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ARS Home » Southeast Area » Stoneville, Mississippi » Cotton Ginning Research » Research » Publications at this Location » Publication #313218
Title: Removal of plastic materials using adjustments and revisions to standard seed cotton clean equipment: Progress Report

Author
item Hardin Iv, Robert
item Byler, Richard
item Delhom, Chris

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 2/1/2015
Publication Date: 5/1/2015
Publication URL: http://www.cotton.org/beltwide/proceedings/2005-2015/index.htm
Citation: Hardin IV, R.G., Byler, R.K., Delhom, C.D. 2015. Removal of plastic materials using adjustments and revisions to standard seed cotton clean equipment: Progress Report. National Cotton Council Beltwide Cotton Conference. 973-980.

Interpretive Summary: Cotton from the U.S. is known to be relatively free from contamination but in the past few years increasing levels of plastic have been found in it. The ideal solution would be for there to be no plastic included in the seed cotton arriving at cotton gins but because of increasing use of plastic shopping bags, plastic agricultural mulch, and protection of seed cotton with plastic material some plastic contamination of seed cotton is inevitable. In a previous study it was found that normal seed cotton cleaning machines found in cotton gins are not very efficient in removing sheet plastic, especially for larger and thinner plastic material such as used in shopping bags. The purpose of this work was to examine various ways of operating a cylinder cleaner, a type of cleaning machine found in virtually all seed cotton cleaning lines of existing cotton gins, to more effectively remove plastic. In this study several air flow rates, seed cotton processing rates, and sizes of plastic material were studied. Mathematical models were developed based on the data collected to predict plastic removal and cotton fiber loss. Analysis of the models showed that at lower airflow rates decreasing the seed cotton processing rate resulted in better overall results but at higher airflow rates increasing the seed cotton processing rate resulted in better overall results. Data addressing this issue was not previously available and this work will allow the existing cleaning machines to be used to more efficiently remove plastic contaminates.

Technical Abstract: U.S. cotton is known to be relatively free of contamination but occasionally pieces of sheet plastic are found in cotton bales produced in the U.S. A previous study showed that current cotton ginning equipment is not very efficient in removing plastic included in the seed cotton. The purpose of this work was to examine how several operating conditions affect the sheet plastic removal efficiency and fiber loss of one type of gin cleaning machine, the cylinder cleaner. Two types of plastic were used in the study with 5 levels each of airflow through the machine, seed cotton processing rate, and size of plastic contaminant. Mathematical models were developed predicting the plastic removal and fiber loss given values of airflow, seed cotton processing rate, and plastic contaminant type and size within the ranges studied. Plastic removal decreased linearly with increasing processing rate while fiber loss increased quadratically with increasing processing rate. Desirability functions showed that at a given low airflow rate decreasing the seed cotton processing rate resulted in better operation (less fiber loss with slightly less plastic removed), but at a given high airflow rate higher processing rates resulted in better operation.