ASSESSING the ECONOMIC IMPACT of PRESCRIPTION LINT CLEANING TECHNOLOGY Claudia Leonardi LSU Agcenter Baton Rouge, LA Kenneth W

676 2006 Beltwide Cotton Conferences, San Antonio, Texas - January 3 - 6, 2006

ASSESSING THE ECONOMIC IMPACT OF PRESCRIPTION LINT CLEANING TECHNOLOGY Claudia Leonardi LSU AgCenter Baton Rouge, LA Kenneth W. Paxton Dept. of Agric. Economics and AgriBusiness Baton Rouge, LA

Abstract

This study evaluates the economic impact of prescription lint cleaning on the ginning industry. Specifically, the study evaluates the commercial version of the USDA-ARS developed technology that automatically controls the number of grid bars used in the cleaning process. This technology is manufactured by Continental Eagle and marketed under the trade name Louvermax®. Data from initial tests of the technology, as well as data from commercial gins, are used to estimate the potential impacts of adopting the technology. Impacts are estimated on a per bale basis and extrapolated to the industry level, based on the number of bales processed through the technology. Results indicate that adoption of the technology does “save” cotton. On average, the technology saved about 6.9 pounds per bale. At the current loan rate of $0.52 per pound of lint, this would translate into about $3.59 per bale. With over two million bales processed using the technology, this would imply an impact in excess of seven million dollars in saved lint alone.

Introduction

Automation of the ginning process has made tremendous progress since the mid 1990s with the introduction and adoption of automatic gin process control technology. This technology demonstrated that a significant amount of cotton could be satisfactorily ginned with considerably less processing. By matching the cleaning and drying needs to market demands for quality, the producer realizes a gain in the amount of lint without incurring grade reductions. The net result is a weight gain without offsetting penalties for grade reductions. An extension of this technology is to automatically control the internal operation of the gin machines. Anthony (1999) patented a method that allows for the automated selection of the number of grid bars in saw-type lint cleaners. The underlying assumption of this technology is that once enough trash is removed to achieve a grade objective, subsequent grid bars should be bypassed. This is true because each grid bar removes some good fiber from the cotton even if there is no trash. The only way to avoid this loss is to not use the grid bars in the cleaning process.

Previous Work

Several studies have evaluated the effect of the number of operating grid bars on the amount of waste and on the quality of saleable cotton resulting from the ginning process. A number of these studies are cited below. The effect of decreasing the number of grid bars was similar across studies. Decreasing the number of grid bars from 15 to 1 or 0 reduced the amount of material separated from the cotton, resulting in lower waste (Anthony, 1999; Anthony, 2000; McAlister et al., 2002).

In the 1999 report, the amount of material removed with five, four, three, two, and one grid bars was 27.6, 23.5, 16.0, 12.4, and 6.6 lb. per 500 lb. bale, respectively (Anthony, 1999). Furthermore, of the material ejected through the grid bars, 67.3% for five, 54.8% for four, 48.6% for three, and 33.3% for two grid bars, respectively, could have been retained as part of the lint (Anthony, 1999). In a follow-up publication, which reported five studies, Anthony (2000) further investigated the effect of the number of grid bars on the amount of waste and lint quality.

