Author
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Brushwood, Donald |
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Submitted to: American Association of Textile Chemists and Colorists Review
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/25/2001 Publication Date: 5/1/2002 Citation: Brushwood, D.E. Metals in domestic and non-domestic cottons and their frictional properties. American Association of Textile Chemists and Colorists Review. 2002. v.2(5)p. 20-24. Interpretive Summary: Metals on raw cottons have been a concern of textile processors for years. Excessive amounts of metals can adversely affect yarn color and wet dyeing and finishing quality. High levels of certain metals such as calcium and magnesium have been known to form complex insoluable salts in wet processing that inhibit the dyeing process. Also, some metals have been suspected of causing frictional problems on modern high-speed textile machinery. A limited number of domestic and non-domestic raw cottons were analyzed for metals commonly found to be present using Atomic Absorption Spectroscopy. Selected cottons from the U.S. and six foreign growing areas were also subjected to RotorRing friction testing. General comparisons are made between metals in U.S. and foreign grown cottons. The influence of individual, and overall metal, as well as residual non-cellulosic ash content on fiber friction values were determined for each cotton and averaged growing area as the content of the individual metals, potassium, calcium, and magnesium increased, RotorRing friction measurements tended to decrease as ash content increased. Typical U.S. and Chinese grown cottons contained lower overall metal contents and lower ash residues with higher friction test results. Cottons from areas where open bolls normally are exposed to little or no moisture (rain or overhead irrigation) generally had higher metal contents and ash residues. Technical Abstract: Metal content in domestic and imported cottons has become a very important consideration for textile processors in recent years. Metals may contribute to problems that occur in yarn manufacturing, fabric production, bleaching and dyeing, and overall processing and product quality. There is also increased concern, due to more stringent EPA requirements, about concentrations of harmful metals in solid and liquid textile wastes. Cottons from international growing areas as well as within the U.S. were analyzed for potassium, calcium, magnesium, sodium, iron copper, manganese, and zinc by atomic absorption spectroscopy. Potassium was the most dominant metal (2000-7000 ppm) followed by calcium and magnesium (350-1500 ppm), sodium (100-400 ppm), and iron (0-160 ppm). Concentrations of copper, manganese, and zinc varied from 1 to 10 ppm. General comparison of metal levels between foreign and domestically grown cottons is presented. Selected cottons, both domestic and non-domestic, were subjected to RotorRing friction tests to study effects of metal content on processing friction. Friction, both fiber-to-metal and fiber-to-fiber, decreased as levels of potassium, calcium, magnesium on the fiber, and percent ash increased. |
