Unit – I:
Preparatory Process: Sequence of preparatory process prior to dyeing for natural & manmade fibre fabrics with special reference to cotton, wool, polyester and blends.
Singeing and Desizing: Objects of desizing, Mechanism of desizing. Inter-relation of desizing with singeing and sizing, Various methods of desizing: Hydrolytic & oxidative method of desizing, Evaluation of efficiency of desizing.
Scouring: Object of scouring, Scouring with alkali assisted desizing, Inter-relation between desizing and scouring, Study of batch-wise & continuous methods of scouring. Evaluation of efficiency of scouring
Bleaching: Objects of bleaching, Introduction to bleaching agents like sodium hypochlorite, hydrogen peroxide & per-acetic acid, Bleaching of cotton, polyester & its blends, Batch-wise & continuous machinery for bleaching, Bleaching of wool ,silk, Concept of AOX, Evaluation of efficiency of bleaching. Continuous scouring and bleaching: Pre-treatment Range
Mercerization: Introduction & objects of mercerization, Effect of mercerization on structure of cellulose, Machinery used for yarn, woven and knit fabrics, Concept of hot mercerization & liquid ammonia mercerization, testing methods to evaluate efficiency of mercerization like Barium Activity, Number, Axial Ratio & Luster index.
UNIT – V:
Direct Dyes: Generalised formula of Direct dyes: Classification of direct dyes; Mechanism of Direct dyes and procedure for application of direct dyes; dye-fibre bond; effect of different process parameters (e.g. temp, time, pH) & role of various additives in dyeing process; fastness properties of direct dyes; after treatments for direct dyes.