Electrochemical Sensors for the Control of the Concentration of Bleaching Agent to Optimize the Quality of Bleached and Dyed Textile Products
I. Introduction 123
II. Bleaching Agents 124 A. Sodium hypochlorite 124 B. Sodium chlorite 126 C. Hydrogen peroxide 126 D. Bleaching with enzymes 136
I. INTRODUCTION The term “ cleaning of textiles” is understood as the series of treatments at the textile material to obtain a white, uncontaminated product. During these treat ments, many contaminating products are removed from the textile product. The treatments included in the term cleaning are as follows:
Unstrengthening of the textile product to remove amylum, poly(vinyl alcohol), acrylates or carboxymethyl cellulose which were affixed before weaving to strengthen the fiber against deformation and breakage 
Washing and cooking  to remove natural fats, oils, pectines, hemicelluloses, proteins, mineral compounds, and sugars
Oxidative  or reductive  bleaching to remove all the natural coloring pig ments which cannot be removed by the preceeding treatments
It is clear that all these processes have an influence on the quality and unifor mity of the treated textile product but the last mentioned process (bleaching) is the most important because it directly fixes the quality (degree of whiteness  and degree of desizing) of the textile product. This quality is strongly dependent on the conditions used in the process, such as concentration and type of bleaching agent, pH, temperature, and additives used . Therefore, it is clear why this chapter is dedicated to the bleaching of textiles and how one can achieve the best quality for a textile product.