Foreign textile mills prefer cotton bales wrapped in cotton bagging, while domestic mills prefer theirs secured with PE (polyethylene) film according to surveys conducted in 2008 with the help of the National Cotton Council, Cotton Council International and the National Council of Textile Organizations.
According to the NCC's Dale Thompson, foreign mills participating in the 2008 Bale Packaging and Lint Contamination Survey ranged from small in size to large corporate operations and some were large users of U.S. cotton. Most domestic mills surveyed were large users of U.S. cotton, and about half of them used U.S. cotton exclusively. All domestic users responded to the survey. Eighty-one Chinese mills responded to the survey.
Mills were asked to rate their answers on a scale of 0 to 4, with 0 being poor and 4 being superior. Mills were asked to rate bale ties, bagging material and answer questions on internal (inside the bale) sources of contamination.
The mills were asked to rate three types of bale ties - PET straps (made from thermoplastic polymer resins) steel and wire - relative to contamination risk, recycling potential and safety. Thompson noted that less than 1 percent of U.S. cotton is tied with steel straps, “but it's still used in other parts of the world so we included it.”
Foreign mills did not report significant differences between the three bale ties, with most rating them all between above average and superior. Foreign mills said rust was the primary contaminant they encountered with steel straps and wire. “With plastics, it's more small particles of plastic becoming entwined in the bale.”
Domestic mills rated PET straps favorably above all others for contamination, recycling potential and safety, while rating them average for breakage.
Four types of cotton bagging were evaluated in the surveys - burlap, cotton, PE film and woven polypropylene - for durability, contamination risk, recycling potential and cleanliness.
Foreign mills rated cotton bagging the highest, and rated burlap between poor and average. Surprisingly, foreign mills rated burlap very favorably for contamination risk. “Despite what we hear from foreign mills in their interviews that burlap is a big issue for contamination, they said in the surveys that burlap was better than other materials. Maybe, there were some miscommunications on that particular question.”
Cotton bagging also came out on top in foreign mill surveys for cleanliness and recycling potential.
Domestic mills rated PE film and woven polypropylene more favorably for contamination risk and durability than other materials. Domestic mills were asked an additional survey question on moisture transfer and rated the natural fibers, burlap and cotton, considerably below the other packaging materials.
All factors considered for ties, domestic mills and foreign mills rated PET straps the highest. For bagging material, all factors considered, both domestic and foreign mills gave burlap their lowest rating. Foreign mills rated cotton as the best bagging material, while domestic mills preferred PE film.
The surveys revealed that domestic mills dealt with somewhat less internal contamination than foreign mills over the last 12 months. On average, domestic mills and foreign mills had fairly low occurrences of internal contamination.
However, Thompson said CCI recently received a complaint from a mill in Thailand that uses a lot of U.S. cotton, “saying they were seeing more plastic contamination from U.S. growths of cotton. Looking at those contaminated samples, it looks like foreign matter that's getting in those bales.
“The take-home message is to please work with growers and around the gins to make sure you're doing everything you can to keep those contaminants out of the seedcotton so they don't get into the lint stream.”