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Title: COLOR CHANGES VIA TREATMENTS

Author
item Foulk, Jonn
item McAlister Iii, David

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Proceedings
Publication Acceptance Date: 1/8/2002
Publication Date: 7/1/2002
Citation: Proceedings 2002 Beltwide Cotton Council, National Cotton Council, Memphis, TN, 10 pages.

Interpretive Summary: Cotton remains one of the most important natural fibers. Since cotton is produced in the field rather than at a manufacturing facility, it remains difficult to understand all chemical and physical properties that are affected by production, further processing, and utilization. Bulk testing of multiple cotton fibers with the HVI has led to a broad understanding of the cotton fiber properties in product processing. With increased processing speeds, cotton fiber classification improvements are required. This study will evaluate how cotton identified at the gin as sticky cotton may be affected by heat, acid catalysis, and water rinsing treatments to lower cotton stickiness. Many events impact cotton fibers, so results from these tests may help expedite processing in textile mills.

Technical Abstract: Cotton differences are not well understood chemically and the protective exterior complexity of raw cotton further entangles matters. Several cottons had previously been identified as potentially sticky and problematic cotton by the acid-base pH spray indicator test. Since the acid-base pH spray indicator is often not accurate in finding sticky cotton, these bales had been previously tested for stickiness on the minicard. Sugar and other components of cotton's protective cuticle layer have diverse melting points, varying degrees of hydrolysis, and can cause a multitude of chemical reactions. To evaluate the removal effectiveness and fiber properties of treatments, each sample was prepared for testing that included atomizing samples with citric acid, rinsing samples with heated deionized water, or preparing a control. To evaluate differences among treated and untreated cotton samples, these cotton samples were either unheated or heated at 133 deg C with steam or dry heat for 1, 2, and 4 h. Following these treatments, samples were tested for sugar content and HVI fiber properties. This study evaluated steps that could be taken at the cotton gin or textile mill to adequately remove sugar from cotton. Heat treatments, rinsing, and acid catalysis likely all affect the surface components and cotton fiber themselves. The lack of these surface components likely decreases the lubrication and the ease of future processing. Citric acid catalysis, water rinsing, and additional heat (both dry and steam) appear to lower cotton sugar levels. Fiber quality decreases with steam, dry heat, and acid catalysis. Water rinsing appears to be the most advantageous process to lower sugar levels while maintaining or improving fiber quality.