginners, and textile mills. While these three groups share an interest in UNR cotton, they do not share the same opinion on its merits. Producers favor UNR because of the potential for increased yield, a shorter growing season, and lower equipment costs. Conversely, cotton ginners, buyers, and spinners are wary of UNR cotton because of perceived increased levels of non-lint material. For gins not prepared to handle UNR stripperharvested cotton, increased non-lint content can reduce the cleaning efficiency of the gin and increase wear on ginning equipment. Spinners are wary of UNR cotton because studies have shown that increased non-lint content in cotton fiber can cause an increased number of ends-down in spinning, increased waste in the card room, and reduced yarn and fabric quality. Little research has been conducted on the impact of UNR cotton in the textile plant. This study focuses on the impact of harvesting methods on waste, percentage efficiency, and processing and yarn quality, which are important factors to the yarn spinner. The results indicate that an alternative harvesting method could make UNR an attractive planting choice, particularly in marginal fields.
Stink bugs [Acrosternum hilare (Say), Nezara viridula (L.), and Euschistus servus (Say)] have bec... more Stink bugs [Acrosternum hilare (Say), Nezara viridula (L.), and Euschistus servus (Say)] have become an important pest of cotton (Gossypium hirsutum L.) concurrent with the expansion of acres planted to transgenic cotton cultivars. The objective of this study was to determine the effect of stink bug damage on the textile mill performance of cotton cultivars that represented all combinations of transgenic technology (available in 2002). Six cotton cultivars (Stoneville 474 and its five transgenic siblings; ST 4793R, ST 4691B, ST 4892 BR, ST BXN 47, and ST BXN 49B) were grown with and without insecticide applications for stink bug control in 2002 and 2003. Stink bug damage was assessed in early August and in late August of each season.
Textile manufacturers have raised concerns that mill performance of cotton (Gossypium hirsutum L.... more Textile manufacturers have raised concerns that mill performance of cotton (Gossypium hirsutum L.) has been compromised by transgenic technology. The objective of this study was to compare two transgenic Bollgard (BG) and glyphosate tolerant (RR) cotton cultivars to their conventional parents for fiber properties, processing characteristics, and fabric quality. Field experiments were conducted with 'Deltapine 458 BG/RR' and 'Deltapine 655 BG/RR' and their recurrent parents, 'Deltapine 5415' and 'Deltapine 5690'. These cultivars were planted at three planting dates (mid-April, early May, and mid-May) in 2000 and 2001. Ginned cotton was tested for fiber properties, processing waste, spinning performance, yarn characteristics, and white specks in dyed fabric. The transgenic and recurrent parent cultivars were not different in lint yield at any planting date in either year, and only small differences in HVI fiber properties occurred. Similarly, differences between the transgenic and recurrent parent cultivars for processing waste, spinning performance, yarn quality, and white specks were small, even when statistically significant. Differences between the transgenic and recurrent parent cultivars tended to be of the same magnitude or smaller than differences among planting dates. Late-planted cotton tended to have better yarn quality than early-planted cotton. The results indicate little difference in processing quality or efficiency between these transgenic cultivars and their recurrent parents.
This study was designed to quantitatively assess the effects of short fiber (< 12.7 mm long) in r... more This study was designed to quantitatively assess the effects of short fiber (< 12.7 mm long) in raw cotton on the quality of 20s ring spun yarn. Twenty-eight bales of cotton with a wide range of fiber properties and an especially diverse population of short fiber content were utilized. Properties of the raw cotton were measured by High Volume Instrumentation (HVI), Advanced Fiber Information System (AFIS) instruments, and the manual Suter-Webb (SW) Array method. Ring spun yarns produced from these cottons were tested for process and product quality. Results indicate that most of the yarn properties-especially yarn strength, irregularity, and frequency of thick and thin defects-are strongly correlated with each of the three measures of short fiber content. A pool of 23 potential predictors from the AFIS, HVI, and SW fiber properties was utilized to develop "best" regression models for seven yarn properties. In five of the seven models, the short fiber content variable was the most important predictor, exceptions being the models for yarn strength and elongation. For five of the yarn properties, models developed using the four basic HVI properties alone were nearly as good in predicting yarn quality as those using all 23 fiber properties. Exceptions were models for elongation and for ends down.
This study evaluated the Continental Eagle version of the ARS-developed louvers for saw-type lint... more This study evaluated the Continental Eagle version of the ARS-developed louvers for saw-type lint cleaners in a commercial gin plant to determine the subsequent impact on fiber quality at the gin and mill levels. The study was conducted without re-gard as to whether the cotton ...
