ENZYMATIC DEINKING OF OLD NEWSPRINT USING CELLULASE

Abstract

Use of Enzymes has increased in paper technology in the recent past. Application of Enzymes in secondary fiber processing is a relatively new field. The use of secondary fiber has increased substantially over the years world wide. It has been accepted that in the manufacture. of writing and printing papers, flotation deinking gives better results. The pulping for the same is carried out normally in the presence of sodium hydroxide, hydrogen peroxide, sodium silicate, surfactant and some collector chemicals.P.K.Agnihotri et.al(5) had estimate the optimum condition for operation with onp, bong and their blends. In this work onp has been exposed for cellulase enzymes for different dosages of enzymes with different temperature and processing time. After 11 trials, it has been estimated that best dosages for enzyme is 0.4m1/100 gm of onp, 55°C temperature, 30minuite soaking time and 15 minutes pulping time. It was further observed that if the enzyme not washed out after pulping processes the properties go on changing with time. It was also observed that the high dosage of enzyme ink foam is disperses out in the pulp suspension and sheet formed as uniformly disperse ink particles with dark color. The deinkability factor for the best run is found with lml dosage 0.4 ml per 100 gm ONP, 74.35% ISO Brightness and 93% ERIC 950 value as shown in Table8.