Cleaner Cotton Means Greater Profits
January 2021 Update: ARS's system for Removing Plastic Contamination During Cotton Ginning Process received a 2021 Excellence in Technology Transfer Award from the Federal Laboratory Consortium for Technology Transfer. This award is presented annually to laboratory employees who have accomplished outstanding work in the process of transferring federally developed technology.
A team of Agricultural Research Service (ARS) scientists in Texas and New Mexico recently completed a successful commercial trial of a new technology aimed at solving a quality-control problem and raising the cotton producer's bottom line.
Cotton is harvested by machine. As the harvester moves across the field, it collects the cotton and rolls it into large round "modules." The harvester also applies a colored plastic wrap around each module to compact the cotton and protect it on its journey to the cotton ginning facility. Ginning removes the seeds, leaves, dirt, and other organic debris from the raw cotton fibers.
The problem is that if the wrapping is damaged or not removed correctly from the modules prior to ginning, small bits of the plastic wrap sometimes make their way through the ginning process and end up in the market-ready cotton. The presence of plastic in the ginned bales has lowered the price U.S. cotton can command on the international market.
ARS engineering technician Kevin Tran performs system tests on the VIPR (Visual Inspection Plastic Removal) system. VIPR detects and removes plastic shreds from seed cotton as it falls down the gin stand feeder apron. (Photo by USDA/ARS, D4406-1)
"The system we developed is designed to protect cotton growers from receiving steep discounts on their cotton due to this plastic contamination," said Mathew Pelletier, an agricultural engineer in the ARS Cotton Production and Processing Research Unit, in Lubbock, TX. He said that Cotton Incorporated economists estimate that plastic contamination is one of the driving forces behind the loss of a premium of $0.07 per pound on the international market, which U.S. growers used to enjoy for having a reputation for some of cleanest cottons in the world. This loss is costing U.S. growers upwards of $750 million annually. The Lubbock team partnered with scientists at the ARS Southwestern Cotton Ginning Research Laboratory in Mesilla Park, NM, to design a solution.
In the simplest terms, the high-speed system uses machine vision to detect the plastic shreds, and then it ejects them with a blast of air—referred to as a "pneumatic knife." The team kept costs in mind throughout development, using low-cost processors and color imagers from the cell phone industry, open-source software, and some custom-designed hardware.
The system was tested last season at a commercial cotton gin and was shown to remove up to 90 percent of the plastic wrap found in the cotton stream. "By reducing the contamination level down to 10 percent of current levels, we've gotten it to where it was before the moduling harvesters were in wide-spread use—2014—when U.S. cotton used to enjoy a premium on international market," Pelletier said.
This technology has successfully addressed one of the top priorities of the U.S. cotton industry, and it has been picked up by a commercial company and is being marketed in the United States and abroad. The researchers hope their invention will help restore U.S. cotton's reputation as one of the cleanest cottons in the world and recapture the premium prices it once commanded.—By Sue Kendall, ARS Office of Communications.