“It’s important that these modules be cut properly so nothing goes into the seed cotton,” Byler says. “Training is important — the person making the cut needs to know where to cut so all the plastic wrap can be removed.”

As for the problem with plastic grocery bags, ag mulch, and other thin plastic contaminants, he says, “Probably the most effective thing that can be done is for ginners to work with their farmers and impress on them the need to keep plastic out of their modules. A lot of farmers use custom harvesters, and they need to be brought into the loop also. Once plastic mulch or plastic bags or other contaminant material gets into the module, it has an impact all along the line.”

The round module system is still relatively new, Valco says. “People are still learning how to deal with it, and increased awareness of the contamination problem at the grower level and at the gin will help to resolve it.”

Byler and researchers at the ginning lab did a preliminary study to see what would happen when various kinds of plastic were introduced into the gin on purpose, and where those pieces would end up. Plastic types included not only round module covers, but irrigation tubing, grocery bags/shopping bags, and plastic mulch.

“Plastic was cut into square and rectangular sizes, all the way up to 3x6 inches, which were then introduced into the seed cotton going through the micro-gin,” Byler says.

“After it ran through the gin, we spent hours determining where all the plastic went, a very labor-intensive process. But it gave us a pretty good idea of where most of the plastic was being removed, where other plastic got through, and how we can improve or change the system to do an even better job.

“The biggest problem we saw was black plastic mulch. The larger pieces that got shredded went through the gin stand and lint cleaner and ended up in the lint. Some of the smaller pieces were taken out by seed cotton cleaning devices. Plastic from round module covers was found the least in the lint.

“What we found was that the smaller pieces, 1x1-inch, acted like leaf and were taken out by the cylinder cleaners, while the larger, heavier materials were removed either by stick machines or extractor feeders. About 56 percent of the plastic that we put into the seed cotton was taken out by the stick machines.”

Unfortunately, Byler says, “A lot of gins have started bypassing stick machines, particularly if they’re running good clean cotton. Stick machines are where there are potential losses of seed cotton. So, this is potentially something we need to rethink in terms of plastic contamination.”

Smaller amounts are being taken out by cylinder cleaners and lint cleaners, he says, and about 12 percent of it “we never found.”

Of the plastic introduced into the ginning system, about 17 percent was later found in the lint.

The study led to an effort, in cooperation with Cotton Incorporated and the National Cotton Ginners Association, to establish an education program on handling of round modules from the field to the gin.

“John Deere was very helpful in assisting us with the project,” Valco says, including  a “Focus on Cotton” webcast  on steps for reducing the potential for plastic contamination. “This is intended more for producers and custom harvesters than ginners. John Deere understands the contamination issue, and they want to be part of the solution.”