Effect of Bagging on Moisture Change in Cotton Bales

Abstract

The purpose of this research was to determine the moisture transfer and weight gain of universal density cotton bales packaged in different materials. Bagging materials investigated included both woven polypropylene bags with extrusion-coated strips to prevent fibrillation as well as similar bags that were fully coated on the interior to reduce contamination. Three bales each were ginned, packaged, and placed in four different types of bags—two types of woven polypropylene 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-coated bales 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 coated woven polypropylene bagging changed moisture much more slowly than those in the stripcoated materials. Bale thickness 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 bales in the four types of bagging. Fiber quality did not change during storage.