A laboratory ginning test was conducted to compare the ginning performance, fiber quality, and sp... more A laboratory ginning test was conducted to compare the ginning performance, fiber quality, and spinning properties of a newly developed small-seeded variety (DP 555 BG/RR) against a larger-seeded standard commercial variety (DP 451 B/RR). Ginning tests concentrated on 1) evaluating seed loss and seedcoat fragment generation during ginning and any effects on spinning performance, and 2) evaluating an experimental ginning rib's effect on seed loss and seedcoat fragment generation. Fiber and spinning tests indicated that, even though DP 451 was somewhat longer, had fewer neps, and had lower seed loss rates, DP 555 made yarn whose properties were as good as or better than that made from DP 451. Evaluation of the experimental rib indicated that it had positive results on fiber and yarn properties for DP 451 but negative results on those same properties for DP 555. These data indicate that further tests need to be conducted to better understand the interaction of seed size and gin stand design, particularly on very small-seeded varieties.
Various statistical parameters of cotton fiber length distributions were calculated from AFIS (Ad... more Various statistical parameters of cotton fiber length distributions were calculated from AFIS (Advanced Fiber Information System) test data of 21 cottons of different varieties and growth locations. The results show that the SFC (short fiber content) defined by 0.5 inches is a good indicator of short fibers in a sample based on the high correlation coefficients with short fiber content values defined by other lengths such as 0.4 or 0.6 inches. However, the measured short fiber content has very high variation, as high as 6.8 times the CV% of UHML (Upper Half Mean Length). The high variation of SFC is one of the major problems hindering its use in the cotton classing system. The LHML (Lower Half Mean Length), a new parameter of short fibers is introduced in this study. The results show that the LHML has very high correlation coefficient with short fiber content, but much lower variation, only 1/3 of the CV% (Coefficient Variance) of the SFC. Therefore, the LHML is a good candidate for substituting the short fiber content. The uniformity index that is used in the U.S classing system correlates to the SFC, but the Upper Half Mean Length has very low correlation with the SFC.
UNITED STATES IS PURSUING NATURAL FIBERS AS SUSTAINABLE, ENVIRONMENTALLY FRIENDLY SOURCES FOR A V... more UNITED STATES IS PURSUING NATURAL FIBERS AS SUSTAINABLE, ENVIRONMENTALLY FRIENDLY SOURCES FOR A VARIETY OF INDUSTRIAL APPLICATIONS. FLAX (LINUM USITATISSIMUM L.) FIBER OFFERS MANY POSSIBILITIES TOWARDS THIS GOAL. SPECIFIC UNITED STATES DEPARTMENT OF AGRICULTURE (USDA) RESEARCH OBJECTIVES ARE TO: (1) EVALUATE TRADITIONAL FARM EQUIPMENT FOR FLAX PRODUCTION, (2) IMPROVE RETTING, ESPECIALLY THORUGH USE OF ENZYMES, (3) DEVELOP OBJECTIVE STANDARDS FOR FIBER QUALITY TESTING, AND (4) TEST FIBERS FOR MANUFACTURING PERFORMANCE AND/OR AESTHETIC PROPERTIES. FIBER FLAX FOR SHORT STAPLE USES CAN BE RAPIDLY HARVESTED BY EQUIPMENT READILY AVAILABLE ON U.S. FARMS. WARM SOUTHERN CLIMATES ALLOW THIS CROP TO BE GROWN IN THE WINTER TO PRODUCE FLAX ON TRADITIONALLY DORMANT FIELDS. ENZYMES TO EXTRACT FIBERS PROVIDE AN ENVIRONMENTALLY FRIENDLY METHOD FOR RELIABLE AND SUSTAINABLE AGRICULTURE. COMMERICAL ENZYMES AND CALCIUM CHELATING AGENTS PROVIDE A KEY STEP IN THE ECONOMIC DEVELOPMENT OF A CONTROLLED AND S...
Tests were conducted using a rotor spray system to apply moisture in the form of fine water dropl... more Tests were conducted using a rotor spray system to apply moisture in the form of fine water droplets to cotton lint at the lint slide just before bale packaging. Initial cotton moisture content ranged from 5.0 to 5.5%, dry basis. Bales in this study will be stored for 3, 6, and 12 months and cotton quality degradation determined after each of these three storage periods. Seven levels of moisture addition are being studied, including 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, and 11.0 % moisture (after rewetting), in addition to bales with no additional moisture added. Although both rotor spray systems and atomizing nozzle spray systems add moisture as water droplets, a rotor spray system will generally apply moisture more uniformly across the width of the lint slide, and will produce a finer droplet size than would an atomizing nozzle system. However, rotor spray systems have more moving parts, and must mount closer to the lint batt as compared to an atomizing nozzle system. Both spray systems p...
