Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/6/2003
Publication Date: 8/1/2003
Citation: Tristao, D.C., Wakelyn, P.J., Hughs, S.E., Denton, P., Bello, H., Isom, R. The effect of outside ambient air conditions on the interstitial relative humidity of linear low density polyethylene film wrapped cotton bales. CD-ROM. Memphis, TN:National Cotton Council. 2003.
Interpretive Summary: A quality issue in the U.S. cotton industry is, how does the fiber moisture and related relative humidity within a cotton bale package affect fiber quality? A related question is, how does bale packaging material shield baled cotton fiber from ambient conditions? A test was conducted to determine if linear low- density polyethylene bale bagging (LLDPE) protected the interior of the cotton bale from ambient relative humidity changes and excess moisture. Daily short-term monitoring showed that sealed LLDPE film bagging kept the bale interior unaffected by ambient relative humidity changes from 40 to 90%. The bale interior remained at less than 10% relative humidity, regardless of ambient humidity and suffered no fiber quality degradation.
Technical Abstract: The J. G. Boswell Company operates a unique, proprietary designed, warehousing facility for baled Pima cotton. An integral part of this storage facility is the bale packaging material'-a specially formulated linear low density polyethylene (LLDPE) film bagging. After the cotton is ginned on a roller gin, the naked bale is inserted into the LLDPE film bag and hermetically sealed. The protected bales are then placed in open storage. The recommended storage conditions state that relative humidity in excess of 50% should be avoided, since high humidity conditions have been documented to have an adverse effect on the maintenance of cotton fiber quality during storage. Limited published research information is available concerning the effects of long term storage on cotton fiber, and no published information exists on the relative humidity of the interstitial area of hermetically sealed LLDPE film wrapped cotton bales. Research was conducted to determine the relative humidity of the interstitial space of a cotton bale wrapped with LLDPE film bagging, and to determine if a constant low relative humidity is maintained regardless of outside ambient air conditions. This research demonstrated that even though the ambient temperature (43 F to 74 F) and relative humidity 44% to 93%) varied significantly, the relative humidity of the interstitial environment remained constant and low (10% or less relative humidity). In addition, anecdotal evidence collected to date by the J. G. Boswell Company indicates that no fiber damage has been incurred when the hermetically sealed, specially formulated LLDPE film bagging is utilized. Therefore, this design and operation for cotton warehousing is as protective of baled cotton as other cotton warehouse storage facilities currently insured in CCC licensed warehouses.