Research reported here was based on the 16-D saw-type lint cleaner, equipped with five grid bars. The number of lint cleaners varied across experiments from two to three lint cleaners, for a maximum of either 10 or 15 possible operating grid bars. Data collected in study one are not reported here because the effect of the number of active grid bars was confounded by the concurrent utilization of other applications. In study two, treatments were ten, five, four, three, two, one, and zero grid bars. Treatments were obtained by equipping the two saw-type lint cleaners with automated louvers. In order to obtain the zero treatment, both saw-type lint cleaners, together with the feed section and condenser, were bypassed. No mean for individual treatment was reported; however, it was stated that lint 677 2006 Beltwide Cotton Conferences, San Antonio, Texas - January 3 - 6, 2006 cleaner waste decreased from 18.9 to 0 lb. per bale as active grid bars decreased from 10 to 0 (Anthony, 2000). Changes in lint quality were evident, mainly when decreasing the number of grid bars from one to zero (Anthony, 2000). Lint quality did not change across treatments when the zero grid bars treatment was excluded, except for color grade index, as determined by the High Volume Instrument (HVI) and manual leaf classification (Anthony, 2000). The manual leaf classification increased from 3 to 4.0 (P ≤ 0.05), decreasing the number of active grid bars from 10 to 1 (Anthony, 2000). The color grade index obtained by HVI decreased from 101.3 to 98.7 as the number of grid bars decreased from 10 to 1 (Anthony, 2000). Opening and cleaning waste increased from 1.4 to 4.6%, decreasing grid bars number from 10 to 0 (Anthony, 2000).

Experiment three was conducted to confirm the amount of waste obtained in experiment two. Therefore, experiments two and three were very similar, with the exception that experiment three was conducted in a controlled environment and different cotton varieties were utilized (Anthony, 2000). Results were confirmed; the amount of lint cleaner waste per bale decreased from 27.5 to 0 lb. (P ≤ 0.05), decreasing the number of grid bars from 10 to 0.

In study four, data were verified in the field utilizing a commercial gin (SERVICO Gin Co.) located in Courtland, Alabama. The gin held three lint cleaners, working in series, that were operated with either one or two active grid bars on the first and second lint cleaner, respectively, or with five active grid bars on each of the three lint cleaners (Anthony, 2000). Ginning cotton with either 15 or 3 active grid bars produced 30 and 8 lb. of waste, respectively (Anthony, 2000).

The last study was a combination of four parts. In the first part, 100 pound lots of cotton were ginned utilizing different arrangements of grid bars: 10, 5, and 2 grid bars (Anthony, 2000). The waste was 26.0, 17.5, and 9 lb. for 10, 5, and 2 active grid bars, respectively (Anthony, 2000). In the remaining three parts, the author was interested in investigating variability in the amount of waste produced across cotton trailers, varieties, and growth locations. The cleaning sequence utilized within each of the following experiments was different. When 21 trailers of seedcotton of unknown varieties were processed, lint cleaner waste ranged from 6.4 to 19.3 lb. per 500 lb. of ginned lint. The waste of 16 different cotton varieties ranged from 11.4 to 18.7 lbs. per 500 lb. bale. Twenty-five varieties were grown simultaneously at two locations only few miles apart and had very similar waste. Waste averaged 18.4 and 18.9 lb. at locations 1 and 2, respectively (Anthony, 2000). Therefore, other factors such as variety and trailer, may affect the amount of waste produced. Overall, based on data reported above, the author concluded that fiber loss can be reduced by 50% or more, which corresponds to approximately 10 lb. per cotton bale. Therefore, assuming a cotton value of $0.60 per lb., reducing the number of active grid bars increased the bale value by $6.

The number of operating grid bars was further investigated utilizing a 24-D saw-type lint cleaner, which was modified to contain seven grid bars (McAlister et al., 2002). Also, in the 24-D saw-type lint cleaner, grid bars were activated by opening and closing louvers. The utilization of all seven grid bars was tested by adding one grid bar at the time. Each grid bar combination was replicated twice within each of the two varieties tested, for a total of 28 observations. Lint waste decreased from 22.7 to 9.1 lb. (P ≤ 0.05), when decreasing the number of operating grid bars from 7 to 1 (McAlister et al., 2002). In the present experiment, the effect of the number of operating grid bars differed among varieties. The Stoneville 4691 variety (hairy leaf) responded more pronouncedly to the change in grid bar numbers than the Delta Pine and Land 50 variety (smooth leaf). Overall, modifying the number of grid bars did not affect the lint quality, except for the leaf grade and the waste percentage present in the cleaned lint. Leaf grades deteriorated as the number of operating grid bars decreased; and was 4.5 for one and 3.9 for seven grid bars, respectively (McAlister et al., 2002). Opening and cleaning waste increased from 1.5 to 2.3% (P ≤ 0.05), when decreasing grid bar numbers from 7 to 1 (McAlister et al., 2002).

