02Dyeing_English.ppt.ppt

* * Introduction to Textile Dyeing Assistant Professor Dr. Apichart Sonthisombat, Rajamangala Institute of Technology Copyright ? 2004 Assist. Prof. Dr. A. Sonthisombat All rights reserved. Basic Textile Terms and Definitions Dyestuff is organic or inorganic substances which can absorb light and reflect some lights to show color. Actually, the dyestuff is water soluble substances. Pigment is a substance that can absorb light and reflect some lights to show color but it is water insoluble substances. Normally it is used for printing (with the presence of binder) or mass-coloration of the synthetic fibers. Staining is an unpleasant of dyeing in the area that we do not want. Exhaustion of the dyestuff to the fibers is as follows: 1. Moving of dyestuff from dyebath to surface of the fiber 2. Adsorption of the dyestuff into the surface of the fiber 3. Diffusion of the dyestuff into the center of the fiber Classification of Dyestuffs Dyestuffs can be classified by many methods as follows: 1. by their ionic (e.g. cationic, anionic and non-ionic) 2. by their fiber dyeabilities (e.g. on cellulosic, protein, polyester, polyamide etc.) 3. by their names (e.g. acid, direct, disperse, reactive, basic etc.) 4. by their chemical structures (e.g. azo, anthraquinone, stilbene etc.) 5. by their origins (e.g. natural, synthetic) 6. by their colors (e.g. red, green, black etc.) Dyeing Processes can be applied in many stages such as 1. Mass-coloration of the molten fibers This method is for dyeing the molten fibers or plastic chips or textile polymers with pigment dyes. After that, the molten or polymers will extrude from a spinneret to form fibers. Normally, the synthetic fibers are added with white pigment in order to give a hiding power (non-see through fabrics). Advantage: give excellent fastness Disadvantage: very difficult to clean 2. Fiber Dyeing is the method of dyeing fibers before blending with other colors to give fancy yarns or fabrics. Note: This is used for special pur