Water, moisture and ash content of mechanically cleaned greige cotton, naturally colored brown cotton, flax and rayon

Authors: Montalvo Jr, Joseph; von Hoven, Terri; Easson, Michael; Hinchliffe, Doug

Submitted to: American Association of Textile Chemists and Colorists (AATCC) Journal of Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2016
Publication Date: 9/21/2016
Citation: Montalvo Jr, J.G., Von Hoven, T.M., Easson, M.W., Hinchliffe, D.J. 2016. Water, moisture and ash content of mechanically cleaned greige cotton, naturally colored brown cotton, flax and rayon. American Association of Textile Chemists and Colorists Journal of Research. 3(5):12-26.

Interpretive Summary: The primary goal of this probing research was to evaluate the recent Karl Fischer Titration reference method (KFT, ASTM D7785) to correctly measure water content of one sample each of mechanically cleaned cotton in its natural form, a naturally colored brown cotton, flax and rayon. KFT testing method confirmation was applied to each sample to ensure accurate water contents. Also, each was analyzed for moisture content by standard oven drying in ambient air, and an alternative oven drying technique in dry air and nitrogen. There was a significant difference between water and moisture contents by oven drying. Similar differences were observed between oven drying in air and nitrogen, and varied with impurities measured as ash content. The findings support the use of KFT to determine water content of these important cellulosic textile fibers.

Technical Abstract: This exploratory research evaluated the Karl Fischer Titration reference method (KFT, ASTM D7785) to accurately measure water content of mechanically cleaned greige cotton, a naturally colored brown cotton, flax and rayon at moisture equilibrium. Each sample was analyzed by KFT, standard oven drying in ambient air, and isothermal thermogravimetric analysis (TGA) using dry air and nitrogen carrier gases. Water content, as measused by KFT was (%): mechanically cleaned greige cotton, 6.82, brown cotton, 7.88, flax, 8.72 and rayon, 11.74. There was a significant difference between water and moisture contents by standard oven drying. Similar differences were observed between TGA in air and nitrogen and varied with ash content. The findings support the use of KFT to determine water content of these diverse cellulosic textile fibers.