The interaction between variety and number of operating grid bars was further investigated in a commercial gin plant (Anthony et al., 2003). Sixteen cotton bales, eight for each of the two varieties tested, were processed utilizing the Continental Eagle version of 24-D saw-type lint cleaner operating with either two or eight grid bars (Anthony et al., 2003). The cotton utilized in the test contained approximately 10% foreign matter before being cleaned. The authors suggested that the amount of foreign matter was higher than what normally would be allowed in order to utilize a lint cleaner with a reduced number of active grid bars (Anthony et al., 2003).

Overall, except for a few dependent variables, the effect of number of grid bars was similar between varieties. Motes per bale averaged 11.5 and 6.0 lb. for eight and two active grid bars, respectively (Anthony et al., 2003). Decreasing the number of active grid bars increased the dust per gram, trash per gram, and the amount of visible foreign matter, 678 2006 Beltwide Cotton Conferences, San Antonio, Texas - January 3 - 6, 2006 as detected by the Advanced Fiber Information System (AFIS). Spinning performance did not differ between treatments. Although opening and cleaning waste collected during mill evaluation increased when decreasing the number of active grid bars, the difference was numerically small. In the previously reported experiments, the number of grid bars tested was not chosen according to the amount of foreign matter present in the cotton. Treatments were applied independently from the level of foreign matter present in the cotton prior to the cleaning. Therefore, some treatments could have been tested utilizing cotton that required either more or less grid bars than the one tested. Probably, the most appropriate utilization of the previously described technology is the application of a number of grid bars that will allow for maximum expulsion of foreign matter and, simultaneously, minimum damage to the cotton’s fiber during ginning.

Materials and Methods

Continental Eagle (Courtland, Alabama) designed and conducted experiments in six countries for the purposed of quantifying changes in the amount of waste generated by utilizing different numbers of active grid bars. Data were collected in the United States (U.S.), Togo, Mali, Burkina Faso, Greece, and Australia. In each country, tests were slightly different. Either one bale or a series of bales were processed through the lint cleaner and the waste (mote) produced was weighed either after each bale or after a series of bales were processed. In Mali, Burkina Faso, and Australia, treatments consisted of one vs. eight grid bars and, except for Australia, only one observation per treatment was collected. In Australia, the experiment was replicated, and four observations, two for each treatment, were collected. In Mali, Burkina Faso, and Australia, each observation was obtained by processing various bales. In Mali, 14 and 17 bales were processed in order to measure the waste for one and eight grids bars, respectively. In Burkina Faso, 30 bales were processed for each treatment. In Australia, two groups, one of 22 and the other of 18 bales, were processed through eight grid bars and two groups, one of 20 and the other of 21 bales, were processed through one grid bar.

In the U.S., Togo, and Greece all eight grid bars were tested by adding a louver at the time; for a total of eight different treatments. When no louvers were inserted, the number of grid bars utilized was eight, when one louver was inserted seven grid bars were operating, when seven louvers were inserted one grid bar was in use. In the U.S., the experiment was replicated four times and a total of 32 observations were collected. In Togo, the experiment was replicated eight times and a total of 64 observations were available. In Greece, the experiment was conducted only once and one observation for each treatment was available.

Data from these experiments were obtained from Continental Eagle and were used to estimate the potential savings resulting from adoption of the technology. A statistical analysis was performed to determine if there were statistical differences among treatments. Results of this analysis, along with data from the literature, are used to develop a composite estimate of the impact of the lint cleaning technology.

