Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: December 22, 2004
Publication Date: July 20, 2005
Citation: Anthony, W.S. Changes in cotton bale moisture, thickness and force to changing environments. Journal of Cotton Science. 9: 72-80 (2005). Interpretive Summary: The Joint Cotton Industry Bale Packaging Committee (JCIBPC) of the National Cotton Council helps the cotton industry improve the packaged bale of cotton. As bale storage and handling practices change and new technology emerges, the industry develops new bagging in response to the new requirements. The JCIBPC thoroughly investigates new bagging to ensure that they perform satisfactorily before approving widespread commercial use. This USDA study reports the results of an investigation of proposed new bagging materials. Eight bales of cotton were packaged at universal density and stored without bagging at ambient conditions for 81 days; then the same eight bales were randomly placed in four (two standard and two experimental) different types of bagging and stored at high (80%) humidity for 100 days (Phase II); and then the same bales were stored for 305 days at moderate (50%) humidity. The bales were weighed periodically, and the dimensions and bale tie forces measured. The bale moistures, dimensions and tie forces changed at different rates under the varying climatic conditions depending on the type of bagging. Although they provided greater protection for the cotton, the experimental baggings did not allow the cotton bales to breath as much as did the standard bagging. As a result, bales packaged in the experimental bagging will not gain or lose as much weight during storage. Both of these factors can possibly reduce profits for segments of the industry. Adoption of the experimental baggings will be hampered by these findings.
Technical Abstract: Moisture transfer in cotton bales, the change in bale thickness, and the change in bale tie forces required to restrain the bale are strongly influenced by the density of bales, the storage climate, and the permeability of the protective covering on the bales. These conclusions were reached based on a three-phase study. In Phase I, eight bales of cotton were packaged at universal density and stored without bagging at ambient conditions for 81 days. The bale thickness and tie force were measured periodically and the bale weights were taken before and after the storage period. The same eight bales were randomly placed in four different types of bagging and stored at 26.7 °C (80 °F) and 80% relative humidity (RH) for 100 days (Phase II). The bagging included two types of experimental bagging and two types of standard bagging. The experimental bagging was less permeable than the standard bagging. Then, the same bales were stored for 305 days at 21.1 °C (70 °F) and 50% RH (Phase III). For Phases II and III, the bales were weighed and their thickness and tie force measured about twice weekly. The bales gained moisture for Phases I and II but lost moisture (weight) for Phase III. In Phase I, bale thickness and tie force increased initially after storage and then responded to the fluctuations in climatic conditions. During Phase II at 80% RH, the bale thickness and tie force increased. However, during Phase III at 50% RH, the thickness and the tie force decreased. The experimental bagging restricted the moisture transfer (change in weight) more than the standard bagging.