Twenty-nine bales of cotton with short fiber content ranging from approximately 5% to 25% were se... more Twenty-nine bales of cotton with short fiber content ranging from approximately 5% to 25% were selected for the purpose of comparing the effectiveness and relationships among the current testing methods for fiber length. The instruments and/or methods used to measure short fiber include HVI, AFIS, and Suter-Webb array. Comparisons between the three methods indicate that they correlate well with each other. The Suter-Webb array technique gives higher estimates of short fiber content than those of HVI and AFIS, and shows greater discrimination among the samples. Highly significant regression models were developed to predict short fiber content from long fiber data (length and strength) and micronaire.
Cotton offers next-to-skin comfort and hence is a preferred fiber for undergarments. There have b... more Cotton offers next-to-skin comfort and hence is a preferred fiber for undergarments. There have been a number of studies on the effect of different fiber types, fabric structure, fabric finishes, etc. on the moisture vapor transport properties. However, there has been no report in the public domain on the relationship between cotton varieties on the moisture vapor transport characteristics of fabrics produced from them. The study reported in this paper focuses on the moisture vapor transport properties (MVTR) of cotton fabrics knitted from 31 different cotton fibers with different pedigrees grown over a three-year period in three major cotton growing regions of US, Southwest (Texas), Mid-South (Mississippi) and Southeast (Georgia). Results indicate that cotton varieties influence the MVTR of knitted fabrics produced from them. This study, for the first time has attempted to link varietal effects on the most important property of cotton—breathability quantified using MVTR. Preliminar...
Mill modernization and global market requirements necessitates the continual improvement of uplan... more Mill modernization and global market requirements necessitates the continual improvement of upland cotton, Gossypium hirustum L., cultivars. Recent focus by breeders is to create upland cotton with superior fiber quality that approaches pima cotton, Gossypium barbadense L. The objective of this study was to perform in-depth analysis of fibers produced by 'FM832' and 'MD51neOK' and their progeny, 'MD15', that express transgressive segregation for fiber bundle strength. Results were generated via the Stelometer, Peyer AL101, Fibrograph, HVI™, AFIS, Favimat, Fiber Dimensional Analysis System (FDAS) 765, and miniature spinning. Single fiber strength and fineness testing was performed using the Favimat, whereas the FDAS 765 performed non-contact dimensional analysis along the fiber length. Traditional fiber bundle testing was compared to single fiber testing and miniature spinning yarn testing. Cottons in this study were broken at different loading rates from 0.3 ...
The study of the addition of water to cotton at ginning dates back to the early 1950's. Since... more The study of the addition of water to cotton at ginning dates back to the early 1950's. Since this time, technologies have changed which allow for more control and higher volumes of water to be added to cotton at the lint slide than ever before. The objective of the study reported here, which is part two of the study reported by Hughs (2004), was to determine an acceptable bale moisture range within which fiber quality, yarn quality, microbial activity and dyed fabric quality degradation can safely be avoided after 6 months of bale storage. Approximately 50 pounds of cotton were sampled from each of the three bales for each moisture treatment as described by Hughs (2004) in part one of this study, after six months in storage. In addition to the HVI fiber properties reported by Hughs (2004), additional testing of the fibers was performed on the Advanced Fiber Information System (AFIS) followed by microbial activity determinations. The resulting 20/1 open-end spun yarns were subje...
Cotton always has trash associated with its fibers, which is known to affect processing efficienc... more Cotton always has trash associated with its fibers, which is known to affect processing efficiency. Rotor spinning is more sensitive to trash levels in cotton compared with ring spinning, the other major spinning system. Trash trapped in the rotor grove is typically pulverized cotton fiber and trash particles whose origens cannot be visually determined (e.g. leaf, fiber, bark, seed coat, etc.). New techniques or instruments are necessary to reliably provide rapid, consistent, and quantitative identification of cotton trash sources. The goal of this research was to identify the origens and to understand the impact of each type of pulverized substance on textile processing. Research has been done with infrared microscopy in order to confirm the utility of infrared mapping of cotton biological components. The mid-infrared region is between the wave numbers 4000 and 650 cm-1 and can be evaluated with Fourier-transform infrared (FT-IR) as a qualitative and quantitative analytical tool fo...