Statistical Analysis

Bale weight and amount of waste per bale were different across countries. Therefore, in order to report the amount of waste on a similar scale across countries, the amount of waste was expressed as a percentage of the net bale weight. Observations were plotted by country (Figure 1). As stated previously, experiments were replicated within some countries. The difference among replicates was assumed to be random and each treatment was present within each experiment. Therefore, replication within country was treated as a blocking factor.

Data were analyzed as a randomized block design nested within country, utilizing the mixed procedure of SAS (SAS, 2003). The model included country, treatment, and country by treatment as fixed effects, and block within country and treatment by block within country as random effects. In order to establish the best models, the simple linear, polynomial, and curvilinear effect of treatment on the dependent variable was assessed. The best model was chosen based on the residual plot, the Shapiro-Wilk residual’s test of normality, and Akaike Information Criterion. ˆ b1 The power model that gave the best fit was Yi = b0 X i where Yi was the waste expressed as a percentage of net bale weight and X i was the number of active grid bars tested. In order to test the power model, the statistical analysis was estimated by taking the logarithm of both Yi and X i . Observations were weighed by the number of 679 2006 Beltwide Cotton Conferences, San Antonio, Texas - January 3 - 6, 2006 bales ginned to obtain each value. The 95% CI were utilized to determine difference in the parameter’s estimates across countries.

6

5

4

3

2 Mote, as a % of bale net wt net bale % of a as Mote, 1

0 012345678 # of active grid bars

Figure 1. Effect of number of active grid bars on amount of waste (mote), expressed as a percentage of bale net weight. Data were collected in six countries: U.S. (●), Togo (○), Mali (■), Greece (▲), Burkina Faso (x), and Australia (□). A significant country, treatment, and country by treatment interaction was observed (P < 0.001). Therefore, parameter’s estimates were obtained for each country.

Results

Waste expressed as a percentage of net bale weight was different across countries (P < 0.001); it decreased as the number of active grid bars decreased (P < 0.001), and the decrease was not the same across countries (P < 0.001). Therefore, the two parameters, b0 and b1, and corresponding 95% confidence intervals were estimated for each country (Table 1). The b0 parameter represents the percentage of waste produced when one grid bar is utilized. The b1 parameter is a measurement of the inclination of the line; therefore, the higher the b1 the bigger the change in percentage of waste is, decreasing from 8 to 1 the number of grid bars.

Results of the analysis demonstrated that countries had differing amounts of waste from the lint cleaning process. In order to establish which countries differ from each other, a 95% confidence interval of b0 was calculated. Countries such as Australia, U.S., and Burkina Faso produced different percentages of waste, by ginning cotton with one grid bar. Furthermore, the waste produced in each of the previously listed countries was different from the remaining countries (Table 1). Overall, waste expressed as a percentage of bale net weight was the highest in U.S. and the lowest in Australia. When one grid bar was utilized, waste expressed as a percentage of net bale weight was 3.36% for the U.S. and 0.11% for Australia. Greece and Mali had the same waste percentage (0.79%) when one grid bar was utilized.

As stated previously, decreasing the number of grid bars from 8 to 1 decreased the percentage of waste produced (P < 0.001). The extent of the decrease was different across countries (P < 0.001). According to 95% CI, the “slopes” 680 2006 Beltwide Cotton Conferences, San Antonio, Texas - January 3 - 6, 2006

(b1) for Australia and Burkina Faso were different from each other and from the “slopes” of the remaining four countries. The decrease in percentage of waste was similar in Greece, Mali, and Togo. In the U.S. for example, by decreasing the number of grid bars from eight to one, the

Table 1. Relationship between number of grid bars and waste produced. Waste produced changed by country. Mote b1 (as a % of bale net weight) = b0 x (number of grid bars) .

