On-board module builders have been a boon to cotton producers in terms of time, cost savings and efficiency. And as much as the equipment has impacted harvest time in the field, its quick adoption by growers has also led to adjustments and other issues at the gin.
Take the increase in plastic contamination, for example.
“Plastic contamination is an issue that has really popped up in the last three-to-four years,” said Tommy Valco, cotton technology transfer coordinator for USDA-ARS in Stoneville, MS. “As we’ve introduced the round module system into our production practices, plastic in the gin has become an increasing problem and concern, not only for those in the ginning operation, but also in the marketing and textile processing of our cotton.
“The round module system really accelerated at a rate that many of us didn’t think possible,” he continued. “Now, we have gins running 60-to-80 percent of their cotton in round modules, and it has required a lot of changes within the ginning system.”
By no means is the round module system solely responsible for plastic contamination issues. Pieces of irrigation tubing, plastic grocery or shopping bags, plastic mulch, flagging tape and other plastic items have entered gins through seed cotton delivered in conventional and half-modules, as well. The plastic wrapping on the round modules just provides another “opportunity” for plastic to enter the system if the module isn’t handled properly in the field or in the gin.
According to Valco, the USDA Gin Lab has conducted a preliminary study to see what happens when plastic goes into a gin. Researchers cut plastic from multiple sources into sizes ranging from 1”x 1” up to 3”x 6”, mixed them into seed cotton in a microgin, and then spent hours trying to find traces of the plastic after the ginning process was finished.
“It was very labor intensive,” reported Valco, “but it gave us a good idea of where plastic was being removed in a gin.”
The results showed that most of the smaller pieces basically acted like leaf material and were taken out by the cylinder cleaners. Larger, heavier materials were removed by stick machines or the extractor feeder. Roughly 56 percent of the plastic put into the seed cotton came out through the stick machines. But 17 percent was still found in the lint.
“Now we know where most of the plastic is being removed,” pointed out Valco. “Now the question becomes how can we change the equipment to do an even better job?”
The study results also prompted another question – how can we reduce the potential for plastic contamination? That led Cotton Incorporated and the National Cotton Ginners Association – with cooperation from John Deere – to develop guidelines for properly handling round modules in the field and at the gin.
The program – primarily intended for growers – provides simple, yet effective, steps for handling and staging round modules in the field to help reduce tears in the wrapping and damage to the modules:
- Properly stage the modules in the field. Align modules in groups of four and space them four-to-eight inches apart to allow for air circulation and drying. Place them in well-drained areas such as turn rows for easy access by module trucks or trailers. “This helps two ways,” explained Valco. “If you do get rain, the round modules withstand weather very well. But if they’re placed too close together and get rain, you’ll start seeing boll or mildew growth and degradation of the cotton in that area.”
- Proper alignment helps in loading. Proper spacing helps here, too. If the modules are too close together when the module truck starts picking them up, the top corner of the module can flip over and create a pressure point on the chains. That increases friction and can cause the module wrap to split. If they are not lined up properly, the modules can also run into the truck headboard or sides, causing the wrap to tear or strip.
- Handle the modules carefully in the field. Tractor-mounted fork lifts or spears should be used to move and position modules. Lift them high enough above stalks to prevent tearing the wrap. And don’t push or slide the modules on the ground. If flatbed trailers are being used for transport, lifts, wheel-loaders or telehandlers should be used to lift modules high enough to load onto the trailers.
- Be prepared to handle wrap damage in the field. Repair tears with tape to secure the wrap before loading. Be sure to pick up all pieces of plastic and remove them from the field.
- Ginners should modify module trucks. Change to less aggressive lugs and modify the feed chains to prevent tearing the wrap and the module. Synchronize chain speed and ground speed, and keep operators trained. “Often, when the round modules come off the truck onto the module feeder, we see some ripping and tearing of the cover,” added Valco. “Shards of plastic come off and can be easily introduced into the system at that point.”
More details and tips on proper handling of the modules can be found in the Focus on Cotton webcast pages, created by Cotton Incorporated and the Plant Management Network.