Cotton trash is known to affect textile-processing efficiency. Removal of cotton trash has often ... more Cotton trash is known to affect textile-processing efficiency. Removal of cotton trash has often been a means to improve textile spinning. To combat trash and efficiency problems, Hamrick Mills (as do other textile mills) specifies cotton bales, which they acquire, should be no higher than a 3 leaf for processing on their Murata Airjet Spinner (MJS) or Murata Vortex Spinner (MVS). This leaf grade cut-off point is based on their past spinning experiences which point toward processing problems during weaving and excessive loom stops. This research determined how HVI Trashmeter software evaluates cotton trash and its particle size distribution in a 40-bale textile mill laydown. This study compared the distribution of particles within all bales and how similar these bales were to one another. The study further compared the change in trash particle distribution and HVI properties through the bales. Further work is needed to determine if leaf grade or trash particle distribution provide e...
Cotton trash is known to affect textile -processing efficiency. Removal of cotton trash is a mean... more Cotton trash is known to affect textile -processing efficiency. Removal of cotton trash is a means to improve textile spinning. To combat trash and efficiency problems, textile mills frequently specify that cotton bales, which they acquire, should be no higher than a 3 leaf for processing on Murata Airjet Spinner (MJS) or Murata Vortex Spinner (MVS) equipment. This leaf grade cut-off point is based on past spinning experiences, which point toward processing problems during weaving and excessive loom stops. This research evaluates how High Volume Instrument (HVI™) Trashmeter software analyzes cotton trash and its particle size distribution in a 40-bale textile mill laydown. This study compared the distribution of particles within all bales and how similar these bales were to one another and HVI™ properties throughout the bales. Bales of known and constant leaf grade appear to have different trash particle size distributions. Further work is needed to determine if trash particle distr...
Temperature and relative humidity are important considerations for carding cotton in textile manu... more Temperature and relative humidity are important considerations for carding cotton in textile manufacturing. It has been suggested that high relative humidity decreases the stiffness of fibers and increases the moisture content of the fibers. With the recent interest in moisture addition at the gin, it is important to determine if increased fiber moisture content in the cotton bale will also
Transactions of the ASABE, 2007
The study of the addition of water to cotton at ginning dates back to the early 1950s. Since that... more The study of the addition of water to cotton at ginning dates back to the early 1950s. Since that time, technologies have changed, allowing for more control and higher volumes of water to be added to cotton at the lint slide than ever before. The objective of this study was to determine an acceptable bale moisture range within which fiber quality, yarn quality, and dyed fabric quality degradation can safely be avoided after six months of bale storage. Approximately 22.7 kg (50 lbs) of cotton were sampled from each of the three bales for each of the four moisture treatments after six months in storage. In addition to the HVI fiber properties, additional testing of the fibers was performed on the Advanced Fiber Information System (AFIS), as well as a microbial assay to determine any microbial damage to the cotton during storage. The resulting 20/1 open-end spun yarns were subjected to typical yarn quality measurements (C.V., defects, strength, and elongation) and then circular-knit into panels so that yarn from each treatment was butt-knit to more easily observe color or shade change. HVI data indicated that the moisture treatment levels and storage period had an adverse impact on color Rd and +b with increasing amounts of water added at the lint slide. Although microbial data were collected, the data did not indicate any significant activity during the six months of storage. As for yarn quality, it appears that 9.1 kg (20 lbs) or more of water added to bales of cotton at the lint slide resulted in significant as well as practical reductions in yarn quality. With respect to the six-month storage period and the treatments used in this study, although there were color changes to the cotton fiber, there appeared to be no impact on the bleached and dyed fabric. Additionally, it appears that the point of diminishing return for adding moisture to cotton at the lint slide lies between 6% and 8.5%.
2005 Tampa, FL July 17-20, 2005, 2005
Cotton is prepared for mechanical harvest using desiccant and defoliant chemicals. Conventional c... more Cotton is prepared for mechanical harvest using desiccant and defoliant chemicals. Conventional chemical defoliation is not effective immediately, it requires a period of good weather, and it is restricted in organic production. Thermal defoliation may be an alternative to chemical defoliation if it does not harm the crop. This study was conducted to determine what impact thermal defoliation has on fiber value, yield, and gross returns. A thermal defoliation machine that used propane to heat treatment air was tested on several varieties at various locations in three states over two years. A mixed statistical model was used to compare thermal defoliation to conventional chemical defoliation and harvesting two or three days after treatment to harvesting two or three weeks after treatment. There were no statistically significant differences in yield or value between treatments or harvest dates. Thermal defoliation does not negatively impact fiber value or yield, and thermally defoliated cotton may be harvested early without reducing gross returns.
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Papers by David McAlister