Specifications for cotton bale bagging are developed by the Joint Cotton Industry Bale Packaging Committee (JCIBPC) of the National Cotton Council. Over the past 38 years cotton bales have improved in appearance and protection afforded by the package – both ties and bags. Bagging materials have evolved from jute wrap and strip-coated woven polypropylene (WPP), having great air and water vapor permeability, to polyethylene (PE) film and fully-coated WPP. Permeability characteristics of these later materials may hinder adequate movement of air and moisture in or out of the bag for basic protection of lint.

Researchers at Texas A&M University in the Biological and Agricultural Engineering Department are working with National Cotton Council staff to determine a method for achieving adequate permeability characteristics.

Standard Test Methods for Water Vapor Transmission of Materials, ASTM E 96 Procedure C, was employed to test PE and WPP materials with a variety of puncture pin sizes and hole densities. Samples were cut from materials and secured onto vapometer permeability cups with desiccant. Cups were weighed every 24 hours and permeance was determined. Results as of mid-December will be reported.