b0(% waste) b1(slope) Country1 estimate 95% CI estimate 95% CI Australia 0.11 0.09 – 0.13 0.79 0.73 – 0.86 Burkina Faso 0.36 0.31 – 0.44 0.60 0.53 – 0.67 Greece 0.79 0.67 – 0.99 0.26 0.17 – 0.35 Mali 0.79 0.66 – 0.95 0.36 0.29 – 0.42 Togo 1.02 0.96 – 1.10 0.31 0.28 – 0.34 U.S. 3.36 3.04 – 3.70 0.15 0.11 – 0.20 1A significant country, treatment, and country by treatment interaction was observed (P < 0.001). Therefore, parameter’s estimates and 95% Confidence Interval (CI) were obtained for each country. percentage of waste decreased from 4.74% to 3.36%. Considering a 500 lb. bale, the decrease in waste percentage corresponded to a weight decrease of 6.9 lb. (from 23.7 to 16.8 lb.). In a similar commercial-type setting, Anthony et al. (2003) reported that lint waste decreased from 11.5 to 6.0 lb. (P ≤ 0.05) when decreasing the number of operating grid bars from 8 to 2. Although the absolute values of waste amounts were quite different between experiments, the reduction in amount of waste was similar. In the U.S., although cotton value varied from year to year, when a cotton value of $0.52 per lb. was considered, reducing the number of active grid bars from 8 to 1 increased the bale value by $3.59. Although, b1 was the smallest for the U.S., when the percentage of waste was converted into amount per bale and to dollars, the maximum gain by decreasing the number of grid bars was in the U.S.

Summary and Conclusions

The previous research cited here clearly indicates that the technology can reduce the amount of fiber loss through excessive processing during the cleaning phase of ginning. Further, evidence from commercial installations of the technology clearly demonstrated that similar savings in lint fiber are possible in a commercial setting. While estimates of the amount of savings vary, all previous research indicates a saving in lint fiber by reducing the number of active grid bars engaged in the cleaning process. Given all the available estimates, it appears that on average the technology could save about 6.9 pounds of lint per bale. At the current loan rate of $0.52 per pound, this would imply a $3.59 per bale value. Current estimates are that the technology will be used to process about 2 million bales. If this is correct, then the technology will have about a 7 million dollar impact. This does not include an estimate for additional revenue to the gin for processing additional cotton (6.9 more pounds per bale). Evidence examined in this research suggests that there is no change in fiber properties when employing this technology.

References

Anthony, W.S. 1999. Can lint cleaner waste be reduced? In Proc., Beltwide Cotton Conf., Pages 1403-1407. National Cotton Council, Memphis, Tennessee.

Anthony, W.S. 2000. Methods to reduce lint cleaner waste and damage. Transaction of the ASAE. Vol. 43(2):221- 229.

Anthony, W.S., F. Clark, D. Steele, E. Edwards, G. Pate, and D. D. McAlister, III. 2003. Evaluation of lint cleaner louvers at a commercial gin. In Proc., Beltwide Cotton Conf., CD-ROM. National Cotton Council, Memphis, Tennessee. 681 2006 Beltwide Cotton Conferences, San Antonio, Texas - January 3 - 6, 2006

McAlister, III, D.D. 2001. Gin process control and the resultant textile yarn and knit fabric quality. App. Eng. In Agric., Vol. 17(6):761-764.

McAlister, III, D.D., W.S. Anthony, and E. Edwards. 2002. Quality impact of louvers on a 24-D lint cleaner. In Proc., Beltwide Cotton Conf., CD-ROM. National Cotton Council, Memphis, Tennessee.

National Agricultural Statistics Service (NASS). 2005. Cotton Ginning. http://jan.mannlib.cornell.edu/ reports/nassr/field/pcg-bb/2005/ctgn1305.txt. Accessed August 8, 2005.

Personal communication with officials at Continental Eagle Corporation, Prattville, Alabama, August 8, 2005.

SAS® User’s Guide: Statistic, Release 9.1. 3rd Edition, 2002-2003. SAS Inst., Inc., Cary, North Carolina.