THE EFFECT OF BEATING ON THE DYEING OF CELLULOSE

Abstract

Abstract: Dyes and pigments are important colorants used in dyeing of paper, cardboard, fabric, food, plastic, wood materials. The dyes and pigments used for this are very diverse and have a wide range. With the increasing in demand for dyed paper day by day, the development of new technologies has become necessary. Since the natural colour of the paper is not much of a concern, the papers have been started to be dyed in different shapes to obtain products with shades ranging from bright pastel to dark and saturated tones. Tone and density can be adjusted according to need and requests. Colouring in paper is usually coloured by adding pigments or dyes to the pulp during pre-production preparation. Almost 95% of dyed papers are prepared in this way. For this purpose, direct acidic and basic dyes are used. The effectiveness used pigment or dye varies depending on the raw material and the environmental conditions. The purpose of this study, beating and pH is to improve the effect on cellulosic dyeing and paper properties. For this, two different types of pulp were selected as bleached softwood kraft pulp (BSWP) and bleached hardwood kraft pulp (BHWP). The dyeing process was carried out using four different colours in the beaten and the unbeaten pulp (60minute with Valley’s beater). They produced sheets from the dyed pulp. It was made colour measurements on the produced sheets and compared obtained values. The results will help to give an idea of the effectiveness of coloured inks used during printing on coloured paper.