Chemistry and Materials Research www.iiste.org ISSN 2224- 3224 (Print) ISSN 2225- 0956 (Online) Vol.3 No.5, 2013 13 Calculation of Dyestuffs and Auxiliaries for Effective Wet Processing Technology Lablu Miah Department of Apparel Manufacturing Management and Technology, Shanto Mariam University of Creative Technology, House #1, Road#14, Sector#13, Uttara, Dhaka, Bangladesh. Tel: +88-01717095394 E-mail: lablu_ahammad@yahoo.com Muhassina Ahmed Department of textile engineering, City University, Bulu Ocean Tower, 40 Kemal Ataturk Avenue, Banani, Dhaka, Bangladesh. Tel: +88-01714361487 E-mail: skyfeatherod@yahoo.com Abstract Wet processing technology (Dyeing) is known as much valuable process for increasing the attractiveness of the textile material and that is very much costly as well as time consuming. So it is very important to take caution to calculate the accurate amount of auxiliaries (Caustic soda-NaoH, Soda ash-Na 2 Co 3 , Salt- NaCl etc) and dyestuff should be taken to get quality dyed fabric (appropriate shade, even shade). We know, the process by which a textile material change its color as well as properties (physical, chemical properties) in wet condition that is known as wet processing technology (pre-treatment, dyeing/printing and after treatment) pretreatment involved desizing, scouring, bleaching and after treatment involved washing, neutralization as well as to impart some stabilizing, textural and functional effect of finishing. At the initial stage of calculation, needs to calculate the lap deep before go for bulk productions. For this a lots of work is done in the dyeing laboratory. In the dyeing lab, lab dip or sample is developed by the dyeing master. Lab dip plays an important role in shade matching & this is an important task before bulk production. Keywords: Chemical (auxiliaries) calculation, Dyestuff calculation, Achieve accurate shade offered by buyer. 1. Introduction Wet processing (dyeing) plays crucial rule in the textile world for imparting the coloring substance to make it more attractive for users. Complete wet processing needs some different stages. In all the stages the materials (fibers, yarns, fabrics etc) are to treat with various chemicals. As a result there can be probabilities to take the wrong amount of chemicals and dyestuffs that will make the huge damage of the materials. So to avoid this problem it’s necessary to calculate the accurate amount of chemicals as well as dyestuffs to use during the process for achieving the excellent result. For this way reprocess will be reduced and excellent result will be found. To accomplish all the process (pretreatment, dyeing/printing and after treatment first) of all the material should be weighted and processed with certain amount of chemical and dyestuffs that are found by required calculation according to recipe. 1.1 Equipments needed for Recipe calculation: 1. Microprocessor pH Meter 2. Digital pipette 3. Digital Weighting Meter with Glass Box (Explorer, USA) 1.1.1 Calculation for Lab Deep: Recipe Calculation Formula: Required Dye = (Shade percentage (%) x Weight of the fabric in gram (gm) /percentage (%) of Stock solution. Or, Required solution = F w S p / C s Where , F w = weight of fabric, yarn, or fiber S p = shade percentage C s = concentration of stock solution