MOISTURE CHANGE OF COTTON BALES DURING STORAGE

Abstract

The purpose of this research was to determine the moisture transfer and weight gain of universal density cottonbales packaged in different materials. Bagging materials investigated included both woven polypropylene bags withextrusion-coated strips to prevent fibrillation as well as similar bags that were fully coated on the interior to reducecontamination. Three bales each were ginned, packaged, and placed in four different types of bags two types of wovenpolypropylene spiral sewn bags with alternating extrusion-coated and uncoated strips, and two types of fully coated bags.Initial moisture contents averaged 3.6%. The bales were stored for 140 days at 70% relative humidity (RH) and then at 50%RH for 88 additional days. Bales were weighed and measured for thickness twice each week. After 140 days, the strip-coatedbales averaged 6.9% moisture and the fully coated bags averaged 5.3%. After an additional 88 days of storage at 50% RH,the strip-coated bales averaged 5.9% moisture and the fully coated bags still averaged 5.3%. The bales in the fully coatedwoven polypropylene bagging changed moisture much more slowly than those bales in the strip-coated materials. Balethickness changed from as little as 0.3 cm (0.1 in.) to as much as 2.2 cm (0.8 in.) as moisture content changed for the balesin the four types of bagging. Fiber quality did not change during storage.