Best Practices to Prevent Plastic Contamination
By Kara Bishop
Six years ago, while visiting textile mills in China, workers handed Vikki Martin, vice president of the fiber competition division of Cotton Incorporated, a bag of heavily contaminated cotton with U.S. bale tags. Surveys as early as seven years ago had international textile mills reporting more contamination than previous harvest years, raising red flags to U.S. cotton industry researchers.
“Unfortunately, the timing was almost consecutive with the adoption of round bale module harvesters in the U.S. production system,” she added.
The round bale module harvester has revolutionized cotton harvesting, reducing overhead in equipment and employees alike. However, the amount of extraneous matter calls has increased every year for the last four years, resulting in damage to the U.S. “contamination-free” cotton reputation as well as significant discounts in profit for producers.
Research partnerships between Cotton Incorporated and United States Department of Agriculture Agricultural Research Service (USDA-ARS) have generated best practices for producers and gin operations to effectively combat plastic contamination in planting, harvesting and ginning.
While producers usually plant fence row to fence row, adjustments may be helpful to maintain quality of product.
“I understand that producers don’t want to waste space or potentially lose profit by doing so,” said Ed Barnes, Ph.D., senior director of agricultural and environmental research for Cotton Incorporated. “However, dropping modules on top of cut stalks is damaging the plastic wrap and can cause plastic contamination.”
Leaving more space at the end of each fence row or finding a way to drop modules in a turnrow can prevent the contamination showing up in quality reports, Barnes added. While there hasn’t been a significant amount of damage reported due to dropping modules on cut stalks, every little bit counts when preserving the integrity of U.S. cotton.
Damage primarily occurs during transportation. Harvest/Transportation damage sources include:
- Module trucks
- Unsynchronized chains
- Poor alignment in the field – sidewalls hitting the modules
- Fork lifts
- Not lifting bales high enough when loading
- Clipping the edge of the bale when turning too soon
- Fork lifts
Researchers have been studying methods for plastic removal from cotton for years — the Visual Imaging Plastic Removal System or VIPR is the only piece of equipment that has made it through feasibility evaluations into commercialization. Lummus Ag Technology, in partnership with Bratney Cos., developed the machine and testing resulted in a detection/ejection efficiency of 89.44%, according to Ross Rutherford, vice president of product management and marketing for Lummus Ag Technology.
While the VIPR is available, it’s a hefty investment. “The gins that bought the VIPR system for beta testing paid $45,000,” Martin said. “While the machine does a good job with the bright colors of the module wraps, it struggles to detect pale, clear colors, nor does it pick up on black plastics, which is the second leading plastic contamination source next to module wrap.”
A new system that recently passed feasibility evaluations involves ultrasonic sensors. The sensors detect plastic regardless of color. During feasibility testing, it was discovered that noise and movement in the gin did not disrupt the sensory technology.
“The next step is to test the system using moving cotton,” Martin added. “Several systems have made it through feasibility, but only the VIPR has made it past moving cotton. We’re hopeful this system will make it through, as testing beyond color could be a game changer for ginning operations.”
Currently, the most affordable and practical way for gins to prevent plastic contamination is a camera system costing less than 500 dollars. The system was developed at the USDA-ARS Cotton Production and Processing Research Unit. To read the recommendations and specifications, visit: https://bit.ly/3fGzdpB
While technology is helpful in addressing this issue, it’s not the only solution. Education opportunities should be taken advantage of to address each gin employee’s role in plastic contamination prevention.
Since there is no adhesive on the inner plastic layer of the wrap on the round modules, it’s very easy for that plastic to get trapped under the cotton when the wrap is cut at the gin. “It’s crucial that the gin employee unwrapping the module watch for any layers of plastic getting trapped under the bale, as this is a primary source of plastic contamination,” Barnes added.
While plastic can’t be 100% eliminated, education plus technology may be the key to restoring the U.S. cotton reputation.